Revert "Revert "ART: Start RuntimeCallbacks""
This reverts commit bf6331a45f730e1f1044af2ce43bceda660ae6fc.
Switch to using the mutator lock.
Bug: 31684920
Test: m test-art-host-gtest-runtime_callbacks_test
Test: art/tools/run-jdwp-tests.sh --mode=host --debug
Change-Id: I6ce0f71de2aa9f90cd23cfca7723a793b560b16b
diff --git a/runtime/runtime_callbacks.h b/runtime/runtime_callbacks.h
new file mode 100644
index 0000000..1060d85
--- /dev/null
+++ b/runtime/runtime_callbacks.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+#ifndef ART_RUNTIME_RUNTIME_CALLBACKS_H_
+#define ART_RUNTIME_RUNTIME_CALLBACKS_H_
+
+#include <vector>
+
+#include "base/macros.h"
+#include "base/mutex.h"
+
+namespace art {
+
+class Thread;
+class ThreadLifecycleCallback;
+
+// Note: RuntimeCallbacks uses the mutator lock to synchronize the callback lists. A thread must
+// hold the exclusive lock to add or remove a listener. A thread must hold the shared lock
+// to dispatch an event. This setup is chosen as some clients may want to suspend the
+// dispatching thread or all threads.
+//
+// To make this safe, the following restrictions apply:
+// * Only the owner of a listener may ever add or remove said listener.
+// * A listener must never add or remove itself or any other listener while running.
+// * It is the responsibility of the owner to not remove the listener while it is running
+// (and suspended).
+//
+// The simplest way to satisfy these restrictions is to never remove a listener, and to do
+// any state checking (is the listener enabled) in the listener itself. For an example, see
+// Dbg.
+
+class RuntimeCallbacks {
+ public:
+ void AddThreadLifecycleCallback(ThreadLifecycleCallback* cb)
+ REQUIRES(Locks::mutator_lock_);
+ void RemoveThreadLifecycleCallback(ThreadLifecycleCallback* cb)
+ REQUIRES(Locks::mutator_lock_);
+
+ void ThreadStart(Thread* self)
+ REQUIRES_SHARED(Locks::mutator_lock_);
+ void ThreadDeath(Thread* self)
+ REQUIRES_SHARED(Locks::mutator_lock_);
+
+ private:
+ std::vector<ThreadLifecycleCallback*> thread_callbacks_
+ GUARDED_BY(Locks::mutator_lock_);
+};
+
+} // namespace art
+
+#endif // ART_RUNTIME_RUNTIME_CALLBACKS_H_