pthread_cond_signal_int_np

Wakes one thread that is waiting on a condition variable (called from interrupt level only).

Syntax

pthread_cond_signal_int_np( cond );

Argument Data Type Access

cond opaque pthread_cond_t modify

C Binding

#include 


int
pthread_cond_signal_int_np(
         pthread_cond_t   *cond);

Arguments

cond: Condition variable to be signaled.

Description

This routine wakes one thread waiting on a condition variable. It can only be called from a software interrupt handler routine (such as from a Digital UNIX signal handler or OpenVMS AST). Calling this routine implies that it might be possible for a single waiting thread to proceed.

The scheduling policies of the waiting threads determine which thread is awakened. For policies SCHED_FIFO and SCHED_RR, a blocked thread is chosen in priority order, using first-in/first-out (FIFO) within priorities.

This routine does not cause a thread blocked on a condition variable to resume execution immediately. A thread resumes execution at some time after the interrupt handler returns.

You can call this routine regardless of whether the associated mutex is locked. Never try to lock a mutex from an interrupt handler.

Note: This routine allows you to signal a thread from a software interrupt handler. Do not call this routine from noninterrupt code. To signal a thread from the normal noninterrupt level, use pthread_cond_signal.

Return Values

If an error condition occurs, this routine returns an integer value indicating the type of error. Possible return values are as follows:

Return Description

0 Successful completion. [EINVAL] The value specified by cond is invalid.

Associated Routines

   pthread_cond_wait
   pthread_cond_timedwait
   pthread_cond_signal
   pthread_cond_broadcast