AudioService: fix cross deadlock in VolumeStreamState

Synchronize modifications of volume index by VolumeStreamState
class mutex instead of using synchronized methods.
This avoids possible cross deadlock when modifying volume on
two stream types simultaneously and one is slave to the other.

Bug: 13730145.

Change-Id: I13406c71010ce0c2e2f08f660b6101f310396c98

1 files changed, 147 insertions, 133 deletions

diff --git a/media/java/android/media/AudioService.java b/media/java/android/media/AudioService.java
index b836f50b6b52..1ca0f5d74764 100644
--- a/media/java/android/media/AudioService.java
+++ b/media/java/android/media/AudioService.java
@@ -2857,54 +2857,56 @@ public class AudioService extends IAudioService.Stub {
             return name + "_" + suffix;
         }
 
-        public synchronized void readSettings() {
-            // force maximum volume on all streams if fixed volume property is set
-            if (mUseFixedVolume) {
-                mIndex.put(AudioSystem.DEVICE_OUT_DEFAULT, mIndexMax);
-                return;
-            }
-            // do not read system stream volume from settings: this stream is always aliased
-            // to another stream type and its volume is never persisted. Values in settings can
-            // only be stale values
-            if ((mStreamType == AudioSystem.STREAM_SYSTEM) ||
-                    (mStreamType == AudioSystem.STREAM_SYSTEM_ENFORCED)) {
-                int index = 10 * AudioManager.DEFAULT_STREAM_VOLUME[mStreamType];
-                synchronized (mCameraSoundForced) {
-                    if (mCameraSoundForced) {
-                        index = mIndexMax;
+        public void readSettings() {
+            synchronized (VolumeStreamState.class) {
+                // force maximum volume on all streams if fixed volume property is set
+                if (mUseFixedVolume) {
+                    mIndex.put(AudioSystem.DEVICE_OUT_DEFAULT, mIndexMax);
+                    return;
+                }
+                // do not read system stream volume from settings: this stream is always aliased
+                // to another stream type and its volume is never persisted. Values in settings can
+                // only be stale values
+                if ((mStreamType == AudioSystem.STREAM_SYSTEM) ||
+                        (mStreamType == AudioSystem.STREAM_SYSTEM_ENFORCED)) {
+                    int index = 10 * AudioManager.DEFAULT_STREAM_VOLUME[mStreamType];
+                    synchronized (mCameraSoundForced) {
+                        if (mCameraSoundForced) {
+                            index = mIndexMax;
+                        }
                     }
+                    mIndex.put(AudioSystem.DEVICE_OUT_DEFAULT, index);
+                    return;
                 }
-                mIndex.put(AudioSystem.DEVICE_OUT_DEFAULT, index);
-                return;
-            }
 
-            int remainingDevices = AudioSystem.DEVICE_OUT_ALL;
+                int remainingDevices = AudioSystem.DEVICE_OUT_ALL;
 
-            for (int i = 0; remainingDevices != 0; i++) {
-                int device = (1 << i);
-                if ((device & remainingDevices) == 0) {
-                    continue;
-                }
-                remainingDevices &= ~device;
-
-                // retrieve current volume for device
-                String name = getSettingNameForDevice(device);
-                // if no volume stored for current stream and device, use default volume if default
-                // device, continue otherwise
-                int defaultIndex = (device == AudioSystem.DEVICE_OUT_DEFAULT) ?
-                                        AudioManager.DEFAULT_STREAM_VOLUME[mStreamType] : -1;
-                int index = Settings.System.getIntForUser(
-                        mContentResolver, name, defaultIndex, UserHandle.USER_CURRENT);
-                if (index == -1) {
-                    continue;
-                }
+                for (int i = 0; remainingDevices != 0; i++) {
+                    int device = (1 << i);
+                    if ((device & remainingDevices) == 0) {
+                        continue;
+                    }
+                    remainingDevices &= ~device;
+
+                    // retrieve current volume for device
+                    String name = getSettingNameForDevice(device);
+                    // if no volume stored for current stream and device, use default volume if default
+                    // device, continue otherwise
+                    int defaultIndex = (device == AudioSystem.DEVICE_OUT_DEFAULT) ?
+                                            AudioManager.DEFAULT_STREAM_VOLUME[mStreamType] : -1;
+                    int index = Settings.System.getIntForUser(
+                            mContentResolver, name, defaultIndex, UserHandle.USER_CURRENT);
+                    if (index == -1) {
+                        continue;
+                    }
 
-                // ignore settings for fixed volume devices: volume should always be at max or 0
-                if ((mStreamVolumeAlias[mStreamType] == AudioSystem.STREAM_MUSIC) &&
-                        ((device & mFixedVolumeDevices) != 0)) {
-                    mIndex.put(device, (index != 0) ? mIndexMax : 0);
-                } else {
-                    mIndex.put(device, getValidIndex(10 * index));
+                    // ignore settings for fixed volume devices: volume should always be at max or 0
+                    if ((mStreamVolumeAlias[mStreamType] == AudioSystem.STREAM_MUSIC) &&
+                            ((device & mFixedVolumeDevices) != 0)) {
+                        mIndex.put(device, (index != 0) ? mIndexMax : 0);
+                    } else {
+                        mIndex.put(device, getValidIndex(10 * index));
+                    }
                 }
             }
         }
@@ -2922,32 +2924,34 @@ public class AudioService extends IAudioService.Stub {
             AudioSystem.setStreamVolumeIndex(mStreamType, index, device);
         }
 
-        public synchronized void applyAllVolumes() {
-            // apply default volume first: by convention this will reset all
-            // devices volumes in audio policy manager to the supplied value
-            int index;
-            if (isMuted()) {
-                index = 0;
-            } else {
-                index = (getIndex(AudioSystem.DEVICE_OUT_DEFAULT) + 5)/10;
-            }
-            AudioSystem.setStreamVolumeIndex(mStreamType, index, AudioSystem.DEVICE_OUT_DEFAULT);
-            // then apply device specific volumes
-            Set set = mIndex.entrySet();
-            Iterator i = set.iterator();
-            while (i.hasNext()) {
-                Map.Entry entry = (Map.Entry)i.next();
-                int device = ((Integer)entry.getKey()).intValue();
-                if (device != AudioSystem.DEVICE_OUT_DEFAULT) {
-                    if (isMuted()) {
-                        index = 0;
-                    } else if ((device & AudioSystem.DEVICE_OUT_ALL_A2DP) != 0 &&
-                            mAvrcpAbsVolSupported) {
-                        index = (mIndexMax + 5)/10;
-                    } else {
-                        index = ((Integer)entry.getValue() + 5)/10;
+        public void applyAllVolumes() {
+            synchronized (VolumeStreamState.class) {
+                // apply default volume first: by convention this will reset all
+                // devices volumes in audio policy manager to the supplied value
+                int index;
+                if (isMuted()) {
+                    index = 0;
+                } else {
+                    index = (getIndex(AudioSystem.DEVICE_OUT_DEFAULT) + 5)/10;
+                }
+                AudioSystem.setStreamVolumeIndex(mStreamType, index, AudioSystem.DEVICE_OUT_DEFAULT);
+                // then apply device specific volumes
+                Set set = mIndex.entrySet();
+                Iterator i = set.iterator();
+                while (i.hasNext()) {
+                    Map.Entry entry = (Map.Entry)i.next();
+                    int device = ((Integer)entry.getKey()).intValue();
+                    if (device != AudioSystem.DEVICE_OUT_DEFAULT) {
+                        if (isMuted()) {
+                            index = 0;
+                        } else if ((device & AudioSystem.DEVICE_OUT_ALL_A2DP) != 0 &&
+                                mAvrcpAbsVolSupported) {
+                            index = (mIndexMax + 5)/10;
+                        } else {
+                            index = ((Integer)entry.getValue() + 5)/10;
+                        }
+                        AudioSystem.setStreamVolumeIndex(mStreamType, index, device);
                     }
-                    AudioSystem.setStreamVolumeIndex(mStreamType, index, device);
                 }
             }
         }
@@ -2957,94 +2961,104 @@ public class AudioService extends IAudioService.Stub {
                             device);
         }
 
-        public synchronized boolean setIndex(int index, int device) {
-            int oldIndex = getIndex(device);
-            index = getValidIndex(index);
-            synchronized (mCameraSoundForced) {
-                if ((mStreamType == AudioSystem.STREAM_SYSTEM_ENFORCED) && mCameraSoundForced) {
-                    index = mIndexMax;
+        public boolean setIndex(int index, int device) {
+            synchronized (VolumeStreamState.class) {
+                int oldIndex = getIndex(device);
+                index = getValidIndex(index);
+                synchronized (mCameraSoundForced) {
+                    if ((mStreamType == AudioSystem.STREAM_SYSTEM_ENFORCED) && mCameraSoundForced) {
+                        index = mIndexMax;
+                    }
                 }
-            }
-            mIndex.put(device, index);
-
-            if (oldIndex != index) {
-                // Apply change to all streams using this one as alias
-                // if changing volume of current device, also change volume of current
-                // device on aliased stream
-                boolean currentDevice = (device == getDeviceForStream(mStreamType));
-                int numStreamTypes = AudioSystem.getNumStreamTypes();
-                for (int streamType = numStreamTypes - 1; streamType >= 0; streamType--) {
-                    if (streamType != mStreamType &&
-                            mStreamVolumeAlias[streamType] == mStreamType) {
-                        int scaledIndex = rescaleIndex(index, mStreamType, streamType);
-                        mStreamStates[streamType].setIndex(scaledIndex,
-                                                           device);
-                        if (currentDevice) {
+                mIndex.put(device, index);
+
+                if (oldIndex != index) {
+                    // Apply change to all streams using this one as alias
+                    // if changing volume of current device, also change volume of current
+                    // device on aliased stream
+                    boolean currentDevice = (device == getDeviceForStream(mStreamType));
+                    int numStreamTypes = AudioSystem.getNumStreamTypes();
+                    for (int streamType = numStreamTypes - 1; streamType >= 0; streamType--) {
+                        if (streamType != mStreamType &&
+                                mStreamVolumeAlias[streamType] == mStreamType) {
+                            int scaledIndex = rescaleIndex(index, mStreamType, streamType);
                             mStreamStates[streamType].setIndex(scaledIndex,
-                                                               getDeviceForStream(streamType));
+                                                               device);
+                            if (currentDevice) {
+                                mStreamStates[streamType].setIndex(scaledIndex,
+                                                                   getDeviceForStream(streamType));
+                            }
                         }
                     }
+                    return true;
+                } else {
+                    return false;
                 }
-                return true;
-            } else {
-                return false;
             }
         }
 
-        public synchronized int getIndex(int device) {
-            Integer index = mIndex.get(device);
-            if (index == null) {
-                // there is always an entry for AudioSystem.DEVICE_OUT_DEFAULT
-                index = mIndex.get(AudioSystem.DEVICE_OUT_DEFAULT);
+        public int getIndex(int device) {
+            synchronized (VolumeStreamState.class) {
+                Integer index = mIndex.get(device);
+                if (index == null) {
+                    // there is always an entry for AudioSystem.DEVICE_OUT_DEFAULT
+                    index = mIndex.get(AudioSystem.DEVICE_OUT_DEFAULT);
+                }
+                return index.intValue();
             }
-            return index.intValue();
         }
 
         public int getMaxIndex() {
             return mIndexMax;
         }
 
-        public synchronized void setAllIndexes(VolumeStreamState srcStream) {
-            int srcStreamType = srcStream.getStreamType();
-            // apply default device volume from source stream to all devices first in case
-            // some devices are present in this stream state but not in source stream state
-            int index = srcStream.getIndex(AudioSystem.DEVICE_OUT_DEFAULT);
-            index = rescaleIndex(index, srcStreamType, mStreamType);
-            Set set = mIndex.entrySet();
-            Iterator i = set.iterator();
-            while (i.hasNext()) {
-                Map.Entry entry = (Map.Entry)i.next();
-                entry.setValue(index);
-            }
-            // Now apply actual volume for devices in source stream state
-            set = srcStream.mIndex.entrySet();
-            i = set.iterator();
-            while (i.hasNext()) {
-                Map.Entry entry = (Map.Entry)i.next();
-                int device = ((Integer)entry.getKey()).intValue();
-                index = ((Integer)entry.getValue()).intValue();
+        public void setAllIndexes(VolumeStreamState srcStream) {
+            synchronized (VolumeStreamState.class) {
+                int srcStreamType = srcStream.getStreamType();
+                // apply default device volume from source stream to all devices first in case
+                // some devices are present in this stream state but not in source stream state
+                int index = srcStream.getIndex(AudioSystem.DEVICE_OUT_DEFAULT);
                 index = rescaleIndex(index, srcStreamType, mStreamType);
-
-                setIndex(index, device);
+                Set set = mIndex.entrySet();
+                Iterator i = set.iterator();
+                while (i.hasNext()) {
+                    Map.Entry entry = (Map.Entry)i.next();
+                    entry.setValue(index);
+                }
+                // Now apply actual volume for devices in source stream state
+                set = srcStream.mIndex.entrySet();
+                i = set.iterator();
+                while (i.hasNext()) {
+                    Map.Entry entry = (Map.Entry)i.next();
+                    int device = ((Integer)entry.getKey()).intValue();
+                    index = ((Integer)entry.getValue()).intValue();
+                    index = rescaleIndex(index, srcStreamType, mStreamType);
+
+                    setIndex(index, device);
+                }
             }
         }
 
-        public synchronized void setAllIndexesToMax() {
-            Set set = mIndex.entrySet();
-            Iterator i = set.iterator();
-            while (i.hasNext()) {
-                Map.Entry entry = (Map.Entry)i.next();
-                entry.setValue(mIndexMax);
+        public void setAllIndexesToMax() {
+            synchronized (VolumeStreamState.class) {
+                Set set = mIndex.entrySet();
+                Iterator i = set.iterator();
+                while (i.hasNext()) {
+                    Map.Entry entry = (Map.Entry)i.next();
+                    entry.setValue(mIndexMax);
+                }
             }
         }
 
-        public synchronized void mute(IBinder cb, boolean state) {
-            VolumeDeathHandler handler = getDeathHandler(cb, state);
-            if (handler == null) {
-                Log.e(TAG, "Could not get client death handler for stream: "+mStreamType);
-                return;
+        public void mute(IBinder cb, boolean state) {
+            synchronized (VolumeStreamState.class) {
+                VolumeDeathHandler handler = getDeathHandler(cb, state);
+                if (handler == null) {
+                    Log.e(TAG, "Could not get client death handler for stream: "+mStreamType);
+                    return;
+                }
+                handler.mute(state);
             }
-            handler.mute(state);
         }
 
         public int getStreamType() {