NAME

ksemaphore, ke_semaphore_init, ke_semaphore_reset, ke_semaphore_release, ke_semaphore_release_maxone — dispatcher mutex object

SYNOPSIS

#include <kdk/kern.h>

void
ke_semaphore_init(ksemaphore_t *sem, unsigned count);

void
ke_semaphore_reset(ksemaphore_t *sem, unsigned count);

void
ke_semaphore_release(ksemaphore_t *sem, unsigned adjustment);

void
ke_semaphore_release_maxone(ksemaphore_t *sem);

DESCRIPTION

The dispatcher semaphore object is a dispatcher object that can be waited on by ke_wait(9), defined by the ksemaphore_t type.

The semaphore object is a counter that can be incremented and decremented. When the counter is zero, waiters will be put to sleep until the counter is incremented.

Waiters sleep until the counter is positive, and the counter is decremented when a waiter is satisfied.

The ke_semaphore_init() function initialises a semaphore object, setting its counter to the value specified by the count parameter.

The ke_semaphore_reset() function resets a semaphore object, setting its counter to the value specified by the count parameter.

The ke_semaphore_release() function increments the counter of a semaphore object by the value specified by the adjustment parameter.

The ke_semaphore_release_maxone() function increments the counter of a semaphore object by one only if the counter was zero.

CONTEXT

All these functions may be called from any context at or below kIPLDPC.

CODE REFERENCES

These functions are implemented in kernel/kern/semaphore.c.

The interface is declared in kernel/include/kdk/kern.h.

SEE ALSO

ke_wait(9),

HISTORY

These interfaces have always been in Keyronex.