From 2443760584e8e9798b65b297f1636953c287e5d8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fran=C3=A7ois=20Gaffie?= <francois.gaffie@renault.com>
Date: Mon, 23 Apr 2018 15:08:59 +0200
Subject: [PATCH] audio policy service: fix audioserver port cb upon APS crash
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In case of an audioserver crash, clients that registered AudioPort
cb are no more notified of Port and Patch update (only Service Died
continues to work).
The AudioPolicyService client shall upon registration set again the
cb flag to continue beeing notified.

Also clear binder caller identity before registering a client to
audio flinger and audio policy services to avoid registering the
wrong client when get_audio_flinger() or get_audio_policy_service()
is called while executing a binder call.

Bug: 78506562
Test: launch a test app registering to Port Callback. Check upon
setDeviceConnectionState and createAudioPatch that cb are called.
Kill the audio server, and check cb continue to be called.

Change-Id: If1e803f59cb02fba84b6259e9da2d7031235d9c2
Signed-off-by: François Gaffie <francois.gaffie@renault.com>
---
 media/libaudioclient/AudioSystem.cpp             | 6 ++++++
 media/libaudioclient/include/media/AudioSystem.h | 1 +
 2 files changed, 7 insertions(+)

diff --git a/media/libaudioclient/AudioSystem.cpp b/media/libaudioclient/AudioSystem.cpp
index 1c4a80e82a..39ee437044 100644
--- a/media/libaudioclient/AudioSystem.cpp
+++ b/media/libaudioclient/AudioSystem.cpp
@@ -20,6 +20,7 @@
 #include <utils/Log.h>
 #include <binder/IServiceManager.h>
 #include <binder/ProcessState.h>
+#include <binder/IPCThreadState.h>
 #include <media/AudioResamplerPublic.h>
 #include <media/AudioSystem.h>
 #include <media/IAudioFlinger.h>
@@ -75,7 +76,9 @@ const sp<IAudioFlinger> AudioSystem::get_audio_flinger()
         af = gAudioFlinger;
     }
     if (afc != 0) {
+        int64_t token = IPCThreadState::self()->clearCallingIdentity();
         af->registerClient(afc);
+        IPCThreadState::self()->restoreCallingIdentity(token);
     }
     return af;
 }
@@ -767,7 +770,10 @@ const sp<IAudioPolicyService> AudioSystem::get_audio_policy_service()
         ap = gAudioPolicyService;
     }
     if (apc != 0) {
+        int64_t token = IPCThreadState::self()->clearCallingIdentity();
         ap->registerClient(apc);
+        ap->setAudioPortCallbacksEnabled(apc->isAudioPortCbEnabled());
+        IPCThreadState::self()->restoreCallingIdentity(token);
     }
 
     return ap;
diff --git a/media/libaudioclient/include/media/AudioSystem.h b/media/libaudioclient/include/media/AudioSystem.h
index 22b700d6b7..0c4d6ee9a8 100644
--- a/media/libaudioclient/include/media/AudioSystem.h
+++ b/media/libaudioclient/include/media/AudioSystem.h
@@ -431,6 +431,7 @@ private:
 
         int addAudioPortCallback(const sp<AudioPortCallback>& callback);
         int removeAudioPortCallback(const sp<AudioPortCallback>& callback);
+        bool isAudioPortCbEnabled() const { return (mAudioPortCallbacks.size() != 0); }
 
         // DeathRecipient
         virtual void binderDied(const wp<IBinder>& who);