audio policy: reuse direct output when possible

Modified getOutput() logic to not systematically
open a new direct output when a profile matches a request.
This causes a problem when transitioning between two
multichannel tracks as the audio HAL will most of the times
only support one direct output stream open at a time.

Instead, reuse an open output if all the parameters match
or force close the output before reopening it.

Also modify releaseOuput():
- close a direct output only if no client is using it anymore
- call closeOutput() instead of removing the output from
the open output list: this factors in code executed when closing an
output stream.

Bug 8388941

Change-Id: Ic3d3beb21063622ddf57a5b932f93d56f2986f54

1 files changed, 1 insertions, 0 deletions

diff --git a/include/hardware_legacy/AudioPolicyManagerBase.h b/include/hardware_legacy/AudioPolicyManagerBase.h
index c5a917c..7ba71e7 100644
--- a/include/hardware_legacy/AudioPolicyManagerBase.h
+++ b/include/hardware_legacy/AudioPolicyManagerBase.h
@@ -275,6 +275,7 @@ protected:
             const IOProfile *mProfile;          // I/O profile this output derives from
             bool mStrategyMutedByDevice[NUM_STRATEGIES]; // strategies muted because of incompatible
                                                 // device selection. See checkDeviceMuteStrategies()
+            uint32_t mDirectOpenCount; // number of clients using this output (direct outputs only)
         };
 
         // descriptor for audio inputs. Used to maintain current configuration of each opened audio input