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pthread_cond_broadcast(3c) [opensolaris man page]

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

NAME
pthread_cond_signal, pthread_cond_broadcast - signal or broadcast a condition SYNOPSIS
cc -mt [ flag... ] file... -lpthread [ library... ] #include <pthread.h> int pthread_cond_signal(pthread_cond_t *cond); int pthread_cond_broadcast(pthread_cond_t *cond); DESCRIPTION
These two functions are used to unblock threads blocked on a condition variable. The pthread_cond_signal() call unblocks at least one of the threads that are blocked on the specified condition variable cond (if any threads are blocked on cond). The pthread_cond_broadcast() call unblocks all threads currently blocked on the specified condition variable cond. If more than one thread is blocked on a condition variable, the scheduling policy determines the order in which threads are unblocked. When each thread unblocked as a result of a pthread_cond_signal() or pthread_cond_broadcast() returns from its call to pthread_cond_wait() or pthread_cond_timedwait(), the thread owns the mutex with which it called pthread_cond_wait() or pthread_cond_timedwait(). The thread(s) that are unblocked contend for the mutex according to the scheduling policy (if applicable), and as if each had called pthread_mutex_lock(). The pthread_cond_signal() or pthread_cond_broadcast() functions may be called by a thread whether or not it currently owns the mutex that threads calling pthread_cond_wait() or pthread_cond_timedwait() have associated with the condition variable during their waits; however, if predictable scheduling behavior is required, then that mutex is locked by the thread calling pthread_cond_signal() or pthread_cond_broad- cast(). The pthread_cond_signal() and pthread_cond_broadcast() functions have no effect if there are no threads currently blocked on cond. RETURN VALUES
If successful, the pthread_cond_signal() and pthread_cond_broadcast() functions return 0. Otherwise, an error number is returned to indi- cate the error. ERRORS
The pthread_cond_signal() and pthread_cond_broadcast() function may fail if: EINVAL The value cond does not refer to an initialized condition variable. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ SEE ALSO
pthread_cond_init(3C), pthread_cond_wait(3C), pthread_cond_timedwait(3C), attributes(5), condition(5), standards(5) SunOS 5.11 23 Mar 2005 pthread_cond_signal(3C)

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pthread_cond_signal(3T) 												   pthread_cond_signal(3T)

NAME
pthread_cond_signal(), pthread_cond_broadcast() - unblock one or all threads waiting on a condition variable SYNOPSIS
PARAMETERS
cond Pointer to the condition variable to be signaled or broadcast. DESCRIPTION
The function is used to wake-up one of the threads that are waiting for the occurrence of a condition associated with condition variable cond. If there are no threads blocked on cond, this function has no effect. If more than one thread is blocked on cond, the scheduling policy determines which thread is unblocked. It is possible that more than one thread can be unblocked due to a spurious wakeup. The function is used to wake-up all threads that are waiting for the occurrence of a condition associated with the condition variable cond. If there are no threads blocked on cond, this function has no effect. If more than one thread is blocked on cond, the scheduling policy determines the order in which threads are unblocked. The condition variabled denoted by cond must have been dynamically initialized by a call to or statically initialized with the macro An unblocked thread will reacquire the mutex it held when it started the condition wait before returning from or The threads that are unblocked contend for the mutex according to their scheduling policy and priority. The or functions can be called by a thread whether or not it currently owns the condition variable's associated mutex. For predictable scheduling behavior and to prevent lost wake-ups, the mutex should be held when signaling a condition variable. Usage When using condition variables, there is a boolean predicate associated with each condition wait. If this predicate is false, the thread should do a condition wait. Spurious wakeups may occur when waiting on a condition variable. Because the return values from and do not imply anything about the value of this predicate, the predicate should always be re-evaluated. Applications using condition variables typically acquire a mutex and enter a loop which checks the predicate. Depending on the value of the predicate, the thread either breaks out of the loop or waits on the condition. On return from the condition wait, the predicate is re- evaluated. RETURN VALUE
Upon successful completion, and return zero. Otherwise, an error number is returned to indicate the error (the variable is not set). ERRORS
For each of the following conditions, if the condition is detected, the and functions return the corresponding error number: [EINVAL] cond is not a valid condition variable. [EFAULT] cond parameter points to an illegal address. AUTHOR
and were derived from the IEEE POSIX P1003.1c standard. SEE ALSO
pthread_cond_init(3T), pthread_cond_wait(3T). STANDARDS CONFORMANCE
Pthread Library pthread_cond_signal(3T)
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