OboeAudioService: add thread to service for passing timestamps

Cleanup several TODOs.

Test: test_aaudio in CTS
Change-Id: I7fc956b6a21cbb592f98e1e5a8f43ebd6926d796
Signed-off-by: Phil Burk <philburk@google.com>
diff --git a/services/oboeservice/OboeThread.h b/services/oboeservice/OboeThread.h
new file mode 100644
index 0000000..48fafc7
--- /dev/null
+++ b/services/oboeservice/OboeThread.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 OBOE_THREAD_H
+#define OBOE_THREAD_H
+
+#include <atomic>
+#include <pthread.h>
+
+#include <oboe/OboeDefinitions.h>
+
+namespace oboe {
+
+class Runnable {
+public:
+    Runnable() {};
+    virtual ~Runnable() = default;
+
+    virtual void run() {}
+};
+
+/**
+ * Abstraction for a host thread.
+ */
+class OboeThread
+{
+public:
+    OboeThread();
+    OboeThread(Runnable *runnable);
+    virtual ~OboeThread() = default;
+
+    /**
+     * Start the thread running.
+     */
+    oboe_result_t start(Runnable *runnable = nullptr);
+
+    /**
+     * Join the thread.
+     * The caller must somehow tell the thread to exit before calling join().
+     */
+    oboe_result_t stop();
+
+    /**
+     * This will get called in the thread.
+     * Override this or pass a Runnable to start().
+     */
+    virtual void run() {};
+
+    void dispatch(); // called internally from 'C' thread wrapper
+
+private:
+    Runnable*                mRunnable = nullptr; // TODO make atomic with memory barrier?
+    bool                     mHasThread = false;
+    pthread_t                mThread; // initialized in constructor
+
+};
+
+} /* namespace oboe */
+
+#endif ///OBOE_THREAD_H