NAME
pthread_mutex_consistent —
mark state protected by robust mutex as
consistent
SYNOPSIS
#include
<pthread.h>
int pthread_mutex_consistent(pthread_mutex_t *mutex);
DESCRIPTION
If mutex is a robust mutex in an inconsistent
state, the pthread_mutex_consistent () function can
be used to mark the state protected by the mutex referenced by
mutex as consistent again.
If an owner of a robust mutex terminates while holding the mutex, the mutex becomes inconsistent and the next thread that acquires the mutex lock shall be notified of the state by the return value [EOWNERDEAD]. In this case, the mutex does not become normally usable again until the state is marked consistent.
If the thread which acquired the mutex lock with the return value
[EOWNERDEAD] terminates before calling either
pthread_mutex_consistent () or
pthread_mutex_unlock(3), the next thread that acquires the
mutex lock shall be notified about the state of the mutex by the return
value [EOWNERDEAD].
The behavior is undefined if the value specified by the
mutex argument to
pthread_mutex_consistent () does not refer to an
initialized mutex.
RETURN VALUE
Upon successful completion, the
pthread_mutex_consistent () function shall return
zero. Otherwise, an error value shall be returned to indicate the error.
ERRORS
The pthread_mutex_consistent () function
shall fail if:
- [EINVAL]
- The mutex object referenced by mutex is not robust or does not protect an inconsistent state.
These functions shall not return an error code of [EINTR].
EXAMPLES
None.
APPLICATION USAGE
The pthread_mutex_consistent () function
is only responsible for notifying the implementation that the state
protected by the mutex has been recovered and that normal operations with
the mutex can be resumed. It is the responsibility of the application to
recover the state so it can be reused. If the application is not able to
perform the recovery, it can notify the implementation that the situation is
unrecoverable by a call to pthread_mutex_unlock(3) without
a prior call to pthread_mutex_consistent (), in
which case subsequent threads that attempt to lock the mutex will fail to
acquire the lock and be returned [ENOTRECOVERABLE].
RATIONALE
If an implementation detects that the value specified by the
mutex argument to
pthread_mutex_consistent () does not refer to an
initialized mutex, it is recommended that the function should fail and
report an [EINVAL] error.
FUTURE DIRECTIONS
None.
SEE ALSO
pthread_mutex_lock(3) , pthread_mutexattr_getrobust(3)
XBD <pthread.h>
CHANGE HISTORY
First released in Issue 7.