condition.c revision dafcb997e390efa4423883dafd100c975c4095d6
/*
* Copyright (C) 2004 Internet Systems Consortium, Inc. ("ISC")
* Copyright (C) 1998-2001 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 ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC 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.
*/
/* $Id: condition.c,v 1.18 2004/03/05 05:11:56 marka Exp $ */
#include <config.h>
#include <isc/condition.h>
#include <isc/assertions.h>
#include <isc/util.h>
#include <isc/time.h>
#define LSIGNAL 0
#define LBROADCAST 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[LSIGNAL] = h;
h = CreateEvent(NULL, TRUE, FALSE, NULL);
if (h == NULL) {
(void)CloseHandle(cond->events[LSIGNAL]);
/* XXX */
return (ISC_R_UNEXPECTED);
}
cond->events[LBROADCAST] = 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[LSIGNAL])) {
/* 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[LBROADCAST])) {
/* 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[LSIGNAL]);
(void)CloseHandle(cond->events[LBROADCAST]);
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[LBROADCAST])) {
/* 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;
isc_uint64_t microseconds;
isc_time_t now;
if (isc_time_now(&now) != ISC_R_SUCCESS) {
/* XXX */
return (ISC_R_UNEXPECTED);
}
microseconds = isc_time_microdiff(t, &now);
if (microseconds > 0xFFFFFFFFi64 * 1000)
milliseconds = 0xFFFFFFFF;
else
milliseconds = (DWORD)(microseconds / 1000);
return (wait(cond, mutex, milliseconds));
}