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30.Dd May 9, 2010
31.Dt PTHREAD_COND_TIMEDWAIT 3
32.Os
33.Sh NAME
34.Nm pthread_cond_timedwait
35.Nd "wait on a condition variable for a specific amount of time"
36.Sh LIBRARY
37.Lb libpthread
38.Sh SYNOPSIS
39.In pthread.h
40.Ft int
41.Fn pthread_cond_timedwait "pthread_cond_t *cond" "pthread_mutex_t *mutex" "const struct timespec *abstime"
42.Sh DESCRIPTION
43The
44.Fn pthread_cond_timedwait
45function atomically blocks the current thread waiting on the condition
46variable specified by
47.Fa cond ,
48and releases the mutex specified by
49.Fa mutex .
50The waiting thread unblocks only after another thread calls
51.Xr pthread_cond_signal 3 ,
52or
53.Xr pthread_cond_broadcast 3
54with the same condition variable, or if the system time reaches the
55time specified in
56.Fa abstime ,
57and the current thread reacquires the lock on
58.Fa mutex .
59.Pp
60The clock used to measure
61.Fa abstime
62can be specified during creation of the condition variable using
63.Xr pthread_condattr_setclock 3 .
64.Sh RETURN VALUES
65If successful, the
66.Fn pthread_cond_timedwait
67function will return zero.
68Otherwise an error number will be returned to
69indicate the error.
70.Sh ERRORS
71The
72.Fn pthread_cond_timedwait
73function will fail if:
74.Bl -tag -width Er
75.It Bq Er EINVAL
76The value specified by
77.Fa cond ,
78.Fa mutex
79or
80.Fa abstime
81is invalid.
82.It Bq Er ETIMEDOUT
83The system time has reached or exceeded the time specified in
84.Fa abstime .
85.It Bq Er EPERM
86The specified
87.Fa mutex
88was not locked by the calling thread.
89.El
90.Sh SEE ALSO
91.Xr pthread_cond_broadcast 3 ,
92.Xr pthread_cond_destroy 3 ,
93.Xr pthread_cond_init 3 ,
94.Xr pthread_cond_signal 3 ,
95.Xr pthread_cond_wait 3 ,
96.Xr pthread_condattr_setclock 3
97.Sh STANDARDS
98The
99.Fn pthread_cond_timedwait
100function conforms to
101.St -p1003.1-96 .
102