Open System Services System Calls Reference Manual (G06.25+, H06.03+)

System Functions (n - p) pthread_cond_signal_int_np(2)
NAME
pthread_cond_signal_int_np
- Unblocks one thread that is waiting on the specified condition
variable; callable only from an interrupt-handler routine
LIBRARY
G-series native OSS processes: /G/system/sysnn/zsptsrl
H-series OSS processes: /G/system/zdllnnn/zsptdll
SYNOPSIS
#include <spthread.h>
int pthread_cond_signal_int_np(
pthread_cond_t *cond );
PARAMETERS
cond specifies the condition variable to be signaled.
DESCRIPTION
This function unblocks one thread waiting on the condition variable specified by cond. Calling
this function implies that data guarded by the associated mutex has changed, so the waiting
thread might be able to proceed.
If no threads are waiting on the specified condition variable, this function takes no action. The
signal does not propagate to the next condition variable wait.
The scheduling policy of the waiting threads determines which thread is unblocked. A blocked
thread is chosen in priority order, using a first-in/first-out (FIFO) algorithm within priorities.
This function does not cause a thread blocked on a condition variable to resume execution
immediately. The thread resumes execution at some time after the interrupt-handler routine
returns.
You can call this function regardless of whether the associated mutex is locked by some other
thread. Never lock a mutex from an interrupt- handler routine.
NOTES
This function allows you to signal a thread from a software interrupt handler. Do not call this
function from noninterrupt code. To signal a thread from the normal noninterrupt level, use the
pthread_cond_signal( ) function.
RETURN VALUES
On successful completion, this function returns a 0 (zero). If an error condition occurs, this func-
tion returns -1 and sets errno to indicate the type of error.
ERRORS
The following error conditions can occur:
[EINVAL] The value specified by the cond parameter is not a valid condition variable.
RELATED INFORMATION
Functions: pthread_cond_broadcast(2), pthread_cond_destroy(2), pthread_cond_init(2),
pthread_cond_timedwait(2), pthread_cond_wait(2).
STANDARDS CONFORMANCE
This function is an extension to the XPG4 Version 2 specification and to the following industry
standards:
• IEEE Std 1003.1c-1995, POSIX System Application Program Interface
527186-003 Hewlett-Packard Company 5−47