1.\" $OpenBSD: pthread_mutex_lock.3,v 1.8 2007/05/31 19:19:37 jmc Exp $
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3.\" Copyright (c) 1997 Brian Cully <shmit@kublai.com>
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30.\" $FreeBSD: pthread_mutex_lock.3,v 1.5 1999/08/28 00:03:07 peter Exp $
31.\"
32.Dd $Mdocdate: May 31 2007 $
33.Dt PTHREAD_MUTEX_LOCK 3
34.Os
35.Sh NAME
36.Nm pthread_mutex_lock
37.Nd lock a mutex
38.Sh SYNOPSIS
39.Fd #include <pthread.h>
40.Ft int
41.Fn pthread_mutex_lock "pthread_mutex_t *mutex"
42.Sh DESCRIPTION
43The
44.Fn pthread_mutex_lock
45function locks
46.Fa mutex .
47If the mutex is already locked, the calling thread will block until the
48mutex becomes available.
49.Sh RETURN VALUES
50If successful,
51.Fn pthread_mutex_lock
52will return zero, otherwise an error number will be returned to
53indicate the error.
54.Sh ERRORS
55.Fn pthread_mutex_lock
56will fail if:
57.Bl -tag -width Er
58.It Bq Er EBUSY
59Currently
60.Fa mutex
61is locked by another thread.
62.It Bq Er EINVAL
63The value specified by
64.Fa mutex
65is invalid.
66.It Bq Er EDEADLK
67A deadlock would occur if the thread blocked waiting for
68.Fa mutex .
69.El
70.Sh SEE ALSO
71.Xr pthread_mutex_destroy 3 ,
72.Xr pthread_mutex_init 3 ,
73.Xr pthread_mutex_trylock 3 ,
74.Xr pthread_mutex_unlock 3
75.Sh STANDARDS
76.Fn pthread_mutex_lock
77conforms to
78.St -p1003.1-96 .
79