Search Results

Search found 21054 results on 843 pages for 'void'.

Page 825/843 | < Previous Page | 821 822 823 824 825 826 827 828 829 830 831 832  | Next Page >

  • C# DotNetNuke Module: GridVIew AutoGenerateEditButton is skipping over a field on update.

    - by AlexMax
    I have a GridView with an automatically generated Edit button. I wanted some customized behavior for the Image column, since I wanted it to be a drop down list of items as opposed to a simple input field, and I also wanted some nice "fallback" in case the value in the database didn't actually exist in the drop down list. With the code I have done so far, I have gotten the behavior I desire out of the Image field. The problem is that when i attempt to update that particular field, I get an error spit out back at me that it can't find a method to update the form with: ObjectDataSource 'objDataSource' could not find a non-generic method 'UpdateDiscovery' that has parameters: ModuleId, Visible, Position, Title, Link, ItemId. That's not good, because I DO have an UpdateDiscovery method. However, between Title and Link, there is supposed to be another param that belongs to the Image field, and it's not being passed. I realize that it's probably the update button doesn't know to pass that field, since it's a TemplateField and not a BoundField, and when I use Bind('image') as the selected value for the drop down list, it seems to update fine...but only as long as the field in the database when I try and edit the row actually exists, otherwise it bombs out and gives me an error about the value not existing in the drop down list. I have the following GridView defined: <asp:GridView ID="grdDiscoverys" runat="server" DataSourceID="objDataSource" EnableModelValidation="True" AutoGenerateColumns="false" AutoGenerateEditButton="true" AutoGenerateDeleteButton="true" DataKeyNames="ItemId" OnRowDataBound="cmdDiscovery_RowDataBound"> <Columns> <asp:BoundField DataField="ItemId" HeaderText="#" ReadOnly="true" /> <asp:BoundField DataField="Visible" HeaderText="Visible" /> <asp:BoundField DataField="Position" HeaderText="Position" /> <asp:TemplateField HeaderText="Image"> <ItemTemplate> <asp:Label ID="lblViewImage" runat="server" /> </ItemTemplate> <EditItemTemplate> <asp:DropDownList ID="ddlEditImage" runat="server" title="Image" DataValueField="Key" DataTextField="Value" /> </EditItemTemplate> </asp:TemplateField> <asp:BoundField DataField="Title" HeaderText="Title" /> <asp:BoundField DataField="Link" HeaderText="Link" /> </Columns> </asp:GridView> The datasource that this is tied to: <asp:ObjectDataSource ID="objDataSource" runat="server" TypeName="MyCompany.Modules.Discovery.DiscoveryController" SelectMethod="GetDiscoverys" UpdateMethod="UpdateDiscovery" DeleteMethod="DeleteDiscovery"> <SelectParameters> <asp:QueryStringParameter Name="ModuleId" QueryStringField="mid" /> </SelectParameters> <UpdateParameters> <asp:QueryStringParameter Name="ModuleId" QueryStringField="mid" /> </UpdateParameters> <DeleteParameters> <asp:QueryStringParameter Name="ModuleId" QueryStringField="mid" /> </DeleteParameters> </asp:ObjectDataSource> The cmdDiscovery_RowDataBound method that gets called when the row's data is bound is the following C# code: protected void cmdDiscovery_RowDataBound(object sender, GridViewRowEventArgs e) { try { if (e.Row.RowIndex >= 0) { int intImage = ((DiscoveryInfo)e.Row.DataItem).Image; if (grdDiscoverys.EditIndex == -1) { // View Label lblViewImage = ((Label)e.Row.FindControl("lblViewImage")); if (GetFileDictionary().ContainsKey(intImage)) { lblViewImage.Text = GetFileDictionary()[intImage]; } else { lblViewImage.Text = "Missing Image"; } } else { // Edit DropDownList ddlEditImage = ((DropDownList)e.Row.FindControl("ddlEditImage")); ddlEditImage.DataSource = GetFileDictionary(); ddlEditImage.DataBind(); if (GetFileDictionary().ContainsKey(intImage)) { ddlEditImage.SelectedValue = intImage.ToString(); } } } } catch (Exception exc) { //Module failed to load Exceptions.ProcessModuleLoadException(this, exc); } } How do I make sure that the Image value in the drop down list is passed to the update function?

    Read the article

  • trie reg exp parse step over char and continue

    - by forest.peterson
    Setup: 1) a string trie database formed from linked nodes and a vector array linking to the next node terminating in a leaf, 2) a recursive regular expression function that if A) char '*' continues down all paths until string length limit is reached, then continues down remaining string paths if valid, and B) char '?' continues down all paths for 1 char and then continues down remaining string paths if valid. 3) after reg expression the candidate strings are measured for edit distance against the 'try' string. Problem: the reg expression works fine for adding chars or swapping ? for a char but if the remaining string has an error then there is not a valid path to a terminating leaf; making the matching function redundant. I tried adding a 'step-over' ? char if the end of the node vector was reached and then followed every path of that node - allowing this step-over only once; resulted in a memory exception; I cannot find logically why it is accessing the vector out of range - bactracking? Questions: 1) how can the regular expression step over an invalid char and continue with the path? 2) why is swapping the 'sticking' char for '?' resulting in an overflow? Function: void Ontology::matchRegExpHelper(nodeT *w, string inWild, Set<string> &matchSet, string out, int level, int pos, int stepover) { if (inWild=="") { matchSet.add(out); } else { if (w->alpha.size() == pos) { int testLength = out.length() + inWild.length(); if (stepover == 0 && matchSet.size() == 0 && out.length() > 8 && testLength == tokenLength) {//candidate generator inWild[0] = '?'; matchRegExpHelper(w, inWild, matchSet, out, level, 0, stepover+1); } else return; //giveup on this path } if (inWild[0] == '?' || (inWild[0] == '*' && (out.length() + inWild.length() ) == level ) ) { //wild matchRegExpHelper(w->alpha[pos].next, inWild.substr(1), matchSet, out+w->alpha[pos].letter, level, 0, stepover);//follow path -> if ontology is full, treat '*' like a '?' } else if (inWild[0] == '*') matchRegExpHelper(w->alpha[pos].next, '*'+inWild.substr(1), matchSet, out+w->alpha[pos].letter, level, 0, stepover); //keep adding chars if (inWild[0] == w->alpha[pos].letter) //follow self matchRegExpHelper(w->alpha[pos].next, inWild.substr(1), matchSet, out+w->alpha[pos].letter, level, 0, stepover); //follow char matchRegExpHelper(w, inWild, matchSet, out, level, pos+1, stepover);//check next path } } Error Message: +str "Attempt to access index 1 in a vector of size 1." std::basic_string<char,std::char_traits<char>,std::allocator<char> > +err {msg="Attempt to access index 1 in a vector of size 1." } ErrorException Note: this function works fine for hundreds of test strings with '*' wilds if the extra stepover gate is not used Semi-Solved: I place a pos < w->alpha.size() condition on each path that calls w->alpha[pos]... - this prevented the backtrack calls from attempting to access the vector with an out of bounds index value. Still have other issues to work out - it loops infinitely adding the ? and backtracking to remove it, then repeat. But, moving forward now. Revised question: why during backtracking is the position index accumulating and/or not deincrementing - so at somepoint it calls w->alpha[pos]... with an invalid position that is either remaining from the next node or somehow incremented pos+1 when passing upward?

    Read the article

  • Need some help accessing password string / Debugging

    - by Josh Lake
    I'm doing this code for the sole purpose in trying out how to get the password field masked. Any suggestions on where to go next? #include <iostream> #include <cmath> #include <stdio.h> #include <cstring> #include <conio.h> using namespace std; inline void keep_window_open() { char ch; cin>>ch; } int main() { cout << "Welcome to the Classified Network, DOD842349729961971\n"; cout << "Username: \n"; string admin = "gardinerca"; string root_password = "password1"; string full_name = "User Name"; string name; cin >> name; if (name == admin) { printf("Password: "); char password[10]; int i; for (i = 0; i <= 10; i++) { int c = getch(); if (c == '\n' || c == EOF) break; password[i] = c; printf("*"); } password[i] = '\0'; if (strcmp(password, root_password) == 0) { system("CLS"); cout << "Welcome " << full_name << " to the Classified Network\n"; cout << "Would you like to play a game? (Y or N)\n"; string play_game; cin >> play_game; if (play_game == "Y") { cout << "How many balls can you stick in your mouth?\n"; int balls; cin >> balls; string one; string two; one = "One Ball"; two = "Two Ball's"; if (balls == 1) cout << "You can honestly stick " << one << " in your mouth?"; } else { cout << "You have selected the No Option. Thats fine...we don't want to play with you either\n"; } } else { cout << "Invaild Password. Please contact system administrator.\n"; cin.clear(); system ("PAUSE"); } else { cout << "No Username found. Please contact system administrator.\n"; cin.clear(); system ("PAUSE"); } return 0; }

    Read the article

  • Resumable upload from Java client to Grails web application?

    - by dersteps
    After almost 2 workdays of Googling and trying several different possibilities I found throughout the web, I'm asking this question here, hoping that I might finally get an answer. First of all, here's what I want to do: I'm developing a client and a server application with the purpose of exchanging a lot of large files between multiple clients on a single server. The client is developed in pure Java (JDK 1.6), while the web application is done in Grails (2.0.0). As the purpose of the client is to allow users to exchange a lot of large files (usually about 2GB each), I have to implement it in a way, so that the uploads are resumable, i.e. the users are able to stop and resume uploads at any time. Here's what I did so far: I actually managed to do what I wanted to do and stream large files to the server while still being able to pause and resume uploads using raw sockets. I would send a regular request to the server (using Apache's HttpClient library) to get the server to send me a port that was free for me to use, then open a ServerSocket on the server and connect to that particular socket from the client. Here's the problem with that: Actually, there are at least two problems with that: I open those ports myself, so I have to manage open and used ports myself. This is quite error-prone. I actually circumvent Grails' ability to manage a huge amount of (concurrent) connections. Finally, here's what I'm supposed to do now and the problem: As the problems I mentioned above are unacceptable, I am now supposed to use Java's URLConnection/HttpURLConnection classes, while still sticking to Grails. Connecting to the server and sending simple requests is no problem at all, everything worked fine. The problems started when I tried to use the streams (the connection's OutputStream in the client and the request's InputStream in the server). Opening the client's OutputStream and writing data to it is as easy as it gets. But reading from the request's InputStream seems impossible to me, as that stream is always empty, as it seems. Example Code Here's an example of the server side (Groovy controller): def test() { InputStream inStream = request.inputStream if(inStream != null) { int read = 0; byte[] buffer = new byte[4096]; long total = 0; println "Start reading" while((read = inStream.read(buffer)) != -1) { println "Read " + read + " bytes from input stream buffer" //<-- this is NEVER called } println "Reading finished" println "Read a total of " + total + " bytes" // <-- 'total' will always be 0 (zero) } else { println "Input Stream is null" // <-- This is NEVER called } } This is what I did on the client side (Java class): public void connect() { final URL url = new URL("myserveraddress"); final byte[] message = "someMessage".getBytes(); // Any byte[] - will be a file one day HttpURLConnection connection = url.openConnection(); connection.setRequestMethod("GET"); // other methods - same result // Write message DataOutputStream out = new DataOutputStream(connection.getOutputStream()); out.writeBytes(message); out.flush(); out.close(); // Actually connect connection.connect(); // is this placed correctly? // Get response BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream())); String line = null; while((line = in.readLine()) != null) { System.out.println(line); // Prints the whole server response as expected } in.close(); } As I mentioned, the problem is that request.inputStream always yields an empty InputStream, so I am never able to read anything from it (of course). But as that is exactly what I'm trying to do (so I can stream the file to be uploaded to the server, read from the InputStream and save it to a file), this is rather disappointing. I tried different HTTP methods, different data payloads, and also rearranged the code over and over again, but did not seem to be able to solve the problem. What I hope to find I hope to find a solution to my problem, of course. Anything is highly appreciated: hints, code snippets, library suggestions and so on. Maybe I'm even having it all wrong and need to go in a totally different direction. So, how can I implement resumable file uploads for rather large (binary) files from a Java client to a Grails web application without manually opening ports on the server side?

    Read the article

  • How to play audio in Java Application

    - by user577829
    I'm making a java application and I need to play audio. I'm playing mainly small sound files of my cannon firing (its a cannon shooting game) and the projectiles exploding, though I plan on having looping background music. I have found two different methods to accomplish this, but both don't work how I want. The first method is literally a method: public void playSoundFile(File file) {//http://java.ittoolbox.com/groups/technical-functional/java-l/sound-in-an-application-90681 try { //get an AudioInputStream AudioInputStream ais = AudioSystem.getAudioInputStream(file); //get the AudioFormat for the AudioInputStream AudioFormat audioformat = ais.getFormat(); System.out.println("Format: " + audioformat.toString()); System.out.println("Encoding: " + audioformat.getEncoding()); System.out.println("SampleRate:" + audioformat.getSampleRate()); System.out.println("SampleSizeInBits: " + audioformat.getSampleSizeInBits()); System.out.println("Channels: " + audioformat.getChannels()); System.out.println("FrameSize: " + audioformat.getFrameSize()); System.out.println("FrameRate: " + audioformat.getFrameRate()); System.out.println("BigEndian: " + audioformat.isBigEndian()); //ULAW format to PCM format conversion if ((audioformat.getEncoding() == AudioFormat.Encoding.ULAW) || (audioformat.getEncoding() == AudioFormat.Encoding.ALAW)) { AudioFormat newformat = new AudioFormat(AudioFormat.Encoding.PCM_SIGNED, audioformat.getSampleRate(), audioformat.getSampleSizeInBits() * 2, audioformat.getChannels(), audioformat.getFrameSize() * 2, audioformat.getFrameRate(), true); ais = AudioSystem.getAudioInputStream(newformat, ais); audioformat = newformat; } //checking for a supported output line DataLine.Info datalineinfo = new DataLine.Info(SourceDataLine.class, audioformat); if (!AudioSystem.isLineSupported(datalineinfo)) { //System.out.println("Line matching " + datalineinfo + " is not supported."); } else { //System.out.println("Line matching " + datalineinfo + " is supported."); //opening the sound output line SourceDataLine sourcedataline = (SourceDataLine) AudioSystem.getLine(datalineinfo); sourcedataline.open(audioformat); sourcedataline.start(); //Copy data from the input stream to the output data line int framesizeinbytes = audioformat.getFrameSize(); int bufferlengthinframes = sourcedataline.getBufferSize() / 8; int bufferlengthinbytes = bufferlengthinframes * framesizeinbytes; byte[] sounddata = new byte[bufferlengthinbytes]; int numberofbytesread = 0; while ((numberofbytesread = ais.read(sounddata)) != -1) { int numberofbytesremaining = numberofbytesread; sourcedataline.write(sounddata, 0, numberofbytesread); } } } catch (Exception e) { e.printStackTrace(); } } The problem with this is that my entire program stops until the sound file is finished, or at least nearly finished. The second method is this: File file = new File("Launch1.wav"); AudioClip clip; try { clip = JApplet.newAudioClip(file.toURL()); clip.play(); } catch (Exception e) { e.getMessage(); } The problem I have here is that every time the sound file ends early or doesn't play at all depending on where I place the code. Is their any way to play sound without the above mentioned problems? Am I doing something wrong? Any help is greatly appreciated.

    Read the article

  • backgroundworker+wpf -> frozen window

    - by Valetudox
    -progressbar always 0% -the window is froozen (while DoWork r.) -if System.threading.thread.sleep(1) on - works perfectly whats the problem? private void btnNext_Click(object sender, RoutedEventArgs e) { this._worker = new BackgroundWorker(); this._worker.DoWork += delegate(object s, DoWorkEventArgs args) { long current = 1; long max = generalMaxSzam(); for (int i = 1; i <= 30; i++) { for (int j = i+1; j <= 30; j++) { for (int c = j+1; c <= 30; c++) { for (int h = c+1; h <= 30; h++) { for (int d = h+1; d <= 30; d++) { int percent = Convert.ToInt32(((decimal)current / (decimal)max) * 100); this._worker.ReportProgress(percent); current++; //System.Threading.Thread.Sleep(1); - it works well } } } } } }; this._worker.WorkerReportsProgress = true; this._worker.RunWorkerCompleted += delegate(object s, RunWorkerCompletedEventArgs args) { this.Close(); }; this._worker.ProgressChanged += delegate(object s, ProgressChangedEventArgs args) { this.statusPG.Value = args.ProgressPercentage; }; this._worker.RunWorkerAsync(); } <Window x:Class="SzerencsejatekProgram.Create" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Létrehozás" mc:Ignorable="d" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" Height="500" Width="700"> <DockPanel> <Button DockPanel.Dock="Right" Name="btnNext" Width="80" Click="btnNext_Click">Tovább</Button> <StatusBar DockPanel.Dock="Bottom"> <StatusBar.ItemsPanel> <ItemsPanelTemplate> <Grid> <Grid.ColumnDefinitions> <ColumnDefinition Width="*"/> <ColumnDefinition Width="Auto"/> <ColumnDefinition Width="auto"/> <ColumnDefinition Width="auto"/> </Grid.ColumnDefinitions> </Grid> </ItemsPanelTemplate> </StatusBar.ItemsPanel> <StatusBarItem Grid.Column="1"> <TextBlock Name="statusText"></TextBlock> </StatusBarItem> <StatusBarItem Grid.Column="2"> <ProgressBar Name="statusPG" Width="80" Height="18" IsEnabled="False" /> </StatusBarItem> <StatusBarItem Grid.Column="3"> <Button Name="statusB" IsCancel="True" IsEnabled="False">Cancel</Button> </StatusBarItem> </StatusBar> </DockPanel> </Window>

    Read the article

  • how can udp data can passed through RS232 in ansi c?

    - by moon
    i want to transmit and receive data on RS232 using udp and i want to know about techniques which allow me to transmit and receive data on a faster rate and also no lose of data is there? thanx in advance. i have tried but need improvements if possible #include <stdio.h> #include <dos.h> #include<string.h> #include<conio.h> #include<iostream.h> #include<stdlib.h> #define PORT1 0x3f8 void main() { int c,ch,choice,i,a=0; char filename[30],filename2[30],buf; FILE *in,*out; clrscr(); while(1){ outportb(PORT1+0,0x03); outportb(PORT1+1,0); outportb(PORT1+3,0x03); outportb(PORT1+2,0xc7); outportb(PORT1+4,0x0b); cout<<"\n==============================================================="; cout<<"\n\t*****Serial Communication By BADR-U-ZAMAN******\nCommunication between two computers By serial port"; cout<<"\nPlease select\n[1]\tFor sending file \n[2]\tFor receiving file \n[3]\tTo exit\n"; cout<<"=================================================================\n"; cin>>choice; if(choice==1) { strcpy(filename,"C:\\TC\\BIN\\badr.cpp"); cout<<filename; for(i=0;i<=strlen(filename);i++) outportb(PORT1,filename[i]); in=fopen(filename,"r"); if (in==NULL) { cout<<"cannot open a file"; a=1; } if(a!=1) cout<<"\n\nFile sending.....\n\n"; while(!feof(in)) { buf=fgetc(in); cout<<buf; outportb(PORT1,buf); delay(5); } } else { if(choice==3) exit(0); i=0; buf='a'; while(buf!=NULL) { c=inportb(PORT1+5); if(c&1) { buf=inportb(PORT1); filename2[i]=buf; i++; } } out=fopen(filename2,"t"); cout<<"\n Filename received:"<<filename[2]; cout<<"\nReading from the port..."; cout<<"writing to file"<<filename2; do { c=inportb(PORT1+5); if(c&1) { buf=inportb(PORT1); cout<<buf; fputc(buf,out); delay(5); } if(kbhit()) { ch=getch(); } }while(ch!=27); } getch(); } }

    Read the article

  • No improvement in speed when using Ehcache with Hibernate

    - by paddydub
    I'm getting no improvement in speed when using Ehcache with Hibernate Here are the results I get when i run the test below. The test is reading 80 Stop objects and then the same 80 Stop objects again using the cache. On the second read it is hitting the cache, but there is no improvement in speed. Any idea's on what I'm doing wrong? Speed Test: First Read: Reading stops 1-80 : 288ms Second Read: Reading stops 1-80 : 275ms Cache Info: elementsInMemory: 79 elementsInMemoryStore: 79 elementsInDiskStore: 0 JunitCacheTest public class JunitCacheTest extends TestCase { static Cache stopCache; public void testCache() { ApplicationContext context = new ClassPathXmlApplicationContext("beans-hibernate.xml"); StopDao stopDao = (StopDao) context.getBean("stopDao"); CacheManager manager = new CacheManager(); stopCache = (Cache) manager.getCache("ie.dataStructure.Stop.Stop"); //First Read for (int i=1; i<80;i++) { Stop toStop = stopDao.findById(i); } //Second Read for (int i=1; i<80;i++) { Stop toStop = stopDao.findById(i); } System.out.println("elementsInMemory " + stopCache.getSize()); System.out.println("elementsInMemoryStore " + stopCache.getMemoryStoreSize()); System.out.println("elementsInDiskStore " + stopCache.getDiskStoreSize()); } public static Cache getStopCache() { return stopCache; } } HibernateStopDao @Repository("stopDao") public class HibernateStopDao implements StopDao { private SessionFactory sessionFactory; @Transactional(readOnly = true) public Stop findById(int stopId) { Cache stopCache = JunitCacheTest.getStopCache(); Element cacheResult = stopCache.get(stopId); if (cacheResult != null){ return (Stop) cacheResult.getValue(); } else{ Stop result =(Stop) sessionFactory.getCurrentSession().get(Stop.class, stopId); Element element = new Element(result.getStopID(),result); stopCache.put(element); return result; } } } ehcache.xml <cache name="ie.dataStructure.Stop.Stop" maxElementsInMemory="1000" eternal="false" timeToIdleSeconds="5200" timeToLiveSeconds="5200" overflowToDisk="true"> </cache> stop.hbm.xml <class name="ie.dataStructure.Stop.Stop" table="stops" catalog="hibernate3" mutable="false" > <cache usage="read-only"/> <comment></comment> <id name="stopID" type="int"> <column name="STOPID" /> <generator class="assigned" /> </id> <property name="coordinateID" type="int"> <column name="COORDINATEID" not-null="true"> <comment></comment> </column> </property> <property name="routeID" type="int"> <column name="ROUTEID" not-null="true"> <comment></comment> </column> </property> </class> Stop public class Stop implements Comparable<Stop>, Serializable { private static final long serialVersionUID = 7823769092342311103L; private Integer stopID; private int routeID; private int coordinateID; }

    Read the article

  • java if else statement

    - by user554320
    I am a new student who is trying to use java if else statements at the moment. I have attched my class and i need to say if this code get 0 errors for all 4 errors(error11, error12, error13 and error14), need to display the text "Answer". This code was working without the if else statements and there are 2 errors in those 2 lines. Please explain me how to do it? public static void deltaR() { int x; int x11, x12, x13, x14; int x21, x22, x23, x24; //inputs double w10, w11, w12;//weights for first neuron int d11, d12, d13, d14;//desired output for first neuron double net11, net12, net13, net14;//sum of weights times inputs int y11, y12, y13, y14;//outputs int error11, error12, error13, error14;//error //double w20, w21, w22;//weights for second neuron //int d21, d22, d23, d24;//desired output for second neuron //double net21, net22, net23, net24;//sum of weights times input //int y21, y22, y23, y24;//outputs //int error21, error22, error23, error24;//error if (error11 = 0, error12 = 0, error13 = 0, error14 = 0) { System.out.println("Answer"); } else if (error11 != 0, error12 != 0, error13 != 0, error14 != 0) { double coe=0.5;//learning coefficient x=1; x11=0; x12=0; x13=1; x14=1; x21=0; x22=1; x23=0; x24=1; d11= 0; d12= 1; d13= 0; d14= 1; w10=0.5; w11=-1; w12=1.5; net11=(x*w10 + x11*w11 + x21*w12); net12=(x*w10 + x12*w11 + x22*w12); net13=(x*w10 + x13*w11 + x23*w12); net14=(x*w10 + x14*w11 + x24*w12); if (net11>=0) y11=1; else y11=0; if (net12>=0) y12=1; else y12=0; if (net13>=0) y13=1; else y13=0; if (net14>=0) y14=1; else y14=0; error11=(d11-y11); error12=(d12-y12); error13=(d13-y13); error14=(d14-y14); System.out.println("net value 1: "+net11); System.out.println("net value 2: "+net12); System.out.println("net value 3: "+net13); System.out.println("net value 4: "+net14); System.out.println("output 1: "+y11); System.out.println("output 2: "+y12); System.out.println("output 3: "+y13); System.out.println("output 4: "+y14); System.out.println("error1: "+error11); System.out.println("error2: "+error12); System.out.println("error3: "+error13); System.out.println("error4: "+error14); } } }

    Read the article

  • Explicit method tables in C# instead of OO - good? bad?

    - by FunctorSalad
    Hi! I hope the title doesn't sound too subjective; I absolutely do not mean to start a debate on OO in general. I'd merely like to discuss the basic pros and cons for different ways of solving the following sort of problem. Let's take this minimal example: you want to express an abstract datatype T with functions that may take T as input, output, or both: f1 : Takes a T, returns an int f2 : Takes a string, returns a T f3 : Takes a T and a double, returns another T I'd like to avoid downcasting and any other dynamic typing. I'd also like to avoid mutation whenever possible. 1: Abstract-class-based attempt abstract class T { abstract int f1(); // We can't have abstract constructors, so the best we can do, as I see it, is: abstract void f2(string s); // The convention would be that you'd replace calls to the original f2 by invocation of the nullary constructor of the implementing type, followed by invocation of f2. f2 would need to have side-effects to be of any use. // f3 is a problem too: abstract T f3(double d); // This doesn't express that the return value is of the *same* type as the object whose method is invoked; it just expresses that the return value is *some* T. } 2: Parametric polymorphism and an auxilliary class (all implementing classes of TImpl will be singleton classes): abstract class TImpl<T> { abstract int f1(T t); abstract T f2(string s); abstract T f3(T t, double d); } We no longer express that some concrete type actually implements our original spec -- an implementation is simply a type Foo for which we happen to have an instance of TImpl. This doesn't seem to be a problem: If you want a function that works on arbitrary implementations, you just do something like: // Say we want to return a Bar given an arbitrary implementation of our abstract type Bar bar<T>(TImpl<T> ti, T t); At this point, one might as well skip inheritance and singletons altogether and use a 3 First-class function table class /* or struct, even */ TDictT<T> { readonly Func<T,int> f1; readonly Func<string,T> f2; readonly Func<T,double,T> f3; TDict( ... ) { this.f1 = f1; this.f2 = f2; this.f3 = f3; } } Bar bar<T>(TDict<T> td; T t); Though I don't see much practical difference between #2 and #3. Example Implementation class MyT { /* raw data structure goes here; this class needn't have any methods */ } // It doesn't matter where we put the following; could be a static method of MyT, or some static class collecting dictionaries static readonly TDict<MyT> MyTDict = new TDict<MyT>( (t) => /* body of f1 goes here */ , // f2 (s) => /* body of f2 goes here */, // f3 (t,d) => /* body of f3 goes here */ ); Thoughts? #3 is unidiomatic, but it seems rather safe and clean. One question is whether there are any performance concerns with it. I don't usually need dynamic dispatch, and I'd prefer if these function bodies get statically inlined in places where the concrete implementing type is known statically. Is #2 better in that regard?

    Read the article

  • App is crashing as soon as UITableView gets reloaded

    - by OhhMee
    Hello, I'm developing an app where TableView needs to reload as soon as the login process gets completed. The app crashes with error EXC_BAD_ACCESS when the table data gets reloaded. It doesn't crash when I remove all case instances except case 0: What could be the reason behind it? Here's the code: - (void)viewDidLoad { [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(loginDone:) name:@"loginDone" object:nil]; statTableView.backgroundColor = [UIColor clearColor]; } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger) section { return 6; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier]; } // Configure the cell. switch (indexPath.row) { case 0 : cell.textLabel.text = @"Foo:"; NSLog(@"%@", data7); UILabel *myLabel2 = [[UILabel alloc] initWithFrame:CGRectMake(200, 10, 20, 30)]; myLabel2.text = (@"%@", data7); myLabel2.textColor = [UIColor blackColor]; myLabel2.backgroundColor = [UIColor whiteColor]; myLabel2.font = [UIFont fontWithName:@"Trebuchet MS" size:14]; [cell.contentView addSubview:myLabel2]; break; case 1: cell.textLabel.text = @"Foo: "; UILabel *myLabel4 = [[UILabel alloc] initWithFrame:CGRectMake(200, 10, 20, 30)]; myLabel4.text = (@"%@", data11); myLabel4.textColor = [UIColor blackColor]; myLabel4.backgroundColor = [UIColor whiteColor]; myLabel4.font = [UIFont fontWithName:@"Trebuchet MS" size:14]; [cell.contentView addSubview:myLabel4]; break; case 2: cell.textLabel.text = @"Foo: "; UILabel *myLabel8 = [[UILabel alloc] initWithFrame:CGRectMake(200, 10, 20, 30)]; myLabel8.text = (@"%@", data3); myLabel8.textColor = [UIColor blackColor]; myLabel8.backgroundColor = [UIColor whiteColor]; myLabel8.font = [UIFont fontWithName:@"Trebuchet MS" size:14]; [cell.contentView addSubview:myLabel8]; break; case 3: cell.textLabel.text = @"Foo: "; UILabel *myLabel10 = [[UILabel alloc] initWithFrame:CGRectMake(200, 10, 20, 30)]; myLabel10.text = [NSString stringWithFormat:@"%@", data4]; if ([data4 isEqualToString:@"0"]) { myLabel10.text = @"None"; } myLabel10.textColor = [UIColor blackColor]; myLabel10.backgroundColor = [UIColor whiteColor]; myLabel10.font = [UIFont fontWithName:@"Trebuchet MS" size:14]; [cell.contentView addSubview:myLabel10]; break; case 4: cell.textLabel.text = @"Foo: "; UILabel *myLabel12 = [[UILabel alloc] initWithFrame:CGRectMake(200, 10, 20, 30)]; myLabel12.text = [NSString stringWithFormat:@"%@", data5]; myLabel12.textColor = [UIColor blackColor]; if ([data5 isEqualToString:@"Foo"]) { myLabel12.textColor = [UIColor redColor]; myLabel12.text = @"Nil"; } myLabel12.backgroundColor = [UIColor whiteColor]; myLabel12.font = [UIFont fontWithName:@"Trebuchet MS" size:14]; [cell.contentView addSubview:myLabel12]; break; case 5: cell.textLabel.text = @"Foo: "; UILabel *myLabel14 = [[UILabel alloc] initWithFrame:CGRectMake(200, 10, 50, 30)]; if ([data6 isEqualToString:@"Foo"]) { myLabel14.textColor = [UIColor colorWithRed:(0/255.f) green:(100/255.f) blue:(0/255.f) alpha:1.0]; myLabel14.text = @"No Dues"; } else { myLabel14.text = [NSString stringWithFormat:@"%@", data6]; myLabel14.textColor = [UIColor redColor]; } myLabel14.backgroundColor = [UIColor whiteColor]; myLabel14.font = [UIFont fontWithName:@"Trebuchet MS" size:14]; [cell.contentView addSubview:myLabel14]; break; /* [myLabel2 release]; [myLabel4 release]; [myLabel8 release]; [myLabel10 release]; [myLabel12 release]; [myLabel14 release]; */ } return cell; }

    Read the article

  • Javascript parent and child window functions

    - by Mike Thornley
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML> <HEAD> <TITLE>Lab 9-3</TITLE> <SCRIPT LANGUAGE="JavaScript"> <!-- function myFunction(){ myWin = open("","","width=200,height=200"); with(myWin.document){ open(); write("<HTML><HEAD><TITLE>Child Window</TITLE>"); write("<SCRIPT>function myTest(){"); write("alert('This function is defined in the child window "); write("and is called from the parent window.'); this.focus();}"); write("</SCRIPT></HEAD><BODY><H3>Child Window</H3><HR>"); write("<FORM><INPUT TYPE='button' VALUE='parent window function' "); // Use opener property write("onClick='opener.winFunction();'>"); write("<P><INPUT TYPE='button' VALUE='close window' "); write("onClick='window.close();'>"); write("</FORM></BODY></HTML>"); close(); } } function winFunction(){ alert("This function is defined in the parent window\n" + "and is called from the child window."); myWin.focus(); } //--> </SCRIPT> </HEAD> <BODY> <H3>CIW Web Languages</H3> <HR> <FORM NAME="myForm"> <INPUT TYPE="button" VALUE="open new window" onClick="myFunction();"> <!-- Invoke child window function --> <input type="button" value="Click to open child window" onclick="javascript:void(myWin.myTest());"/> </FORM> <P> </BODY> </HTML> To explain further what my initial query was, the code above, should open the child window (myWin) with the second button, the 'Open child window' button without the need to open the window with the first button or do anything else. It should simply call the myWin.myTest()function The child window will open when the second button is pressed but needs to have the child window open first (first button push) before it'll work. This is not the intended purpose, the 'Open child window' button should work without anything else needing to be done. For some reason the parent window isn't communicating with the myWin window and myTest fucntion. It's not homework, it's part of a certification course lab and is coded in the manner I have been shown to understand as correct. DTD isn't included as the focus is the JavaScript. I code correctly with regards to that and other W3C requirements.

    Read the article

  • Value gets changed upon comiting. | CallableStatements

    - by Triztian
    Hello, I having a weird problem with a DAO class and a StoredProcedure, what is happening is that I use a CallableStatement object which takes 15 IN parameters, the value of the field id_color is retrieved correctly from the HTML forms it even is set up how it should in the CallableStatement setter methods, but the moment it is sent to the database the id_color is overwriten by the value 3 here's the "context": I have the following class DAO.CoverDAO which handles the CRUD operations of this table CREATE TABLE `cover_details` ( `refno` int(10) unsigned NOT NULL AUTO_INCREMENT, `shape` tinyint(3) unsigned NOT NULL , `id_color` tinyint(3) unsigned NOT NULL ', `reversefold` bit(1) NOT NULL DEFAULT b'0' , `x` decimal(6,3) unsigned NOT NULL , `y` decimal(6,3) unsigned NOT NULL DEFAULT '0.000', `typecut` varchar(10) NOT NULL, `cornershape` varchar(20) NOT NULL, `z` decimal(6,3) unsigned DEFAULT '0.000' , `othercornerradius` decimal(6,3) unsigned DEFAULT '0.000'', `skirt` decimal(5,3) unsigned NOT NULL DEFAULT '7.000', `foamTaper` varchar(3) NOT NULL, `foamDensity` decimal(2,1) unsigned NOT NULL , `straplocation` char(1) NOT NULL ', `straplength` decimal(6,3) unsigned NOT NULL, `strapinset` decimal(6,3) unsigned NOT NULL, `spayear` varchar(20) DEFAULT 'Not Specified', `spamake` varchar(20) DEFAULT 'Not Specified', `spabrand` varchar(20) DEFAULT 'Not Specified', PRIMARY KEY (`refno`) ) ENGINE=MyISAM AUTO_INCREMENT=143 DEFAULT CHARSET=latin1 $$ The the way covers are being inserted is by a stored procedure, which is the following: CREATE DEFINER=`root`@`%` PROCEDURE `putCover`( IN shape TINYINT, IN color TINYINT(3), IN reverse_fold BIT, IN x DECIMAL(6,3), IN y DECIMAL(6,3), IN type_cut VARCHAR(10), IN corner_shape VARCHAR(10), IN cutsize DECIMAL(6,3), IN corner_radius DECIMAL(6,3), IN skirt DECIMAL(5,3), IN foam_taper VARCHAR(7), IN foam_density DECIMAL(2,1), IN strap_location CHAR(1), IN strap_length DECIMAL(6,3), IN strap_inset DECIMAL(6,3) ) BEGIN INSERT INTO `dbre`.`cover_details` (`dbre`.`cover_details`.`shape`, `dbre`.`cover_details`.`id_color`, `dbre`.`cover_details`.`reversefold`, `dbre`.`cover_details`.`x`, `dbre`.`cover_details`.`y`, `dbre`.`cover_details`.`typecut`, `dbre`.`cover_details`.`cornershape`, `dbre`.`cover_details`.`z`, `dbre`.`cover_details`.`othercornerradius`, `dbre`.`cover_details`.`skirt`, `dbre`.`cover_details`.`foamTaper`, `dbre`.`cover_details`.`foamDensity`, `dbre`.`cover_details`.`strapLocation`, `dbre`.`cover_details`.`strapInset`, `dbre`.`cover_details`.`strapLength` ) VALUES (shape,color,reverse_fold, x,y,type_cut,corner_shape, cutsize,corner_radius,skirt,foam_taper,foam_density, strap_location,strap_inset,strap_length); END As you can see basically it just fills each field, now, the CoverDAO.create(CoverDTO cover) method which creates the cover is like so: public void create(CoverDTO cover) throws DAOException { Connection link = null; CallableStatement query = null; try { link = MySQL.getConnection(); link.setAutoCommit(false); query = link.prepareCall("{CALL putCover(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)}"); query.setLong(1,cover.getShape()); query.setInt(2,cover.getColor()); query.setBoolean(3, cover.getReverseFold()); query.setBigDecimal(4,cover.getX()); query.setBigDecimal(5,cover.getY()); query.setString(6,cover.getTypeCut()); query.setString(7,cover.getCornerShape()); query.setBigDecimal(8, cover.getZ()); query.setBigDecimal(9, cover.getCornerRadius()); query.setBigDecimal(10, cover.getSkirt()); query.setString(11, cover.getFoamTaper()); query.setBigDecimal(12, cover.getFoamDensity()); query.setString(13, cover.getStrapLocation()); query.setBigDecimal(14, cover.getStrapLength()); query.setBigDecimal(15, cover.getStrapInset()); query.executeUpdate(); link.commit(); } catch (SQLException e) { throw new DAOException(e); } finally { close(link, query); } } The CoverDTO is made of accessesor methods, the MySQL object basically returns the connection from a pool. Here is the pset Query with dummy but appropriate data: putCover(1,10,0,80.000,80.000,'F','Cut',0.000,0,15.000,'4x2',1.5,'A',10.000,5.000) As you can see everything is fine just when I write to the DB instead of 10 in the second parameter a 3 is written. I have done the following: Traced the id_color value to the create method, still got replaced by a 3 Hardcoded the value in the DAO create method, still got replaced by a 3 Called the procedure from the MySQL Workbench, it worked fined so I assume something is happening in the create method, any help is really appreciated.

    Read the article

  • ValidationProperty not returning entered value for textbox in custom ontrol

    - by nat
    hi I have a custom control, (relevant code at the bottom) it consists of some text/links and a hidden textbox (rather than a hidden input). when rendered, the user via another dialog and some JS sets the value of the textbox to an integer and clicks submit on the form. i am trying to assure that the user has entered a number (via the JS) and that the textbox is not still set to its default of "0" the requiredfieldvalidator works just fine, if i dont change the value it spots it on the client and fills the validation summary on the page with the appropriate message. unfortunately when i do fill the textbox, the validator also rejests the post as the controls textbox text value is still set to "0", even though on the form it has changed. clearly i am doing something wrong.. but cant work out what it is? could someone enlighten me please, this is driving me potty if i step through the code, when the get of the mediaidtext is hit,the findcontrol finds does not the textbox, if i inspect the controls collection however i can find the textbox, but its value is still "0" it also seems that when findcontrol is called, the createchildcontrols is called again - thus resetting the value back to "0" there.. ! how can i ever assure the control realises that the textbox value has changed? many thanks code below nat [ValidationProperty("MediaIdText")] public class MediaLibraryFileControl: CompositeControl { private int mediaId = 0; public int MediaId { get { return mediaId; } set { mediaId = value; } } public string MediaIdText { get { string txt = "0"; Control ctrl = this.FindControl(this.UniqueID+ "_hidden"); try { txt = ((TextBox)ctrl).Text; MediaId = Convert.ToInt32(txt); } catch { MediaId = 0; } return txt; } } protected override void CreateChildControls() { this.Controls.Add(new LiteralControl("<span>")); this.Controls.Add(new LiteralControl("<span id=\"" + TextControlName + "\">" + getMediaDetails() + "</span>")); TextBox tb = new TextBox(); tb.Text = this.MediaId.ToString(); tb.ID = this.UniqueID + "_hidden"; tb.CssClass = "hidden"; this.Controls.Add(tb); if (Select == true) { this.Controls.Add(new LiteralControl(string.Format("&nbsp;[<a href=\"javascript:{0}(this,'{1}','{2}')\" class=\"select\">{3}</a>]", dialog, this.UniqueID, this.categoryId, "select"))); this.Controls.Add(new LiteralControl(string.Format("&nbsp;[<a href=\"javascript:{0}(this,'{1}')\" class=\"select\">{2}</a>]", clearDialog, this.ID, "clear"))); } this.Controls.Add(new LiteralControl("</span>")); } protected virtual string getMediaDetails() { //... return String.Empty; } } this is the code adding the validationcontrol the editcontrol is the instance of the control above public override Control RenderValidationControl(Control editControl) { Control ctrl = new PlaceHolder(); RequiredFieldValidator req = new RequiredFieldValidator(); req.ID = editControl.ClientID + "_validator"; req.ControlToValidate = editControl.ID; req.Display = ValidatorDisplay.None; req.InitialValue = "0"; req.EnableClientScript = false; req.ErrorMessage = "control cannot be blank"; ctrl.Controls.Add(req); return ctrl; }

    Read the article

  • data not reloading into tableview from core data on minor update

    - by Martin KS
    I've got a basic photo album application, on the first view a list of albums is displayed with a subtitle showing how many images are in each album. I've got everything working to add albums, and add images to albums. The problem is that the image count lines are accurate whenever the app loads, but I can't get them to update during execution. The following viewdidload correctly populates all lines of the tableview when the app loads: - (void)viewDidLoad { [super viewDidLoad]; // Set the title. self.title = @"Photo albums"; // Configure the add and edit buttons. self.navigationItem.leftBarButtonItem = self.editButtonItem; addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(addAlbum)]; addButton.enabled = YES; self.navigationItem.rightBarButtonItem = addButton; /* Fetch existing albums. Create a fetch request; find the Album entity and assign it to the request; add a sort descriptor; then execute the fetch. */ NSFetchRequest *request = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Album" inManagedObjectContext:managedObjectContext]; [request setEntity:entity]; // Order the albums by name. NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"albumName" ascending:NO]; NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil]; [request setSortDescriptors:sortDescriptors]; [sortDescriptor release]; [sortDescriptors release]; // Execute the fetch -- create a mutable copy of the result. NSError *error = nil; NSMutableArray *mutableFetchResults = [[managedObjectContext executeFetchRequest:request error:&error] mutableCopy]; if (mutableFetchResults == nil) { // Handle the error. } LocationsAppDelegate *mainDelegate = (LocationsAppDelegate *)[[UIApplication sharedApplication] delegate]; // Set master albums array to the mutable array, then clean up. [mainDelegate setAlbumsArray:mutableFetchResults]; [mutableFetchResults release]; [request release]; } But when I run similar code inside viewdidappear, nothing happens: { /* Fetch existing albums. Create a fetch request; find the Album entity and assign it to the request; add a sort descriptor; then execute the fetch. */ NSFetchRequest *request = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Album" inManagedObjectContext:managedObjectContext]; [request setEntity:entity]; // Order the albums by creation date, most recent first. NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"albumName" ascending:NO]; NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil]; [request setSortDescriptors:sortDescriptors]; [sortDescriptor release]; [sortDescriptors release]; // Execute the fetch -- create a mutable copy of the result. NSError *error = nil; NSMutableArray *mutableFetchResults = [[managedObjectContext executeFetchRequest:request error:&error] mutableCopy]; if (mutableFetchResults == nil) { // Handle the error. } LocationsAppDelegate *mainDelegate = (LocationsAppDelegate *)[[UIApplication sharedApplication] delegate]; // Set master albums array to the mutable array, then clean up. [mainDelegate setAlbumsArray:mutableFetchResults]; [self.tableView reloadData]; [mutableFetchResults release]; [request release]; } Apologies if I've missed the answer to this question elsewhere, but what am I missing?

    Read the article

  • "C variable type sizes are machine dependent." Is it really true? signed & unsigned numbers ;

    - by claws
    Hello, I've been told that C types are machine dependent. Today I wanted to verify it. void legacyTypes() { /* character types */ char k_char = 'a'; //Signedness --> signed & unsigned signed char k_char_s = 'a'; unsigned char k_char_u = 'a'; /* integer types */ int k_int = 1; /* Same as "signed int" */ //Signedness --> signed & unsigned signed int k_int_s = -2; unsigned int k_int_u = 3; //Size --> short, _____, long, long long short int k_s_int = 4; long int k_l_int = 5; long long int k_ll_int = 6; /* real number types */ float k_float = 7; double k_double = 8; } I compiled it on a 32-Bit machine using minGW C compiler _legacyTypes: pushl %ebp movl %esp, %ebp subl $48, %esp movb $97, -1(%ebp) # char movb $97, -2(%ebp) # signed char movb $97, -3(%ebp) # unsigned char movl $1, -8(%ebp) # int movl $-2, -12(%ebp)# signed int movl $3, -16(%ebp) # unsigned int movw $4, -18(%ebp) # short int movl $5, -24(%ebp) # long int movl $6, -32(%ebp) # long long int movl $0, -28(%ebp) movl $0x40e00000, %eax movl %eax, -36(%ebp) fldl LC2 fstpl -48(%ebp) leave ret I compiled the same code on 64-Bit processor (Intel Core 2 Duo) on GCC (linux) legacyTypes: .LFB2: .cfi_startproc pushq %rbp .cfi_def_cfa_offset 16 movq %rsp, %rbp .cfi_offset 6, -16 .cfi_def_cfa_register 6 movb $97, -1(%rbp) # char movb $97, -2(%rbp) # signed char movb $97, -3(%rbp) # unsigned char movl $1, -12(%rbp) # int movl $-2, -16(%rbp)# signed int movl $3, -20(%rbp) # unsigned int movw $4, -6(%rbp) # short int movq $5, -32(%rbp) # long int movq $6, -40(%rbp) # long long int movl $0x40e00000, %eax movl %eax, -24(%rbp) movabsq $4620693217682128896, %rax movq %rax, -48(%rbp) leave ret Observations char, signed char, unsigned char, int, unsigned int, signed int, short int, unsigned short int, signed short int all occupy same no. of bytes on both 32-Bit & 64-Bit Processor. The only change is in long int & long long int both of these occupy 32-bit on 32-bit machine & 64-bit on 64-bit machine. And also the pointers, which take 32-bit on 32-bit CPU & 64-bit on 64-bit CPU. Questions: I cannot say, what the books say is wrong. But I'm missing something here. What exactly does "Variable types are machine dependent mean?" As you can see, There is no difference between instructions for unsigned & signed numbers. Then how come the range of numbers that can be addressed using both is different? I was reading http://stackoverflow.com/questions/2511246/how-to-maintain-fixed-size-of-c-variable-types-over-different-machines I didn't get the purpose of the question or their answers. What maintaining fixed size? They all are the same. I didn't understand how those answers are going to ensure the same size.

    Read the article

  • Broken Multithreading With Core Data

    - by spamguy
    This is a better-focused version of an earlier question that touches upon an entirely different subject from before. I am working on a Cocoa Core Data application with multiple threads. There is a Song and Artist; every Song has an Artist relation. There is a delegate code file not cited here; it more or less looks like the template XCode generates. I am far better working with the former technology than the latter, and any multithreading capability came from a Core Data template. When I'm doing all my ManagedObjectContext work in one method, I am fine. When I put fetch-or-insert-then-return-object work into a separate method, the application halts (but does not crash) at the new method's return statement, seen below. The new method even gets its own MOC to be safe, and it has not helped any. The result is one addition to Song and a halt after generating an Artist. I get no errors or exceptions, and I don't know why. I've debugged out the wazoo. My theory is that any errors occurring are in another thread, and the one I'm watching is waiting on something forever. What did I do wrong with getArtistObject: , and how can I fix it? Thanks. - (void)main { NSInteger songCount = 1; NSManagedObjectContext *moc = [[NSManagedObjectContext alloc] init]; [moc setPersistentStoreCoordinator:[[self delegate] persistentStoreCoordinator]]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(contextDidSave:) name:NSManagedObjectContextDidSaveNotification object:moc]; /* songDict generated here */ for (id key in songDict) { NSManagedObject *song = [NSEntityDescription insertNewObjectForEntityForName:@"Song" inManagedObjectContext:moc]; [song setValue:[songDictItem objectForKey:@"Name"] forKey:@"title"]; [song setValue:[self getArtistObject:(NSString *) [songDictItem objectForKey:@"Artist"]] forKey:@"artist"]; [songDictItem release]; songCount++; } NSError *error; if (![moc save:&error]) [NSApp presentError:error]; [[NSNotificationCenter defaultCenter] removeObserver:self name:NSManagedObjectContextDidSaveNotification object:moc]; [moc release], moc = nil; [[self delegate] importDone]; } - (NSManagedObject*) getArtistObject:(NSString*)theArtist { NSError *error = nil; NSManagedObjectContext *moc = [[NSManagedObjectContext alloc] init]; [moc setPersistentStoreCoordinator:[[self delegate] persistentStoreCoordinator]]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(contextDidSave:) name:NSManagedObjectContextDidSaveNotification object:moc]; NSFetchRequest *fetch = [[[NSFetchRequest alloc] init] autorelease]; NSEntityDescription *entityDescription = [NSEntityDescription entityForName:@"Artist" inManagedObjectContext:moc]; [fetch setEntity:entityDescription]; // object to be returned NSManagedObject *artistObject = [[NSManagedObject alloc] initWithEntity:entityDescription insertIntoManagedObjectContext:moc]; // set predicate (artist name) NSPredicate *pred = [NSPredicate predicateWithFormat:[NSString stringWithFormat:@"name = \"%@\"", theArtist]]; [fetch setPredicate:pred]; NSArray *response = [moc executeFetchRequest:fetch error:&error]; if (error) [NSApp presentError:error]; if ([response count] == 0) // empty resultset --> no artists with this name { [artistObject setValue:theArtist forKey:@"name"]; NSLog(@"%@ not found. Adding.", theArtist); return artistObject; } else return [response objectAtIndex:0]; } @end

    Read the article

  • Why does sending post data with WebRequest take so long?

    - by Paramiliar
    I am currently creating a C# application to tie into a php / MySQL online system. The application needs to send post data to scripts and get the response. When I send the following data username=test&password=test I get the following responses... Starting request at 22/04/2010 12:15:42 Finished creating request : took 00:00:00.0570057 Transmitting data at 22/04/2010 12:15:42 Transmitted the data : took 00:00:06.9316931 <<-- Getting the response at 22/04/2010 12:15:49 Getting response 00:00:00.0360036 Finished response 00:00:00.0360036 Entire call took 00:00:07.0247024 As you can see it is taking 6 seconds to actually send the data to the script, I have done further testing bye sending data from telnet and by sending post data from a local file to the url and they dont even take a second so this is not a problem with the hosted script on the site. Why is it taking 6 seconds to transmit the data when it is two simple strings? I use a custom class to send the data class httppostdata { WebRequest request; WebResponse response; public string senddata(string url, string postdata) { var start = DateTime.Now; Console.WriteLine("Starting request at " + start.ToString()); // create the request to the url passed in the paramaters request = (WebRequest)WebRequest.Create(url); // set the method to post request.Method = "POST"; // set the content type and the content length request.ContentType = "application/x-www-form-urlencoded"; request.ContentLength = postdata.Length; // convert the post data into a byte array byte[] byteData = Encoding.UTF8.GetBytes(postdata); var end1 = DateTime.Now; Console.WriteLine("Finished creating request : took " + (end1 - start)); var start2 = DateTime.Now; Console.WriteLine("Transmitting data at " + start2.ToString()); // get the request stream and write the data to it Stream dataStream = request.GetRequestStream(); dataStream.Write(byteData, 0, byteData.Length); dataStream.Close(); var end2 = DateTime.Now; Console.WriteLine("Transmitted the data : took " + (end2 - start2)); // get the response var start3 = DateTime.Now; Console.WriteLine("Getting the response at " + start3.ToString()); response = request.GetResponse(); //Console.WriteLine(((WebResponse)response).StatusDescription); dataStream = response.GetResponseStream(); StreamReader reader = new StreamReader(dataStream); var end3 = DateTime.Now; Console.WriteLine("Getting response " + (end3 - start3)); // read the response string serverresponse = reader.ReadToEnd(); var end3a = DateTime.Now; Console.WriteLine("Finished response " + (end3a - start3)); Console.WriteLine("Entire call took " + (end3a - start)); //Console.WriteLine(serverresponse); reader.Close(); dataStream.Close(); response.Close(); return serverresponse; } } And to call it I use private void btnLogin_Click(object sender, EventArgs e) { // string postdata; if (txtUsername.Text.Length < 3 || txtPassword.Text.Length < 3) { MessageBox.Show("Missing your username or password."); } else { string postdata = "username=" + txtUsername.Text + "&password=" + txtPassword.Text; httppostdata myPost = new httppostdata(); string response = myPost.senddata("http://www.domainname.com/scriptname.php", postdata); MessageBox.Show(response); } }

    Read the article

  • Confusion on C++ Python extensions. Things like getting C++ values for python values.

    - by Matthew Mitchell
    I'm wanted to convert some of my python code to C++ for speed but it's not as easy as simply making a C++ function and making a few function calls. I have no idea how to get a C++ integer from a python integer object. I have an integer which is an attribute of an object that I want to use. I also have integers which are inside a list in the object which I need to use. I wanted to test making a C++ extension with this function: def setup_framebuffer(surface,flip=False): #Create texture if not done already if surface.texture is None: create_texture(surface) #Render child to parent if surface.frame_buffer is None: surface.frame_buffer = glGenFramebuffersEXT(1) glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, c_uint(int(surface.frame_buffer))) glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, surface.texture, 0) glPushAttrib(GL_VIEWPORT_BIT) glViewport(0,0,surface._scale[0],surface._scale[1]) glMatrixMode(GL_PROJECTION) glLoadIdentity() #Load the projection matrix if flip: gluOrtho2D(0,surface._scale[0],surface._scale[1],0) else: gluOrtho2D(0,surface._scale[0],0,surface._scale[1]) That function calls create_texture, so I will have to pass that function to the C++ function which I will do with the third argument. This is what I have so far, while trying to follow information on the python documentation: #include <Python.h> #include <GL/gl.h> static PyMethodDef SpamMethods[] = { ... {"setup_framebuffer", setup_framebuffer, METH_VARARGS,"Loads a texture from a Surface object to the OpenGL framebuffer."}, ... {NULL, NULL, 0, NULL} /* Sentinel */ }; static PyObject * setup_framebuffer(PyObject *self, PyObject *args){ bool flip; PyObject *create_texture, *arg_list,*pyflip,*frame_buffer_id; if (!PyArg_ParseTuple(args, "OOO", &surface,&pyflip,&create_texture)){ return NULL; } if (PyObject_IsTrue(pyflip) == 1){ flip = true; }else{ flip = false; } Py_XINCREF(create_texture); //Create texture if not done already if(texture == NULL){ arglist = Py_BuildValue("(O)", surface) result = PyEval_CallObject(create_texture, arglist); Py_DECREF(arglist); if (result == NULL){ return NULL; } Py_DECREF(result); } Py_XDECREF(create_texture); //Render child to parent frame_buffer_id = PyObject_GetAttr(surface, Py_BuildValue("s","frame_buffer")) if(surface.frame_buffer == NULL){ glGenFramebuffersEXT(1,frame_buffer_id); } glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, surface.frame_buffer)); glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, surface.texture, 0); glPushAttrib(GL_VIEWPORT_BIT); glViewport(0,0,surface._scale[0],surface._scale[1]); glMatrixMode(GL_PROJECTION); glLoadIdentity(); //Load the projection matrix if (flip){ gluOrtho2D(0,surface._scale[0],surface._scale[1],0); }else{ gluOrtho2D(0,surface._scale[0],0,surface._scale[1]); } Py_INCREF(Py_None); return Py_None; } PyMODINIT_FUNC initcscalelib(void){ PyObject *module; module = Py_InitModule("cscalelib", Methods); if (m == NULL){ return; } } int main(int argc, char *argv[]){ /* Pass argv[0] to the Python interpreter */ Py_SetProgramName(argv[0]); /* Initialize the Python interpreter. Required. */ Py_Initialize(); /* Add a static module */ initscalelib(); }

    Read the article

  • Tomcat does save logged users during restart

    - by mabuzer
    How to force Tomcat to save logged users, so that the they kept logged in even after Tomcat has restarted? Right now the user has to login again everytime. Added the following lines into web-app context.xml: <Manager className="org.apache.catalina.session.PersistentManager"> <Store className="org.apache.catalina.session.FileStore"/> </Manager> but still I see login page after Tomcat restart, I use Tomcat 6.0.26 Update I managed to solve it like this: 1) Make my own extended version of FormAuthentication class: package com.alz.tomcat; import java.io.IOException; import java.security.Principal; import org.apache.catalina.Session; import org.apache.catalina.deploy.LoginConfig; import org.apache.catalina.connector.Request; import org.apache.catalina.connector.Response; import org.apache.catalina.authenticator.Constants; import org.apache.catalina.authenticator.FormAuthenticator; /** * * @author mabuzer */ public class Authenticator extends FormAuthenticator { @Override public boolean authenticate(Request request, Response response, LoginConfig config) throws IOException { String username = (String) request.getSession().getAttribute("USERNAME"); String password = (String) request.getSession().getAttribute("PASSWORD"); Principal principal = request.getUserPrincipal(); Session session = request.getSessionInternal(true); if (request.getUserPrincipal() == null && !isNull(username) && !isNull(password)) { principal = context.getRealm().authenticate(username, password); if (principal != null) { session.setNote(Constants.FORM_PRINCIPAL_NOTE, principal); if (!matchRequest(request)) { register(request, response, principal, Constants.FORM_METHOD, username, password); return (true); } } return super.authenticate(request, response, config); } else { return super.authenticate(request, response, config); } } private boolean isNull(String str) { if (str == null || "".equals(str)) { return true; } else { return false; } } } 2) Have your own ContextConfig class: package com.alz.tomcat; import java.util.HashMap; import org.apache.catalina.Valve; /** * * @author [email protected] */ public class ContextConfig extends org.apache.catalina.startup.ContextConfig { public ContextConfig() { super(); // we need to append our authenticator setCustomAuthenticators(customAuthenticators); customAuthenticators = new HashMap(); customAuthenticators.put("Authenticator" , new Authenticator()); } } 3) Have a class extends LifeCycleListener to set replace default ContextConfig the one you made: package com.alz.tomcat; import org.apache.catalina.Lifecycle; import org.apache.catalina.LifecycleEvent; import org.apache.catalina.core.StandardHost; /** * * @author [email protected] */ public class LifeCycleListener implements org.apache.catalina.LifecycleListener { public void lifecycleEvent(LifecycleEvent lifeCycleEvent) { if (Lifecycle.BEFORE_START_EVENT.equals(lifeCycleEvent.getType())) { StandardHost aStandardHost = (StandardHost) lifeCycleEvent.getLifecycle(); aStandardHost.setConfigClass("com.alz.tomcat.ContextConfig"); } } } 4) Final step which is to add your LifeCycleListener to server.xml in Host tag like this: <Host appBase="webapps" autoDeploy="true" name="localhost" unpackWARs="true" xmlNamespaceAware="false" xmlValidation="false"> <Listener className="com.alz.tomcat.LifeCycleListener"/> </Host>

    Read the article

  • Problem with large number of markers on the map...

    - by bobetko
    I am working on an Android app that already exists on iPhone. In the app, there is a Map activity that has (I counted) around 800 markers in four groups marked by drawable in four different colors. Each group can be turned on or off. Information about markers I have inside List. I create a mapOverlay for each group, then I attach that overlay to the map. I strongly believe that coding part I did properly. But I will attach my code anyway... The thing is, my Nexus One can't handle map with all those markers. It takes around 15 seconds just to draw 500 markers. Then when all drawn, map is not quite smooth. It is sort of hard to zoom and navigate around. It can be done, but experience is bad and I would like to see if something can be done there. iPhone seems doesn't have problems showing all these markers. It takes roughly about 1-2 seconds to show all of them and zooming and panning is not that bad. Slow down is noticeable but still acceptable. I personally think it is no good to draw all those markers, but app is designed by somebody else and I am not supposed to make any drastic changes. I am not sure what to do here. It seems I will have to come up with different functionality, maybe use GPS location, if known, and draw only markers within some radius, or, if location not known, use center of the screen(map) and draw markers around that. I will have to have reasonable explanation for my bosses in case I make these changes. I appreciate if anybody has any idas. And the code: ... for (int m = 0; m < ArrList.size(); m++) { tName = ArrList.get(m).get("name").toString(); tId = ArrList.get(m).get("id").toString(); tLat = ArrList.get(m).get("lat").toString();; tLng = ArrList.get(m).get("lng").toString();; try { lat = Double.parseDouble(tLat); lng = Double.parseDouble(tLng); p1 = new GeoPoint( (int) (lat * 1E6), (int) (lng * 1E6)); OverlayItem overlayitem = new OverlayItem(p1, tName, tId); itemizedoverlay.addOverlay(overlayitem); } catch (NumberFormatException e) { Log.d(TAG, "NumberFormatException" + e); } } mapOverlays.add(itemizedoverlay); mapView.postInvalidate(); ................................ public class HelloItemizedOverlay extends ItemizedOverlay<OverlayItem> { private ArrayList<OverlayItem> mOverlays = new ArrayList<OverlayItem>(); private Context mContext; public HelloItemizedOverlay(Drawable defaultMarker, Context context) { super(boundCenterBottom(defaultMarker)); mContext = context; } public void addOverlay(OverlayItem overlay) { mOverlays.add(overlay); populate(); } @Override protected OverlayItem createItem(int i) { return mOverlays.get(i); } @Override public int size() { return mOverlays.size(); } @Override protected boolean onTap(int index) { final OverlayItem item = mOverlays.get(index); ... EACH MARKER WILL HAVE ONCLICK EVENT THAT WILL PRODUCE CLICABLE ... BALOON WITH MARKER'S NAME. return true; } }

    Read the article

  • Failing to add different items in combobox on dynamic radiobutton click

    - by Steven Wilson
    I am working on radiobuttons and combobox in my wpf App. Although I am a C++ developer, I recently moved to C#. My app deals with dynamic generation of the above mentioned components. Basically I have created 4 dynamic radiobuttons in my app and on clicking each, i should should add different items to my combobox. Here is the code: XAML: <ItemsControl ItemsSource="{Binding Children}"> <ItemsControl.ItemTemplate> <DataTemplate> <StackPanel Orientation="Vertical" > <RadioButton Content="{Binding RadioBase}" Margin="0,10,0,0" IsChecked="{Binding BaseCheck}" GroupName="SlotGroup" Height="15" Width="80" HorizontalAlignment="Center" VerticalAlignment="Center"/> </StackPanel> </DataTemplate> </ItemsControl.ItemTemplate> </ItemsControl> <ComboBox Visibility="{Binding IsRegisterItemsVisible}" ItemsSource="{Binding RegComboList}" SelectedItem="{Binding SelectedRegComboList, Mode=TwoWay}" SelectedIndex="0" /> FPGARadioWidgetViewModel Class: public ObservableCollection<FPGAViewModel> Children { get; set; } public FPGARadioWidgetViewModel() { Children = new ObservableCollection<FPGAViewModel>(); Children.Add(new FPGAViewModel() { RadioBase = "Base 0x0", ID = 0 }); Children.Add(new FPGAViewModel() { RadioBase = "Base 0x40", ID = 1 }); Children.Add(new FPGAViewModel() { RadioBase = "Base 0x80", ID = 2 }); Children.Add(new FPGAViewModel() { RadioBase = "Base 0xc0", ID = 3 }); } FPGAViewModel Class: private bool sBaseCheck; public bool BaseCheck { get { return this.sBaseCheck; } set { this.sBaseCheck = value; AddComboItems(); this.OnPropertyChanged("BaseCheck"); } } private ObservableCollection<string> _RegComboList; public ObservableCollection<string> RegComboList { get { return _RegComboList; } set { _RegComboList = value; OnPropertyChanged("RegComboList"); } } private void AddComboItems() { int baseRegister = 0x40 * ID; ObservableCollection<string> combo = new ObservableCollection<string>(); for (int i = 0; i < 0x40; i++) { int reg = (i * 8) + baseRegister; combo[i] = "0x" + reg.ToString("X"); } RegComboList = new ObservableCollection<String>(combo); OnPropertyChanged("RegComboList"); } private bool isRegisterItemsVisible = false; public bool IsRegisterItemsVisible { get { return isRegisterItemsVisible; } set { isRegisterItemsVisible = value; OnPropertyChanged("IsRegisterItemsVisible"); OnPropertyChanged("RegComboList"); } } If you notice, on clicking a particular radiobutton, it should add items with different value in combobox based on ID. It has to be made sure that on clicking any radiobutton only the items of that should be added and previous content of combobox should be cleared. I am trying to do the same thing using my above code but nothing seems to appear in combobox when i debug. Please help :)

    Read the article

  • NSMutableArray memory leak when reloading objects

    - by Davin
    I am using Three20/TTThumbsviewcontroller to load photos. I am struggling since quite a some time now to fix memory leak in setting photosource. I am beginner in Object C & iOS memory management. Please have a look at following code and suggest any obvious mistakes or any errors in declaring and releasing variables. -- PhotoViewController.h @interface PhotoViewController : TTThumbsViewController <UIPopoverControllerDelegate,CategoryPickerDelegate,FilterPickerDelegate,UISearchBarDelegate>{ ...... NSMutableArray *_photoList; ...... @property(nonatomic,retain) NSMutableArray *photoList; -- PhotoViewController.m @implementation PhotoViewController .... @synthesize photoList; ..... - (void)LoadPhotoSource:(NSString *)query:(NSString *)title:(NSString* )stoneName{ NSLog(@"log- in loadPhotosource method"); if (photoList == nil) photoList = [[NSMutableArray alloc] init ]; [photoList removeAllObjects]; @try { sqlite3 *db; NSFileManager *fileMgr = [NSFileManager defaultManager]; NSString* documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]; NSString *dbPath = [documentsPath stringByAppendingPathComponent: @"DB.s3db"]; BOOL success = [fileMgr fileExistsAtPath:dbPath]; if(!success) { NSLog(@"Cannot locate database file '%@'.", dbPath); } if(!(sqlite3_open([dbPath UTF8String], &db) == SQLITE_OK)) { NSLog(@"An error has occured."); } NSString *_sql = query;//[NSString stringWithFormat:@"SELECT * FROM Products where CategoryId = %i",[categoryId integerValue]]; const char *sql = [_sql UTF8String]; sqlite3_stmt *sqlStatement; if(sqlite3_prepare(db, sql, -1, &sqlStatement, NULL) != SQLITE_OK) { NSLog(@"Problem with prepare statement"); } if ([stoneName length] != 0) { NSString *wildcardSearch = [NSString stringWithFormat:@"%@%%",[stoneName stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]]; sqlite3_bind_text(sqlStatement, 1, [wildcardSearch UTF8String], -1, SQLITE_STATIC); } while (sqlite3_step(sqlStatement)==SQLITE_ROW) { NSString* urlSmallImage = @"Mahallati_NoImage.png"; NSString* urlThumbImage = @"Mahallati_NoImage.png"; NSString *designNo = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement,2)]; designNo = [designNo stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]; NSString *desc = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement,7)]; desc = [desc stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]; NSString *caption = designNo;//[designNo stringByAppendingString:desc]; caption = [caption stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]; NSString *smallFilePath = [documentsPath stringByAppendingPathComponent: [NSString stringWithFormat:@"Small%@.JPG",designNo] ]; smallFilePath = [smallFilePath stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]; if ([fileMgr fileExistsAtPath:smallFilePath]){ urlSmallImage = [NSString stringWithFormat:@"Small%@.JPG",designNo]; } NSString *thumbFilePath = [documentsPath stringByAppendingPathComponent: [NSString stringWithFormat:@"Thumb%@.JPG",designNo] ]; thumbFilePath = [thumbFilePath stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]; if ([fileMgr fileExistsAtPath:thumbFilePath]){ urlThumbImage = [NSString stringWithFormat:@"Thumb%@.JPG",designNo]; } NSNumber *photoProductId = [NSNumber numberWithInt:(int)sqlite3_column_int(sqlStatement, 0)]; NSNumber *photoPrice = [NSNumber numberWithInt:(int)sqlite3_column_int(sqlStatement, 6)]; char *productNo1 = sqlite3_column_text(sqlStatement, 3); NSString* productNo; if (productNo1 == NULL) productNo = nil; else productNo = [NSString stringWithUTF8String:productNo1]; Photo *jphoto = [[[Photo alloc] initWithCaption:caption urlLarge:[NSString stringWithFormat:@"documents://%@",urlSmallImage] urlSmall:[NSString stringWithFormat:@"documents://%@",urlSmallImage] urlThumb:[NSString stringWithFormat:@"documents://%@",urlThumbImage] size:CGSizeMake(123, 123) productId:photoProductId price:photoPrice description:desc designNo:designNo productNo:productNo ] autorelease]; [photoList addObject:jphoto]; [jphoto release]; } } @catch (NSException *exception) { NSLog(@"An exception occured: %@", [exception reason]); } self.photoSource = [[[MockPhotoSource alloc] initWithType:MockPhotoSourceNormal title:[NSString stringWithFormat: @"%@",title] photos: photoList photos2:nil] autorelease]; } Memory leaks happen when calling above LoadPhotosource method again with different query... I feel its something wrong in declaring NSMutableArray (photoList), but can't figure out how to fix memory leak. Any suggestion is really appreciated.

    Read the article

  • Lockless queue implementation ends up having a loop under stress

    - by Fozi
    I have lockless queues written in C in form of a linked list that contains requests from several threads posted to and handled in a single thread. After a few hours of stress I end up having the last request's next pointer pointing to itself, which creates an endless loop and locks up the handling thread. The application runs (and fails) on both Linux and Windows. I'm debugging on Windows, where my COMPARE_EXCHANGE_PTR maps to InterlockedCompareExchangePointer. This is the code that pushes a request to the head of the list, and is called from several threads: void push_request(struct request * volatile * root, struct request * request) { assert(request); do { request->next = *root; } while(COMPARE_EXCHANGE_PTR(root, request, request->next) != request->next); } This is the code that gets a request from the end of the list, and is only called by a single thread that is handling them: struct request * pop_request(struct request * volatile * root) { struct request * volatile * p; struct request * request; do { p = root; while(*p && (*p)->next) p = &(*p)->next; // <- loops here request = *p; } while(COMPARE_EXCHANGE_PTR(p, NULL, request) != request); assert(request->next == NULL); return request; } Note that I'm not using a tail pointer because I wanted to avoid the complication of having to deal with the tail pointer in push_request. However I suspect that the problem might be in the way I find the end of the list. There are several places that push a request into the queue, but they all look generaly like this: // device->requests is defined as struct request * volatile requests; struct request * request = malloc(sizeof(struct request)); if(request) { // fill out request fields push_request(&device->requests, request); sem_post(device->request_sem); } The code that handles the request is doing more than that, but in essence does this in a loop: if(sem_wait_timeout(device->request_sem, timeout) == sem_success) { struct request * request = pop_request(&device->requests); // handle request free(request); } I also just added a function that is checking the list for duplicates before and after each operation, but I'm afraid that this check will change the timing so that I will never encounter the point where it fails. (I'm waiting for it to break as I'm writing this.) When I break the hanging program the handler thread loops in pop_request at the marked position. I have a valid list of one or more requests and the last one's next pointer points to itself. The request queues are usually short, I've never seen more then 10, and only 1 and 3 the two times I could take a look at this failure in the debugger. I thought this through as much as I could and I came to the conclusion that I should never be able to end up with a loop in my list unless I push the same request twice. I'm quite sure that this never happens. I'm also fairly sure (although not completely) that it's not the ABA problem. I know that I might pop more than one request at the same time, but I believe this is irrelevant here, and I've never seen it happening. (I'll fix this as well) I thought long and hard about how I can break my function, but I don't see a way to end up with a loop. So the question is: Can someone see a way how this can break? Can someone prove that this can not? Eventually I will solve this (maybe by using a tail pointer or some other solution - locking would be a problem because the threads that post should not be locked, I do have a RW lock at hand though) but I would like to make sure that changing the list actually solves my problem (as opposed to makes it just less likely because of different timing).

    Read the article

  • The best JSF coding pattern for editing JPA entities using @RequestScoped only

    - by AlanObject
    I am in a project where I will write a lot of pages like this, so I want to use the most efficient (to write) coding pattern. Background: In the past I have used CODI's @ViewAccessScoped to preserve state between requests, and more recently I have started using flash scoped objects to save state. I can't use JSF @ViewScoped because I use CDI and they don't play well together. So I want to see if I can do this with only @RequestScoped backing beans. The page is designed like this (the p namespace is Primefaces): <f:metadata> <f:viewParam name="ID" value="#{backing.id}" /> </f:metadata> .... <h1>Edit Object Page</h1> <h:form id="formObj" rendered="#{backing.accessOK}"> <p:panelGrid columns="2"> <h:outputLabel value="Field #1:"/> <p:inputText value="#{backing.record.field1}" /> (more input fields) <h:outputLabel value="Action:" /> <h:panelGroup> <p:commandButton value="Save" action="#{backing.save}" /> <p:commandButton value="Cancel" action="backing.cancel" /> </h:panelGroup> </p:panelGrid> <p:messages showDetail="true" showSummary="true" /> </h:form> If the page is requested, the method accessOK() has the ability to keep the h:form from being rendered. Instead, the p:messages is shown with whatever FacesMessage(s) the accessOK() method cares to set. The pattern for the bean backing looks like this: @Named @RequestScoped public class Backing { private long id; private SomeJPAEntity record; private Boolean accessOK; public long getId() { return id; } public void setId(long value) { id = value; } public boolean accessOK() { if (accessOK != null) return accessOK; if (getRecord() == null) { // add a FacesMessage that explains the record // does not exist return accessOK = false; // note single = } // do any other access checks, such as write permissions return accessOK = true; } public SomeJPAEntity getRecord() { if (record != null) return record; if (getId() > 0) record = // get the record from DB else record = new SomeJPAEntity(); return record; } public String execute() { if (!accessOK()) return null; // bad edit // do other integrity checks here. If fail, set FacesMessages // and return null; if (getId() > 0) // merge the record back into the data base else // persist the record } } Here is what goes wrong with this model. When the Save button is clicked, a new instance of Backing is built, and then there are a lot of calls to the getRecord() getter before the setID() setter is called. So the logic in getRecord() breaks because it cannot rely on the id property being valid when it is called. When this was a @ViewAccessScoped (or ViewScoped) backing bean, then both the id and record properties are already set when the form is processed with the commandButton. Alternatively you can save those properties in flash storage but that has its own problems I want to avoid. So is there a way to make this programming model work within the specification?

    Read the article

< Previous Page | 821 822 823 824 825 826 827 828 829 830 831 832  | Next Page >