empty row - Page 109 - Developer IT

Easiest way to alternate row colors in PHP/HTML?

- by thrashr888

Here's a PHP example of mine. Can anyone find a shorter/easier way to do this? <? foreach($posts as $post){?> <div class="<?=($c++%2==1)?‘odd’:NULL?>"> <?=$post?> </div> <? }?> <style> .odd{background-color:red;} </style> Examples in other languages would be fun to see as well.

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Complex SELECT statement; one-to-many all details in one row

- by RubyWedge

There are two tables: Products ID (Primary Key), ProductName PlannedByMonths ProductID (Primary Key) (Link to the Products table many-to-one), MonthNumber (Primary Key), QtytoProduce, How to write SELECT statement to retrieve results in the following format? ProductName, QtytoProduceMonth1, QtytoProduceMonth2, QtytoProduceMonth3, QtytoProduceMonth4, QtytoProduceMonth5, QtytoProduceMonth6, QtytoProduceMonth7, QtytoProduceMonth8, QtytoProduceMonth9, QtytoProduceMonth10, QtytoProduceMonth11, QtytoProduceMonth12 Thank you.

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How to split row into multiple rows from the MySQL?

- by user2818537

I have a MySQL data table, in which I have more than 2 columns. First column has a unique value clinical trial value whereas second column has disease information. There are, in most of the cases, more than 2 disease names in one cell for a single id. I want to spilt those rows which cell contains two or more than two diseases. There is a pattern for searching also, i.e. small character is immediately followed by capital character., e.g. MalariaDengueTuberculosis like this. Suppose for these three diseases there is unique id, it should show like the following: NCT-ID disease 4534343654 Maleria 4534343654 Dengue 4534343654 Tubercoulsosis

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Null pointer to struct which has zero size (empty)... It is a good practice?

- by ProgramWriter

Hi2All.. I have some null struct, for example: struct null_type { NullType& someNonVirtualMethod() { return *this; } }; And in some function i need to pass reference to this type. Reason: template <typename T1 = null_type, typename T2 = null_type, ... > class LooksLikeATupleButItsNotATuple { public: LooksLikeATupleButItsNotATuple(T1& ref1 = defParamHere, T2& ref2 = andHere..) : _ref1(ref1), _ref2(ref2), ... { } void someCompositeFunctionHere() { _ref1.someNonVirtualMethod(); _ref2.someNonVirtualMethod(); ... } private: T1& _ref1; T2& _ref2; ...; }; It is a good practice to use null reference as a default parameter?: *static_cast<NullType*>(0) It works on MSVC, but i have some doubts...

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how to insert row in first line of text file ?

- by Gold

hi i have test file that contain 1,2,3 2,3,4 5,6,7 i need to insert in the first line this: A,B,C it will be like this: A,B,C 1,2,3 2,3,4 5,6,7 how i can do it ? thank's in advance

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CSS - How to align 2 fields into 1 row?

- by user1809157

I'm newbie in css. My jsfiddle here http://jsfiddle.net/PAHdH/ <div> <label>Name: </label><p>John</p> <label>Age: </label><p>35</p> <label>Level: </label><p>60</p> <label>Score: </label><p>5000</p> </div> label{ display: inline-block; float: left; clear: left; width: 150px; text-align: left; color:black; } p {margin-bottom:2px; padding:0;} ? I would like to change to Name: John Age: 35 Level: 60 Score: 5000 It should be like a table with 4 columns.

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Grabbing the right record in a drop down from mysql

- by 86Stang

I'm using a form where the user can edit an entry. Everything is populating and all is well with the exception that I can't get the drop down to show the project that they've already assigned the image to. $project_qry = "SELECT * from projects ORDER BY title ASC"; $project_res = mysql_query($project_qry); $project_drop = "<select name=\"project_id\">\n"; while ($row = mysql_fetch_array($project_res)) { if ($project_id == $row[title]) { $project_drop .= "<option value=\"$row[id]\" selected>$row[title]</option>\n"; } else { $project_drop .= "<option value=\"$row[id]\">$row[title]</option>\n"; } } $project_drop .= "</select>\n"; I'm sure it's something devilishly simple but I'm stumped.

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How know if an iframe content is empty or not?

- by celsowm

I need know if this page returns something, because this page have a login in ASP and my server is a PHP.

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dojo if i have only the value of the Column Portlet, Can i place to GridContainer?

- by user3639054

i faced with problem situation. I don't know even how to solve the problem. So i would like to get advice. i saved value of Column Portlet and value of nbZones GridContainer in MongoDB. My situation is that if i get value of Column and ROW Portlet and value of nbZones GridContainer in MongoDB, Portlet and GridContainer value was taken from the DB to the location of the original place of it? my MongoDB Data { "GridSeq":1, "nbZones":3, "Portlet":[ { "row":1, "col":0 } ] } i calculate row value following code. var perColumn=[]; var id=portlet.get('id'); var col = portlet.get('column'); if (perColumn[col] !== undefined) { perColumn[col]++; } else { perColumn[col] = 0; } var row = perColumn[col]; console.log('id:'+id + ",row: " + row + ",col: " + col);

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how should i get ONE row from mysql? ( fetch_array etc? )

- by Haroldo

I'm pretty sure i'm doing an extra loop here: $q = "SELECT * FROM genres WHERE genre.g_url = '$genre_url' LIMIT 1"; $res = mysql_query($q); while ($r = mysql_fetch_array($res, MYSQL_ASSOC)){ foreach( array_key_exists($r) as $k ){ $g[$k] = $r[$k]; } } return $g;

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What is the proper way to test is variable is empty in a batch file, If NOT "%1" == "" GOTO SomeLabe

- by blak3r

I need to test if a variable is set or not. I've tried several techniques but they seem to fail whenever %1 is surrounded by quotes such as the case when %1 = "c:\some path with spaces". IF NOT %1 GOTO MyLabel // This is invalid syntax IF "%1" == "" GOTO MyLabel // Works unless %1, otherwise fatally kills bat execution IF %1 == GOTO MyLabel // Gives an unexpected GOTO error. According to this site. These are the support IF syntax types. So, I don't see a way to do it. IF [NOT] ERRORLEVEL number command IF [NOT] string1==string2 command IF [NOT] EXIST filename command

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Block Hover Effect - Why doesn't it work correctly in FF3.6?

- by Brian Ojeda

Why doesn't following code work correctly in FireFox 3.6? I have tested in IE7, IE8, and Chrome with out any issues. Issue: The first block hover link (the table's 3rd row) doesn't apply the same style/effect as the following below it. Notes: I am trying to create my own table framework. This project is something I am doing to learn more about CSS. Before I started, I thought I knew a lot about CSS. However, to my surprise I was wrong. Who knew? Moving on... As side note, I do not want to take the time to support IE6. So, if you see a problem related IE6, please don't waste your time telling. One another side note, the following style script and HTML listed when this question is strip-down/bare-bone of the complete CSS/HTML. It should be enough to assist me. CSS: /* Main Properties */ .ojtable{display:block;clear:both; margin-left:auto;margin-right:auto; margin-top:0px; width:650px;} .ojtable-row, .ojtable-head {display:block;clear:both;position:relative; margin-left:0px;margin-right:0px;padding:0px;} .col-1, .col-2, .col-3, .col-4, .col-5, .col-6, .col-7, .col-8, .col-9, .col-10, .col-11, .col-12, .col-13, .col-1-b1, .col-2-b1, .col-3-b1, .col-4-b1, .col-5-b1, .col-6-b1, .col-7-b1, .col-8-b1, .col-9-b1, .col-10-b1, .col-11-b1, .col-12-b1, .col-13-b1 {display:block;float:left;position:relative; margin-left:0px;margin-right:0px;padding:0px 2px;} /* Border */ .border-b1{border:solid #000000; border-width:0 0 1px 0;} .border-ltr{border:solid #000000; border-width:1px 1px 0 1px;} /* Header */ .ojtable-row{width:100%;} .ojtable-head{width:100%;} /* No Border*/ .col-2{width:96px;} /* Border: 1px */ .col-2-b1{width:95px;} .col-7-b1{width:345px;} /*--- Clear Floated Elements ---*/ /* Credit: http://sonspring.com/journal/clearing-floats */ .clear { clear: both; display: block; overflow: hidden; visibility: hidden; width: 0; height: 0; } /* Credit: http://perishablepress.com/press/2008/02/05/ lessons-learned-concerning-the-clearfix-css-hack/ */ .clearfix:after { visibility: hidden; display: block; font-size: 0; content: " "; clear: both; height: 0; } .clearfix { display:inline-block; } /* start commented backslash hack \*/ * html .clearfix { height: 1%; } .clearfix { display: block; } /* close commented backslash hack */ /*--- Hover Effect for the Tables ---*/ a {text-decoration:none;} * .ojtable a .ojtable-row{width:650px; display:block; text-decoration:none;} * html .ojtable a .ojtable-row {width:650px;}/* Hover Fix for IE */ .ojtable a:hover .ojtable-row{background:#AAAAAA; cursor:pointer;} HTML: <div class="ojtable border-ltr clearfix"> <div class="ojtable-row border-b1 clearfix"> <div class="col-13">Newest Blogs</div> </div> <div class="ojtable-row border-b1 clearfix"> <div class="col-7-b1 border-r1">Name</div> <div class="col-4-b1 border-r1">Creater's Name</div> <div class="col-2">Dated Created</div> </div> <a href="#"><div class="ojtable-row border-b1 clearfix"> <div class="col-7-b1 border-r1">Why jQuery?</div> <div class="col-4-b1 border-r1">Gramcracker</div> <div class="col-2">Mar 11 2010</div> </div></a> <a href="#"><div class="ojtable-row border-b1 clearfix"> <div class="col-7-b1 border-r1">Thank You For Your Help</div> <div class="col-4-b1 border-r1">O'Hater</div> <div class="col-2">Nov 2 2009</div> </div></a> <a href="#"><div class="ojtable-row border-b1 clearfix"> <div class="col-7-b1 border-r1">Click Me! Hahaha!</div> <div class="col-4-b1 border-r1">Brian Ojeda</div> <div class="col-2">Nov 29 2008</div> </div></a> <a href="#"><div class="ojtable-row border-b1 clearfix"> <div class="col-7-b1 border-r1">Moment of Zen</div> <div class="col-4-b1 border-r1">Jedi</div> <div class="col-2">Mar 11 2010</div> </div></a> <a href="#"><div class="ojtable-row border-b1 clearfix"> <div class="col-7-b1 border-r1"></div> <div class="col-4-b1 border-r1">SGT OJ</div> <div class="col-2">Mar 11 2010</div> </div></a> </div>  PS: Thank you for assistant, if you do choose to help.

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Customized listfield with image displaying from a url

- by arunabha

I am displaying a customized list field with text on the right side and image on the left side.The image comes from a URL dynamically.Initially i am placing a blank image on the left of the list field,then call URLBitmapField class's setURL method,which actually does the processing and places the processed image on top of the blank image.The image gets displayed on the list field,but to see that processed image i need to press any key or click on the list field items.I want the processed image to be displayed automatically in the list field after the processing.Can anyone tell me where i am getting wrong? import java.util.Vector; import net.rim.device.api.system.Bitmap; import net.rim.device.api.system.Display; import net.rim.device.api.ui.ContextMenu; import net.rim.device.api.ui.DrawStyle; import net.rim.device.api.ui.Field; import net.rim.device.api.ui.Font; import net.rim.device.api.ui.Graphics; import net.rim.device.api.ui.Manager; import net.rim.device.api.ui.MenuItem; import net.rim.device.api.ui.UiApplication; import net.rim.device.api.ui.component.BitmapField; import net.rim.device.api.ui.component.Dialog; import net.rim.device.api.ui.component.LabelField; import net.rim.device.api.ui.component.ListField; import net.rim.device.api.ui.component.ListFieldCallback; import net.rim.device.api.ui.component.NullField; import net.rim.device.api.ui.container.FullScreen; import net.rim.device.api.ui.container.MainScreen; import net.rim.device.api.ui.container.VerticalFieldManager; import net.rim.device.api.util.Arrays; import net.rim.device.api.ui.component.ListField; public class TaskListField extends UiApplication { // statics // ------------------------------------------------------------------ public static void main(String[] args) { TaskListField theApp = new TaskListField(); theApp.enterEventDispatcher(); } public TaskListField() { pushScreen(new TaskList()); } } class TaskList extends MainScreen implements ListFieldCallback { private Vector rows; private Bitmap p1; private Bitmap p2; private Bitmap p3; String Task; ListField listnew = new ListField(); private VerticalFieldManager metadataVFM; TableRowManager row; public TaskList() { super(); URLBitmapField artistImgField; listnew.setRowHeight(80); listnew.setCallback(this); rows = new Vector(); for (int x = 0; x <3; x++) { row = new TableRowManager(); artistImgField = new URLBitmapField(Bitmap .getBitmapResource("res/images/bg.jpg")); row.add(artistImgField); String photoURL = "someimagefrmurl.jpg"; Log.info(photoURL); // strip white spaces in the url, which is causing the // images to not display properly for (int i = 0; i < photoURL.length(); i++) { if (photoURL.charAt(i) == ' ') { photoURL = photoURL.substring(0, i) + "%20" + photoURL.substring(i + 1, photoURL.length()); } } Log.info("Processed URL: " + photoURL); artistImgField.setURL(photoURL); LabelField task = new LabelField("Display"); row.add(task); LabelField task1 = new LabelField( "Now Playing" + String.valueOf(x)); Font myFont = Font.getDefault().derive(Font.PLAIN, 12); task1.setFont(myFont); row.add(task1); rows.addElement(row); } listnew.setSize(rows.size()); this.add(listnew); //listnew.invalidate(); } // ListFieldCallback Implementation public void drawListRow(ListField listField, Graphics g, int index, int y, int width) { TableRowManager rowManager = (TableRowManager) rows.elementAt(index); rowManager.drawRow(g, 0, y, width, listnew.getRowHeight()); } protected void drawFocus(Graphics graphics, boolean on) { } private class TableRowManager extends Manager { public TableRowManager() { super(0); } // Causes the fields within this row manager to be layed out then // painted. public void drawRow(Graphics g, int x, int y, int width, int height) { // Arrange the cell fields within this row manager. layout(width, height); // Place this row manager within its enclosing list. setPosition(x, y); // Apply a translating/clipping transformation to the graphics // context so that this row paints in the right area. g.pushRegion(getExtent()); // Paint this manager's controlled fields. subpaint(g); g.setColor(0x00CACACA); g.drawLine(0, 0, getPreferredWidth(), 0); // Restore the graphics context. g.popContext(); } // Arrages this manager's controlled fields from left to right within // the enclosing table's columns. protected void sublayout(int width, int height) { // set the size and position of each field. int fontHeight = Font.getDefault().getHeight(); int preferredWidth = getPreferredWidth(); // start with the Bitmap Field of the priority icon Field field = getField(0); layoutChild(field, 146,80); setPositionChild(field, 0, 0); // set the task name label field field = getField(1); layoutChild(field, preferredWidth - 16, fontHeight + 1); setPositionChild(field, 149, 3); // set the list name label field field = getField(2); layoutChild(field, 150, fontHeight + 1); setPositionChild(field, 149, fontHeight + 6); setExtent(360, 480); } // The preferred width of a row is defined by the list renderer. public int getPreferredWidth() { return listnew.getWidth(); } // The preferred height of a row is the "row height" as defined in the // enclosing list. public int getPreferredHeight() { return listnew.getRowHeight(); } } public Object get(ListField listField, int index) { // TODO Auto-generated method stub return null; } public int getPreferredWidth(ListField listField) { return 0; } public int indexOfList(ListField listField, String prefix, int start) { // TODO Auto-generated method stub return 0; } }

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Implementation of Nib project to Storyboard, Xcode

- by Blake Loizides

I have made a tabbed bar application in storyboard in xcode. I,m new to xcode. I got a Sample TableView XIB project from apple that I edited to my needs,The project has a UITableView that I Customized with Images, And with help of a certain forum member I was able to link up each image to a New View Controller. I tried to port or integrate My Nib Project Code to my StoryBoard Tabbed Bar Application.I thought I had everything right had to comment out a few things to get no errors, But the project only goes to a Blank Table View. Below are 2 links, 1 to my StoryBoard Tabbed Bar Application with the Table Code that I tried to integrate and the other My Successful Nib Project. Also is some code and pictures. If anybody has some free time and does not mind to help I would be extremely grateful for any input given. link1 - Storyboard link2 - XIB DecorsViewController_iPhone.m // // TableViewsViewController.m // TableViews // // Created by Axit Patel on 9/2/10. // Copyright Bayside High School 2010. All rights reserved. // #import "DecorsViewController_iPhone.h" #import "SelectedCellViewController.h" @implementation DecorsViewController_iPhone #pragma mark - Synthesizers @synthesize sitesArray; @synthesize imagesArray; #pragma mark - View lifecycle // Implement viewDidLoad to do additional setup after loading the view, typically from a nib. - (void)viewDidLoad { // Load up the sitesArray with a dummy array : sites NSArray *sites = [[NSArray alloc] initWithObjects:@"a", @"b", @"c", @"d", @"e", @"f", @"g", @"h", nil]; self.sitesArray = sites; //[sites release]; UIImage *PlumTree = [UIImage imageNamed:@"a.png"]; UIImage *CherryRoyale = [UIImage imageNamed:@"b.png"]; UIImage *MozambiqueWenge = [UIImage imageNamed:@"c.png"]; UIImage *RoyaleMahogany = [UIImage imageNamed:@"d.png"]; UIImage *Laricina = [UIImage imageNamed:@"e.png"]; UIImage *BurntOak = [UIImage imageNamed:@"f.png"]; UIImage *AutrianOak = [UIImage imageNamed:@"g.png"]; UIImage *SilverAcacia = [UIImage imageNamed:@"h.png"]; NSArray *images = [[NSArray alloc] initWithObjects: PlumTree, CherryRoyale, MozambiqueWenge, RoyaleMahogany, Laricina, BurntOak, AutrianOak, SilverAcacia, nil]; self.imagesArray = images; //[images release]; [super viewDidLoad]; } #pragma mark - Table View datasource methods // Required Methods // Return the number of rows in a section - (NSInteger)tableView:(UITableView *)table numberOfRowsInSection:(NSInteger)section { return [sitesArray count]; } // Returns cell to render for each row - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"CellIdentifier"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier]; // Configure cell NSUInteger row = [indexPath row]; // Sets the text for the cell //cell.textLabel.text = [sitesArray objectAtIndex:row]; // Sets the imageview for the cell cell.imageView.image = [imagesArray objectAtIndex:row]; // Sets the accessory for the cell cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator; // Sets the detailtext for the cell (subtitle) //cell.detailTextLabel.text = [NSString stringWithFormat:@"This is row: %i", row + 1]; return cell; } // Optional // Returns the number of section in a table view -(NSInteger) numberOfSectionsInTableView:(UITableView *)tableView { return 1; } #pragma mark - #pragma mark Table View delegate methods // Return the height for each cell -(CGFloat) tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath { return 78; } // Sets the title for header in the tableview -(NSString *) tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section { return @"Decors"; } // Sets the title for footer -(NSString *) tableView:(UITableView *)tableView titleForFooterInSection:(NSInteger)section { return @"Decors"; } // Sets the indentation for rows -(NSInteger) tableView:(UITableView *)tableView indentationLevelForRowAtIndexPath:(NSIndexPath *)indexPath { return 0; } // Method that gets called from the "Done" button (From the @selector in the line - [viewControllerToShow.navigationItem setRightBarButtonItem:[[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(dismissView)] autorelease]];) - (void)dismissView { [self dismissViewControllerAnimated:YES completion:NULL]; } // This method is run when the user taps the row in the tableview - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { [tableView deselectRowAtIndexPath:indexPath animated:YES]; SelectedCellViewController *viewControllerToShow = [[SelectedCellViewController alloc] initWithNibName:@"SelectedCellViewController" bundle:[NSBundle mainBundle]]; [viewControllerToShow setLabelText:[NSString stringWithFormat:@"You selected cell: %d - %@", indexPath.row, [sitesArray objectAtIndex:indexPath.row]]]; [viewControllerToShow setImage:(UIImage *)[imagesArray objectAtIndex:indexPath.row]]; [viewControllerToShow setModalPresentationStyle:UIModalPresentationFormSheet]; [viewControllerToShow setModalTransitionStyle:UIModalTransitionStyleFlipHorizontal]; [viewControllerToShow.navigationItem setRightBarButtonItem:[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(dismissView)]]; UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:viewControllerToShow]; viewControllerToShow = nil; [self presentViewController:navController animated:YES completion:NULL]; navController = nil; // UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Tapped row!" // message:[NSString stringWithFormat:@"You tapped: %@", [sitesArray objectAtIndex:indexPath.row]] // delegate:nil // cancelButtonTitle:@"Yes, I did!" // otherButtonTitles:nil]; // [alert show]; // [alert release]; } #pragma mark - Memory management - (void)didReceiveMemoryWarning { NSLog(@"Memory Warning!"); [super didReceiveMemoryWarning]; } - (void)viewDidUnload { self.sitesArray = nil; self.imagesArray = nil; [super viewDidUnload]; } //- (void)dealloc { //[sitesArray release]; //[imagesArray release]; // [super dealloc]; //} //@end //- (void)viewDidUnload //{ // [super viewDidUnload]; // Release any retained subviews of the main view. //} - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) { return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown); } else { return YES; } } @end DecorsViewController_iPhone.h #import <UIKit/UIKit.h> @interface DecorsViewController_iPhone : UIViewController <UITableViewDelegate, UITableViewDataSource> { NSArray *sitesArray; NSArray *imagesArray; } @property (nonatomic, retain) NSArray *sitesArray; @property (nonatomic, retain) NSArray *imagesArray; @end SelectedCellViewController.m #import "SelectedCellViewController.h" @implementation SelectedCellViewController @synthesize labelText; @synthesize image; - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil { if ((self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil])) { } return self; } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; } #pragma mark - View lifecycle - (void)viewDidLoad { [super viewDidLoad]; [label setText:self.labelText]; [imageView setImage:self.image]; } - (void)viewDidUnload { self.labelText = nil; self.image = nil; // [label release]; // [imageView release]; [super viewDidUnload]; } - (BOOL)shouldAutorotateToInterfaceOrientation: (UIInterfaceOrientation)interfaceOrientation { return (interfaceOrientation == UIInterfaceOrientationPortrait); } @end SelectedCellViewController.h @interface SelectedCellViewController : UIViewController { NSString *labelText; UIImage *image; IBOutlet UILabel *label; IBOutlet UIImageView *imageView; } @property (nonatomic, copy) NSString *labelText; @property (nonatomic, retain) UIImage *image; @end

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ASP.NET Podcast Show #148 - ASP.NET WebForms to build a Mobile Web Application

- by Wallym

Check the podcast site for the original url. This is the video and source code for an ASP.NET WebForms app that I wrote that is optimized for the iPhone and mobile environments. Subscribe to everything. Subscribe to WMV. Subscribe to M4V for iPhone/iPad. Subscribe to MP3. Download WMV. Download M4V for iPhone/iPad. Download MP3. Link to iWebKit. Source Code: <%@ Page Title="MapSplore" Language="C#" MasterPageFile="iPhoneMaster.master" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="AT_iPhone_Default" %> <asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server"></asp:Content><asp:Content ID="Content2" ContentPlaceHolderID="Content" Runat="Server" ClientIDMode="Static"> <asp:ScriptManager ID="sm" runat="server" EnablePartialRendering="true" EnableHistory="false" EnableCdn="true" /> <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=true"></script> <script language="javascript" type="text/javascript">  </script> <asp:HiddenField ID="Latitude" runat="server" /> <asp:HiddenField ID="Longitude" runat="server" /> <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js%22%3E%3C/script> <script language="javascript" type="text/javascript"> $(document).ready(function () { GetLocation(); setupMapDiv(); setupPlaceIveBeen(); }); function GetLocation() { if (navigator.geolocation != null) { navigator.geolocation.getCurrentPosition(getData); } else { var mess = document.getElementById('<%=Message.ClientID %>'); mess.innerHTML = "Sorry, your browser does not support geolocation. " + "Try the latest version of Safari on the iPhone, Android browser, or the latest version of FireFox."; } } function UpdateLocation_Click() { GetLocation(); } function getData(position) { var latitude = position.coords.latitude; var longitude = position.coords.longitude; var hdLat = document.getElementById('<%=Latitude.ClientID %>'); var hdLon = document.getElementById('<%=Longitude.ClientID %>'); hdLat.value = latitude; hdLon.value = longitude; } </script> <asp:Label ID="Message" runat="server" /> <asp:UpdatePanel ID="upl" runat="server"> <ContentTemplate> <asp:Panel ID="pnlStart" runat="server" Visible="true"> <div id="topbar"> <div id="title">MapSplore</div> </div> <div id="content"> <ul class="pageitem"> <li class="menu"> <asp:LinkButton ID="lbLocalDeals" runat="server" onclick="lbLocalDeals_Click"> <asp:Image ID="imLocalDeals" runat="server" ImageUrl="~/Images/ArtFavor_Money_Bag_Icon.png" Height="30" /> <span class="name">Local Deals.</span> <span class="arrow"></span> </asp:LinkButton> </li> <li class="menu"> <asp:LinkButton ID="lbLocalPlaces" runat="server" onclick="lbLocalPlaces_Click"> <asp:Image ID="imLocalPlaces" runat="server" ImageUrl="~/Images/Andy_Houses_on_the_horizon_-_Starburst_remix.png" Height="30" /> <span class="name">Local Places.</span> <span class="arrow"></span> </asp:LinkButton> </li> <li class="menu"> <asp:LinkButton ID="lbWhereIveBeen" runat="server" onclick="lbWhereIveBeen_Click"> <asp:Image ID="imImHere" runat="server" ImageUrl="~/Images/ryanlerch_flagpole.png" Height="30" /> <span class="name">I've been here.</span> <span class="arrow"></span> </asp:LinkButton> </li> <li class="menu"> <asp:LinkButton ID="lbMyStats" runat="server"> <asp:Image ID="imMyStats" runat="server" ImageUrl="~/Images/Anonymous_Spreadsheet.png" Height="30" /> <span class="name">My Stats.</span> <span class="arrow"></span> </asp:LinkButton> </li> <li class="menu"> <asp:LinkButton ID="lbAddAPlace" runat="server" onclick="lbAddAPlace_Click"> <asp:Image ID="imAddAPlace" runat="server" ImageUrl="~/Images/jean_victor_balin_add.png" Height="30" /> <span class="name">Add a Place.</span> <span class="arrow"></span> </asp:LinkButton> </li> <li class="button"> <input type="button" value="Update Your Current Location" onclick="UpdateLocation_Click()"> </li> </ul> </div> </asp:Panel> <div> <asp:Panel ID="pnlCoupons" runat="server" Visible="false"> <div id="topbar"> <div id="title">MapSplore</div> <div id="leftbutton"> <asp:LinkButton runat="server" Text="Return" ID="ReturnFromDeals" OnClick="ReturnFromDeals_Click" /></div></div> <div class="content"> <asp:ListView ID="lvCoupons" runat="server"> <LayoutTemplate> <ul class="pageitem" runat="server"> <asp:PlaceHolder ID="itemPlaceholder" runat="server" /> </ul> </LayoutTemplate> <ItemTemplate> <li class="menu"> <asp:LinkButton ID="lbBusiness" runat="server" Text='<%#Eval("Place.Name") %>' OnClick="lbBusiness_Click"> <span class="comment"> <asp:Label ID="lblAddress" runat="server" Text='<%#Eval("Place.Address1") %>' /> <asp:Label ID="lblDis" runat="server" Text='<%# Convert.ToString(Convert.ToInt32(Eval("Place.Distance"))) + " meters" %>' CssClass="smallText" /> <asp:HiddenField ID="hdPlaceId" runat="server" Value='<%#Eval("PlaceId") %>' /> <asp:HiddenField ID="hdGeoPromotionId" runat="server" Value='<%#Eval("GeoPromotionId") %>' /> </span> <span class="arrow"></span> </asp:LinkButton></li></ItemTemplate></asp:ListView><asp:GridView ID="gvCoupons" runat="server" AutoGenerateColumns="false"> <HeaderStyle BackColor="Silver" /> <AlternatingRowStyle BackColor="Wheat" /> <Columns> <asp:TemplateField AccessibleHeaderText="Business" HeaderText="Business"> <ItemTemplate> <asp:Image ID="imPlaceType" runat="server" Text='<%#Eval("Type") %>' ImageUrl='<%#Eval("Image") %>' /> <asp:LinkButton ID="lbBusiness" runat="server" Text='<%#Eval("Name") %>' OnClick="lbBusiness_Click" /> <asp:LinkButton ID="lblAddress" runat="server" Text='<%#Eval("Address1") %>' CssClass="smallText" /> <asp:Label ID="lblDis" runat="server" Text='<%# Convert.ToString(Convert.ToInt32(Eval("Distance"))) + " meters" %>' CssClass="smallText" /> <asp:HiddenField ID="hdPlaceId" runat="server" Value='<%#Eval("PlaceId") %>' /> <asp:HiddenField ID="hdGeoPromotionId" runat="server" Value='<%#Eval("GeoPromotionId") %>' /> <asp:Label ID="lblInfo" runat="server" Visible="false" /> </ItemTemplate> </asp:TemplateField> </Columns> </asp:GridView> </div> </asp:Panel> <asp:Panel ID="pnlPlaces" runat="server" Visible="false"> <div id="topbar"> <div id="title"> MapSplore</div><div id="leftbutton"> <asp:LinkButton runat="server" Text="Return" ID="ReturnFromPlaces" OnClick="ReturnFromPlaces_Click" /></div></div> <div id="content"> <asp:ListView ID="lvPlaces" runat="server"> <LayoutTemplate> <ul id="ulPlaces" class="pageitem" runat="server"> <asp:PlaceHolder ID="itemPlaceholder" runat="server" /> <li class="menu"> <asp:LinkButton ID="lbNotListed" runat="server" CssClass="name" OnClick="lbNotListed_Click"> Place not listed <span class="arrow"></span> </asp:LinkButton> </li> </ul> </LayoutTemplate> <ItemTemplate> <li class="menu"> <asp:LinkButton ID="lbImHere" runat="server" CssClass="name" OnClick="lbImHere_Click"> <%#DisplayName(Eval("Name")) %>  <%# Convert.ToString(Convert.ToInt32(Eval("Distance"))) + " meters" %> <asp:HiddenField ID="hdPlaceId" runat="server" Value='<%#Eval("PlaceId") %>' /> <span class="arrow"></span> </asp:LinkButton></li></ItemTemplate></asp:ListView> </div> </asp:Panel> <asp:Panel ID="pnlImHereNow" runat="server" Visible="false"> <div id="topbar"> <div id="title"> MapSplore</div><div id="leftbutton"> <asp:LinkButton runat="server" Text="Places" ID="lbImHereNowReturn" OnClick="lbImHereNowReturn_Click" /></div></div> <div id="rightbutton"> <asp:LinkButton runat="server" Text="Beginning" ID="lbBackToBeginning" OnClick="lbBackToBeginning_Click" /> </div> <div id="content"> <ul class="pageitem"> <asp:HiddenField ID="hdPlaceId" runat="server" /> <asp:HiddenField ID="hdPlaceLat" runat="server" /> <asp:HiddenField ID="hdPlaceLon" runat="server" /> <asp:HiddenField ID="hdPlaceTitle" runat="server" /> <asp:Button ID="btnImHereNow" runat="server" Text="I'm here" OnClick="btnImHereNow_Click" /> <asp:Label ID="lblPlaceTitle" runat="server" /><br /> <asp:TextBox ID="txtWhatsHappening" runat="server" TextMode="MultiLine" Rows="2" style="width:300px" /><br /> <div id="divImHere" style="width:300px; height:300px"></div> </div> </ul> </asp:Panel> <asp:Panel runat="server" ID="pnlIveBeenHere" Visible="false"> <div id="topbar"> <div id="title"> Where I've been</div><div id="leftbutton"> <asp:LinkButton ID="lbIveBeenHereBack" runat="server" Text="Back" OnClick="lbIveBeenHereBack_Click" /></div></div> <div id="content"> <asp:ListView ID="lvWhereIveBeen" runat="server"> <LayoutTemplate> <ul id="ulWhereIveBeen" class="pageitem" runat="server"> <asp:PlaceHolder ID="itemPlaceholder" runat="server" /> </ul> </LayoutTemplate> <ItemTemplate> <li class="menu" runat="server"> <asp:LinkButton ID="lbPlaceIveBeen" runat="server" OnClick="lbPlaceIveBeen_Click" CssClass="name"> <asp:Label ID="lblPlace" runat="server" Text='<%#Eval("PlaceName") %>' /> at <asp:Label ID="lblTime" runat="server" Text='<%#Eval("ATTime") %>' CssClass="content" /> <asp:HiddenField ID="hdATID" runat="server" Value='<%#Eval("ATID") %>' /> <span class="arrow"></span> </asp:LinkButton> </li> </ItemTemplate> </asp:ListView> </div> </asp:Panel> <asp:Panel runat="server" ID="pnlPlaceIveBeen" Visible="false"> <div id="topbar"> <div id="title"> I've been here </div> <div id="leftbutton"> <asp:LinkButton ID="lbPlaceIveBeenBack" runat="server" Text="Back" OnClick="lbPlaceIveBeenBack_Click" /> </div> <div id="rightbutton"> <asp:LinkButton ID="lbPlaceIveBeenBeginning" runat="server" Text="Beginning" OnClick="lbPlaceIveBeenBeginning_Click" /> </div> </div> <div id="content"> <ul class="pageitem"> <li> <asp:HiddenField ID="hdPlaceIveBeenPlaceId" runat="server" /> <asp:HiddenField ID="hdPlaceIveBeenLatitude" runat="server" /> <asp:HiddenField ID="hdPlaceIveBeenLongitude" runat="server" /> <asp:Label ID="lblPlaceIveBeenName" runat="server" /><br /> <asp:Label ID="lblPlaceIveBeenAddress" runat="server" /><br /> <asp:Label ID="lblPlaceIveBeenCity" runat="server" />, <asp:Label ID="lblPlaceIveBeenState" runat="server" /> <asp:Label ID="lblPlaceIveBeenZipCode" runat="server" /><br /> <asp:Label ID="lblPlaceIveBeenCountry" runat="server" /><br /> <div id="divPlaceIveBeen" style="width:300px; height:300px"></div> </li> </ul> </div> </asp:Panel> <asp:Panel ID="pnlAddPlace" runat="server" Visible="false"> <div id="topbar"><div id="title">MapSplore</div><div id="leftbutton"><asp:LinkButton ID="lbAddPlaceReturn" runat="server" Text="Back" OnClick="lbAddPlaceReturn_Click" /></div><div id="rightnav"></div></div><div id="content"> <ul class="pageitem"> <li id="liPlaceAddMessage" runat="server" visible="false"> <asp:Label ID="PlaceAddMessage" runat="server" /> </li> <li class="bigfield"> <asp:TextBox ID="txtPlaceName" runat="server" placeholder="Name of Establishment" /> </li> <li class="bigfield"> <asp:TextBox ID="txtAddress1" runat="server" placeholder="Address 1" /> </li> <li class="bigfield"> <asp:TextBox ID="txtCity" runat="server" placeholder="City" /> </li> <li class="select"> <asp:DropDownList ID="ddlProvince" runat="server" placeholder="Select State" /> <span class="arrow"></span> </li> <li class="bigfield"> <asp:TextBox ID="txtZipCode" runat="server" placeholder="Zip Code" /> </li> <li class="select"> <asp:DropDownList ID="ddlCountry" runat="server" onselectedindexchanged="ddlCountry_SelectedIndexChanged" /> <span class="arrow"></span> </li> <li class="bigfield"> <asp:TextBox ID="txtPhoneNumber" runat="server" placeholder="Phone Number" /> </li> <li class="checkbox"> <span class="name">You Here Now:</span> <asp:CheckBox ID="cbYouHereNow" runat="server" Checked="true" /> </li> <li class="button"> <asp:Button ID="btnAdd" runat="server" Text="Add Place" onclick="btnAdd_Click" /> </li> </ul></div> </asp:Panel> <asp:Panel ID="pnlImHere" runat="server" Visible="false"> <asp:TextBox ID="txtImHere" runat="server" TextMode="MultiLine" Rows="3" Columns="40" /><br /> <asp:DropDownList ID="ddlPlace" runat="server" /><br /> <asp:Button ID="btnHere" runat="server" Text="Tell Everyone I'm Here" onclick="btnHere_Click" /><br /> </asp:Panel> </div> </ContentTemplate> </asp:UpdatePanel> </asp:Content> Code Behind .cs file: using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.HtmlControls;using System.Web.UI.WebControls;using LocationDataModel; public partial class AT_iPhone_Default : ViewStatePage{ private iPhoneDevice ipd; protected void Page_Load(object sender, EventArgs e) { LocationDataEntities lde = new LocationDataEntities(); if (!Page.IsPostBack) { var Countries = from c in lde.Countries select c; foreach (Country co in Countries) { ddlCountry.Items.Add(new ListItem(co.Name, co.CountryId.ToString())); } ddlCountry_SelectedIndexChanged(ddlCountry, null); if (AppleIPhone.IsIPad()) ipd = iPhoneDevice.iPad; if (AppleIPhone.IsIPhone()) ipd = iPhoneDevice.iPhone; if (AppleIPhone.IsIPodTouch()) ipd = iPhoneDevice.iPodTouch; } } protected void btnPlaces_Click(object sender, EventArgs e) { } protected void btnAdd_Click(object sender, EventArgs e) { bool blImHere = cbYouHereNow.Checked; string Place = txtPlaceName.Text, Address1 = txtAddress1.Text, City = txtCity.Text, ZipCode = txtZipCode.Text, PhoneNumber = txtPhoneNumber.Text, ProvinceId = ddlProvince.SelectedItem.Value, CountryId = ddlCountry.SelectedItem.Value; int iProvinceId, iCountryId; double dLatitude, dLongitude; DataAccess da = new DataAccess(); if ((!String.IsNullOrEmpty(ProvinceId)) && (!String.IsNullOrEmpty(CountryId))) { iProvinceId = Convert.ToInt32(ProvinceId); iCountryId = Convert.ToInt32(CountryId); if (blImHere) { dLatitude = Convert.ToDouble(Latitude.Value); dLongitude = Convert.ToDouble(Longitude.Value); da.StorePlace(Place, Address1, String.Empty, City, iProvinceId, ZipCode, iCountryId, PhoneNumber, dLatitude, dLongitude); } else { da.StorePlace(Place, Address1, String.Empty, City, iProvinceId, ZipCode, iCountryId, PhoneNumber); } liPlaceAddMessage.Visible = true; PlaceAddMessage.Text = "Awesome, your place has been added. Add Another!"; txtPlaceName.Text = String.Empty; txtAddress1.Text = String.Empty; txtCity.Text = String.Empty; ddlProvince.SelectedIndex = -1; txtZipCode.Text = String.Empty; txtPhoneNumber.Text = String.Empty; } else { liPlaceAddMessage.Visible = true; PlaceAddMessage.Text = "Please select a State and a Country."; } } protected void ddlCountry_SelectedIndexChanged(object sender, EventArgs e) { string CountryId = ddlCountry.SelectedItem.Value; if (!String.IsNullOrEmpty(CountryId)) { int iCountryId = Convert.ToInt32(CountryId); LocationDataModel.LocationDataEntities lde = new LocationDataModel.LocationDataEntities(); var prov = from p in lde.Provinces where p.CountryId == iCountryId orderby p.ProvinceName select p; ddlProvince.Items.Add(String.Empty); foreach (Province pr in prov) { ddlProvince.Items.Add(new ListItem(pr.ProvinceName, pr.ProvinceId.ToString())); } } else { ddlProvince.Items.Clear(); } } protected void btnImHere_Click(object sender, EventArgs e) { int i = 0; DataAccess da = new DataAccess(); double Lat = Convert.ToDouble(Latitude.Value), Lon = Convert.ToDouble(Longitude.Value); List<Place> lp = da.NearByLocations(Lat, Lon); foreach (Place p in lp) { ListItem li = new ListItem(p.Name, p.PlaceId.ToString()); if (i == 0) { li.Selected = true; } ddlPlace.Items.Add(li); i++; } pnlAddPlace.Visible = false; pnlImHere.Visible = true; } protected void lbImHere_Click(object sender, EventArgs e) { string UserName = Membership.GetUser().UserName; ListViewItem lvi = (ListViewItem)(((LinkButton)sender).Parent); HiddenField hd = (HiddenField)lvi.FindControl("hdPlaceId"); long PlaceId = Convert.ToInt64(hd.Value); double dLatitude = Convert.ToDouble(Latitude.Value); double dLongitude = Convert.ToDouble(Longitude.Value); DataAccess da = new DataAccess(); Place pl = da.GetPlace(PlaceId); pnlImHereNow.Visible = true; pnlPlaces.Visible = false; hdPlaceId.Value = PlaceId.ToString(); hdPlaceLat.Value = pl.Latitude.ToString(); hdPlaceLon.Value = pl.Longitude.ToString(); hdPlaceTitle.Value = pl.Name; lblPlaceTitle.Text = pl.Name; } protected void btnHere_Click(object sender, EventArgs e) { string UserName = Membership.GetUser().UserName; string WhatsH = txtImHere.Text; long PlaceId = Convert.ToInt64(ddlPlace.SelectedValue); double dLatitude = Convert.ToDouble(Latitude.Value); double dLongitude = Convert.ToDouble(Longitude.Value); DataAccess da = new DataAccess(); da.StoreUserAT(UserName, PlaceId, WhatsH, dLatitude, dLongitude); } protected void btnLocalCoupons_Click(object sender, EventArgs e) { double dLatitude = Convert.ToDouble(Latitude.Value); double dLongitude = Convert.ToDouble(Longitude.Value); DataAccess da = new DataAccess(); } protected void lbBusiness_Click(object sender, EventArgs e) { string UserName = Membership.GetUser().UserName; GridViewRow gvr = (GridViewRow)(((LinkButton)sender).Parent.Parent); HiddenField hd = (HiddenField)gvr.FindControl("hdPlaceId"); string sPlaceId = hd.Value; Int64 PlaceId; if (!String.IsNullOrEmpty(sPlaceId)) { PlaceId = Convert.ToInt64(sPlaceId); } } protected void lbLocalDeals_Click(object sender, EventArgs e) { double dLatitude = Convert.ToDouble(Latitude.Value); double dLongitude = Convert.ToDouble(Longitude.Value); DataAccess da = new DataAccess(); pnlCoupons.Visible = true; pnlStart.Visible = false; List<GeoPromotion> lgp = da.NearByDeals(dLatitude, dLongitude); lvCoupons.DataSource = lgp; lvCoupons.DataBind(); } protected void lbLocalPlaces_Click(object sender, EventArgs e) { DataAccess da = new DataAccess(); double Lat = Convert.ToDouble(Latitude.Value); double Lon = Convert.ToDouble(Longitude.Value); List<LocationDataModel.Place> places = da.NearByLocations(Lat, Lon); lvPlaces.DataSource = places; lvPlaces.SelectedIndex = -1; lvPlaces.DataBind(); pnlPlaces.Visible = true; pnlStart.Visible = false; } protected void ReturnFromPlaces_Click(object sender, EventArgs e) { pnlPlaces.Visible = false; pnlStart.Visible = true; } protected void ReturnFromDeals_Click(object sender, EventArgs e) { pnlCoupons.Visible = false; pnlStart.Visible = true; } protected void btnImHereNow_Click(object sender, EventArgs e) { long PlaceId = Convert.ToInt32(hdPlaceId.Value); string UserName = Membership.GetUser().UserName; string WhatsHappening = txtWhatsHappening.Text; double UserLat = Convert.ToDouble(Latitude.Value); double UserLon = Convert.ToDouble(Longitude.Value); DataAccess da = new DataAccess(); da.StoreUserAT(UserName, PlaceId, WhatsHappening, UserLat, UserLon); } protected void lbImHereNowReturn_Click(object sender, EventArgs e) { pnlImHereNow.Visible = false; pnlPlaces.Visible = true; } protected void lbBackToBeginning_Click(object sender, EventArgs e) { pnlStart.Visible = true; pnlImHereNow.Visible = false; } protected void lbWhereIveBeen_Click(object sender, EventArgs e) { string UserName = Membership.GetUser().UserName; pnlStart.Visible = false; pnlIveBeenHere.Visible = true; DataAccess da = new DataAccess(); lvWhereIveBeen.DataSource = da.UserATs(UserName, 0, 15); lvWhereIveBeen.DataBind(); } protected void lbIveBeenHereBack_Click(object sender, EventArgs e) { pnlIveBeenHere.Visible = false; pnlStart.Visible = true; } protected void lbPlaceIveBeen_Click(object sender, EventArgs e) { LinkButton lb = (LinkButton)sender; ListViewItem lvi = (ListViewItem)lb.Parent.Parent; HiddenField hdATID = (HiddenField)lvi.FindControl("hdATID"); Int64 ATID = Convert.ToInt64(hdATID.Value); DataAccess da = new DataAccess(); pnlIveBeenHere.Visible = false; pnlPlaceIveBeen.Visible = true; var plac = da.GetPlaceViaATID(ATID); hdPlaceIveBeenPlaceId.Value = plac.PlaceId.ToString(); hdPlaceIveBeenLatitude.Value = plac.Latitude.ToString(); hdPlaceIveBeenLongitude.Value = plac.Longitude.ToString(); lblPlaceIveBeenName.Text = plac.Name; lblPlaceIveBeenAddress.Text = plac.Address1; lblPlaceIveBeenCity.Text = plac.City; lblPlaceIveBeenState.Text = plac.Province.ProvinceName; lblPlaceIveBeenZipCode.Text = plac.ZipCode; lblPlaceIveBeenCountry.Text = plac.Country.Name; } protected void lbNotListed_Click(object sender, EventArgs e) { SetupAddPoint(); pnlPlaces.Visible = false; } protected void lbAddAPlace_Click(object sender, EventArgs e) { SetupAddPoint(); } private void SetupAddPoint() { double lat = Convert.ToDouble(Latitude.Value); double lon = Convert.ToDouble(Longitude.Value); DataAccess da = new DataAccess(); var zip = da.WhereAmIAt(lat, lon); if (zip.Count > 0) { var z0 = zip[0]; txtCity.Text = z0.City; txtZipCode.Text = z0.ZipCode; ddlProvince.ClearSelection(); if (z0.ProvinceId.HasValue == true) { foreach (ListItem li in ddlProvince.Items) { if (li.Value == z0.ProvinceId.Value.ToString()) { li.Selected = true; break; } } } } pnlAddPlace.Visible = true; pnlStart.Visible = false; } protected void lbAddPlaceReturn_Click(object sender, EventArgs e) { pnlAddPlace.Visible = false; pnlStart.Visible = true; liPlaceAddMessage.Visible = false; PlaceAddMessage.Text = String.Empty; } protected void lbPlaceIveBeenBack_Click(object sender, EventArgs e) { pnlIveBeenHere.Visible = true; pnlPlaceIveBeen.Visible = false; } protected void lbPlaceIveBeenBeginning_Click(object sender, EventArgs e) { pnlPlaceIveBeen.Visible = false; pnlStart.Visible = true; } protected string DisplayName(object val) { string strVal = Convert.ToString(val); if (AppleIPhone.IsIPad()) { ipd = iPhoneDevice.iPad; } if (AppleIPhone.IsIPhone()) { ipd = iPhoneDevice.iPhone; } if (AppleIPhone.IsIPodTouch()) { ipd = iPhoneDevice.iPodTouch; } return (iPhoneHelper.DisplayContentOnMenu(strVal, ipd)); }} iPhoneHelper.cs file: using System;using System.Collections.Generic;using System.Linq;using System.Web; public enum iPhoneDevice{ iPhone, iPodTouch, iPad}/// <summary>/// Summary description for iPhoneHelper/// </summary>/// public class iPhoneHelper{ public iPhoneHelper() { // // TODO: Add constructor logic here // } // This code is stupid in retrospect. Use css to solve this problem public static string DisplayContentOnMenu(string val, iPhoneDevice ipd) { string Return = val; string Elipsis = "..."; int iPadMaxLength = 30; int iPhoneMaxLength = 15; if (ipd == iPhoneDevice.iPad) { if (Return.Length > iPadMaxLength) { Return = Return.Substring(0, iPadMaxLength - Elipsis.Length) + Elipsis; } } else { if (Return.Length > iPhoneMaxLength) { Return = Return.Substring(0, iPhoneMaxLength - Elipsis.Length) + Elipsis; } } return (Return); }} Source code for the ViewStatePage: using System;using System.Data;using System.Data.SqlClient;using System.Configuration;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Web.UI.HtmlControls; /// <summary>/// Summary description for BasePage/// </summary>#region Base class for a page.public class ViewStatePage : System.Web.UI.Page{ PageStatePersisterToDatabase myPageStatePersister; public ViewStatePage() : base() { myPageStatePersister = new PageStatePersisterToDatabase(this); } protected override PageStatePersister PageStatePersister { get { return myPageStatePersister; } } }#endregion #region This class will override the page persistence to store page state in a database.public class PageStatePersisterToDatabase : PageStatePersister{ private string ViewStateKeyField = "__VIEWSTATE_KEY"; private string _exNoConnectionStringFound = "No Database Configuration information is in the web.config."; public PageStatePersisterToDatabase(Page page) : base(page) { } public override void Load() { // Get the cache key from the web form data System.Int64 key = Convert.ToInt64(Page.Request.Params[ViewStateKeyField]); Pair state = this.LoadState(key); // Abort if cache object is not of type Pair if (state == null) throw new ApplicationException("Missing valid " + ViewStateKeyField); // Set view state and control state ViewState = state.First; ControlState = state.Second; } public override void Save() { // No processing needed if no states available if (ViewState == null && ControlState != null) return; System.Int64 key; IStateFormatter formatter = this.StateFormatter; Pair statePair = new Pair(ViewState, ControlState); // Serialize the statePair object to a string. string serializedState = formatter.Serialize(statePair); // Save the ViewState and get a unique identifier back. key = SaveState(serializedState); // Register hidden field to store cache key in // Page.ClientScript does not work properly with Atlas. //Page.ClientScript.RegisterHiddenField(ViewStateKeyField, key.ToString()); ScriptManager.RegisterHiddenField(this.Page, ViewStateKeyField, key.ToString()); } private System.Int64 SaveState(string PageState) { System.Int64 i64Key = 0; string strConn = String.Empty, strProvider = String.Empty; string strSql = "insert into tblPageState ( SerializedState ) values ( '" + SqlEscape(PageState) + "');select scope_identity();"; SqlConnection sqlCn; SqlCommand sqlCm; try { GetDBConnectionString(ref strConn, ref strProvider); sqlCn = new SqlConnection(strConn); sqlCm = new SqlCommand(strSql, sqlCn); sqlCn.Open(); i64Key = Convert.ToInt64(sqlCm.ExecuteScalar()); if (sqlCn.State != ConnectionState.Closed) { sqlCn.Close(); } sqlCn.Dispose(); sqlCm.Dispose(); } finally { sqlCn = null; sqlCm = null; } return i64Key; } private Pair LoadState(System.Int64 iKey) { string strConn = String.Empty, strProvider = String.Empty, SerializedState = String.Empty, strMinutesInPast = GetMinutesInPastToDelete(); Pair PageState; string strSql = "select SerializedState from tblPageState where tblPageStateID=" + iKey.ToString() + ";" + "delete from tblPageState where DateUpdated<DateAdd(mi, " + strMinutesInPast + ", getdate());"; SqlConnection sqlCn; SqlCommand sqlCm; try { GetDBConnectionString(ref strConn, ref strProvider); sqlCn = new SqlConnection(strConn); sqlCm = new SqlCommand(strSql, sqlCn); sqlCn.Open(); SerializedState = Convert.ToString(sqlCm.ExecuteScalar()); IStateFormatter formatter = this.StateFormatter; if ((null == SerializedState) || (String.Empty == SerializedState)) { throw (new ApplicationException("No ViewState records were returned.")); } // Deserilize returns the Pair object that is serialized in // the Save method. PageState = (Pair)formatter.Deserialize(SerializedState); if (sqlCn.State != ConnectionState.Closed) { sqlCn.Close(); } sqlCn.Dispose(); sqlCm.Dispose(); } finally { sqlCn = null; sqlCm = null; } return PageState; } private string SqlEscape(string Val) { string ReturnVal = String.Empty; if (null != Val) { ReturnVal = Val.Replace("'", "''"); } return (ReturnVal); } private void GetDBConnectionString(ref string ConnectionStringValue, ref string ProviderNameValue) { if (System.Configuration.ConfigurationManager.ConnectionStrings.Count > 0) { ConnectionStringValue = System.Configuration.ConfigurationManager.ConnectionStrings["ApplicationServices"].ConnectionString; ProviderNameValue = System.Configuration.ConfigurationManager.ConnectionStrings["ApplicationServices"].ProviderName; } else { throw new ConfigurationErrorsException(_exNoConnectionStringFound); } } private string GetMinutesInPastToDelete() { string strReturn = "-60"; if (null != System.Configuration.ConfigurationManager.AppSettings["MinutesInPastToDeletePageState"]) { strReturn = System.Configuration.ConfigurationManager.AppSettings["MinutesInPastToDeletePageState"].ToString(); } return (strReturn); }}#endregion AppleiPhone.cs file: using System;using System.Collections.Generic;using System.Linq;using System.Web; /// <summary>/// Summary description for AppleIPhone/// </summary>public class AppleIPhone{ public AppleIPhone() { // // TODO: Add constructor logic here // } static public bool IsIPhoneOS() { return (IsIPad() || IsIPhone() || IsIPodTouch()); } static public bool IsIPhone() { return IsTest("iPhone"); } static public bool IsIPodTouch() { return IsTest("iPod"); } static public bool IsIPad() { return IsTest("iPad"); } static private bool IsTest(string Agent) { bool bl = false; string ua = HttpContext.Current.Request.UserAgent.ToLower(); try { bl = ua.Contains(Agent.ToLower()); } catch { } return (bl); }} Master page .cs: using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.UI;using System.Web.UI.HtmlControls;using System.Web.UI.WebControls; public partial class MasterPages_iPhoneMaster : System.Web.UI.MasterPage{ protected void Page_Load(object sender, EventArgs e) { HtmlHead head = Page.Header; HtmlMeta meta = new HtmlMeta(); if (AppleIPhone.IsIPad() == true) { meta.Content = "width=400,user-scalable=no"; head.Controls.Add(meta); } else { meta.Content = "width=device-width, user-scalable=no"; meta.Attributes.Add("name", "viewport"); } meta.Attributes.Add("name", "viewport"); head.Controls.Add(meta); HtmlLink cssLink = new HtmlLink(); HtmlGenericControl script = new HtmlGenericControl("script"); script.Attributes.Add("type", "text/javascript"); script.Attributes.Add("src", ResolveUrl("~/Scripts/iWebKit/javascript/functions.js")); head.Controls.Add(script); cssLink.Attributes.Add("rel", "stylesheet"); cssLink.Attributes.Add("href", ResolveUrl("~/Scripts/iWebKit/css/style.css") ); cssLink.Attributes.Add("type", "text/css"); head.Controls.Add(cssLink); HtmlGenericControl jsLink = new HtmlGenericControl("script"); //jsLink.Attributes.Add("type", "text/javascript"); //jsLink.Attributes.Add("src", ResolveUrl("~/Scripts/jquery-1.4.1.min.js") ); //head.Controls.Add(jsLink); HtmlLink appleIcon = new HtmlLink(); appleIcon.Attributes.Add("rel", "apple-touch-icon"); appleIcon.Attributes.Add("href", ResolveUrl("~/apple-touch-icon.png")); HtmlMeta appleMobileWebAppStatusBarStyle = new HtmlMeta(); appleMobileWebAppStatusBarStyle.Attributes.Add("name", "apple-mobile-web-app-status-bar-style"); appleMobileWebAppStatusBarStyle.Attributes.Add("content", "black"); head.Controls.Add(appleMobileWebAppStatusBarStyle); } internal string FindPath(string Location) { string Url = Server.MapPath(Location); return (Url); }}

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Parallelism in .NET – Part 2, Simple Imperative Data Parallelism

- by Reed

In my discussion of Decomposition of the problem space, I mentioned that Data Decomposition is often the simplest abstraction to use when trying to parallelize a routine. If a problem can be decomposed based off the data, we will often want to use what MSDN refers to as Data Parallelism as our strategy for implementing our routine. The Task Parallel Library in .NET 4 makes implementing Data Parallelism, for most cases, very simple. Data Parallelism is the main technique we use to parallelize a routine which can be decomposed based off data. Data Parallelism refers to taking a single collection of data, and having a single operation be performed concurrently on elements in the collection. One side note here: Data Parallelism is also sometimes referred to as the Loop Parallelism Pattern or Loop-level Parallelism. In general, for this series, I will try to use the terminology used in the MSDN Documentation for the Task Parallel Library. This should make it easier to investigate these topics in more detail. Once we’ve determined we have a problem that, potentially, can be decomposed based on data, implementation using Data Parallelism in the TPL is quite simple. Let’s take our example from the Data Decomposition discussion – a simple contrast stretching filter. Here, we have a collection of data (pixels), and we need to run a simple operation on each element of the pixel. Once we know the minimum and maximum values, we most likely would have some simple code like the following: for (int row=0; row < pixelData.GetUpperBound(0); ++row) { for (int col=0; col < pixelData.GetUpperBound(1); ++col) { pixelData[row, col] = AdjustContrast(pixelData[row, col], minPixel, maxPixel); } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This simple routine loops through a two dimensional array of pixelData, and calls the AdjustContrast routine on each pixel. As I mentioned, when you’re decomposing a problem space, most iteration statements are potentially candidates for data decomposition. Here, we’re using two for loops – one looping through rows in the image, and a second nested loop iterating through the columns. We then perform one, independent operation on each element based on those loop positions. This is a prime candidate – we have no shared data, no dependencies on anything but the pixel which we want to change. Since we’re using a for loop, we can easily parallelize this using the Parallel.For method in the TPL: Parallel.For(0, pixelData.GetUpperBound(0), row => { for (int col=0; col < pixelData.GetUpperBound(1); ++col) { pixelData[row, col] = AdjustContrast(pixelData[row, col], minPixel, maxPixel); } }); Here, by simply changing our first for loop to a call to Parallel.For, we can parallelize this portion of our routine. Parallel.For works, as do many methods in the TPL, by creating a delegate and using it as an argument to a method. In this case, our for loop iteration block becomes a delegate creating via a lambda expression. This lets you write code that, superficially, looks similar to the familiar for loop, but functions quite differently at runtime. We could easily do this to our second for loop as well, but that may not be a good idea. There is a balance to be struck when writing parallel code. We want to have enough work items to keep all of our processors busy, but the more we partition our data, the more overhead we introduce. In this case, we have an image of data – most likely hundreds of pixels in both dimensions. By just parallelizing our first loop, each row of pixels can be run as a single task. With hundreds of rows of data, we are providing fine enough granularity to keep all of our processors busy. If we parallelize both loops, we’re potentially creating millions of independent tasks. This introduces extra overhead with no extra gain, and will actually reduce our overall performance. This leads to my first guideline when writing parallel code: Partition your problem into enough tasks to keep each processor busy throughout the operation, but not more than necessary to keep each processor busy. Also note that I parallelized the outer loop. I could have just as easily partitioned the inner loop. However, partitioning the inner loop would have led to many more discrete work items, each with a smaller amount of work (operate on one pixel instead of one row of pixels). My second guideline when writing parallel code reflects this: Partition your problem in a way to place the most work possible into each task. This typically means, in practice, that you will want to parallelize the routine at the “highest” point possible in the routine, typically the outermost loop. If you’re looking at parallelizing methods which call other methods, you’ll want to try to partition your work high up in the stack – as you get into lower level methods, the performance impact of parallelizing your routines may not overcome the overhead introduced. Parallel.For works great for situations where we know the number of elements we’re going to process in advance. If we’re iterating through an IList<T> or an array, this is a typical approach. However, there are other iteration statements common in C#. In many situations, we’ll use foreach instead of a for loop. This can be more understandable and easier to read, but also has the advantage of working with collections which only implement IEnumerable<T>, where we do not know the number of elements involved in advance. As an example, lets take the following situation. Say we have a collection of Customers, and we want to iterate through each customer, check some information about the customer, and if a certain case is met, send an email to the customer and update our instance to reflect this change. Normally, this might look something like: foreach(var customer in customers) { // Run some process that takes some time... DateTime lastContact = theStore.GetLastContact(customer); TimeSpan timeSinceContact = DateTime.Now - lastContact; // If it's been more than two weeks, send an email, and update... if (timeSinceContact.Days > 14) { theStore.EmailCustomer(customer); customer.LastEmailContact = DateTime.Now; } } Here, we’re doing a fair amount of work for each customer in our collection, but we don’t know how many customers exist. If we assume that theStore.GetLastContact(customer) and theStore.EmailCustomer(customer) are both side-effect free, thread safe operations, we could parallelize this using Parallel.ForEach: Parallel.ForEach(customers, customer => { // Run some process that takes some time... DateTime lastContact = theStore.GetLastContact(customer); TimeSpan timeSinceContact = DateTime.Now - lastContact; // If it's been more than two weeks, send an email, and update... if (timeSinceContact.Days > 14) { theStore.EmailCustomer(customer); customer.LastEmailContact = DateTime.Now; } }); Just like Parallel.For, we rework our loop into a method call accepting a delegate created via a lambda expression. This keeps our new code very similar to our original iteration statement, however, this will now execute in parallel. The same guidelines apply with Parallel.ForEach as with Parallel.For. The other iteration statements, do and while, do not have direct equivalents in the Task Parallel Library. These, however, are very easy to implement using Parallel.ForEach and the yield keyword. Most applications can benefit from implementing some form of Data Parallelism. Iterating through collections and performing “work” is a very common pattern in nearly every application. When the problem can be decomposed by data, we often can parallelize the workload by merely changing foreach statements to Parallel.ForEach method calls, and for loops to Parallel.For method calls. Any time your program operates on a collection, and does a set of work on each item in the collection where that work is not dependent on other information, you very likely have an opportunity to parallelize your routine.

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Adding DTrace Probes to PHP Extensions

- by cj

The powerful DTrace tracing facility has some PHP-specific probes that can be enabled with --enable-dtrace. DTrace for Linux is being created by Oracle and is currently in tech preview. Currently it doesn't support userspace tracing so, in the meantime, Systemtap can be used to monitor the probes implemented in PHP. This was recently outlined in David Soria Parra's post Probing PHP with Systemtap on Linux. My post shows how DTrace probes can be added to PHP extensions and traced on Linux. I was using Oracle Linux 6.3. Not all Linux kernels are built with Systemtap, since this can impact stability. Check whether your running kernel (or others installed) have Systemtap enabled, and reboot with such a kernel: # grep CONFIG_UTRACE /boot/config-`uname -r` # grep CONFIG_UTRACE /boot/config-* When you install Systemtap itself, the package systemtap-sdt-devel is needed since it provides the sdt.h header file: # yum install systemtap-sdt-devel You can now install and build PHP as shown in David's article. Basically the build is with: $ cd ~/php-src $ ./configure --disable-all --enable-dtrace $ make (For me, running 'make' a second time failed with an error. The workaround is to do 'git checkout Zend/zend_dtrace.d' and then rerun 'make'. See PHP Bug 63704) David's article shows how to trace the probes already implemented in PHP. You can also use Systemtap to trace things like userspace PHP function calls. For example, create test.php: <?php $c = oci_connect('hr', 'welcome', 'localhost/orcl'); $s = oci_parse($c, "select dbms_xmlgen.getxml('select * from dual') xml from dual"); $r = oci_execute($s); $row = oci_fetch_array($s, OCI_NUM); $x = $row[0]->load(); $row[0]->free(); echo $x; ?> The normal output of this file is the XML form of Oracle's DUAL table: $ ./sapi/cli/php ~/test.php <?xml version="1.0"?> <ROWSET> <ROW> <DUMMY>X</DUMMY> </ROW> </ROWSET> To trace the PHP function calls, create the tracing file functrace.stp: probe process("sapi/cli/php").function("zif_*") { printf("Started function %s\n", probefunc()); } probe process("sapi/cli/php").function("zif_*").return { printf("Ended function %s\n", probefunc()); } This makes use of the way PHP userspace functions (not builtins) like oci_connect() map to C functions with a "zif_" prefix. Login as root, and run System tap on the PHP script: # cd ~cjones/php-src # stap -c 'sapi/cli/php ~cjones/test.php' ~cjones/functrace.stp Started function zif_oci_connect Ended function zif_oci_connect Started function zif_oci_parse Ended function zif_oci_parse Started function zif_oci_execute Ended function zif_oci_execute Started function zif_oci_fetch_array Ended function zif_oci_fetch_array Started function zif_oci_lob_load <?xml version="1.0"?> <ROWSET> <ROW> <DUMMY>X</DUMMY> </ROW> </ROWSET> Ended function zif_oci_lob_load Started function zif_oci_free_descriptor Ended function zif_oci_free_descriptor Each call and return is logged. The Systemtap scripting language allows complex scripts to be built. There are many examples on the web. To augment this generic capability and the PHP probes in PHP, other extensions can have probes too. Below are the steps I used to add probes to OCI8: I created a provider file ext/oci8/oci8_dtrace.d, enabling three probes. The first one will accept a parameter that runtime tracing can later display: provider php { probe oci8__connect(char *username); probe oci8__nls_start(); probe oci8__nls_done(); }; I updated ext/oci8/config.m4 with the PHP_INIT_DTRACE macro. The patch is at the end of config.m4. The macro takes the provider prototype file, a name of the header file that 'dtrace' will generate, and a list of sources files with probes. When --enable-dtrace is used during PHP configuration, then the outer $PHP_DTRACE check is true and my new probes will be enabled. I've chosen to define an OCI8 specific macro, HAVE_OCI8_DTRACE, which can be used in the OCI8 source code: diff --git a/ext/oci8/config.m4 b/ext/oci8/config.m4 index 34ae76c..f3e583d 100644 --- a/ext/oci8/config.m4 +++ b/ext/oci8/config.m4 @@ -341,4 +341,17 @@ if test "$PHP_OCI8" != "no"; then PHP_SUBST_OLD(OCI8_ORACLE_VERSION) fi + + if test "$PHP_DTRACE" = "yes"; then + AC_CHECK_HEADERS([sys/sdt.h], [ + PHP_INIT_DTRACE([ext/oci8/oci8_dtrace.d], + [ext/oci8/oci8_dtrace_gen.h],[ext/oci8/oci8.c]) + AC_DEFINE(HAVE_OCI8_DTRACE,1, + [Whether to enable DTrace support for OCI8 ]) + ], [ + AC_MSG_ERROR( + [Cannot find sys/sdt.h which is required for DTrace support]) + ]) + fi + fi In ext/oci8/oci8.c, I added the probes at, for this example, semi-arbitrary places: diff --git a/ext/oci8/oci8.c b/ext/oci8/oci8.c index e2241cf..ffa0168 100644 --- a/ext/oci8/oci8.c +++ b/ext/oci8/oci8.c @@ -1811,6 +1811,12 @@ php_oci_connection *php_oci_do_connect_ex(char *username, int username_len, char } } +#ifdef HAVE_OCI8_DTRACE + if (DTRACE_OCI8_CONNECT_ENABLED()) { + DTRACE_OCI8_CONNECT(username); + } +#endif + /* Initialize global handles if they weren't initialized before */ if (OCI_G(env) == NULL) { php_oci_init_global_handles(TSRMLS_C); @@ -1870,11 +1876,22 @@ php_oci_connection *php_oci_do_connect_ex(char *username, int username_len, char size_t rsize = 0; sword result; +#ifdef HAVE_OCI8_DTRACE + if (DTRACE_OCI8_NLS_START_ENABLED()) { + DTRACE_OCI8_NLS_START(); + } +#endif PHP_OCI_CALL_RETURN(result, OCINlsEnvironmentVariableGet, (&charsetid_nls_lang, 0, OCI_NLS_CHARSET_ID, 0, &rsize)); if (result != OCI_SUCCESS) { charsetid_nls_lang = 0; } smart_str_append_unsigned_ex(&hashed_details, charsetid_nls_lang, 0); + +#ifdef HAVE_OCI8_DTRACE + if (DTRACE_OCI8_NLS_DONE_ENABLED()) { + DTRACE_OCI8_NLS_DONE(); + } +#endif } timestamp = time(NULL); The oci_connect(), oci_pconnect() and oci_new_connect() calls all use php_oci_do_connect_ex() internally. The first probe simply records that the PHP application made a connection call. I already showed a way to do this without needing a probe, but adding a specific probe lets me record the username. The other two probes can be used to time how long the globalization initialization takes. The relationships between the oci8_dtrace.d names like oci8__connect, the probe guards like DTRACE_OCI8_CONNECT_ENABLED() and probe names like DTRACE_OCI8_CONNECT() are obvious after seeing the pattern of all three probes. I included the new header that will be automatically created by the dtrace tool when PHP is built. I did this in ext/oci8/php_oci8_int.h: diff --git a/ext/oci8/php_oci8_int.h b/ext/oci8/php_oci8_int.h index b0d6516..c81fc5a 100644 --- a/ext/oci8/php_oci8_int.h +++ b/ext/oci8/php_oci8_int.h @@ -44,6 +44,10 @@ # endif # endif /* osf alpha */ +#ifdef HAVE_OCI8_DTRACE +#include "oci8_dtrace_gen.h" +#endif + #if defined(min) #undef min #endif Now PHP can be rebuilt: $ cd ~/php-src $ rm configure && ./buildconf --force $ ./configure --disable-all --enable-dtrace \ --with-oci8=instantclient,/home/cjones/instantclient $ make If 'make' fails, do the 'git checkout Zend/zend_dtrace.d' trick I mentioned. The new probes can be seen by logging in as root and running: # stap -l 'process.provider("php").mark("oci8*")' -c 'sapi/cli/php -i' process("sapi/cli/php").provider("php").mark("oci8__connect") process("sapi/cli/php").provider("php").mark("oci8__nls_done") process("sapi/cli/php").provider("php").mark("oci8__nls_start") To test them out, create a new trace file, oci.stp: global numconnects; global start; global numcharlookups = 0; global tottime = 0; probe process.provider("php").mark("oci8-connect") { printf("Connected as %s\n", user_string($arg1)); numconnects += 1; } probe process.provider("php").mark("oci8-nls_start") { start = gettimeofday_us(); numcharlookups++; } probe process.provider("php").mark("oci8-nls_done") { tottime += gettimeofday_us() - start; } probe end { printf("Connects: %d, Charset lookups: %ld\n", numconnects, numcharlookups); printf("Total NLS charset initalization time: %ld usecs/connect\n", (numcharlookups 0 ? tottime/numcharlookups : 0)); } This calculates the average time that the NLS character set lookup takes. It also prints out the username of each connection, as an example of using parameters. Login as root and run Systemtap over the PHP script: # cd ~cjones/php-src # stap -c 'sapi/cli/php ~cjones/test.php' ~cjones/oci.stp Connected as cj <?xml version="1.0"?> <ROWSET> <ROW> <DUMMY>X</DUMMY> </ROW> </ROWSET> Connects: 1, Charset lookups: 1 Total NLS charset initalization time: 164 usecs/connect This shows the time penalty of making OCI8 look up the default character set. This time would be zero if a character set had been passed as the fourth argument to oci_connect() in test.php.

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Zipcodes in CSV Generation

- by BRADINO

When exporting to CSV format, then opening in a spreadsheet program like Excel zipcodes that start with a zero or zeroes have the preceding zeros stripped off. Obviously it is because the spreadsheet sees that column as integers and preceding zeros in integers are useless. A quick and dirty trick to force Excel (hopefully you are using OpenOffice) to display the full zipcode, we wrap it in double quotes and put an equal sign in front of it, to force it to be a string like this: $zipcode = 00123; $data = '="' . $zipcode . '"' ; So if you are doing the straight query to CSV export, using the fputcsv function it would look something like this. Basically just overwrite the value in the row and then continue along. while ($row = mysql_fetch_assoc($query)){ $row['zipcode'] = '="'.$row['zipcode'].'"'; fputcsv($output, $row); } php csv zipcode csv number csv force string

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Beware Sneaky Reads with Unique Indexes

- by Paul White NZ

A few days ago, Sandra Mueller (twitter | blog) asked a question using twitter’s #sqlhelp hash tag: “Might SQL Server retrieve (out-of-row) LOB data from a table, even if the column isn’t referenced in the query?” Leaving aside trivial cases (like selecting a computed column that does reference the LOB data), one might be tempted to say that no, SQL Server does not read data you haven’t asked for. In general, that’s quite correct; however there are cases where SQL Server might sneakily retrieve a LOB column… Example Table Here’s a T-SQL script to create that table and populate it with 1,000 rows: CREATE TABLE dbo.LOBtest ( pk INTEGER IDENTITY NOT NULL, some_value INTEGER NULL, lob_data VARCHAR(MAX) NULL, another_column CHAR(5) NULL, CONSTRAINT [PK dbo.LOBtest pk] PRIMARY KEY CLUSTERED (pk ASC) ); GO DECLARE @Data VARCHAR(MAX); SET @Data = REPLICATE(CONVERT(VARCHAR(MAX), 'x'), 65540); WITH Numbers (n) AS ( SELECT ROW_NUMBER() OVER (ORDER BY (SELECT 0)) FROM master.sys.columns C1, master.sys.columns C2 ) INSERT LOBtest WITH (TABLOCKX) ( some_value, lob_data ) SELECT TOP (1000) N.n, @Data FROM Numbers N WHERE N.n <= 1000; Test 1: A Simple Update Let’s run a query to subtract one from every value in the some_value column: UPDATE dbo.LOBtest WITH (TABLOCKX) SET some_value = some_value - 1; As you might expect, modifying this integer column in 1,000 rows doesn’t take very long, or use many resources. The STATITICS IO and TIME output shows a total of 9 logical reads, and 25ms elapsed time. The query plan is also very simple: Looking at the Clustered Index Scan, we can see that SQL Server only retrieves the pk and some_value columns during the scan: The pk column is needed by the Clustered Index Update operator to uniquely identify the row that is being changed. The some_value column is used by the Compute Scalar to calculate the new value. (In case you are wondering what the Top operator is for, it is used to enforce SET ROWCOUNT). Test 2: Simple Update with an Index Now let’s create a nonclustered index keyed on the some_value column, with lob_data as an included column: CREATE NONCLUSTERED INDEX [IX dbo.LOBtest some_value (lob_data)] ON dbo.LOBtest (some_value) INCLUDE ( lob_data ) WITH ( FILLFACTOR = 100, MAXDOP = 1, SORT_IN_TEMPDB = ON ); This is not a useful index for our simple update query; imagine that someone else created it for a different purpose. Let’s run our update query again: UPDATE dbo.LOBtest WITH (TABLOCKX) SET some_value = some_value - 1; We find that it now requires 4,014 logical reads and the elapsed query time has increased to around 100ms. The extra logical reads (4 per row) are an expected consequence of maintaining the nonclustered index. The query plan is very similar to before (click to enlarge): The Clustered Index Update operator picks up the extra work of maintaining the nonclustered index. The new Compute Scalar operators detect whether the value in the some_value column has actually been changed by the update. SQL Server may be able to skip maintaining the nonclustered index if the value hasn’t changed (see my previous post on non-updating updates for details). Our simple query does change the value of some_data in every row, so this optimization doesn’t add any value in this specific case. The output list of columns from the Clustered Index Scan hasn’t changed from the one shown previously: SQL Server still just reads the pk and some_data columns. Cool. Overall then, adding the nonclustered index hasn’t had any startling effects, and the LOB column data still isn’t being read from the table. Let’s see what happens if we make the nonclustered index unique. Test 3: Simple Update with a Unique Index Here’s the script to create a new unique index, and drop the old one: CREATE UNIQUE NONCLUSTERED INDEX [UQ dbo.LOBtest some_value (lob_data)] ON dbo.LOBtest (some_value) INCLUDE ( lob_data ) WITH ( FILLFACTOR = 100, MAXDOP = 1, SORT_IN_TEMPDB = ON ); GO DROP INDEX [IX dbo.LOBtest some_value (lob_data)] ON dbo.LOBtest; Remember that SQL Server only enforces uniqueness on index keys (the some_data column). The lob_data column is simply stored at the leaf-level of the non-clustered index. With that in mind, we might expect this change to make very little difference. Let’s see: UPDATE dbo.LOBtest WITH (TABLOCKX) SET some_value = some_value - 1; Whoa! Now look at the elapsed time and logical reads: Scan count 1, logical reads 2016, physical reads 0, read-ahead reads 0, lob logical reads 36015, lob physical reads 0, lob read-ahead reads 15992. CPU time = 172 ms, elapsed time = 16172 ms. Even with all the data and index pages in memory, the query took over 16 seconds to update just 1,000 rows, performing over 52,000 LOB logical reads (nearly 16,000 of those using read-ahead). Why on earth is SQL Server reading LOB data in a query that only updates a single integer column? The Query Plan The query plan for test 3 looks a bit more complex than before: In fact, the bottom level is exactly the same as we saw with the non-unique index. The top level has heaps of new stuff though, which I’ll come to in a moment. You might be expecting to find that the Clustered Index Scan is now reading the lob_data column (for some reason). After all, we need to explain where all the LOB logical reads are coming from. Sadly, when we look at the properties of the Clustered Index Scan, we see exactly the same as before: SQL Server is still only reading the pk and some_value columns – so what’s doing the LOB reads? Updates that Sneakily Read Data We have to go as far as the Clustered Index Update operator before we see LOB data in the output list: [Expr1020] is a bit flag added by an earlier Compute Scalar. It is set true if the some_value column has not been changed (part of the non-updating updates optimization I mentioned earlier). The Clustered Index Update operator adds two new columns: the lob_data column, and some_value_OLD. The some_value_OLD column, as the name suggests, is the pre-update value of the some_value column. At this point, the clustered index has already been updated with the new value, but we haven’t touched the nonclustered index yet. An interesting observation here is that the Clustered Index Update operator can read a column into the data flow as part of its update operation. SQL Server could have read the LOB data as part of the initial Clustered Index Scan, but that would mean carrying the data through all the operations that occur prior to the Clustered Index Update. The server knows it will have to go back to the clustered index row to update it, so it delays reading the LOB data until then. Sneaky! Why the LOB Data Is Needed This is all very interesting (I hope), but why is SQL Server reading the LOB data? For that matter, why does it need to pass the pre-update value of the some_value column out of the Clustered Index Update? The answer relates to the top row of the query plan for test 3. I’ll reproduce it here for convenience: Notice that this is a wide (per-index) update plan. SQL Server used a narrow (per-row) update plan in test 2, where the Clustered Index Update took care of maintaining the nonclustered index too. I’ll talk more about this difference shortly. The Split/Sort/Collapse combination is an optimization, which aims to make per-index update plans more efficient. It does this by breaking each update into a delete/insert pair, reordering the operations, removing any redundant operations, and finally applying the net effect of all the changes to the nonclustered index. Imagine we had a unique index which currently holds three rows with the values 1, 2, and 3. If we run a query that adds 1 to each row value, we would end up with values 2, 3, and 4. The net effect of all the changes is the same as if we simply deleted the value 1, and added a new value 4. By applying net changes, SQL Server can also avoid false unique-key violations. If we tried to immediately update the value 1 to a 2, it would conflict with the existing value 2 (which would soon be updated to 3 of course) and the query would fail. You might argue that SQL Server could avoid the uniqueness violation by starting with the highest value (3) and working down. That’s fine, but it’s not possible to generalize this logic to work with every possible update query. SQL Server has to use a wide update plan if it sees any risk of false uniqueness violations. It’s worth noting that the logic SQL Server uses to detect whether these violations are possible has definite limits. As a result, you will often receive a wide update plan, even when you can see that no violations are possible. Another benefit of this optimization is that it includes a sort on the index key as part of its work. Processing the index changes in index key order promotes sequential I/O against the nonclustered index. A side-effect of all this is that the net changes might include one or more inserts. In order to insert a new row in the index, SQL Server obviously needs all the columns – the key column and the included LOB column. This is the reason SQL Server reads the LOB data as part of the Clustered Index Update. In addition, the some_value_OLD column is required by the Split operator (it turns updates into delete/insert pairs). In order to generate the correct index key delete operation, it needs the old key value. The irony is that in this case the Split/Sort/Collapse optimization is anything but. Reading all that LOB data is extremely expensive, so it is sad that the current version of SQL Server has no way to avoid it. Finally, for completeness, I should mention that the Filter operator is there to filter out the non-updating updates. Beating the Set-Based Update with a Cursor One situation where SQL Server can see that false unique-key violations aren’t possible is where it can guarantee that only one row is being updated. Armed with this knowledge, we can write a cursor (or the WHILE-loop equivalent) that updates one row at a time, and so avoids reading the LOB data: SET NOCOUNT ON; SET STATISTICS XML, IO, TIME OFF; DECLARE @PK INTEGER, @StartTime DATETIME; SET @StartTime = GETUTCDATE(); DECLARE curUpdate CURSOR LOCAL FORWARD_ONLY KEYSET SCROLL_LOCKS FOR SELECT L.pk FROM LOBtest L ORDER BY L.pk ASC; OPEN curUpdate; WHILE (1 = 1) BEGIN FETCH NEXT FROM curUpdate INTO @PK; IF @@FETCH_STATUS = -1 BREAK; IF @@FETCH_STATUS = -2 CONTINUE; UPDATE dbo.LOBtest SET some_value = some_value - 1 WHERE CURRENT OF curUpdate; END; CLOSE curUpdate; DEALLOCATE curUpdate; SELECT DATEDIFF(MILLISECOND, @StartTime, GETUTCDATE()); That completes the update in 1280 milliseconds (remember test 3 took over 16 seconds!) I used the WHERE CURRENT OF syntax there and a KEYSET cursor, just for the fun of it. One could just as well use a WHERE clause that specified the primary key value instead. Clustered Indexes A clustered index is the ultimate index with included columns: all non-key columns are included columns in a clustered index. Let’s re-create the test table and data with an updatable primary key, and without any non-clustered indexes: IF OBJECT_ID(N'dbo.LOBtest', N'U') IS NOT NULL DROP TABLE dbo.LOBtest; GO CREATE TABLE dbo.LOBtest ( pk INTEGER NOT NULL, some_value INTEGER NULL, lob_data VARCHAR(MAX) NULL, another_column CHAR(5) NULL, CONSTRAINT [PK dbo.LOBtest pk] PRIMARY KEY CLUSTERED (pk ASC) ); GO DECLARE @Data VARCHAR(MAX); SET @Data = REPLICATE(CONVERT(VARCHAR(MAX), 'x'), 65540); WITH Numbers (n) AS ( SELECT ROW_NUMBER() OVER (ORDER BY (SELECT 0)) FROM master.sys.columns C1, master.sys.columns C2 ) INSERT LOBtest WITH (TABLOCKX) ( pk, some_value, lob_data ) SELECT TOP (1000) N.n, N.n, @Data FROM Numbers N WHERE N.n <= 1000; Now here’s a query to modify the cluster keys: UPDATE dbo.LOBtest SET pk = pk + 1; The query plan is: As you can see, the Split/Sort/Collapse optimization is present, and we also gain an Eager Table Spool, for Halloween protection. In addition, SQL Server now has no choice but to read the LOB data in the Clustered Index Scan: The performance is not great, as you might expect (even though there is no non-clustered index to maintain): Table 'LOBtest'. Scan count 1, logical reads 2011, physical reads 0, read-ahead reads 0, lob logical reads 36015, lob physical reads 0, lob read-ahead reads 15992. Table 'Worktable'. Scan count 1, logical reads 2040, physical reads 0, read-ahead reads 0, lob logical reads 34000, lob physical reads 0, lob read-ahead reads 8000. SQL Server Execution Times: CPU time = 483 ms, elapsed time = 17884 ms. Notice how the LOB data is read twice: once from the Clustered Index Scan, and again from the work table in tempdb used by the Eager Spool. If you try the same test with a non-unique clustered index (rather than a primary key), you’ll get a much more efficient plan that just passes the cluster key (including uniqueifier) around (no LOB data or other non-key columns): A unique non-clustered index (on a heap) works well too: Both those queries complete in a few tens of milliseconds, with no LOB reads, and just a few thousand logical reads. (In fact the heap is rather more efficient). There are lots more fun combinations to try that I don’t have space for here. Final Thoughts The behaviour shown in this post is not limited to LOB data by any means. If the conditions are met, any unique index that has included columns can produce similar behaviour – something to bear in mind when adding large INCLUDE columns to achieve covering queries, perhaps. Paul White Email: [email protected] Twitter: @PaulWhiteNZ

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SSIS Design Pattern: Loading Variable-Length Rows

- by andyleonard

Introduction I encounter flat file sources with variable-length rows on occassion. Here, I supply one SSIS Design Pattern for loading them. What's a Variable-Length Row Flat File? Great question - let's start with a definition. A variable-length row flat file is a text source of some flavor - comma-separated values (CSV), tab-delimited file (TDF), or even fixed-length, positional-, or ordinal-based (where the location of the data on the row defines its field). The major difference between a "normal"...(read more)

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Know more about Enqueue Deadlock Detection

- by Liu Maclean(???)

??? ORACLE ALLSTAR???????????????????,??????? ???????enqueue lock?????????3 ??????,????????????????????????????ora-00060 dead lock??process???3s: SQL> select * from v$version; BANNER ---------------------------------------------------------------- Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bi PL/SQL Release 10.2.0.5.0 - Production CORE 10.2.0.5.0 Production TNS for Linux: Version 10.2.0.5.0 - Production NLSRTL Version 10.2.0.5.0 - Production SQL> select * from global_name; GLOBAL_NAME -------------------------------------------------------------------------------- www.oracledatabase12g.com PROCESS A: set timing on; update maclean1 set t1=t1+1; PROCESS B: update maclean2 set t1=t1+1; PROCESS A: update maclean2 set t1=t1+1; PROCESS B: update maclean1 set t1=t1+1; ??3s? PROCESS A ?? ERROR at line 1: ORA-00060: deadlock detected while waiting for resource Elapsed: 00:00:03.02 ????Process A????????????? 3s,?????????????,??????? ?????????? ???????: SQL> col name for a30 SQL> col value for a5 SQL> col DESCRIB for a50 SQL> set linesize 140 pagesize 1400 SQL> SELECT x.ksppinm NAME, y.ksppstvl VALUE, x.ksppdesc describ 2 FROM SYS.x$ksppi x, SYS.x$ksppcv y 3 WHERE x.inst_id = USERENV ('Instance') 4 AND y.inst_id = USERENV ('Instance') 5 AND x.indx = y.indx 6 AND x.ksppinm='_enqueue_deadlock_scan_secs'; NAME VALUE DESCRIB ------------------------------ ----- -------------------------------------------------- _enqueue_deadlock_scan_secs 0 deadlock scan interval SQL> alter system set "_enqueue_deadlock_scan_secs"=18 scope=spfile; System altered. Elapsed: 00:00:00.01 SQL> startup force; ORACLE instance started. Total System Global Area 851443712 bytes Fixed Size 2100040 bytes Variable Size 738198712 bytes Database Buffers 104857600 bytes Redo Buffers 6287360 bytes Database mounted. Database opened. PROCESS A: SQL> set timing on; SQL> update maclean1 set t1=t1+1; 1 row updated. Elapsed: 00:00:00.06 Process B SQL> update maclean2 set t1=t1+1; 1 row updated. SQL> update maclean1 set t1=t1+1; Process A: SQL> SQL> alter session set events '10704 trace name context forever,level 10:10046 trace name context forever,level 8'; Session altered. SQL> update maclean2 set t1=t1+1; update maclean2 set t1=t1+1 * ERROR at line 1: ORA-00060: deadlock detected while waiting for resource Elapsed: 00:00:18.05 ksqcmi: TX,90011,4a9 mode=6 timeout=21474836 WAIT #12: nam='enq: TX - row lock contention' ela= 2930070 name|mode=1415053318 usn<<16 | slot=589841 sequence=1193 obj#=56810 tim=1308114759849120 WAIT #12: nam='enq: TX - row lock contention' ela= 2930636 name|mode=1415053318 usn<<16 | slot=589841 sequence=1193 obj#=56810 tim=1308114762779801 WAIT #12: nam='enq: TX - row lock contention' ela= 2930439 name|mode=1415053318 usn<<16 | slot=589841 sequence=1193 obj#=56810 tim=1308114765710430 *** 2012-06-12 09:58:43.089 WAIT #12: nam='enq: TX - row lock contention' ela= 2931698 name|mode=1415053318 usn<<16 | slot=589841 sequence=1193 obj#=56810 tim=1308114768642192 WAIT #12: nam='enq: TX - row lock contention' ela= 2930428 name|mode=1415053318 usn<<16 | slot=589841 sequence=1193 obj#=56810 tim=1308114771572755 WAIT #12: nam='enq: TX - row lock contention' ela= 2931408 name|mode=1415053318 usn<<16 | slot=589841 sequence=1193 obj#=56810 tim=1308114774504207 DEADLOCK DETECTED ( ORA-00060 ) [Transaction Deadlock] The following deadlock is not an ORACLE error. It is a deadlock due to user error in the design of an application or from issuing incorrect ad-hoc SQL. The following information may aid in determining the deadlock: ??????Process A?’enq: TX – row lock contention’ ?????ORA-00060 deadlock detected????3s ??? 18s , ???hidden parameter “_enqueue_deadlock_scan_secs”?????,????????0? ??????????: SQL> alter system set "_enqueue_deadlock_scan_secs"=4 scope=spfile; System altered. Elapsed: 00:00:00.01 SQL> alter system set "_enqueue_deadlock_time_sec"=9 scope=spfile; System altered. Elapsed: 00:00:00.00 SQL> startup force; ORACLE instance started. Total System Global Area 851443712 bytes Fixed Size 2100040 bytes Variable Size 738198712 bytes Database Buffers 104857600 bytes Redo Buffers 6287360 bytes Database mounted. Database opened. SQL> set linesize 140 pagesize 1400 SQL> show parameter dead NAME TYPE VALUE ------------------------------------ -------------------------------- ------------------------------ _enqueue_deadlock_scan_secs integer 4 _enqueue_deadlock_time_sec integer 9 SQL> set timing on SQL> select * from maclean1 for update wait 8; T1 ---------- 11 Elapsed: 00:00:00.01 PROCESS B SQL> select * from maclean2 for update wait 8; T1 ---------- 3 SQL> select * from maclean1 for update wait 8; select * from maclean1 for update wait 8 PROCESS A SQL> select * from maclean2 for update wait 8; select * from maclean2 for update wait 8 * ERROR at line 1: ORA-30006: resource busy; acquire with WAIT timeout expired Elapsed: 00:00:08.00 ???????? ??? select for update wait?enqueue request timeout ?????8s? ,???????”_enqueue_deadlock_scan_secs”=4(deadlock scan interval),?4s???deadlock detected,????Process A????deadlock ???, ??????? ??Process A?????8s?raised??”ORA-30006: resource busy; acquire with WAIT timeout expired”??,??ORA-00060,?????process A???????? ????????”_enqueue_deadlock_time_sec”(requests with timeout <= this will not have deadlock detection)???,?enqueue request time < “_enqueue_deadlock_time_sec”?Server process?????dead lock detection,?????????enqueue request ??????timeout??????(_enqueue_deadlock_time_sec????5,?timeout<5s),???????????????;??????timeout>”_enqueue_deadlock_time_sec”???,Oracle????????????????????? ??????????: SQL> show parameter dead NAME TYPE VALUE ------------------------------------ -------------------------------- ------------------------------ _enqueue_deadlock_scan_secs integer 4 _enqueue_deadlock_time_sec integer 9 Process A: SQL> set timing on; SQL> select * from maclean1 for update wait 10; T1 ---------- 11 Process B: SQL> select * from maclean2 for update wait 10; T1 ---------- 3 SQL> select * from maclean1 for update wait 10; PROCESS A: SQL> select * from maclean2 for update wait 10; select * from maclean2 for update wait 10 * ERROR at line 1: ORA-00060: deadlock detected while waiting for resource Elapsed: 00:00:06.02 ??????? select for update wait 10?10s??, ?? 10s?????_enqueue_deadlock_time_sec???(9s),??Process A???????? ???????????????6s ???????_enqueue_deadlock_scan_secs?4s ? ???????????,???????????_enqueue_deadlock_scan_secs?????????3???? ??: enqueue lock?????????????? 1. ?????????deadlock detection??3s????, ????????_enqueue_deadlock_scan_secs(deadlock scan interval)???,??????0,????????_enqueue_deadlock_scan_secs?????????3???, ?_enqueue_deadlock_scan_secs=0 ??3s??, ?_enqueue_deadlock_scan_secs=4??6s??,????? 2. ???????_enqueue_deadlock_time_sec(requests with timeout <= this will not have deadlock detection)???,?enqueue request timeout< _enqueue_deadlock_time_sec(????5),?Server process?????????enqueue request timeout>_enqueue_deadlock_time_sec ????_enqueue_deadlock_scan_secs???????, ??request timeout??????select for update wait [TIMEOUT]??? ??: ???10.2.0.1?????????2?hidden parameter , ???patchset 10.2.0.3????? _enqueue_deadlock_time_sec, ?patchset 10.2.0.5??????_enqueue_deadlock_scan_secs? ?????RAC???????????10s, ???????_lm_dd_interval(dd time interval in seconds) ,????????8.0.6???? ???????????????,??????, ?10g???????60s,?11g???????10s? ???????11g??_lm_dd_interval?????????????,?????11g??LMD????????????,??????????RAC?LMD?Deadlock Detection???????CPU,???11g?Oracle????Team???LMD????????CPU????: ????????11g?LMD???????,???????11g??? UTS TRACE ????? DD???: SQL> select * from v$version; BANNER -------------------------------------------------------------------------------- Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production PL/SQL Release 11.2.0.3.0 - Production CORE 11.2.0.3.0 Production TNS for Linux: Version 11.2.0.3.0 - Production NLSRTL Version 11.2.0.3.0 - Production SQL> SQL> select * from global_name 2 ; GLOBAL_NAME -------------------------------------------------------------------------------- www.oracledatabase12g.com SQL> alter system set "_lm_dd_interval"=20 scope=spfile; System altered. SQL> startup force; ORACLE instance started. Total System Global Area 1570009088 bytes Fixed Size 2228704 bytes Variable Size 1325403680 bytes Database Buffers 234881024 bytes Redo Buffers 7495680 bytes Database mounted. Database opened. SQL> set linesize 140 pagesize 1400 SQL> show parameter lm_dd NAME TYPE VALUE ------------------------------------ -------------------------------- ------------------------------ _lm_dd_interval integer 20 SQL> select count(*) from gv$instance; COUNT(*) ---------- 2 instance 1: SQL> oradebug setorapid 12 Oracle pid: 12, Unix process pid: 8608, image: [email protected] (LMD0) ? LMD0??? UTS TRACE??RAC???????????? SQL> oradebug event 10046 trace name context forever,level 8:10708 trace name context forever,level 103: trace[rac.*] disk high; Statement processed. Elapsed: 00:00:00.00 SQL> update maclean1 set t1=t1+1; 1 row updated. instance 2: SQL> update maclean2 set t1=t1+1; 1 row updated. SQL> update maclean1 set t1=t1+1; Instance 1: SQL> update maclean2 set t1=t1+1; update maclean2 set t1=t1+1 * ERROR at line 1: ORA-00060: deadlock detected while waiting for resource Elapsed: 00:00:20.51 LMD0???UTS TRACE 2012-06-12 22:27:00.929284 : [kjmpbmsg:process][type 22][msg 0x7fa620ac85a8][from 1][seq 8148.0][len 192] 2012-06-12 22:27:00.929346 : [kjmxmpm][type 22][seq 0.0][msg 0x7fa620ac85a8][from 1] *** 2012-06-12 22:27:00.929 * kjddind: received DDIND msg with subtype x6 * reqp->dd_master_inst_kjxmddi == 1 * kjddind: dump sgh: 2012-06-12 22:27:00.929346*: kjddind: req->timestamp [0.15], kjddt [0.13] 2012-06-12 22:27:00.929346*: >> DDmsg:KJX_DD_REMOTE,TS[0.15],Inst 1->2,ddxid[id1,id2,inst:2097153,31,1],ddlock[0x95023930,829],ddMasterInst 1 2012-06-12 22:27:00.929346*: lock [0x95023930,829], op = [mast] 2012-06-12 22:27:00.929346*: reqp->timestamp [0.15], kjddt [0.13] 2012-06-12 22:27:00.929346*: kjddind: updated local timestamp [0.15] * kjddind: case KJX_DD_REMOTE 2012-06-12 22:27:00.929346*: ADD IO NODE WFG: 0 frame pointer 2012-06-12 22:27:00.929346*: PUSH: type=res, enqueue(0xffffffff.0xffffffff)=0xbbb9af40, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: PROCESS: type=res, enqueue(0xffffffff.0xffffffff)=0xbbb9af40, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: POP: type=res, enqueue(0xffffffff.0xffffffff)=0xbbb9af40, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: kjddopr[TX 0xe000c.0x32][ext 0x5,0x0]: blocking lock 0xbbb9a800, owner 2097154 of inst 2 2012-06-12 22:27:00.929346*: PUSH: type=txn, enqueue(0xffffffff.0xffffffff)=0xbbb9a800, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: PROCESS: type=txn, enqueue(0xffffffff.0xffffffff)=0xbbb9a800, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: ADD NODE TO WFG: type=txn, enqueue(0xffffffff.0xffffffff)=0xbbb9a800, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: POP: type=txn, enqueue(0xffffffff.0xffffffff)=0xbbb9a800, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: kjddopt: converting lock 0xbbce92f8 on 'TX' 0x80016.0x5d4,txid [2097154,34]of inst 2 2012-06-12 22:27:00.929346*: PUSH: type=res, enqueue(0xffffffff.0xffffffff)=0xbbce92f8, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: PROCESS: type=res, enqueue(0xffffffff.0xffffffff)=0xbbce92f8, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929346*: ADD NODE TO WFG: type=res, enqueue(0xffffffff.0xffffffff)=0xbbce92f8, block=KJUSEREX, snode=1 2012-06-12 22:27:00.929855 : GSIPC:AMBUF: rcv buff 0x7fa620aa8cd8, pool rcvbuf, rqlen 1102 2012-06-12 22:27:00.929878 : GSIPC:GPBMSG: new bmsg 0x7fa620aa8d48 mb 0x7fa620aa8cd8 msg 0x7fa620aa8d68 mlen 192 dest x100 flushsz -1 2012-06-12 22:27:00.929878*: << DDmsg:KJX_DD_REMOTE,TS[0.15],Inst 2->1,ddxid[id1,id2,inst:2097153,31,1],ddlock[0x95023930,829],ddMasterInst 1 2012-06-12 22:27:00.929878*: lock [0xbbce92f8,287], op = [mast] 2012-06-12 22:27:00.929878*: ADD IO NODE WFG: 0 frame pointer 2012-06-12 22:27:00.929923 : [kjmpbmsg:compl][msg 0x7fa620ac8588][typ p][nmsgs 1][qtime 0][ptime 0] 2012-06-12 22:27:00.929947 : GSIPC:PBAT: flush start. flag 0x79 end 0 inc 4.4 2012-06-12 22:27:00.929963 : GSIPC:PBAT: send bmsg 0x7fa620aa8d48 blen 224 dest 1.0 2012-06-12 22:27:00.929979 : GSIPC:SNDQ: enq msg 0x7fa620aa8d48, type 65521 seq 8325, inst 1, receiver 0, queued 1 012-06-12 22:27:00.929979 : GSIPC:SNDQ: enq msg 0x7fa620aa8d48, type 65521 seq 8325, inst 1, receiver 0, queued 1 2012-06-12 22:27:00.929996 : GSIPC:BSEND: flushing sndq 0xb491dd28, id 0, dcx 0xbc517770, inst 1, rcvr 0 qlen 0 1 2012-06-12 22:27:00.930014 : GSIPC:BSEND: no batch1 msg 0x7fa620aa8d48 type 65521 len 224 dest (1:0) 2012-06-12 22:27:00.930088 : kjbsentscn[0x0.3f72dc][to 1] 2012-06-12 22:27:00.930144 : GSIPC:SENDM: send msg 0x7fa620aa8d48 dest x10000 seq 8325 type 65521 tkts x1 mlen xe00110 2012-06-12 22:27:00.930531 : GSIPC:KSXPCB: msg 0x7fa620aa8d48 status 30, type 65521, dest 1, rcvr 0 WAIT #0: nam='ges remote message' ela= 1372 waittime=80 loop=0 p3=74 obj#=-1 tim=1339554420931640 2012-06-12 22:27:00.931728 : GSIPC:RCVD: ksxp msg 0x7fa620af6490 sndr 1 seq 0.8149 type 65521 tkts 1 2012-06-12 22:27:00.931746 : GSIPC:RCVD: watq msg 0x7fa620af6490 sndr 1, seq 8149, type 65521, tkts 1 2012-06-12 22:27:00.931763 : GSIPC:RCVD: seq update (0.8148)->(0.8149) tp -15 fg 0x4 from 1 pbattr 0x0 2012-06-12 22:27:00.931779 : GSIPC:TKT: collect msg 0x7fa620af6490 from 1 for rcvr 0, tickets 1 2012-06-12 22:27:00.931794 : kjbrcvdscn[0x0.3f72dc][from 1][idx 2012-06-12 22:27:00.931810 : kjbrcvdscn[no bscn dd_master_inst_kjxmddi == 1 * kjddind: dump sgh: NXTIN (nil) 0 wq 0 cvtops x0 0x0.0x0(ext 0x0,0x0)[0000-0000-00000000] inst 1 BLOCKER 0xbbb9a800 5 wq 1 cvtops x28 TX 0xe000c.0x32(ext 0x5,0x0)[20000-0002-00000022] inst 2 BLOCKED 0xbbce92f8 5 wq 2 cvtops x1 TX 0x80016.0x5d4(ext 0x2,0x0)[20000-0002-00000022] inst 2 NXTOUT (nil) 0 wq 0 cvtops x0 0x0.0x0(ext 0x0,0x0)[0000-0000-00000000] inst 1 2012-06-12 22:27:00.932058*: kjddind: req->timestamp [0.15], kjddt [0.15] 2012-06-12 22:27:00.932058*: >> DDmsg:KJX_DD_VALIDATE,TS[0.15],Inst 1->2,ddxid[id1,id2,inst:2097153,31,1],ddlock[0x95023930,829],ddMasterInst 1 2012-06-12 22:27:00.932058*: lock [(nil),0], op = [vald_dd] 2012-06-12 22:27:00.932058*: kjddind: updated local timestamp [0.15] * kjddind: case KJX_DD_VALIDATE *** 2012-06-12 22:27:00.932 * kjddvald called: kjxmddi stuff: * cont_lockp (nil) * dd_lockp 0x95023930 * dd_inst 1 * dd_master_inst 1 * sgh graph: NXTIN (nil) 0 wq 0 cvtops x0 0x0.0x0(ext 0x0,0x0)[0000-0000-00000000] inst 1 BLOCKER 0xbbb9a800 5 wq 1 cvtops x28 TX 0xe000c.0x32(ext 0x5,0x0)[20000-0002-00000022] inst 2 BLOCKED 0xbbce92f8 5 wq 2 cvtops x1 TX 0x80016.0x5d4(ext 0x2,0x0)[20000-0002-00000022] inst 2 NXTOUT (nil) 0 wq 0 cvtops x0 0x0.0x0(ext 0x0,0x0)[0000-0000-00000000] inst 1 POP WFG NODE: lock=(nil) * kjddvald: dump the PRQ: BLOCKER 0xbbb9a800 5 wq 1 cvtops x28 TX 0xe000c.0x32(ext 0x5,0x0)[20000-0002-00000022] inst 2 BLOCKED 0xbbce92f8 5 wq 2 cvtops x1 TX 0x80016.0x5d4(ext 0x2,0x0)[20000-0002-00000022] inst 2 * kjddvald: KJDD_NXTONOD ->node_kjddsg.dinst_kjddnd =1 * kjddvald: ... which is not my node, my subgraph is validated but the cycle is not complete Global blockers dump start:--------------------------------- DUMP LOCAL BLOCKER/HOLDER: block level 5 res [0x80016][0x5d4],[TX][ext 0x2,0x0] ??dead lock!!! ???????11.2.0.3???? RAC LMD???????????”_lm_dd_interval”????????????20s? ???????10g?_lm_dd_interval???60s,??????Processes?????????????????,????????????Server Process????????60s??????11g?????(??????LMD???????)???????,???????????10s??? Enqueue Deadlock Detection? ?11g??? RAC?LMD???????hidden parameter ????”_lm_dd_interval”???,RAC????????????????,???????????: SQL> col name for a50 SQL> col describ for a60 SQL> col value for a20 SQL> set linesize 140 pagesize 1400 SQL> SELECT x.ksppinm NAME, y.ksppstvl VALUE, x.ksppdesc describ 2 FROM SYS.x$ksppi x, SYS.x$ksppcv y 3 WHERE x.inst_id = USERENV ('Instance') 4 AND y.inst_id = USERENV ('Instance') 5 AND x.indx = y.indx 6 AND x.ksppinm like '_lm_dd%'; NAME VALUE DESCRIB -------------------------------------------------- -------------------- ------------------------------------------------------------ _lm_dd_interval 20 dd time interval in seconds _lm_dd_scan_interval 5 dd scan interval in seconds _lm_dd_search_cnt 3 number of dd search per token get _lm_dd_max_search_time 180 max dd search time per token _lm_dd_maxdump 50 max number of locks to be dumped during dd validation _lm_dd_ignore_nodd FALSE if TRUE nodeadlockwait/nodeadlockblock options are ignored 6 rows selected.

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Popup Details for a Table Record

- by shay.shmeltzer

This one started as an OTN how-to question that seemed like something that should work automatically - turns out you need a couple of small tweaks to get it working. The idea is to have a table on a page showing multiple records, you can click any row in the table - and get a pop-up window that shows more data about that row. At first I thought I'll just need to drag the same view twice to the page - once as a table and then as a form in a pop-up. But then the Form didn't reflect the new row that got selected in the table - you'll always see the first row you selected. Adding a Partial Page Rendering between the table and the pop-up didn't do the trick either. Then I realized that the content delivery attribute of the pop-up was set to lazy, when I switched it to immediate - everything worked. Here is a little demo showing the whole development process: Note that the content delivery method attribute is also something you might want to check if you see your tables being refreshed too often when you scroll through records for example.

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Creating an email notification system based on polling database rows

- by Ashish Sharma

I have to design an email notification system based on the following requirements: The email notifications would be created based on polling rows in a Mysql 5.5 DB table when they are in a particular 'Completed' state. The email notification should be sent out in no more than 5 minutes from the time the row was created in the DB table (At the time of DB table row creation the state of the row might not be 'Completed'). Once 5 minutes for the DB table row expire in reaching the 'Completed' state, separate email notification need to be sent (basically telling the user that the original email notification would be delayed) and then sending the email notification as and when the row state reaches to being 'Completed'. The rest of the system requirements are : Adding relevant checks to monitor the whole system via MBeans interface. The system should be scalable so that if the rate of DB table rows creation increases so does the Email notification system be able to ramp up. So I request suggestions on following lines: What approach should I take in solving the problem described from a programming/Design pattern point of view? Suggestion for any third party plugin/software that can be used to solve the problem described? Points to take care regarding scalability and monitoring the health of the system? Java is the language of preference but I am open to using off the shelf components that can be interfaced with Java language or provide standard ports for communication. Currently I do have an in house grown system (written in Java) that is catering to the specified requirements, but it's now crumbling under increased load and now I want to give the problem a fresh look. thanks in advance Ashish

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C#/.NET Little Wonders: ConcurrentBag and BlockingCollection

- by James Michael Hare

In the first week of concurrent collections, began with a general introduction and discussed the ConcurrentStack<T> and ConcurrentQueue<T>. The last post discussed the ConcurrentDictionary<T> . Finally this week, we shall close with a discussion of the ConcurrentBag<T> and BlockingCollection<T>. For more of the "Little Wonders" posts, see C#/.NET Little Wonders: A Redux. Recap As you'll recall from the previous posts, the original collections were object-based containers that accomplished synchronization through a Synchronized member. With the advent of .NET 2.0, the original collections were succeeded by the generic collections which are fully type-safe, but eschew automatic synchronization. With .NET 4.0, a new breed of collections was born in the System.Collections.Concurrent namespace. Of these, the final concurrent collection we will examine is the ConcurrentBag and a very useful wrapper class called the BlockingCollection. For some excellent information on the performance of the concurrent collections and how they perform compared to a traditional brute-force locking strategy, see this informative whitepaper by the Microsoft Parallel Computing Platform team here. ConcurrentBag<T> – Thread-safe unordered collection. Unlike the other concurrent collections, the ConcurrentBag<T> has no non-concurrent counterpart in the .NET collections libraries. Items can be added and removed from a bag just like any other collection, but unlike the other collections, the items are not maintained in any order. This makes the bag handy for those cases when all you care about is that the data be consumed eventually, without regard for order of consumption or even fairness – that is, it’s possible new items could be consumed before older items given the right circumstances for a period of time. So why would you ever want a container that can be unfair? Well, to look at it another way, you can use a ConcurrentQueue and get the fairness, but it comes at a cost in that the ordering rules and synchronization required to maintain that ordering can affect scalability a bit. Thus sometimes the bag is great when you want the fastest way to get the next item to process, and don’t care what item it is or how long its been waiting. The way that the ConcurrentBag works is to take advantage of the new ThreadLocal<T> type (new in System.Threading for .NET 4.0) so that each thread using the bag has a list local to just that thread. This means that adding or removing to a thread-local list requires very low synchronization. The problem comes in where a thread goes to consume an item but it’s local list is empty. In this case the bag performs “work-stealing” where it will rob an item from another thread that has items in its list. This requires a higher level of synchronization which adds a bit of overhead to the take operation. So, as you can imagine, this makes the ConcurrentBag good for situations where each thread both produces and consumes items from the bag, but it would be less-than-idea in situations where some threads are dedicated producers and the other threads are dedicated consumers because the work-stealing synchronization would outweigh the thread-local optimization for a thread taking its own items. Like the other concurrent collections, there are some curiosities to keep in mind: IsEmpty(), Count, ToArray(), and GetEnumerator() lock collection Each of these needs to take a snapshot of whole bag to determine if empty, thus they tend to be more expensive and cause Add() and Take() operations to block. ToArray() and GetEnumerator() are static snapshots Because it is based on a snapshot, will not show subsequent updates after snapshot. Add() is lightweight Since adding to the thread-local list, there is very little overhead on Add. TryTake() is lightweight if items in thread-local list As long as items are in the thread-local list, TryTake() is very lightweight, much more so than ConcurrentStack() and ConcurrentQueue(), however if the local thread list is empty, it must steal work from another thread, which is more expensive. Remember, a bag is not ideal for all situations, it is mainly ideal for situations where a process consumes an item and either decomposes it into more items to be processed, or handles the item partially and places it back to be processed again until some point when it will complete. The main point is that the bag works best when each thread both takes and adds items. For example, we could create a totally contrived example where perhaps we want to see the largest power of a number before it crosses a certain threshold. Yes, obviously we could easily do this with a log function, but bare with me while I use this contrived example for simplicity. So let’s say we have a work function that will take a Tuple out of a bag, this Tuple will contain two ints. The first int is the original number, and the second int is the last multiple of that number. So we could load our bag with the initial values (let’s say we want to know the last multiple of each of 2, 3, 5, and 7 under 100. 1: var bag = new ConcurrentBag<Tuple<int, int>> 2: { 3: Tuple.Create(2, 1), 4: Tuple.Create(3, 1), 5: Tuple.Create(5, 1), 6: Tuple.Create(7, 1) 7: }; Then we can create a method that given the bag, will take out an item, apply the multiplier again, 1: public static void FindHighestPowerUnder(ConcurrentBag<Tuple<int,int>> bag, int threshold) 2: { 3: Tuple<int,int> pair; 4: 5: // while there are items to take, this will prefer local first, then steal if no local 6: while (bag.TryTake(out pair)) 7: { 8: // look at next power 9: var result = Math.Pow(pair.Item1, pair.Item2 + 1); 10: 11: if (result < threshold) 12: { 13: // if smaller than threshold bump power by 1 14: bag.Add(Tuple.Create(pair.Item1, pair.Item2 + 1)); 15: } 16: else 17: { 18: // otherwise, we're done 19: Console.WriteLine("Highest power of {0} under {3} is {0}^{1} = {2}.", 20: pair.Item1, pair.Item2, Math.Pow(pair.Item1, pair.Item2), threshold); 21: } 22: } 23: } Now that we have this, we can load up this method as an Action into our Tasks and run it: 1: // create array of tasks, start all, wait for all 2: var tasks = new[] 3: { 4: new Task(() => FindHighestPowerUnder(bag, 100)), 5: new Task(() => FindHighestPowerUnder(bag, 100)), 6: }; 7: 8: Array.ForEach(tasks, t => t.Start()); 9: 10: Task.WaitAll(tasks); Totally contrived, I know, but keep in mind the main point! When you have a thread or task that operates on an item, and then puts it back for further consumption – or decomposes an item into further sub-items to be processed – you should consider a ConcurrentBag as the thread-local lists will allow for quick processing. However, if you need ordering or if your processes are dedicated producers or consumers, this collection is not ideal. As with anything, you should performance test as your mileage will vary depending on your situation! BlockingCollection<T> – A producers & consumers pattern collection The BlockingCollection<T> can be treated like a collection in its own right, but in reality it adds a producers and consumers paradigm to any collection that implements the interface IProducerConsumerCollection<T>. If you don’t specify one at the time of construction, it will use a ConcurrentQueue<T> as its underlying store. If you don’t want to use the ConcurrentQueue, the ConcurrentStack and ConcurrentBag also implement the interface (though ConcurrentDictionary does not). In addition, you are of course free to create your own implementation of the interface. So, for those who don’t remember the producers and consumers classical computer-science problem, the gist of it is that you have one (or more) processes that are creating items (producers) and one (or more) processes that are consuming these items (consumers). Now, the crux of the problem is that there is a bin (queue) where the produced items are placed, and typically that bin has a limited size. Thus if a producer creates an item, but there is no space to store it, it must wait until an item is consumed. Also if a consumer goes to consume an item and none exists, it must wait until an item is produced. The BlockingCollection makes it trivial to implement any standard producers/consumers process set by providing that “bin” where the items can be produced into and consumed from with the appropriate blocking operations. In addition, you can specify whether the bin should have a limited size or can be (theoretically) unbounded, and you can specify timeouts on the blocking operations. As far as your choice of “bin”, for the most part the ConcurrentQueue is the right choice because it is fairly light and maximizes fairness by ordering items so that they are consumed in the same order they are produced. You can use the concurrent bag or stack, of course, but your ordering would be random-ish in the case of the former and LIFO in the case of the latter. So let’s look at some of the methods of note in BlockingCollection: BoundedCapacity returns capacity of the “bin” If the bin is unbounded, the capacity is int.MaxValue. Count returns an internally-kept count of items This makes it O(1), but if you modify underlying collection directly (not recommended) it is unreliable. CompleteAdding() is used to cut off further adds. This sets IsAddingCompleted and begins to wind down consumers once empty. IsAddingCompleted is true when producers are “done”. Once you are done producing, should complete the add process to alert consumers. IsCompleted is true when producers are “done” and “bin” is empty. Once you mark the producers done, and all items removed, this will be true. Add() is a blocking add to collection. If bin is full, will wait till space frees up Take() is a blocking remove from collection. If bin is empty, will wait until item is produced or adding is completed. GetConsumingEnumerable() is used to iterate and consume items. Unlike the standard enumerator, this one consumes the items instead of iteration. TryAdd() attempts add but does not block completely If adding would block, returns false instead, can specify TimeSpan to wait before stopping. TryTake() attempts to take but does not block completely Like TryAdd(), if taking would block, returns false instead, can specify TimeSpan to wait. Note the use of CompleteAdding() to signal the BlockingCollection that nothing else should be added. This means that any attempts to TryAdd() or Add() after marked completed will throw an InvalidOperationException. In addition, once adding is complete you can still continue to TryTake() and Take() until the bin is empty, and then Take() will throw the InvalidOperationException and TryTake() will return false. So let’s create a simple program to try this out. Let’s say that you have one process that will be producing items, but a slower consumer process that handles them. This gives us a chance to peek inside what happens when the bin is bounded (by default, the bin is NOT bounded). 1: var bin = new BlockingCollection<int>(5); Now, we create a method to produce items: 1: public static void ProduceItems(BlockingCollection<int> bin, int numToProduce) 2: { 3: for (int i = 0; i < numToProduce; i++) 4: { 5: // try for 10 ms to add an item 6: while (!bin.TryAdd(i, TimeSpan.FromMilliseconds(10))) 7: { 8: Console.WriteLine("Bin is full, retrying..."); 9: } 10: } 11: 12: // once done producing, call CompleteAdding() 13: Console.WriteLine("Adding is completed."); 14: bin.CompleteAdding(); 15: } And one to consume them: 1: public static void ConsumeItems(BlockingCollection<int> bin) 2: { 3: // This will only be true if CompleteAdding() was called AND the bin is empty. 4: while (!bin.IsCompleted) 5: { 6: int item; 7: 8: if (!bin.TryTake(out item, TimeSpan.FromMilliseconds(10))) 9: { 10: Console.WriteLine("Bin is empty, retrying..."); 11: } 12: else 13: { 14: Console.WriteLine("Consuming item {0}.", item); 15: Thread.Sleep(TimeSpan.FromMilliseconds(20)); 16: } 17: } 18: } Then we can fire them off: 1: // create one producer and two consumers 2: var tasks = new[] 3: { 4: new Task(() => ProduceItems(bin, 20)), 5: new Task(() => ConsumeItems(bin)), 6: new Task(() => ConsumeItems(bin)), 7: }; 8: 9: Array.ForEach(tasks, t => t.Start()); 10: 11: Task.WaitAll(tasks); Notice that the producer is faster than the consumer, thus it should be hitting a full bin often and displaying the message after it times out on TryAdd(). 1: Consuming item 0. 2: Consuming item 1. 3: Bin is full, retrying... 4: Bin is full, retrying... 5: Consuming item 3. 6: Consuming item 2. 7: Bin is full, retrying... 8: Consuming item 4. 9: Consuming item 5. 10: Bin is full, retrying... 11: Consuming item 6. 12: Consuming item 7. 13: Bin is full, retrying... 14: Consuming item 8. 15: Consuming item 9. 16: Bin is full, retrying... 17: Consuming item 10. 18: Consuming item 11. 19: Bin is full, retrying... 20: Consuming item 12. 21: Consuming item 13. 22: Bin is full, retrying... 23: Bin is full, retrying... 24: Consuming item 14. 25: Adding is completed. 26: Consuming item 15. 27: Consuming item 16. 28: Consuming item 17. 29: Consuming item 19. 30: Consuming item 18. Also notice that once CompleteAdding() is called and the bin is empty, the IsCompleted property returns true, and the consumers will exit. Summary The ConcurrentBag is an interesting collection that can be used to optimize concurrency scenarios where tasks or threads both produce and consume items. In this way, it will choose to consume its own work if available, and then steal if not. However, in situations where you want fair consumption or ordering, or in situations where the producers and consumers are distinct processes, the bag is not optimal. The BlockingCollection is a great wrapper around all of the concurrent queue, stack, and bag that allows you to add producer and consumer semantics easily including waiting when the bin is full or empty. That’s the end of my dive into the concurrent collections. I’d also strongly recommend, once again, you read this excellent Microsoft white paper that goes into much greater detail on the efficiencies you can gain using these collections judiciously (here). Tweet Technorati Tags: C#,.NET,Concurrent Collections,Little Wonders

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Does hiding images on 404 error affect SEO?

- by Question Overflow

I have a dynamic website that allows registered users to upload and display images on the their profile page. As each user may upload less than the maximum limit of 20 images, there would be some "empty" images on the page. I am using javascript to hide these empty images. The loading of the profile page would generate a series of 404 errors depending on the number of empty images. Would these 404 errors affect the SEO of the page and the website?

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