1 files changed, 202 insertions, 0 deletions
diff --git a/libparc/parc/concurrent/parc_Lock.c b/libparc/parc/concurrent/parc_Lock.c
new file mode 100755
index 00000000..d510b5ed
--- /dev/null
+++ b/libparc/parc/concurrent/parc_Lock.c
@@ -0,0 +1,202 @@
+/*
+ * 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);
+}
+