1pthread_cond_signal(3C)  Standard C Library Functions  pthread_cond_signal(3C)
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NAME

6       pthread_cond_signal,  pthread_cond_broadcast  -  signal  or broadcast a
7       condition
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SYNOPSIS

10       cc -mt [ flag... ] file... -lpthread [ library... ]
11       #include <pthread.h>
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13       int pthread_cond_signal(pthread_cond_t *cond);
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16       int pthread_cond_broadcast(pthread_cond_t *cond);
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DESCRIPTION

20       These two functions are used to unblock threads blocked on a  condition
21       variable.
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24       The  pthread_cond_signal()  call  unblocks  at least one of the threads
25       that are blocked on the  specified  condition  variable  cond  (if  any
26       threads are blocked on cond).
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29       The   pthread_cond_broadcast()  call  unblocks  all  threads  currently
30       blocked on the specified condition variable cond.
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33       If more than one thread is blocked on a condition variable, the  sched‐
34       uling  policy determines the order in which threads are unblocked. When
35       each thread  unblocked  as  a  result  of  a  pthread_cond_signal()  or
36       pthread_cond_broadcast()  returns  from its call to pthread_cond_wait()
37       or pthread_cond_timedwait(), the thread owns the mutex  with  which  it
38       called  pthread_cond_wait()  or pthread_cond_timedwait(). The thread(s)
39       that are unblocked contend for the mutex according  to  the  scheduling
40       policy (if applicable), and as if each had called pthread_mutex_lock().
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43       The  pthread_cond_signal() or pthread_cond_broadcast() functions may be
44       called by a thread whether or not it  currently  owns  the  mutex  that
45       threads  calling  pthread_cond_wait()  or pthread_cond_timedwait() have
46       associated with the condition variable during their waits; however,  if
47       predictable  scheduling behavior is required, then that mutex is locked
48       by the  thread  calling  pthread_cond_signal()  or  pthread_cond_broad‐
49       cast().
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52       The  pthread_cond_signal()  and pthread_cond_broadcast() functions have
53       no effect if there are no threads currently blocked on cond.
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RETURN VALUES

56       If successful, the pthread_cond_signal()  and  pthread_cond_broadcast()
57       functions return  0. Otherwise, an error number is returned to indicate
58       the error.
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ERRORS

61       The  pthread_cond_signal() and  pthread_cond_broadcast()  function  may
62       fail if:
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64       EINVAL    The  value  cond  does  not refer to an initialized condition
65                 variable.
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ATTRIBUTES

69       See attributes(5) for descriptions of the following attributes:
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74       ┌─────────────────────────────┬─────────────────────────────┐
75       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
76       ├─────────────────────────────┼─────────────────────────────┤
77       │Interface Stability          │Standard                     │
78       ├─────────────────────────────┼─────────────────────────────┤
79       │MT-Level                     │MT-Safe                      │
80       └─────────────────────────────┴─────────────────────────────┘
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SEE ALSO

83       pthread_cond_init(3C),    pthread_cond_wait(3C),    pthread_cond_timed‐
84       wait(3C), attributes(5), condition(5), standards(5)
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88SunOS 5.11                        23 Mar 2005          pthread_cond_signal(3C)