condition.c revision 2f072c2982861ec2e86e97f8a3ed199fe45c1f70
/*
* Copyright (C) 1998, 1999 Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
* SOFTWARE.
*/
#include <config.h>
#include <isc/condition.h>
#include <isc/assertions.h>
#define SIGNAL 0
#define BROADCAST 1
isc_result_t
isc_condition_init(isc_condition_t *cond) {
HANDLE h;
REQUIRE(cond != NULL);
cond->waiters = 0;
h = CreateEvent(NULL, FALSE, FALSE, NULL);
if (h == NULL) {
/* XXX */
return (ISC_R_UNEXPECTED);
}
cond->events[SIGNAL] = h;
h = CreateEvent(NULL, TRUE, FALSE, NULL);
if (h == NULL) {
(void)CloseHandle(cond->events[SIGNAL]);
/* XXX */
return (ISC_R_UNEXPECTED);
}
cond->events[BROADCAST] = h;
return (ISC_R_SUCCESS);
}
isc_result_t
isc_condition_signal(isc_condition_t *cond) {
/*
* Unlike pthreads, the caller MUST hold the lock associated with
* the condition variable when calling us.
*/
REQUIRE(cond != NULL);
if (cond->waiters > 0 &&
!SetEvent(cond->events[SIGNAL])) {
/* XXX */
return (ISC_R_UNEXPECTED);
}
return (ISC_R_SUCCESS);
}
isc_result_t
isc_condition_broadcast(isc_condition_t *cond) {
/*
* Unlike pthreads, the caller MUST hold the lock associated with
* the condition variable when calling us.
*/
REQUIRE(cond != NULL);
if (cond->waiters > 0 &&
!SetEvent(cond->events[BROADCAST])) {
/* XXX */
return (ISC_R_UNEXPECTED);
}
return (ISC_R_SUCCESS);
}
isc_result_t
isc_condition_destroy(isc_condition_t *cond) {
REQUIRE(cond != NULL);
(void)CloseHandle(cond->events[SIGNAL]);
(void)CloseHandle(cond->events[BROADCAST]);
return (ISC_R_SUCCESS);
}
static isc_result_t
wait(isc_condition_t *cond, isc_mutex_t *mutex, DWORD milliseconds) {
DWORD result;
cond->waiters++;
LeaveCriticalSection(mutex);
result = WaitForMultipleObjects(2, cond->events, FALSE, milliseconds);
if (result == WAIT_FAILED) {
/* XXX */
return (ISC_R_UNEXPECTED);
}
EnterCriticalSection(mutex);
cond->waiters--;
if (cond->waiters == 0 &&
!ResetEvent(cond->events[BROADCAST])) {
/* XXX */
LeaveCriticalSection(mutex);
return (ISC_R_UNEXPECTED);
}
if (result == WAIT_TIMEOUT)
return (ISC_R_TIMEDOUT);
return (ISC_R_SUCCESS);
}
isc_result_t
isc_condition_wait(isc_condition_t *cond, isc_mutex_t *mutex) {
return (wait(cond, mutex, INFINITE));
}
isc_result_t
isc_condition_waituntil(isc_condition_t *cond, isc_mutex_t *mutex,
isc_time_t t)
{
DWORD milliseconds;
struct isc_time now;
if (isc_time_get(&now) != ISC_R_SUCCESS) {
/* XXX */
return (ISC_R_UNEXPECTED);
}
milliseconds = (DWORD)isc_time_millidiff(t, now);
return (wait(cond, mutex, milliseconds));
}