Search Results

Search found 88840 results on 3554 pages for 'code complexity'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 1027/3554 | < Previous Page | 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034  | Next Page >

  • does PHP 5.3 change the way file_get_contents works?

    - by ceejayoz
    I'm having an odd issue with PHP's file_get_contents. In the past, file_get_contents on a remote file returns the text of that file regardless of the HTTP status code returned. If I hit an API and it sends back JSON error information with a status of 500, file_get_contents gives me that JSON (with no indication that an error code was encountered). I've just set up a Ubuntu 10.04 server, which is the first Ubuntu to have PHP 5.3. Instead of giving me the JSON, PHP throws a warning when a 500 error is present. As a result, I can't parse the JSON and give a nice error message. It's nice that PHP is noticing there's an error in the remote file, but I need the JSON even (especially!) if there's a 500 error. There doesn't appear to be any way to switch this off. Has anyone encountered this? Any tips?

    Read the article

  • Which is better? private static vs private

    - by KiD0M4N
    In this code sample: public class SuperMan { private static bool IsProper(decimal x) { return x > 31.0m && x < 45.0m; } public bool CheckStuff(string a, string b, string c) { // lots of code, some of which introduces a variable x return IsProper(x) && /* other conditions */; } } Should IsProper(..) be a 'private static' or a 'private'. Assuming: IsProper(..) doesn't need to access any instance state.

    Read the article

  • Why javascript IF only works one time?

    - by Emily
    I have javascript code which copy the value of input file and past it in the text box in real time. <script> function copyit(){ var thephoto=document.getElementById('thephoto').value; var fileonchange=document.getElementById('fileonchange').value; if(!thephoto==fileonchange){ document.getElementById('fileonchange').value=thephoto; } } window.setInterval("copyit()", 500); </script> Choose File : <input type="file" id="thephoto"><br> Here Is the file name : <input type="text" id="fileonchange"> Sadly this only works one time and then stops pasting the value when changing the file again. ( i mean you should reload the page to works again) Is IF has a cache or something? you can try the code by yourself to see. Thank you all

    Read the article

  • Why do I get rows of zeros in my 2D fft?

    - by Nicholas Pringle
    I am trying to replicate the results from a paper. "Two-dimensional Fourier Transform (2D-FT) in space and time along sections of constant latitude (east-west) and longitude (north-south) were used to characterize the spectrum of the simulated flux variability south of 40degS." - Lenton et al(2006) The figures published show "the log of the variance of the 2D-FT". I have tried to create an array consisting of the seasonal cycle of similar data as well as the noise. I have defined the noise as the original array minus the signal array. Here is the code that I used to plot the 2D-FT of the signal array averaged in latitude: import numpy as np from numpy import ma from matplotlib import pyplot as plt from Scientific.IO.NetCDF import NetCDFFile ### input directory indir = '/home/nicholas/data/' ### get the flux data which is in ### [time(5day ave for 10 years),latitude,longitude] nc = NetCDFFile(indir + 'CFLX_2000_2009.nc','r') cflux_southern_ocean = nc.variables['Cflx'][:,10:50,:] cflux_southern_ocean = ma.masked_values(cflux_southern_ocean,1e+20) # mask land nc.close() cflux = cflux_southern_ocean*1e08 # change units of data from mmol/m^2/s ### create an array that consists of the seasonal signal fro each pixel year_stack = np.split(cflux, 10, axis=0) year_stack = np.array(year_stack) signal_array = np.tile(np.mean(year_stack, axis=0), (10, 1, 1)) signal_array = ma.masked_where(signal_array > 1e20, signal_array) # need to mask ### average the array over latitude(or longitude) signal_time_lon = ma.mean(signal_array, axis=1) ### do a 2D Fourier Transform of the time/space image ft = np.fft.fft2(signal_time_lon) mgft = np.abs(ft) ps = mgft**2 log_ps = np.log(mgft) log_mgft= np.log(mgft) Every second row of the ft consists completely of zeros. Why is this? Would it be acceptable to add a randomly small number to the signal to avoid this. signal_time_lon = signal_time_lon + np.random.randint(0,9,size=(730, 182))*1e-05 EDIT: Adding images and clarify meaning The output of rfft2 still appears to be a complex array. Using fftshift shifts the edges of the image to the centre; I still have a power spectrum regardless. I expect that the reason that I get rows of zeros is that I have re-created the timeseries for each pixel. The ft[0, 0] pixel contains the mean of the signal. So the ft[1, 0] corresponds to a sinusoid with one cycle over the entire signal in the rows of the starting image. Here are is the starting image using following code: plt.pcolormesh(signal_time_lon); plt.colorbar(); plt.axis('tight') Here is result using following code: ft = np.fft.rfft2(signal_time_lon) mgft = np.abs(ft) ps = mgft**2 log_ps = np.log1p(mgft) plt.pcolormesh(log_ps); plt.colorbar(); plt.axis('tight') It may not be clear in the image but it is only every second row that contains completely zeros. Every tenth pixel (log_ps[10, 0]) is a high value. The other pixels (log_ps[2, 0], log_ps[4, 0] etc) have very low values.

    Read the article

  • Unable to set relative path for flash file in ASP.NET MVC using AC_FL_RunContent

    - by Mahesh
    Hi, I have a website using asp.net mvc in which I need to embed a flash file in view. I am unable to set the relative path for the flash file. Given below is the code I am using: AC_FL_RunContent( 'codebase', 'http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=7,0,19,0', 'width', '487', 'height', '359', 'menu', 'false', 'movie', 'images/butterfly', 'quality', 'high', 'allowscriptaccess', 'sameDomain', 'pluginspage', 'http://www.macromedia.com/go/getflashplayer' ); where I copied butterfly.swf in a directory called images. images directory resides in the views folder. If I use code behind( default.aspx default.aspx.cs) in a different solution with the same folder strucuture, browser is able to load the flash file. Could you please throw some light on the MVC folder structure issue?? Thanks a lot. Mahesh

    Read the article

  • VB.net Excel sorting

    - by Lora
    I am trying to get a macro convert from VBA over to vb.net and I am getting a type mismatched error and can't figure it out. I am hoping someone here will be able to help me. This is the code. Sub SortRawData() Dim oSheet As Excel.Worksheet Dim oRange As Excel.Range Try oSheet = SetActiveSheet(mLocalDocument, "Sheet 1") oRange = mApplication.ActiveSheet.UsedRange oRange.Sort(Key1:=oRange("J2"), Order1:=Excel.XlSortOrder.xlAscending, _ Header:=Excel.XlYesNoGuess.xlYes, OrderCustom:=1, MatchCase:=False, _ Orientation:=Excel.XlSortOrientation.xlSortColumns, _ DataOption1:=Excel.XlSortDataOption.xlSortNormal, _ DataOption2:=Excel.XlSortDataOption.xlSortNormal, _ DataOption3:=Excel.XlSortDataOption.xlSortNormal) Catch ex As Exception ErrorHandler.HandleError(ex.Message, ex.Source, ex.StackTrace) End Try End Sub This is the code from the macro Sub SortRawData(ByRef poRange As Range) Set poRange = Application.ActiveSheet.UsedRange poRange.Sort Key1:=Range("J2"), Order1:=xlAscending _ , Header:=xlYes, OrderCustom:=1, MatchCase:=False, Orientation:= _ xlTopToBottom, DataOption1:=xlSortNormal, DataOption2:=xlSortNormal, _ DataOption3:=xlSortNormal poRange.Sort Key1:=Range("D2"), Order1:=xlAscending, _ Key2:=Range("H2"), Order2:=xlAscending, _ Key3:=Range("L2"), Order3:=xlAscending, _ Header:=xlYes, OrderCustom:=1, MatchCase:=False, Orientation:= _ xlTopToBottom, DataOption1:=xlSortNormal, DataOption2:=xlSortNormal, _ DataOption3:=xlSortNormal End Sub Any help would be appreciated. Thanks!

    Read the article

  • System.IndexOutOfRange Exception Sending Gridview Values to DataTable

    - by SidC
    Hello, I am writing an ASP.NET 3.5 application and need to send gridview values to a datatable for use in a listbox control as part of a quote process. I have written the following VB code in my Page_Load: Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load Dim dtSelParts As DataTable = New DataTable("dtSelParts") Dim column As DataColumn = New DataColumn column.ColumnName = "PartName" column.ColumnName = "PartNumber" column.ColumnName = "Quantity" dtSelParts.Columns.Add(column) For Each row As GridViewRow In MySearch.Rows Dim drSelParts As DataRow drSelParts = dtSelParts.NewRow() For i As Integer = 0 To row.Cells.Count - 1 drSelParts(i) = row.Cells(i).Text Next Next End Sub When I run the partsearch.aspx page, I enter values in the row textbox for parts I want included in the listbox (to be included in quote). However, I receive the error message System.Index.OutOfRangeException: Cannot find column 1 which occurs on the line drSelParts(i) = row.Cells(i).Text. How might I correct the code and resolve the error? Thanks, Sid

    Read the article

  • How do you balance business process changes against the challenges of changing software?

    - by Achilles
    In my admittedly young career I've found myself writing code to support quirky business rules and processes. Inevitably these changes were always in some massively difficult code base and caused many issues. My question has a couple of parts: While software is a tool for businesses to make their lives easier, at what point do we as developers suggest a change in business process rather than in the software as the "magic bullet" to solve a particular problem. How do we as developers evangelize a certain level of reverence for the software as well as the difficulty involved in making changes simply to support the quirks of the business? I understand that these changes in business processes promote our industry, but in an analogy my father would understand: Which is easier, to melt down a hammer to forge a screwdriver to drive screws or to simply use nails since your hammer is already awesome...?

    Read the article

  • Long Running Stored Proc - Report Progress Using BackgroundWorker & Timer

    - by daveywc
    While a long running stored proc (RMR_Seek) is executing (called via a Linq-To-SQL data context) I am trying to call another stored proc (RMR_GetLatestModelMessage) to check a table for the latest status message. The long running stored proc updates the table in question with status messages as it executes. I want to display the status message on a message panel to advise the user of the status of the execution of Proc_A. For various reasons it is not possible to determine how long RMR_Seek will take to execute so a progress bar with percentage increments is not feasible. I thought I'd found the way to do it by calling the long running stored proc from in a BackgroundWorker process DoWork event handler. This worked fine and allowed me to update my message panel with some dummy status messages that were NOT obtained via Proc_B while Proc_A was running. However now that I have tried to implement this fully by calling Proc_B to obtain the status messages I am running into problems that seem to be related to the mix of the backgroundworker and my System.Windows.Forms.Timer. An extract of the code I am using is below. I have tried many different ways around this but each one seems to present its own set of problems. The code below is problematic in the bw_DoWork event. The RMR_Seek stored proc gets called but does not execute properly - it also seems to be inconsistent as to whether _IsCompleted gets set to true. I'm sure there is a better way to achieve what I am trying to do. private bool _IsCompleted; private void RunRevenueSeek() { if (_SelectedModel == null) { MessageBox.Show("Please select a model from the list and try again.", "Model Generation", MessageBoxButtons.OK, MessageBoxIcon.Information); } else { var bw = new BackgroundWorker(); bw.DoWork += new DoWorkEventHandler(bw_DoWork); ProgressPanelControl.Visible = true; _IsCompleted = false; MessageTimer.Start(); // Has an interval of 3000 bw.RunWorkerAsync(); ProgressLabelControl.Text = "Refreshing Data"; this.Update(); ...more code goes here } } private void bw_DoWork(object sender, DoWorkEventArgs e) { using (var dc = new RevMdlrDataClassesDataContext()) { dc.CommandTimeout = 300; dc.RMR_Seek(_SelectedModel.ModelSet_ID); _IsCompleted = true; } } private void MessageTimer_Tick(object sender, EventArgs e) { string message = ""; if (_IsCompleted) { MessageTimer.Stop(); } else { using (var dc = new RevMdlrDataClassesDataContext()) { dc.CommandTimeout = 300; dc.RMR_GetLatestModelMessage(_SelectedModel.ModelSet_ID, ref message); ProgressLabelControl.Text = message; this.Update(); } } }

    Read the article

  • Importing Python module from the Bash

    - by Morlock
    I am launching a Python script from the command line (Bash) under Linux. I need to open Python, import a module, and then have lines of code interpreted. The console must then remain in Python (not quit it). How do I do that? I have tried an alias like this one: alias program="cd /home/myname/programs/; python; import module; line_of_code" But this only starts python and the commands are not executed (no module import, no line of code treated). What is the proper way of doing this, provided I need to keep Python open (not quit it) after the script is executed? Many thanks.

    Read the article

  • Mercurial for Beginners: The Definitive Practical Guide

    - by Laz
    Inspired by Git for beginners: The definitive practical guide. This is a compilation of information on using Mercurial for beginners for practical use. Beginner - a programmer who has touched source control without understanding it very well. Practical - covering situations that the majority of users often encounter - creating a repository, branching, merging, pulling/pushing from/to a remote repository, etc. Notes: Explain how to get something done rather than how something is implemented. Deal with one question per answer. Answer clearly and as concisely as possible. Edit/extend an existing answer rather than create a new answer on the same topic. Please provide a link to the the Mercurial wiki or the HG Book for people who want to learn more. Questions: Installation/Setup How to install Mercurial? How to set up Mercurial? How do you create a new project/repository? How do you configure it to ignore files? Working with the code How do you get the latest code? How do you check out code? How do you commit changes? How do you see what's uncommitted, or the status of your current codebase? How do you destroy unwanted commits? How do you compare two revisions of a file, or your current file and a previous revision? How do you see the history of revisions to a file? How do you handle binary files (visio docs, for instance, or compiler environments)? How do you merge files changed at the "same time"? Tagging, branching, releases, baselines How do you 'mark' 'tag' or 'release' a particular set of revisions for a particular set of files so you can always pull that one later? How do you pull a particular 'release'? How do you branch? How do you merge branches? How do you merge parts of one branch into another branch? Other Good GUI/IDE plugin for Mercurial? Advantages/disadvantages? Any other common tasks a beginner should know? How do I interface with Subversion? Other Mercurial references Mercurial: The Definitive Guide Mercurial Wiki Meet Mercurial | Peepcode Screencast

    Read the article

  • VisualBasic.net Database Boiler Plate

    - by Shiftbit
    Is there any built in .net Classes to assist in the reduction of boiler plate code? I have numerous database operations going on and I find that I am reproducing the connection, command, transaction and occassianlly data set. I am aware of the Java Related Question, however, the solutions pertain to Java. I was wondering if anyone was aware of a .net solution? http://stackoverflow.com/questions/1072925/remove-boilerplate-from-db-code Public Sub ReadData(ByVal connectionString As String) Dim queryString As String = "SELECT EmpNo, EName FROM Emp" Using connection As New OracleConnection(connectionString) Dim command As New OracleCommand(queryString, connection) connection.Open() Using reader As OracleDataReader = command.ExecuteReader() ' Always call Read before accessing data. While reader.Read() Console.WriteLine(reader.GetInt32(0).ToString() + ", " _ + reader.GetString(1)) End While End Using End Using End Sub MSDN

    Read the article

  • First ASM program

    - by Tal
    Hello, I'm trying to run my first ASM 8086 program on MASM on Windows Vista 64bit OS. I put this program on my MASM editor: .model small .stack .data message db "Hello world, I'm learning Assembly !!!", "$" .code main proc mov ax,seg message mov ds,ax mov ah,09 lea dx,message int 21h mov ax,4c00h int 21h main endp end main and the MASM editor gives me this output that I got no idea what's wrong with the program: Assembling: D:\masm32\First.asm D:\masm32\First.asm(9) : error A2004: symbol type conflict D:\masm32\First.asm(19) : warning A4023: with /coff switch, leading underscore required for start address : main _ Assembly Error Where is the problem with this code? This is my first ASM program please remember. Thank you :)

    Read the article

  • jquery.ajax multiple data problem

    - by Guillaume P
    Hi, I've been trying to make this code work for the last 3 hours. I've tried about everytinh, but I'm still unable to get it to work. I only managed to send 1 data. When I use this code, I only manage to retrieve recaptcha_challenge_field. If I remove recaptcha_challenge_field, I retrieve recaptcha_response_field. However, I am unable to retrieve the two at the same time. challengeField = $("#recaptcha_challenge_field").val(); responseField = $("#recaptcha_response_field").val(); var html = $.ajax( { global: false, type: "POST", async: false, dataType: "html", data: "recaptcha_response_field=" + responseField + "&recaptcha_challenge_field=" + challengeField, url: "../ajax.recaptcha.php" }).responseText; if(html == "success") { $("#captchaStatus").html("Success. Submitting form."); return true; } else { $("#captchaStatus").html("Your captcha is incorrect. Please try again"); Recaptcha.reload(); return false; }

    Read the article

  • Query data using LINQ to SQL and Entity Framework with foreign key? (Help me please)

    - by The Wind
    Hello! There is a problem I need help with your query on the data using LINQ to SQL and Entity Framework (I'm using Visual Studio 2010). My picure here: http://img.tamtay.vn/files/photo2/2010/5/28/10/962/4bff3a3b_1093f58f_untitled-1.gif I have three tables: tbl NewsDetails tblNewsCategories tblNewsInCategories (See screen 1 in my picture) Now, I want to retrieve records in the tblNewsDetails table, with condition: CategoryId=1, as the following results: (See screen 2 in my picture) But NewsID and CategoryId in tblNewsInCategories table is two foreign key, I do not see them and I do not know how to use them in your code. My code has errors: (See screen 3 in my picture) Please help me. Thanks! (I am a new member, should not have the right to insert images)

    Read the article

  • Dynamically loading CSS and JavaScript using Prototype

    - by Salman A
    I have a classic ASP application that I've been constantly trying to modularize. Currently, almost all pages are divided in to two pages: an outer page that contains the layout, header, sidebar, footer an inner page that contains ASP code The outer pages use dreamweaver templates so updating layout and replicating changes is easy. The inner pages are managed by me. Now here is the problem: I had to add a lightbox to one page, I chose Lightbox 2 which requires Prototype. I ended up adding Prototype on every page, assuming that sooner or later I'll upgrade all pages, forms, ajax requests and other javascript to use Prototype. I've now added two other plugins -- Modalbox and Protofade; each with a pair of .JS and .CSS files. Since I'll be using these three plugins on specific set of pages I am wondering if I can load the required CSS and JS files dynamically. I do not want to access the document head and add include files there, I'll have to do this from inside a DIV where all ASP code is supposed to go.

    Read the article

  • Can someone explain me implicit conversions in Scala?

    - by Oscar Reyes
    And more specifically how does the BigInt works for convert int to BigInt? In the source code it reads: ... implicit def int2bigInt(i: Int): BigInt = apply(i) ... How is this code invoked? I can understand how this other sample: "Date literals" works. In. val christmas = 24 Dec 2010 Defined by: implicit def dateLiterals(date: Int) = new { import java.util.Date def Dec(year: Int) = new Date(year, 11, date) } When int get's passed the message Dec with an int as parameter, the system looks for another method that can handle the request, in this case Dec(year:Int) Q1. Am I right in my understanding of Date literals? Q2. How does it apply to BigInt? Thanks

    Read the article

  • PHP - How to modify multi-dimensional array item from within a function?

    - by Marc
    My problem is as follows. I have a multidimensional array. I declare my array. Then, I run some code that populates my array partially. Then i run a function, which among others is supposed to modify some item in my array from within the function. This is unfortunately not working. So my question is simple. Is it normal? And if yes, how can I overcome this. Thank you very much in advance for your replies. Cheers. Marc. $list = array([0]=> array( [name]=>'James' [group]=>'' ) ); my_function(); print_r($list); function my_function(){ //some code here $list[0]['group'] = 'groupA'; }

    Read the article

  • How do you use vim's quickfix feature?

    - by hora
    I'm a pretty new Vim user and I've found that its learning curve is quite steep (at least for me). I just installed this vim script for JavaScriptLint error checking, which shows errors in vim's quickfix window once I save a buffer. However, I don't know what to do next.. How do I 'scroll' through all the errors? How do I close the quickfix 'window'? How do I get it to check for errors after I've made changes to my code? I've looked at the vim quickfix docs but the amount of commands are overwhelming and I can't seem to find what I want. Any help would be appreciated. A side question: is there any way to have javascriptlint check for js errors for code residing in a .html file? Thanks!

    Read the article

  • Adding custom filter in spring framework problem?

    - by user298768
    hello there iam trying to make a custom AuthenticationProcessingFilter to save some user data in the session after successful login here's my filter: Code: package projects.internal; import java.io.IOException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.security.Authentication; import org.springframework.security.ui.webapp.AuthenticationProcessingFilter; public class MyAuthenticationProcessingFilter extends AuthenticationProcessingFilter { protected void onSuccessfulAuthentication(HttpServletRequest request, HttpServletResponse response, Authentication authResult) throws IOException { super.onSuccessfulAuthentication(request, response, authResult); request.getSession().setAttribute("myValue", "My value is set"); } } and here's my security.xml file Code: <beans:beans xmlns="http://www.springframework.org/schema/security" xmlns:beans="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.0.xsd"> <global-method-security pre-post-annotations="enabled"> </global-method-security> <http use-expressions="true" auto-config="false" entry-point-ref="authenticationProcessingFilterEntryPoint"> <intercept-url pattern="/" access="permitAll" /> <intercept-url pattern="/images/**" filters="none" /> <intercept-url pattern="/scripts/**" filters="none" /> <intercept-url pattern="/styles/**" filters="none" /> <intercept-url pattern="/p/login.jsp" filters="none" /> <intercept-url pattern="/p/register" filters="none" /> <intercept-url pattern="/p/**" access="isAuthenticated()" /> <form-login login-processing-url="/j_spring_security_check" login-page="/p/login.jsp" authentication-failure-url="/p/login_error.jsp" /> <logout /> </http> <authentication-manager alias="authenticationManager"> <authentication-provider> <jdbc-user-service data-source-ref="dataSource"/> </authentication-provider> </authentication-manager> <beans:bean id="authenticationProcessingFilter" class="projects.internal.MyAuthenticationProcessingFilter"> <custom-filter position="AUTHENTICATION_PROCESSING_FILTER" /> </beans:bean> <beans:bean id="authenticationProcessingFilterEntryPoint" class="org.springframework.security.ui.webapp.AuthenticationProcessingFilterEntryPoint"> </beans:bean> </beans:beans> it gives an error here: Code: <custom-filter position="AUTHENTICATION_PROCESSING_FILTER" /> multiple annotation found at this line:cvc-attribute.3 cvc-complex-type.4 cvc-enumeration-vaild what is the problem? thanks in advance

    Read the article

  • Create iPhone app programmatically, in its entirety

    - by miorel
    I recently became interested in iPhone app development, so I've been looking at online tutorials, and also reading a book, trying out the examples as I go along. I'm getting better, but one of the things I still find quite annoying about the usual development model is that I really have no idea what the SDK is really doing behind the scenes to make the app "work" because Apple protects me from this. For example, when I make connections on interface builder, this presumably corresponds to code being generated somewhere... Where that code is and what it does and how it works are not obvious (to me). So I'm wondering, is it possible to create an iPhone app entirely programmatically? That is, have execution start in some main method, which will then programmatically create any views, register event listeners, etc. And if yes, what are some good resources for something like this?

    Read the article

  • dynamically created datagridview columns not accessible unless added to a form...why?

    - by deostroll
    We simply created a DataGridView control dynamically and bound it to a DataTable. We were tying to style certain columns. But, when we tried to access the columns we got a null reference. On further investigation we found that if we add the DataGridView control to the main form, and then try to access its columns, it works fine!!! Code which throws error: DataGridView gv = new DataGridView(); gv.DataSource = GetDataTable(); //binding it to datatable Debug.Assert(gv.Columns == null); Code which works fine: DataGridView gv = new DataGridView(); gv.DataSource = GetDataTable(); //binding it to datatable this.Controls.Add(gv); //adding to form Debug.Assert(gv.Columns == null); //the assertion fails! Why is this behaviour so? Is there a workaround for this?

    Read the article

  • How to show that the double-checked-lock pattern with Dictionary's TryGetValue is not threadsafe in

    - by Amir
    Recently I've seen some C# projects that use a double-checked-lock pattern on a Dictionary. Something like this: private static readonly object _lock = new object(); private static volatile IDictionary<string, object> _cache = new Dictionary<string, object>(); public static object Create(string key) { object val; if (!_cache.TryGetValue(key, out val)) { lock (_lock) { if (!_cache.TryGetValue(key, out val)) { val = new object(); // factory construction based on key here. _cache.Add(key, val); } } } return val; } This code is incorrect, since the Dictionary can be "growing" the collection in _cache.Add() while _cache.TryGetValue (outside the lock) is iterating over the collection. It might be extremely unlikely in many situations, but is still wrong. Is there a simple program to demonstrate that this code fails? Does it make sense to incorporate this into a unit test? And if so, how?

    Read the article

  • sending instant messages through python (msn)

    - by code_by_night
    ok I am well aware there are many other questions about this, but I have been searching and have yet to find a solid proper answer that doesnt revolve around jabber or something worse. (no offense to jabber users, just I don't want all the extras that come with it) I currently have msnp and twisted.words, I simply want to send and receive messages, have read many examples that have failed to work, and msnp is poorly documented. My preference is msnp as it requires much less code, I'm not looking for something complicated. Using this code I can login, and view my friends that are online (can't send them messages though.): import msnp import time, threading msn = msnp.Session() msn.login('[email protected]', 'XXXXXX') msn.sync_friend_list() class MSN_Thread(threading.Thread): def run(self): msn.start_chat("[email protected]") #this does not work while True: msn.process() time.sleep(1) start_msn = MSN_Thread() start_msn.start() I hope I have been clear enough, its pretty late and my head is not in a clear state after all this msn frustration. edit: since it seems msnp is extremely outdated could anyone recommend with simple examples on how I could achieve this? Don't need anything fancy that requires other accounts.

    Read the article

  • What is the C# equivalent of java.util.regex?

    - by peter.murray.rust
    I am converting Java code to C# and need to replace the use of Java's regex. A typical use is import java.util.regex.Matcher; import java.util.regex.Pattern; //... String myString = "B12"; Pattern pattern = Pattern.compile("[A-Za-z](\\d+)"); Matcher matcher = Pattern.matcher(myString); String serial = (matcher.matches()) ? matcher.group(1) : null; which should extract a capture group from a matched target string. I'd be grateful for simple examples. EDIT: I have now added the C# equivalent of the code as an answer. EDIT: Here is a tutorial on the use of the actual expressions. EDIT: Here is a useful comparison of C# and Java (and Perl.)

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034  | Next Page >