1 files changed, 67 insertions, 0 deletions
diff --git a/runtime/base/quasi_atomic.cc b/runtime/base/quasi_atomic.cc
new file mode 100644
index 0000000000..1a82812981
--- /dev/null
+++ b/runtime/base/quasi_atomic.cc
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2010 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.
+ */
+
+#include "base/quasi_atomic.h"
+
+#include "base/mutex.h"
+#include "base/stl_util.h"
+#include "thread-current-inl.h"
+
+namespace art {
+
+std::vector<Mutex*>* QuasiAtomic::gSwapMutexes = nullptr;
+
+Mutex* QuasiAtomic::GetSwapMutex(const volatile int64_t* addr) {
+  return (*gSwapMutexes)[(reinterpret_cast<uintptr_t>(addr) >> 3U) % kSwapMutexCount];
+}
+
+void QuasiAtomic::Startup() {
+  if (NeedSwapMutexes(kRuntimeISA)) {
+    gSwapMutexes = new std::vector<Mutex*>;
+    for (size_t i = 0; i < kSwapMutexCount; ++i) {
+      gSwapMutexes->push_back(new Mutex("QuasiAtomic stripe", kSwapMutexesLock));
+    }
+  }
+}
+
+void QuasiAtomic::Shutdown() {
+  if (NeedSwapMutexes(kRuntimeISA)) {
+    STLDeleteElements(gSwapMutexes);
+    delete gSwapMutexes;
+  }
+}
+
+int64_t QuasiAtomic::SwapMutexRead64(volatile const int64_t* addr) {
+  MutexLock mu(Thread::Current(), *GetSwapMutex(addr));
+  return *addr;
+}
+
+void QuasiAtomic::SwapMutexWrite64(volatile int64_t* addr, int64_t value) {
+  MutexLock mu(Thread::Current(), *GetSwapMutex(addr));
+  *addr = value;
+}
+
+
+bool QuasiAtomic::SwapMutexCas64(int64_t old_value, int64_t new_value, volatile int64_t* addr) {
+  MutexLock mu(Thread::Current(), *GetSwapMutex(addr));
+  if (*addr == old_value) {
+    *addr = new_value;
+    return true;
+  }
+  return false;
+}
+
+}  // namespace art