aaudio: keep track of streams using strong pointers

Maintain strong pointer to service stream during service calls.
Use simple AAudioStreamTracker instead of complex HandleTracker.

Bug: 65280854
Test: affects all MMAP streams, run all CTS tests, etcetera
Change-Id: I3d2ed8b588ea39c216dacd4dea503b11c33f36f3
diff --git a/services/oboeservice/AAudioStreamTracker.h b/services/oboeservice/AAudioStreamTracker.h
new file mode 100644
index 0000000..70d440d
--- /dev/null
+++ b/services/oboeservice/AAudioStreamTracker.h
@@ -0,0 +1,73 @@
+/*
+ * 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.
+ */
+
+#ifndef AAUDIO_AAUDIO_STREAM_TRACKER_H
+#define AAUDIO_AAUDIO_STREAM_TRACKER_H
+
+#include <time.h>
+#include <pthread.h>
+
+#include <aaudio/AAudio.h>
+
+#include "binding/AAudioCommon.h"
+
+#include "AAudioServiceStreamBase.h"
+
+namespace aaudio {
+
+class AAudioStreamTracker {
+
+public:
+    /**
+     * Remove the stream associated with the handle.
+     * @param streamHandle
+     * @return strong pointer to the stream if found or to nullptr
+     */
+    android::sp<AAudioServiceStreamBase> removeStreamByHandle(aaudio_handle_t streamHandle);
+
+    /**
+     * Look up a stream based on the handle.
+     * @param streamHandle
+     * @return strong pointer to the stream if found or to nullptr
+     */
+    android::sp<aaudio::AAudioServiceStreamBase> getStreamByHandle(aaudio_handle_t streamHandle);
+
+    /**
+     * Store a strong pointer to the stream and return a unique handle for future reference.
+     * The handle is guaranteed not to collide with an existing stream.
+     * @param serviceStream
+     * @return handle for identifying the stream
+     */
+    aaudio_handle_t addStreamForHandle(android::sp<AAudioServiceStreamBase> serviceStream);
+
+    /**
+     * @return string that can be added to dumpsys
+     */
+    std::string dump() const;
+
+private:
+    static aaudio_handle_t bumpHandle(aaudio_handle_t handle);
+
+    // Track stream using a unique handle that wraps. Only use positive half.
+    mutable std::mutex                mHandleLock;
+    std::atomic<aaudio_handle_t>      mPreviousHandle{0};
+    std::map<aaudio_handle_t, android::sp<aaudio::AAudioServiceStreamBase>> mStreamsByHandle;
+};
+
+
+} /* namespace aaudio */
+
+#endif /* AAUDIO_AAUDIO_STREAM_TRACKER_H */