PtCondWait()

Block a thread on a conditional variable

Synopsis:

int PtCondWait( pthread_cond_t *cond );

Arguments:

cond

The condition variable to wait on.

Library:

ph

Description:

PtCondWait() is an equivalent of pthread_cond_wait() that uses the Photon library lock instead of a mutex, which has the effect of an implicit PtLeave() when you block, and PtEnter() when you unblock.

The calling thread is blocked until:

• another thread performs a signal or broadcast on the condition variable (using pthread_cond_signal() or pthread_cond_broadcast())

  Or:

• a signal is delivered to the thread.

In all cases, the thread reacquires the Photon library lock before being unblocked.

Returns:

EOK

Success, or the call was interrupted by a signal.

EAGAIN

Insufficient system resources are available to wait on the condition.

EFAULT

A fault occurred trying to access the buffers provided.

EINVAL

One or more of cond or mutex is invalid.
Concurrent waits on cond used different mutexes.
The current thread doesn't own mutex.

Classification:

Photon

See also:

PtCondTimedWait(), PtEnter(), PtLeave()

pthread_cond_wait() in the QNX Library Reference

"Threads" in the Parallel Operations chapter of the Photon Programmer's Guide