pthread_cond_signal_int_np(3) — Subroutines
NAME
pthread_cond_signal_int_np − Wakes one thread that is waiting on a condition variable.
SYNOPSIS
#include <pthread.h>
int pthread_cond_signal_int_np(
pthread_cond_t ∗cond );
PARAMETERS
condCondition variable signaled.
DESCRIPTION
This routine wakes one thread waiting on a condition variable. It can only be called from a software interrupt handler routine. Do not call this routine from noninterrupt code. If you want to signal a thread from the normal noninterrupt level, use pthread_cond_signal.
Calling this routine implies that it might be possible for a single waiting thread to proceed. Call this routine when any thread waiting on the specified condition variable might find its predicate true.
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 if the associated mutex is locked. Never try to lock a mutex from an interrupt handler.
RETURN VALUES
If an error condition occurs, this routine returns −1 and errno is set to the corresponding error value. Possible return values are as follows:
| Return | Error | Description |
| 0 | Successful completion. | |
| −1 | [EINVAL] | The value specified by cond is invalid. |
RELATED INFORMATION
pthread_cond_broadcast(3), pthread_cond_destroy(3), pthread_cond_init(3), pthread_cond_signal(3), pthread_cond_timedwait(3), pthread_cond_wait(3),