The function "WaitThread()" is freezing the calling program!

[Maya]

Hello..
In the following Dll code, I wrote the function "WaitThread()" but it freezing the calling program & keep it in the "Windows Task Manager" forever!
Is there any explanation?
Thank you.

Code: Select all

ProcedureDLL DoSomeThing(Num)
  ; Do something ...
EndProcedure

ProcedureDLL AttachProcess(Instance)
  DllThread.l = CreateThread (@DoSomeThing(), 0)
  WaitThread(DllThread)           ; <<< Causes the Program to freeze in the "Windows Task Manager" forever!
EndProcedure

[skywalk]

timeout

[Maya]

timeout

I tried "Timeout", but it didn't work when it comes in a Dll:

Code: Select all

ProcedureDLL DoSomeThing(Interval.l)
  ; Do something ...
EndProcedure

ProcedureDLL AttachProcess(Instance)
  DllThread.l = CreateThread (@DoSomeThing(), 1000)
  WaitThread(DllThread)       ; <<< Causes the Program to freeze in the Tasklist 
EndProcedure

[DarkDragon]

timeout

I tried "Timeout", but it didn't work when it comes in a Dll:

Code: Select all

ProcedureDLL DoSomeThing(Interval.l)
  ; Do something ...
EndProcedure

ProcedureDLL AttachProcess(Instance)
  DllThread.l = CreateThread (@DoSomeThing(), 1000)
  WaitThread(DllThread)       ; <<< Causes the Program to freeze in the Tasklist 
EndProcedure

WaitThread blocks the process until DoSomething() returns. AttachProcess is being launched from the main thread, so all GUI and stuff will hang until the thread is done. May I ask, why would you wait for the thread to be done at this point?

[skywalk]

Well, to be honest, I only use waitthread() upon exiting my applications where I want to shutdown any threads.
I have not used it within a dll context.
I use semaphores and mutex to communicate and control running threads.
WaitThread() was not stable for me.

[User_Russian]

https://learn.microsoft.com/en-us/windo ... -practices

[Maya]

WaitThread blocks the process until DoSomething() returns. AttachProcess is being launched from the main thread, so all GUI and stuff will hang until the thread is done. May I ask, why would you wait for the thread to be done at this point?

Hi Daniel,
Yes, my program is get lost only when this function written inside AttachProcess().
I'm working on a new program that hide certain type of files using kernel mini-filter.
Any solution for how to wait for a thread inside a Dll?

[DarkDragon]

WaitThread blocks the process until DoSomething() returns. AttachProcess is being launched from the main thread, so all GUI and stuff will hang until the thread is done. May I ask, why would you wait for the thread to be done at this point?

Hi Daniel,
Yes, my program is get lost only when this function written inside AttachProcess().
I'm working on a new program that hide certain type of files using kernel mini-filter.
Any solution for how to wait for a thread inside a Dll?

Why do you wait or better said: why do you use a thread if you wait for it anyway? You need to solve your problem differently, if you need so much time in your thread to make it hang. What do you do exactly in your thread?

[Maya]

Why do you wait or better said: why do you use a thread if you wait for it anyway? You need to solve your problem differently, if you need so much time in your thread to make it hang. What do you do exactly in your thread?

I'm using the Thread because I need to separate the Thread task when executable run.
Executable need to wait the Thread to be completed before proceeding ahead.

"AttachProcess()" is the ideal place to put the "WaitThread()", but unfortunately, when the Thread is completed, it doesn't allow executable to continue running, but only freezing it inside the Windows Task Manager.
If you don't have the solution, then please dismiss this subject.

[Fred]

Just as a general comment you should never use .l explicitely if not needed (most use are only in structure to reduce their size). You code probably won't work on x64 because of that.

[freak]

"AttachProcess()" is the ideal place to put the "WaitThread()", but unfortunately, when the Thread is completed, it doesn't allow executable to continue running, but only freezing it inside the Windows Task Manager.
If you don't have the solution, then please dismiss this subject.

What you are trying to do is impossible. The reason is that when a thread starts or ends it tries to call the AttachThread() and DetachThread() dll procedures (even if you do not define them in the code). However, they cannot be run as long as the AttachProcess() call you are in is not finished because only one can run at a time. So it is a classic deadlock situation.

You have to find another way to do what you want.

[Maya]

because only one can run at a time. So it is a classic deadlock situation.

Fully Understood.
Thank you fred & freak for this explanation.