Merge "AAudio: Use futex for waitForStateChange"
diff --git a/media/libaaudio/src/client/AudioStreamInternal.cpp b/media/libaaudio/src/client/AudioStreamInternal.cpp
index 9f0564f..34ecd25 100644
--- a/media/libaaudio/src/client/AudioStreamInternal.cpp
+++ b/media/libaaudio/src/client/AudioStreamInternal.cpp
@@ -605,13 +605,6 @@
     return AAUDIO_ERROR_INVALID_STATE;
 }
 
-aaudio_result_t AudioStreamInternal::updateStateMachine() {
-    if (isDataCallbackActive()) {
-        return AAUDIO_OK; // state is getting updated by the callback thread read/write call
-    }
-    return processCommands();
-}
-
 void AudioStreamInternal::logTimestamp(AAudioServiceMessage &command) {
     static int64_t oldPosition = 0;
     static int64_t oldTime = 0;
diff --git a/media/libaaudio/src/client/AudioStreamInternal.h b/media/libaaudio/src/client/AudioStreamInternal.h
index 2367572..4ea61d2 100644
--- a/media/libaaudio/src/client/AudioStreamInternal.h
+++ b/media/libaaudio/src/client/AudioStreamInternal.h
@@ -48,7 +48,7 @@
                                        int64_t *framePosition,
                                        int64_t *timeNanoseconds) override;
 
-    virtual aaudio_result_t updateStateMachine() override;
+    virtual aaudio_result_t processCommands() override;
 
     aaudio_result_t open(const AudioStreamBuilder &builder) override;
 
@@ -110,8 +110,6 @@
 
     aaudio_result_t drainTimestampsFromService();
 
-    aaudio_result_t processCommands();
-
     aaudio_result_t stopCallback_l();
 
     virtual void prepareBuffersForStart() {}
diff --git a/media/libaaudio/src/core/AudioStream.cpp b/media/libaaudio/src/core/AudioStream.cpp
index 06f05b0..8a5186a 100644
--- a/media/libaaudio/src/core/AudioStream.cpp
+++ b/media/libaaudio/src/core/AudioStream.cpp
@@ -21,7 +21,9 @@
 #include <atomic>
 #include <stdint.h>
 
+#include <linux/futex.h>
 #include <media/MediaMetricsItem.h>
+#include <sys/syscall.h>
 
 #include <aaudio/AAudio.h>
 
@@ -362,34 +364,37 @@
 }
 
 void AudioStream::setState(aaudio_stream_state_t state) {
-    ALOGD("%s(s#%d) from %d to %d", __func__, getId(), mState, state);
-    if (state == mState) {
+    aaudio_stream_state_t oldState = mState.load();
+    ALOGD("%s(s#%d) from %d to %d", __func__, getId(), oldState, state);
+    if (state == oldState) {
         return; // no change
     }
     // Track transition to DISCONNECTED state.
     if (state == AAUDIO_STREAM_STATE_DISCONNECTED) {
         android::mediametrics::LogItem(mMetricsId)
                 .set(AMEDIAMETRICS_PROP_EVENT, AMEDIAMETRICS_PROP_EVENT_VALUE_DISCONNECT)
-                .set(AMEDIAMETRICS_PROP_STATE, AudioGlobal_convertStreamStateToText(getState()))
+                .set(AMEDIAMETRICS_PROP_STATE, AudioGlobal_convertStreamStateToText(oldState))
                 .record();
     }
     // CLOSED is a final state
-    if (mState == AAUDIO_STREAM_STATE_CLOSED) {
+    if (oldState == AAUDIO_STREAM_STATE_CLOSED) {
         ALOGW("%s(%d) tried to set to %d but already CLOSED", __func__, getId(), state);
 
     // Once CLOSING, we can only move to CLOSED state.
-    } else if (mState == AAUDIO_STREAM_STATE_CLOSING
+    } else if (oldState == AAUDIO_STREAM_STATE_CLOSING
                && state != AAUDIO_STREAM_STATE_CLOSED) {
         ALOGW("%s(%d) tried to set to %d but already CLOSING", __func__, getId(), state);
 
     // Once DISCONNECTED, we can only move to CLOSING or CLOSED state.
-    } else if (mState == AAUDIO_STREAM_STATE_DISCONNECTED
+    } else if (oldState == AAUDIO_STREAM_STATE_DISCONNECTED
                && !(state == AAUDIO_STREAM_STATE_CLOSING
                    || state == AAUDIO_STREAM_STATE_CLOSED)) {
         ALOGW("%s(%d) tried to set to %d but already DISCONNECTED", __func__, getId(), state);
 
     } else {
-        mState = state;
+        mState.store(state);
+        // Wake up a wakeForStateChange thread if it exists.
+        syscall(SYS_futex, &mState, FUTEX_WAKE_PRIVATE, INT_MAX, NULL, NULL, 0);
     }
 }
 
@@ -408,9 +413,15 @@
         if (durationNanos > timeoutNanoseconds) {
             durationNanos = timeoutNanoseconds;
         }
-        AudioClock::sleepForNanos(durationNanos);
-        timeoutNanoseconds -= durationNanos;
+        struct timespec time;
+        time.tv_sec = durationNanos / AAUDIO_NANOS_PER_SECOND;
+        // Add the fractional nanoseconds.
+        time.tv_nsec = durationNanos - (time.tv_sec * AAUDIO_NANOS_PER_SECOND);
 
+        // Sleep for durationNanos. If mState changes from the callback
+        // thread, this thread will wake up earlier.
+        syscall(SYS_futex, &mState, FUTEX_WAIT_PRIVATE, currentState, &time, NULL, 0);
+        timeoutNanoseconds -= durationNanos;
         aaudio_result_t result = updateStateMachine();
         if (result != AAUDIO_OK) {
             return result;
diff --git a/media/libaaudio/src/core/AudioStream.h b/media/libaaudio/src/core/AudioStream.h
index 5fb4528..8dd5538 100644
--- a/media/libaaudio/src/core/AudioStream.h
+++ b/media/libaaudio/src/core/AudioStream.h
@@ -100,10 +100,17 @@
                                        int64_t *timeNanoseconds) = 0;
 
     /**
-     * Update state machine.()
-     * @return
+     * Update state machine.
+     * @return result of the operation.
      */
-    virtual aaudio_result_t updateStateMachine() = 0;
+    aaudio_result_t updateStateMachine() {
+        if (isDataCallbackActive()) {
+            return AAUDIO_OK; // state is getting updated by the callback thread read/write call
+        }
+        return processCommands();
+    };
+
+    virtual aaudio_result_t processCommands() = 0;
 
     // =========== End ABSTRACT methods ===========================
 
@@ -184,7 +191,7 @@
     // ============== Queries ===========================
 
     aaudio_stream_state_t getState() const {
-        return mState;
+        return mState.load();
     }
 
     virtual int32_t getBufferSize() const {
@@ -674,6 +681,8 @@
 
     const android::sp<MyPlayerBase>   mPlayerBase;
 
+    std::atomic<aaudio_stream_state_t>          mState{AAUDIO_STREAM_STATE_UNINITIALIZED};
+
     // These do not change after open().
     int32_t                     mSamplesPerFrame = AAUDIO_UNSPECIFIED;
     aaudio_channel_mask_t       mChannelMask = AAUDIO_UNSPECIFIED;
@@ -682,7 +691,6 @@
     aaudio_sharing_mode_t       mSharingMode = AAUDIO_SHARING_MODE_SHARED;
     bool                        mSharingModeMatchRequired = false; // must match sharing mode requested
     audio_format_t              mFormat = AUDIO_FORMAT_DEFAULT;
-    aaudio_stream_state_t       mState = AAUDIO_STREAM_STATE_UNINITIALIZED;
     aaudio_performance_mode_t   mPerformanceMode = AAUDIO_PERFORMANCE_MODE_NONE;
     int32_t                     mFramesPerBurst = 0;
     int32_t                     mBufferCapacity = 0;
diff --git a/media/libaaudio/src/legacy/AudioStreamLegacy.cpp b/media/libaaudio/src/legacy/AudioStreamLegacy.cpp
index dd11169..f32ef65 100644
--- a/media/libaaudio/src/legacy/AudioStreamLegacy.cpp
+++ b/media/libaaudio/src/legacy/AudioStreamLegacy.cpp
@@ -127,7 +127,7 @@
             mCallbackEnabled.store(false);
         }
 
-        if (updateStateMachine() != AAUDIO_OK) {
+        if (processCommands() != AAUDIO_OK) {
             forceDisconnect();
             mCallbackEnabled.store(false);
         }
@@ -192,7 +192,7 @@
             mCallbackEnabled.store(false);
         }
 
-        if (updateStateMachine() != AAUDIO_OK) {
+        if (processCommands() != AAUDIO_OK) {
             forceDisconnect();
             mCallbackEnabled.store(false);
         }
diff --git a/media/libaaudio/src/legacy/AudioStreamRecord.cpp b/media/libaaudio/src/legacy/AudioStreamRecord.cpp
index 1e39e0f..9a136a7 100644
--- a/media/libaaudio/src/legacy/AudioStreamRecord.cpp
+++ b/media/libaaudio/src/legacy/AudioStreamRecord.cpp
@@ -364,8 +364,7 @@
     return checkForDisconnectRequest(false);
 }
 
-aaudio_result_t AudioStreamRecord::updateStateMachine()
-{
+aaudio_result_t AudioStreamRecord::processCommands() {
     aaudio_result_t result = AAUDIO_OK;
     aaudio_wrapping_frames_t position;
     status_t err;
diff --git a/media/libaaudio/src/legacy/AudioStreamRecord.h b/media/libaaudio/src/legacy/AudioStreamRecord.h
index 5ce73f9..252ff3c 100644
--- a/media/libaaudio/src/legacy/AudioStreamRecord.h
+++ b/media/libaaudio/src/legacy/AudioStreamRecord.h
@@ -58,7 +58,7 @@
 
     int64_t getFramesWritten() override;
 
-    aaudio_result_t updateStateMachine() override;
+    aaudio_result_t processCommands() override;
 
     aaudio_direction_t getDirection() const override {
         return AAUDIO_DIRECTION_INPUT;
diff --git a/media/libaaudio/src/legacy/AudioStreamTrack.cpp b/media/libaaudio/src/legacy/AudioStreamTrack.cpp
index 6f1dc92..09caa5c 100644
--- a/media/libaaudio/src/legacy/AudioStreamTrack.cpp
+++ b/media/libaaudio/src/legacy/AudioStreamTrack.cpp
@@ -378,8 +378,7 @@
     return checkForDisconnectRequest(false);;
 }
 
-aaudio_result_t AudioStreamTrack::updateStateMachine()
-{
+aaudio_result_t AudioStreamTrack::processCommands() {
     status_t err;
     aaudio_wrapping_frames_t position;
     switch (getState()) {
diff --git a/media/libaaudio/src/legacy/AudioStreamTrack.h b/media/libaaudio/src/legacy/AudioStreamTrack.h
index 0f4d72b..1f877b5 100644
--- a/media/libaaudio/src/legacy/AudioStreamTrack.h
+++ b/media/libaaudio/src/legacy/AudioStreamTrack.h
@@ -79,7 +79,7 @@
         return AAUDIO_DIRECTION_OUTPUT;
     }
 
-    aaudio_result_t updateStateMachine() override;
+    aaudio_result_t processCommands() override;
 
     int64_t incrementClientFrameCounter(int32_t frames) override {
         return incrementFramesWritten(frames);