pthread_mutex_consistent - make a robust mutex consistent

#include <pthread.h>
int pthread_mutex_consistent(pthread_mutex_t *mutex);
Compile and link with -pthread.

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
_POSIX_C_SOURCE >= 200809L

This function makes a robust mutex consistent if it is in an inconsistent state. A mutex can be left in an inconsistent state if its owner terminates while holding the mutex, in which case the next owner who acquires the mutex will succeed and be notified by a return value of EOWNERDEAD from a call to pthread_mutex_lock().

On success, pthread_mutex_consistent() returns 0. Otherwise, it returns a positive error number to indicate the cause of the error.

The mutex is either not robust or is not in an inconsistent state.

pthread_mutex_consistent() was added to glibc in version 2.12.


pthread_mutex_consistent() simply informs the implementation that the state (shared data) guarded by the mutex has been restored to a consistent state and that normal operations can now be performed with the mutex. It is the application's responsibility to ensure that the shared data has been restored to a consistent state before calling pthread_mutex_consistent().
Before the addition of pthread_mutex_consistent() to POSIX, glibc defined the following equivalent nonstandard function if _GNU_SOURCE was defined:
int pthread_mutex_consistent(const pthread_mutex_t *mutex);
This GNU-specific API, which first appeared in glibc 2.4, is nowadays obsolete and should not be used in new programs.

See pthread_mutexattr_setrobust(3).

pthread_mutexattr_init(3), pthread_mutex_lock(3), pthread_mutexattr_getrobust(3), pthread_mutexattr_setrobust(3), pthreads(7)
2019-10-10 Linux