DOC HOME SITE MAP MAN PAGES GNU INFO SEARCH PRINT BOOK
 

_lwp_cond_signal(2)


_lwp_cond_signal -- wake up a single LWP waiting on a condition variable

Synopsis

   #include <synch.h>
   

int _lwp_cond_signal(lwp_cond_t *cond);

Parameters


cond
pointer to condition variable to be signaled

Description

_lwp_cond_signal wakes up a single lightweight process (LWP), if one exists, waiting on the condition cond.

If more than one LWP is waiting on a condition, the scheduling policy determines which LWP is awakened.

_lwp_cond_signal has no effect if there are no LWPs waiting on the indicated condition.

cond parameter

The condition variable denoted by cond must previously have been statically initialized (zero-filled).

Return values

_lwp_cond_signal returns zero for success and an error number for failure, as described below.

Errors

If any of the following conditions is detected, _lwp_cond_signal returns the corresponding value:

EINVAL
Invalid argument specified.

EFAULT
The cond parameter points to an illegal address. (This error may not be detected; a SIGSEGV signal may be posted to the faulting LWP if an illegal address is used.)

Usage

See the description of how to use condition variables under USAGE on cond_init(3synch).

References

_lwp_cond_broadcast(2), _lwp_cond_timedwait(2), _lwp_cond_wait(2), cond_broadcast(3synch), cond_destroy(3synch), cond_init(3synch), cond_signal(3synch), cond_timedwait(3synch), cond_wait(3synch)

Notices

Lightweight processes (LWPs) are internal interfaces and are subject to change. Their use should be avoided.
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 25 April 2004