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Create a block / wait function?

I am looking for a way to create a function that, like the sockets accept function,
blocks / waits untill a specific variable is set or a specific function is called.
At the moment I am using the very system expensive code:
while(!input);

I need a function that can be called inside a thread procedure to keep the thread from consuming all of the processors power.

Any ideas?

itsmeandnobodyelse

On Windows platform use

Sleep(1); // wait 1 millisecond

in your loop.

Regards, Alex

itsmeandnobodyelse

OS/2 you have to use DosSleep, and *NIX it is sleep (as far as i remember).

Regards, Alex

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itsmeandnobodyelse

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chrille_p

ASKER

Im not looking for a function that waits for a couple of seconds.
What I want is a thread-procedure (A) that waits untill function (B) is called...

I could use sleep() in my loop and check a flag every n second, but that would make
the reaction of my function slow. I want it to stop waiting and continue its work
directly when (B) is called.

/Chrille

chrille_p

ASKER

WaitForSingleObject is perfect.

Thanks!

/Chrille

grg99

Depending on the OS, there may be a Sleep() function that is calibrated in milliseconds.

Otherwise you could find some API, any API, that will do a task-switch for you.
On Windows that puts your thread to sleep for about 20-30 milliseconds, a nice ballpark sleep time.

itsmeandnobodyelse

>> Im not looking for a function that waits for a couple of seconds.

Ok, but before using

while(!input);

you should have

while(!input) { sleep(1); }

>> What I want is a thread-procedure (A) that waits untill function (B) is called...

You could use a mutex that gets locked by your main thread, then your thread is waiting on the mutex to be unlocked, what is done at the beginning of function B .

What OS are you working on?

Regards, Alex