#thread-safety

Fixed: What's the best way of implementing a thread-safe Dictionary? #solution #programming #development

What’s the best way of implementing a thread-safe Dictionary?

I was able to implement a thread-safe Dictionary in C# by deriving from IDictionary and defining a private SyncRoot object:

public class SafeDictionary: IDictionary { private readonly object syncRoot = new object(); private Dictionary d = new Dictionary(); public object SyncRoot { get { return syncRoot; } } public void Add(TKey key,…

How to: Automating the InvokeRequired code pattern

Automating the InvokeRequired code pattern

I have become painfully aware of just how often one needs to write the following code pattern in event-driven GUI code, where

private void DoGUISwitch() { // cruisin for a bruisin' through exception city object1.Visible = true; object2.Visible = false; }

becomes:

private void DoGUISwitch() { if (object1.InvokeRequired) { object1.Invoke(new…

Fixed Collection was modified; enumeration operation may not execute #dev #it #asnwer

Collection was modified; enumeration operation may not execute

I can’t get to the bottom of this error, because when the debugger is attached, it does not seem to occur. Below is the code.

This is a WCF server in a Windows service. The method NotifySubscribers is called by the service whenever there is a data event (at random intervals, but not very often – about 800 times per day).

When a…

Fixed What is thread safe or non thread safe in PHP #dev #it #asnwer

What is thread safe or non thread safe in PHP

I saw different binaries for PHP, like non thread or thread safe? What does this mean? What is the difference between these packages?

Answer: What is thread safe or non thread safe in PHP

A Thread Safe version should be used if you install PHP as an Apache module, as a Worker MPM (multi-processing model).

The Non Thread Safeversion should be used if…

How to: Is the != check thread safe?

Is the != check thread safe?

I know that compound operations such as i++ are not thread safe as they involve multiple operations.

But is checking the reference with itself a thread safe operation?

a != a //is this thread-safe

I tried to program this and use multiple threads but it didn’t fail. I guess I could not simulate race on my machine.

EDIT:

public class TestThreadSafety { private Object…

How to: How does lock work exactly?

How does lock work exactly?

I see that for using objects which are not thread safe we wrap the code with a lock like this:

private static readonly Object obj = new Object(); lock (obj) { // thread unsafe code }

So what happens when multiple threads access the same code (let’s assume that it is running in a ASP.NET web application). Are they queued? If so how long will they wait?

What is the…

How to: Collection was modified; enumeration operation may not execute

Collection was modified; enumeration operation may not execute

I can’t get to the bottom of this error, because when the debugger is attached, it does not seem to occur. Below is the code.

This is a WCF server in a Windows service. The method NotifySubscribers is called by the service whenever there is a data event (at random intervals, but not very often – about 800 times per day).

When a…

How to: What is thread safe or non thread safe in PHP

What is thread safe or non thread safe in PHP

I saw different binaries for PHP, like non thread or thread safe? What does this mean? What is the difference between these packages?

Answer: What is thread safe or non thread safe in PHP Needed background on Concurrency approaches:

Different web servers implement different techniques for handling incoming HTTP requests in parallel. A pretty popular…