commit e13c679e4afba66097018516eba9ea15d15bbc7a
author Mikhail Naganov <mnaganov@google.com> Tue May 14 10:32:51 2019 -0700
committer jiabin <jiabin@google.com> Wed Sep 25 14:59:42 2019 -0700
tree 216ecb3fe033354b1d07ce88aa8ccecb15f4c3fa
parent 3e0b02e336f3b5d59c5162e743d10d86be63c66b

audiopolicy: Load the engine library dynamically

Android provides 2 audio policy engines:
libaudiopolicyenginedefault and
libaudiopolicyengineconfigurable. This change makes the engine
to be loaded dynamically based on the configuration (currently
the engine name is hardcoded into AudioPolicyConfig). Dynamic
loading allows building and installing of both libraries without
any conflicts.

Technical changes:

 - AudioPolicyManagerInterface renamed to EngineInterface
   for clarity;

 - For the purpose of dynamic loading, APM does not depend
   anymore on the EngineInstance class. The class got removed
   from the default AP engine, but left in the configurable engine
   because it is also used by its plugins;

 - Added EngineLibrary class to encapsulate dynamic loading
   of the AP engine. The class name EngineInstance is repurposed
   for a smart pointer to EngineInterface;

 - services/audiopolicy/managerdefault/Android.mk converted
   into Android.bp;

 - Added engine loading failure test;

Bug: 132639720
Test: sanity tests for audio; audiopolicy_tests
Change-Id: I0581569a172f810e030aec879225e817bfa7851a
Merged-In: I0581569a172f810e030aec879225e817bfa7851a

services/audiopolicy/managerdefault/AudioPolicyManager.cpp

diff --git a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
index a8fd9cd..39f4072 100644
--- a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
+++ b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
@@ -42,8 +42,6 @@
 #include <set>
 #include <unordered_set>
 #include <vector>
-#include <AudioPolicyManagerInterface.h>
-#include <AudioPolicyEngineInstance.h>
 #include <cutils/properties.h>
 #include <utils/Log.h>
 #include <media/AudioParameter.h>
@@ -4304,17 +4302,18 @@
 }
 
 status_t AudioPolicyManager::initialize() {
-    // Once policy config has been parsed, retrieve an instance of the engine and initialize it.
-    audio_policy::EngineInstance *engineInstance = audio_policy::EngineInstance::getInstance();
-    if (!engineInstance) {
-        ALOGE("%s:  Could not get an instance of policy engine", __FUNCTION__);
-        return NO_INIT;
-    }
-    // Retrieve the Policy Manager Interface
-    mEngine = engineInstance->queryInterface<AudioPolicyManagerInterface>();
-    if (mEngine == NULL) {
-        ALOGE("%s: Failed to get Policy Engine Interface", __FUNCTION__);
-        return NO_INIT;
+    {
+        auto engLib = EngineLibrary::load(
+                        "libaudiopolicyengine" + getConfig().getEngineLibraryNameSuffix() + ".so");
+        if (!engLib) {
+            ALOGE("%s: Failed to load the engine library", __FUNCTION__);
+            return NO_INIT;
+        }
+        mEngine = engLib->createEngine();
+        if (mEngine == nullptr) {
+            ALOGE("%s: Failed to instantiate the APM engine", __FUNCTION__);
+            return NO_INIT;
+        }
     }
     mEngine->setObserver(this);
     status_t status = mEngine->initCheck();