trancoding: lazy-start transcoding service

bug: 186387244
test: atest MediaTranscodeManagerTest; unit tests
Change-Id: I354f32d062b9a46ddfc9f86d5f79c778809799a4

apex/media/framework/java/android/media/MediaTranscodeManager.java

@@ -22,6 +22,7 @@ import android.annotation.IntRange;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.annotation.SystemApi;
+import android.app.ActivityManager;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.res.AssetFileDescriptor;
@@ -36,6 +37,7 @@ import android.util.Log;
 import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.modules.annotation.MinSdk;
+import com.android.modules.utils.build.SdkLevel;
 
 import java.io.FileNotFoundException;
 import java.lang.annotation.Retention;
@@ -119,6 +121,7 @@ public final class MediaTranscodeManager {
     private final String mPackageName;
     private final int mPid;
     private final int mUid;
+    private final boolean mIsLowRamDevice;
     private final ExecutorService mExecutor = Executors.newSingleThreadExecutor();
     private final HashMap<Integer, TranscodingSession> mPendingTranscodingSessions = new HashMap();
     private final Object mLock = new Object();
@@ -199,7 +202,16 @@ public final class MediaTranscodeManager {
         }
     }
 
-    private static IMediaTranscodingService getService(boolean retry) {
+    private IMediaTranscodingService getService(boolean retry) {
+        // Do not try to get the service on pre-S. The service is lazy-start and getting the
+        // service could block.
+        if (!SdkLevel.isAtLeastS()) {
+            return null;
+        }
+        // Do not try to get the service on AndroidGo (low-ram) devices.
+        if (mIsLowRamDevice) {
+            return null;
+        }
         int retryCount = !retry ? 1 :  CONNECT_SERVICE_RETRY_COUNT;
         Log.i(TAG, "get service with retry " + retryCount);
         for (int count = 1;  count <= retryCount; count++) {
@@ -417,6 +429,7 @@ public final class MediaTranscodeManager {
         mPackageName = mContext.getPackageName();
         mUid = Os.getuid();
         mPid = Os.getpid();
+        mIsLowRamDevice = mContext.getSystemService(ActivityManager.class).isLowRamDevice();
         IMediaTranscodingService service = getService(false /*retry*/);
         if (service != null) {
             mTranscodingClient = registerClient(service);

media/java/android/media/MediaServiceManager.java

@@ -45,12 +45,21 @@ public class MediaServiceManager {
      */
     public static final class ServiceRegisterer {
         private final String mServiceName;
+        private final boolean mLazyStart;
+
+        /**
+         * @hide
+         */
+        public ServiceRegisterer(String serviceName, boolean lazyStart) {
+            mServiceName = serviceName;
+            mLazyStart = lazyStart;
+        }
 
         /**
          * @hide
          */
         public ServiceRegisterer(String serviceName) {
-            mServiceName = serviceName;
+            this(serviceName, false /*lazyStart*/);
         }
 
         /**
@@ -61,6 +70,9 @@ public class MediaServiceManager {
          */
         @Nullable
         public IBinder get() {
+            if (mLazyStart) {
+                return ServiceManager.waitForService(mServiceName);
+            }
             return ServiceManager.getService(mServiceName);
         }
     }
@@ -78,7 +90,7 @@ public class MediaServiceManager {
      */
     @NonNull
     public ServiceRegisterer getMediaTranscodingServiceRegisterer() {
-        return new ServiceRegisterer(MEDIA_TRANSCODING_SERVICE);
+        return new ServiceRegisterer(MEDIA_TRANSCODING_SERVICE, true /*lazyStart*/);
     }
 
     /**