pthread_mutex_wakeup_np()
QNX SDP8.0C Library ReferenceAPIDeveloper
Unblock any threads that are waiting on a mutex
Synopsis:
#include <pthread.h>
int pthread_mutex_wakeup_np( pthread_mutex_t * mutex,
pid_t pid,
pthread_t tid );
Arguments:
- mutex
- A pointer to the pthread_mutex_t object for which you want to wake up any waiting threads.
- pid
- The ID of a specific process whose thread or threads you want to unblock, or 0 to unblock a specific thread in the current process (if tid isn't 0) or all threads for all processes (if tid is 0).
- tid
- The ID of a thread in the specified process that you want to unblock, or 0 to unblock all threads.
Library:
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
Description:
The pthread_mutex_wakeup_np() function unblocks any threads
that are waiting on the specified mutex, provided that
PTHREAD_WAKEUP_ENABLE is set in the mutex attributes (see
pthread_mutexattr_setwakeup_np()).
The np
in this function's name stands for non-POSIX.
The waiting threads' call to pthread_mutex_lock() for returns with an error code of EINTR, which is a non-POSIX return code for this function.
Returns:
- EOK
- Success.
- EINVAL
- One of the following:
- The mutex doesn't exist.
- The PTHREAD_WAKEUP_ENABLE flag wasn't set for the mutex.
- You gave a specific thread ID, and that thread isn't blocked on the mutex.
- ESRCH
- The specified process and thread couldn't be found.
Classification:
| Safety: | |
|---|---|
| Cancellation point | No |
| Signal handler | Yes |
| Thread | Yes |
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