rt_sem_wait(2)

NAME

rt_sem_wait - semaphore 'wait' operation (with blocking)

SYNOPSIS

#define MODULE
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/version.h>
#include <linux/errno.h>
#include rt_ipc.h

int rt_sem_wait(rt_sem_t *sem, RTIME timeout);

DESCRIPTION

rt_sem_wait is the semaphore wait (sometimes known as 'take' or 'P') operation. Unlike with rt_sem_trywait, if the semaphore is not available, the calling task blocks until it is. sem points to the structure used in the call to rt_sem_create. An optional timeout can be specified. If timeout is RT_WAIT_FOREVER, the function does not time out. If timeout is RT_NO_WAIT and the semaphore is not available, rt_sem_wait returns immediately. If timeout is any other value, it represent a time at which the call to rt_sem_wait should time out. If that time is reached, rt_sem_wait returns with -ETIME.

RETURN VALUE

On success, 0 is returned. On failure, a negative value is returned as described below.

ERRORS

-ETIME: The timeout period expired.

-EINVAL: sem does not point to a valid rt_sem_t.

AUTHOR

Jerry Epplin <[email protected]>