Add more CTL content

test/ctl/mutex_test.cc

@@ -0,0 +1,114 @@
+// -*- mode:c++; indent-tabs-mode:nil; c-basic-offset:4; coding:utf-8 -*-
+// vi: set et ft=cpp ts=4 sts=4 sw=4 fenc=utf-8 :vi
+//
+// Copyright 2024 Justine Alexandra Roberts Tunney
+//
+// Permission to use, copy, modify, and/or 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 THE AUTHOR DISCLAIMS ALL
+// WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+// AUTHOR 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 "ctl/mutex.h"
+#include "libc/mem/leaks.h"
+
+// #include <mutex>
+// #define ctl std
+
+ctl::mutex mtx;
+int shared_resource = 0;
+const int NUM_THREADS = 5;
+const int ITERATIONS = 100000;
+
+void*
+increment_resource(void* arg)
+{
+    for (int i = 0; i < ITERATIONS; ++i) {
+        mtx.lock();
+        ++shared_resource;
+        mtx.unlock();
+    }
+    return nullptr;
+}
+
+void*
+decrement_resource(void* arg)
+{
+    for (int i = 0; i < ITERATIONS; ++i) {
+        mtx.lock();
+        --shared_resource;
+        mtx.unlock();
+    }
+    return nullptr;
+}
+
+int
+test_basic_locking()
+{
+    shared_resource = 0;
+    pthread_t threads[NUM_THREADS];
+    for (int i = 0; i < NUM_THREADS; ++i)
+        if (pthread_create(&threads[i], 0, increment_resource, 0) != 0)
+            return 1;
+    for (int i = 0; i < NUM_THREADS; ++i)
+        if (pthread_join(threads[i], 0) != 0)
+            return 2;
+    return (shared_resource == NUM_THREADS * ITERATIONS) ? 0 : 3;
+}
+
+int
+test_lock_contention()
+{
+    shared_resource = 0;
+    pthread_t threads[NUM_THREADS * 2];
+    for (int i = 0; i < NUM_THREADS; ++i)
+        if (pthread_create(&threads[i], 0, increment_resource, 0) != 0 ||
+            pthread_create(&threads[i + NUM_THREADS],
+                           nullptr,
+                           decrement_resource,
+                           nullptr) != 0)
+            return 4;
+    for (int i = 0; i < NUM_THREADS * 2; ++i)
+        if (pthread_join(threads[i], 0) != 0)
+            return 5;
+    return (shared_resource == 0) ? 0 : 6;
+}
+
+int
+test_try_lock()
+{
+    ctl::mutex try_mtx;
+    if (!try_mtx.try_lock())
+        return 7;
+    if (try_mtx.try_lock())
+        return 8;
+    try_mtx.unlock();
+    return 0;
+}
+
+int
+main()
+{
+    int result;
+
+    result = test_basic_locking();
+    if (result != 0)
+        return result;
+
+    result = test_lock_contention();
+    if (result != 0)
+        return result;
+
+    result = test_try_lock();
+    if (result != 0)
+        return result;
+
+    CheckForMemoryLeaks();
+}