1.\" $OpenBSD: pthread_mutex_lock.3,v 1.5 1999/11/24 05:35:32 d Exp $
2.\" Copyright (c) 1997 Brian Cully <shmit@kublai.com>
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31.Dd July 30, 1998
32.Dt PTHREAD_MUTEX_LOCK 3
33.Os
34.Sh NAME
35.Nm pthread_mutex_lock
36.Nd lock a mutex
37.Sh SYNOPSIS
38.Fd #include <pthread.h>
39.Ft int
40.Fn pthread_mutex_lock "pthread_mutex_t *mutex"
41.Sh DESCRIPTION
42The
43.Fn pthread_mutex_lock
44function locks
45.Fa mutex .
46If the mutex is already locked, the calling thread will block until the
47mutex becomes available.
48.Sh RETURN VALUES
49If successful,
50.Fn pthread_mutex_lock
51will return zero, otherwise an error number will be returned to
52indicate the error.
53.Sh ERRORS
54.Fn pthread_mutex_lock
55will fail if:
56.Bl -tag -width Er
57.It Bq Er EINVAL
58The value specified by
59.Fa mutex
60is invalid.
61.It Bq Er EDEADLK
62A deadlock would occur if the thread blocked waiting for
63.Fa mutex .
64.El
65.Sh SEE ALSO
66.Xr pthread_mutex_destroy 3 ,
67.Xr pthread_mutex_init 3 ,
68.Xr pthread_mutex_trylock 3 ,
69.Xr pthread_mutex_unlock 3
70.Sh STANDARDS
71.Fn pthread_mutex_lock
72conforms to ISO/IEC 9945-1 ANSI/IEEE
73.Pq Dq Tn POSIX
74Std 1003.1 Second Edition 1996-07-12.
75