pthread_rwlock_tryrdlock()
QNX SDP8.0C Library ReferenceAPIDeveloper
Attempt to acquire a shared lock on a read-write lock
Synopsis:
#include <pthread.h>
int pthread_rwlock_tryrdlock(
pthread_rwlock_t* rwl );
Arguments:
- rwl
- A pointer to a pthread_rwlock_t object that you want to lock for reading.
Library:
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
Description:
The pthread_rwlock_tryrdlock() function attempts to acquire a shared lock on the read-write lock referenced by rwl. If the read-write lock is already exclusively locked by any thread (including the calling thread), the function returns immediately instead of blocking until a read lock can be obtained.
Returns:
- EOK
- Success.
- EAGAIN
- On the first use of a statically initialized read-write lock, insufficient system resources existed to initialize the read-write lock.
- EBUSY
- The read-write lock was already write locked.
- EDEADLK
- The calling thread already has an exclusive lock for rwl.
- EFAULT
- A fault occurred when the kernel tried to access rwl.
- EINVAL
- The read-write lock rwl is invalid.
Classification:
| Safety: | |
|---|---|
| Cancellation point | No |
| Signal handler | Yes |
| Thread | Yes |
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