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/*
* Copyright (c) 2017 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
*/
#include <config.h>
#include <pthread.h>
#include <errno.h>
#include <parc/algol/parc_Object.h>
#include <parc/algol/parc_DisplayIndented.h>
#include <parc/concurrent/parc_Lock.h>
struct PARCLock {
pthread_mutex_t lock;
pthread_mutexattr_t lockAttributes;
pthread_cond_t notification;
bool locked;
bool notified;
};
static void
_parcLock_Finalize(PARCLock **instancePtr)
{
assertNotNull(instancePtr, "Parameter must be a non-null pointer to a PARCLock pointer.");
parcLock_OptionalAssertValid(*instancePtr);
/* cleanup the instance fields here */
}
parcObject_ImplementAcquire(parcLock, PARCLock);
parcObject_ImplementRelease(parcLock, PARCLock);
parcObject_ExtendPARCObject(PARCLock, _parcLock_Finalize, NULL, parcLock_ToString, NULL, NULL, NULL, NULL);
void
parcLock_AssertValid(const PARCLock *instance)
{
assertTrue(parcLock_IsValid(instance),
"PARCLock is not valid.");
}
PARCLock *
parcLock_Create(void)
{
PARCLock *result = parcObject_CreateInstance(PARCLock);
pthread_mutexattr_init(&result->lockAttributes);
pthread_mutexattr_settype(&result->lockAttributes, PTHREAD_MUTEX_ERRORCHECK);
pthread_mutex_init(&result->lock, &result->lockAttributes);
result->locked = false;
pthread_cond_init(&result->notification, NULL);
result->notified = false;
return result;
}
void
parcLock_Display(const PARCLock *lock, int indentation)
{
parcDisplayIndented_PrintLine(indentation, "PARCLock@%p {", lock);
parcDisplayIndented_PrintLine(indentation + 1, ".locked=%s", lock->locked ? "true" : "false");
parcDisplayIndented_PrintLine(indentation, "}");
}
bool
parcLock_IsValid(const PARCLock *instance)
{
bool result = false;
if (instance != NULL) {
result = true;
}
return result;
}
PARCBufferComposer *
parcLock_BuildString(const PARCLock *lock, PARCBufferComposer *composer)
{
parcBufferComposer_Format(composer, "lock{.state=%s }", lock->locked ? "true" : "false");
return composer;
}
char *
parcLock_ToString(const PARCLock *lock)
{
char *result = NULL;
PARCBufferComposer *composer = parcBufferComposer_Create();
if (composer != NULL) {
parcLock_BuildString(lock, composer);
result = parcBufferComposer_ToString(composer);
parcBufferComposer_Release(&composer);
}
return result;
}
bool
parcLock_Unlock(PARCLock *lock)
{
bool result = false;
parcLock_OptionalAssertValid(lock);
if (lock->locked) {
result = (pthread_mutex_unlock(&lock->lock) == 0);
}
return result;
}
bool
parcLock_Lock(PARCLock *lock)
{
bool result = false;
parcLock_OptionalAssertValid(lock);
int error = pthread_mutex_lock(&lock->lock);
if (error == 0) {
lock->locked = true;
result = true;
errno = 0;
} else {
errno = error;
}
return result;
}
bool
parcLock_TryLock(PARCLock *lock)
{
bool result = false;
parcLock_OptionalAssertValid(lock);
result = (pthread_mutex_trylock(&lock->lock) == 0);
if (result) {
lock->locked = true;
}
return result;
}
bool
parcLock_IsLocked(const PARCLock *lock)
{
parcLock_OptionalAssertValid(lock);
return lock->locked;
}
void
parcLock_Wait(PARCLock *lock)
{
parcLock_OptionalAssertValid(lock);
trapUnexpectedStateIf(lock->locked == false,
"You must Lock the object before calling parcLock_Wait");
lock->notified = false;
while (lock->notified == false) {
pthread_cond_wait(&lock->notification, &lock->lock);
}
}
void
parcLock_Notify(PARCLock *lock)
{
parcLock_OptionalAssertValid(lock);
trapUnexpectedStateIf(lock->locked == false,
"You must Lock the object before calling parcLock_Notify");
lock->notified = true;
pthread_cond_signal(&lock->notification);
}
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