Attempt to lock a mutex
Synopsis:
#include <pthread.h>
int pthread_mutex_trylock( pthread_mutex_t* mutex );
Arguments:
- mutex
- A pointer to the pthread_mutex_t object that you want to
try to lock.
Library:
libc
Use the -l c option to
qcc
to link against this library.
This library is usually included automatically.
Description:
The pthread_mutex_trylock() function attempts to lock the mutex
mutex, but doesn't block the calling thread if the mutex is
already locked.
Returns:
- EOK
- Success.
- EAGAIN
- The mutex couldn't be acquired because the maximum number of recursive locks for mutex has been exceeded.
- EBUSY
- The mutex was already locked.
- EINVAL
- One of the following occurred:
- The mutex was created with a protocol attribute of
PTHREAD_PRIO_PROTECT, and the calling thread's priority
is higher than the mutex's current priority ceiling.
- The mutex is invalid, or it has died (see
SyncMutexEvent()).
- ENOTRECOVERABLE
- The mutex is a robust mutex, and the state that it protects isn't recoverable.
All you can do with the mutex is destroy it by calling
pthread_mutex_destroy().
- EOWNERDEAD
- The mutex is a robust mutex and the process containing the previous owning thread
terminated while holding the mutex lock.
The calling thread acquires the mutex lock; it's up to the new owner to make the state consistent (see
pthread_mutex_consistent()).
Classification:
POSIX 1003.1
| Safety: |
|
|---|
| Cancellation point |
No |
| Interrupt handler |
No |
| Signal handler |
Yes |
| Thread |
Yes |