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.Dd March 27, 2017
.Dt PTHREAD_MUTEX_CONSISTENT 3
.Os
.Sh NAME
.Nm pthread_mutex_consistent
.Nd mark state protected by robust mutex as consistent
.Sh LIBRARY
.Lb libpthread
.Sh SYNOPSIS
.In pthread.h
.Ft int
.Fn pthread_mutex_consistent "pthread_mutex_t *mutex"
.Sh DESCRIPTION
If the process containing the thread owning a robust mutex terminates
while holding the mutex, the mutex becomes inconsistent and the next thread
that acquires the mutex lock is notified of the state by the return value
.Er EOWNERDEAD .
In this case, the mutex does not become normally usable again until
the state is marked consistent.
.Pp
The
.Fn pthread_mutex_consistent ,
when called with the
.Fa mutex
argument, which points to the initialized robust mutex in an
inconsistent state, marks the by mutex as consistent again.
The consequent unlock of the mutex, by either
.Fn pthread_mutex_unlock
or other methods, allows other contenders to lock the mutex.
.Pp
If the mutex in the inconsistent state is not marked consistent
by the call to
.Fn pthread_mutex_consistent
before unlock,
further attempts to lock the
.Fa mutex
result in the
.Er ENOTRECOVERABLE
condition reported by the locking functions.
.Sh RETURN VALUES
If successful,
.Fn pthread_mutex_consistent
will return zero, otherwise an error number will be returned to
indicate the error.
.Sh ERRORS
The
.Fn pthread_mutex_lock
function will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The mutex pointed to by the
.Fa mutex
argument is not robust, or is not in the inconsistent state.
.El
.Sh SEE ALSO
.Xr pthread_mutex_init 3 ,
.Xr pthread_mutex_lock 3 ,
.Xr pthread_mutex_unlock 3 ,
.Xr pthread_mutexattr_setrobust 3
.Sh STANDARDS
The
.Fn pthread_mutex_lock
function conforms to
.St -susv4 .