Disabled external gits

cs453-ca/CS453-2021-project/reference/shared-lock.c

@@ -0,0 +1,25 @@
+#include "shared-lock.h"
+
+bool shared_lock_init(struct shared_lock_t* lock) {
+    return pthread_rwlock_init(&lock->rwlock, NULL) == 0;
+}
+
+void shared_lock_cleanup(struct shared_lock_t* lock) {
+    pthread_rwlock_destroy(&lock->rwlock);
+}
+
+bool shared_lock_acquire(struct shared_lock_t* lock) {
+    return pthread_rwlock_wrlock(&lock->rwlock) == 0;
+}
+
+void shared_lock_release(struct shared_lock_t* lock) {
+    pthread_rwlock_unlock(&lock->rwlock);
+}
+
+bool shared_lock_acquire_shared(struct shared_lock_t* lock) {
+    return pthread_rwlock_rdlock(&lock->rwlock) == 0;
+}
+
+void shared_lock_release_shared(struct shared_lock_t* lock) {
+    pthread_rwlock_unlock(&lock->rwlock);
+}