pthread_mutexattr_setprioceiling()
QNX SDP8.0C Library ReferenceAPIDeveloper
Set the priority ceiling of a mutex attribute object
Synopsis:
#include <pthread.h>
int pthread_mutexattr_setprioceiling(
pthread_mutexattr_t* attr,
int prioceiling );
Arguments:
- attr
- A pointer to the pthread_mutexattr_t object that you want to set the attribute in.
- prioceiling
- The new value for the priority ceiling.
Library:
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
Description:
The pthread_mutexattr_setprioceiling() function sets the mutex attribute attr's scheduling priority ceiling to prioceiling. Note that attr must have been previously created with pthread_mutexattr_init().
Note:
- In order to change the priority ceiling to a value above the maximum permitted for unprivileged processes, your process must have the PROCMGR_AID_PRIORITY ability enabled. For more information, see procmgr_ability().
- After you set a mutex's priority ceiling, you should not try to lock that mutex from any process that has a priority that's greater than the mutex's priority ceiling. If you attempt this, the mutex locking will fail.
- Robust mutexes amd mutexes with priority ceilings use more system resources than other mutexes.
Returns:
- EOK
- Success.
- EINVAL
- Invalid value specified by attr or prioceiling.
- EPERM
- The calling process doesn't have the required permission; see procmgr_ability().
Classification:
| Safety: | |
|---|---|
| Cancellation point | No |
| Signal handler | Yes |
| Thread | Yes |
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