adb: add implementations of mutex, recursive_mutex.
Our version of mingw doesn't support std::mutex or
std::recursive_mutex, so implement our own using the Windows primitives.
Bug: http://b/28347842
Change-Id: I4e1d56a89bc5fcb5f859bf5014343697a4a85b77
diff --git a/adb/sysdeps/mutex.h b/adb/sysdeps/mutex.h
new file mode 100644
index 0000000..73c9e6e
--- /dev/null
+++ b/adb/sysdeps/mutex.h
@@ -0,0 +1,107 @@
+#pragma once
+
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#if defined(_WIN32)
+
+#include <windows.h>
+
+#include <android-base/macros.h>
+
+#include "adb.h"
+
+// The prebuilt version of mingw we use doesn't support mutex or recursive_mutex.
+// Therefore, implement our own using the Windows primitives.
+// Put them directly into the std namespace, so that when they're actually available, the build
+// breaks until they're removed.
+
+#include <mutex>
+namespace std {
+
+// CRITICAL_SECTION is recursive, so just wrap it in a Mutex-compatible class.
+class recursive_mutex {
+ public:
+ recursive_mutex() {
+ InitializeCriticalSection(&mutex_);
+ }
+
+ ~recursive_mutex() {
+ DeleteCriticalSection(&mutex_);
+ }
+
+ void lock() {
+ EnterCriticalSection(&mutex_);
+ }
+
+ bool try_lock() {
+ return TryEnterCriticalSection(&mutex_);
+ }
+
+ void unlock() {
+ LeaveCriticalSection(&mutex_);
+ }
+
+ private:
+ CRITICAL_SECTION mutex_;
+
+ DISALLOW_COPY_AND_ASSIGN(recursive_mutex);
+};
+
+class mutex {
+ public:
+ mutex() {
+ }
+
+ ~mutex() {
+ }
+
+ void lock() {
+ mutex_.lock();
+ if (++lock_count_ != 1) {
+ fatal("non-recursive mutex locked reentrantly");
+ }
+ }
+
+ void unlock() {
+ if (--lock_count_ != 0) {
+ fatal("non-recursive mutex unlock resulted in unexpected lock count: %d", lock_count_);
+ }
+ mutex_.unlock();
+ }
+
+ bool try_lock() {
+ if (!mutex_.try_lock()) {
+ return false;
+ }
+
+ if (lock_count_ != 0) {
+ mutex_.unlock();
+ return false;
+ }
+
+ ++lock_count_;
+ return true;
+ }
+
+ private:
+ recursive_mutex mutex_;
+ size_t lock_count_ = 0;
+};
+
+}
+
+#endif
diff --git a/adb/sysdeps_test.cpp b/adb/sysdeps_test.cpp
index fde344a..395d22d 100644
--- a/adb/sysdeps_test.cpp
+++ b/adb/sysdeps_test.cpp
@@ -244,3 +244,60 @@
adb_close(fd);
}
}
+
+#include "sysdeps/mutex.h"
+TEST(sysdeps_mutex, mutex_smoke) {
+ static std::atomic<bool> finished(false);
+ static std::mutex &m = *new std::mutex();
+ m.lock();
+ ASSERT_FALSE(m.try_lock());
+ adb_thread_create([](void*) {
+ ASSERT_FALSE(m.try_lock());
+ m.lock();
+ finished.store(true);
+ adb_sleep_ms(200);
+ m.unlock();
+ }, nullptr);
+
+ ASSERT_FALSE(finished.load());
+ adb_sleep_ms(100);
+ ASSERT_FALSE(finished.load());
+ m.unlock();
+ adb_sleep_ms(100);
+ m.lock();
+ ASSERT_TRUE(finished.load());
+ m.unlock();
+}
+
+// Our implementation on Windows aborts on double lock.
+#if defined(_WIN32)
+TEST(sysdeps_mutex, mutex_reentrant_lock) {
+ std::mutex &m = *new std::mutex();
+
+ m.lock();
+ ASSERT_FALSE(m.try_lock());
+ EXPECT_DEATH(m.lock(), "non-recursive mutex locked reentrantly");
+}
+#endif
+
+TEST(sysdeps_mutex, recursive_mutex_smoke) {
+ static std::recursive_mutex &m = *new std::recursive_mutex();
+
+ m.lock();
+ ASSERT_TRUE(m.try_lock());
+ m.unlock();
+
+ adb_thread_create([](void*) {
+ ASSERT_FALSE(m.try_lock());
+ m.lock();
+ adb_sleep_ms(500);
+ m.unlock();
+ }, nullptr);
+
+ adb_sleep_ms(100);
+ m.unlock();
+ adb_sleep_ms(100);
+ ASSERT_FALSE(m.try_lock());
+ m.lock();
+ m.unlock();
+}
