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.\" $FreeBSD: head/share/man/man3/pthread_mutex_lock.3 300043 2016-05-17 09:56:22Z kib $
.\"
.Dd April 29, 2016
.Dt PTHREAD_MUTEX_LOCK 3
.Os
.Sh NAME
.Nm pthread_mutex_lock
.Nd lock a mutex
.Sh LIBRARY
.Lb libpthread
.Sh SYNOPSIS
.In pthread.h
.Ft int
.Fn pthread_mutex_lock "pthread_mutex_t *mutex"
.Sh DESCRIPTION
The
.Fn pthread_mutex_lock
function locks
.Fa mutex .
If the mutex is already locked, the calling thread will block until the
mutex becomes available.
.Sh RETURN VALUES
If successful,
.Fn pthread_mutex_lock
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 ENOTRECOVERABLE"
.It Bq Er EINVAL
The value specified by
.Fa mutex
is invalid.
.It Bq Er EDEADLK
A deadlock would occur if the thread blocked waiting for
.Fa mutex .
.It Bq Er EOWNERDEAD
The argument
.Fa mutex
points to a robust mutex and the previous owning thread terminated
while holding the mutex lock.
The lock was granted to the caller and it is up to the new owner
to make the state consistent.
.It Bq Er ENOTRECOVERABLE
The state protected by the
.Fa mutex
is not recoverable.
.El
.Sh SEE ALSO
.Xr pthread_mutex_consistent 3 ,
.Xr pthread_mutex_destroy 3 ,
.Xr pthread_mutex_init 3 ,
.Xr pthread_mutex_trylock 3 ,
.Xr pthread_mutex_unlock 3
.Sh STANDARDS
The
.Fn pthread_mutex_lock
function conforms to
.St -p1003.1-96 .