'When does Thread.CurrentThread.Join() make sense?
What is the effect of calling Thread.CurrentThread.Join(), and if/when would it make sense to call it?
Solution 1:[1]
What is the effect of calling Thread.CurrentThread.Join()
You will block the execution of the current thread, and effectively dead lock it. It will cause the current thread to block until the current thread finishes, which will never happen.
, and if/when would it make sense to call it?
It really doesn't make sense to do this. You should never call this method in this manner.
On a side note, since you're using .NET 4, I would recommend avoiding using Thread.Join in general. Using the new Task/Task<T> classes is far nicer in many ways, as you can easily attach continuations (or always call Task.Wait() if you truly need to block).
Solution 2:[2]
Was it really
CurrentThread.Join()
that you saw in real code - which I kind of doubt, unless it's some hack to prevent other threads to join on the current thread - or was it
CurrentThread.Join(someTimeout)
The latter is equivalent to
Thread.Sleep(someTimeout)
except that joining on the current thread allows message pumping to continue if you are in a GUI / COM situation.
Solution 3:[3]
It actually make sense in world of observable. Lets say you have a queue listener in main and you want to keep main thread running forever. Instead of doing while(true) and put your code in the loop, last line you can write this. This way current thread will also be parent thread for other threads spawned within the application. Think of it as entry point for app.
Solution 4:[4]
No, CurrentThread.Join() makes no sense
This could make your program stop running, making the thread A wait for thread A for example.
Solution 5:[5]
If you are making a unit test that tests if timers perform well in lets say a Windows Service and you use Thread.Sleep() statements with more as 60 seconds in it you can get ContextSwitch errors because the Thread.Sleep() is blocking the message pump.
If you are replacing those Thread.Sleep() statements in your unit test with Thread.CurrentThread.Join() then those ContextSwitch error will go away. So its a non blocking solution.
You could say Thread.CurrentThread.Join() is a better Thread.Sleep().
Solution 6:[6]
CurrentThread.Join() can be used to put the current thread to sleep until another thread interrupts it.
For example, you may have a server where the main method sets up a pool of other threads to handle incoming requests, passes a reference to it's current thread to a shutdown-trap, and then goes to sleep until it's time for the server to shut down.
This is not a terribly common pattern but it would be wrong to say that there is no case where you'd want your current thread to sleep until interrupted.
Sources
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Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 | |
| Solution 2 | Evgeniy Berezovsky |
| Solution 3 | rohit |
| Solution 4 | Kauê Gimenes |
| Solution 5 | Herman Van Der Blom |
| Solution 6 | Andrew Rueckert |