AM: Fix deadlock when calling AMS from ATMS/WM (006ee3fe) · Commits · e / os / android_frameworks_base

core/java/android/app/ActivityManagerInternal.java

+7 −2

Original line number	Diff line number	Diff line
		@@ -277,7 +277,12 @@ public abstract class ActivityManagerInternal {
		public abstract void startProcess(String processName, ApplicationInfo info,
		boolean knownToBeDead, String hostingType, ComponentName hostingName);

		/** Starts up the starting activity process for debugging if needed. */
		/** Starts up the starting activity process for debugging if needed.
		* This function needs to be called synchronously from WindowManager context so the caller
		* passes a lock {@code wmLock} and waits to be notified.
		*
		* @param wmLock calls {@code notify} on the object to wake up the caller.
		*/
		public abstract void setDebugFlagsForStartingActivity(ActivityInfo aInfo, int startFlags,
		ProfilerInfo profilerInfo);
		ProfilerInfo profilerInfo, Object wmLock);
		}

services/core/java/com/android/server/am/ActivityManagerService.java

+21 −30

Original line number	Diff line number	Diff line
		@@ -3046,36 +3046,19 @@ public class ActivityManagerService extends IActivityManager.Stub
		public final int startActivityAsUser(IApplicationThread caller, String callingPackage,
		Intent intent, String resolvedType, IBinder resultTo, String resultWho, int requestCode,
		int startFlags, ProfilerInfo profilerInfo, Bundle bOptions, int userId) {
		synchronized (this) {
		/**
		* Flags like {@link android.app.ActivityManager#START_FLAG_DEBUG} maybe be set on this
		* call when called/invoked from the shell command. To avoid deadlock, we go ahead and
		* acquire the AMS lock now since ATMS will need to synchronously call back into AMS
		* later to modify process settings due to the flags.
		* TODO(b/80414790): Investigate a better way of untangling this.
		*/

		return mActivityTaskManager.startActivityAsUser(caller, callingPackage, intent,
		resolvedType, resultTo, resultWho, requestCode, startFlags, profilerInfo,
		bOptions, userId);
		}
		}

		WaitResult startActivityAndWait(IApplicationThread caller, String callingPackage,
		Intent intent, String resolvedType, IBinder resultTo, String resultWho, int requestCode,
		int startFlags, ProfilerInfo profilerInfo, Bundle bOptions, int userId) {
		synchronized (this) {
		/**
		* Flags like {@link android.app.ActivityManager#START_FLAG_DEBUG} maybe be set on this
		* call when called/invoked from the shell command. To avoid deadlock, we go ahead and
		* acquire the AMS lock now since ATMS will need to synchronously call back into AMS
		* later to modify process settings due to the flags.
		* TODO(b/80414790): Investigate a better way of untangling this.
		*/
		return mActivityTaskManager.startActivityAndWait(caller, callingPackage, intent,
		resolvedType, resultTo, resultWho, requestCode, startFlags, profilerInfo,
		bOptions, userId);
		}
		}

		@Override
		public final int startActivityFromRecents(int taskId, Bundle bOptions) {
		@@ -19166,8 +19149,14 @@ public class ActivityManagerService extends IActivityManager.Stub

		@Override
		public void setDebugFlagsForStartingActivity(ActivityInfo aInfo, int startFlags,
		ProfilerInfo profilerInfo) {
		ProfilerInfo profilerInfo, Object wmLock) {
		synchronized (ActivityManagerService.this) {
		/**
		* This function is called from the window manager context and needs to be executed
		* synchronously. To avoid deadlock, we pass a message to AMS to execute the
		* function and notify the passed in lock when it has been completed.
		*/
		synchronized (wmLock) {
		if ((startFlags & ActivityManager.START_FLAG_DEBUG) != 0) {
		setDebugApp(aInfo.processName, true, false);
		}
		@@ -19183,6 +19172,8 @@ public class ActivityManagerService extends IActivityManager.Stub
		if (profilerInfo != null) {
		setProfileApp(aInfo.applicationInfo, aInfo.processName, profilerInfo);
		}
		wmLock.notify();
		}
		}
		}
		}

services/core/java/com/android/server/wm/ActivityStackSupervisor.java

+18 −9

Original line number	Diff line number	Diff line
		@@ -1272,15 +1272,24 @@ public class ActivityStackSupervisor extends ConfigurationContainer implements D
		if (!aInfo.processName.equals("system")) {
		if ((startFlags & (START_FLAG_DEBUG \| START_FLAG_NATIVE_DEBUGGING
		\| START_FLAG_TRACK_ALLOCATION)) != 0 \|\| profilerInfo != null) {
		/**
		* Assume safe to call into AMS synchronously because the call that set these
		* flags should have originated from AMS which will already have its lock held.
		* @see ActivityManagerService#startActivityAndWait(IApplicationThread, String,
		* Intent, String, IBinder, String, int, int, ProfilerInfo, Bundle, int)
		* TODO(b/80414790): Investigate a better way of untangling this.
		*/
		mService.mAmInternal.setDebugFlagsForStartingActivity(
		aInfo, startFlags, profilerInfo);

		// Mimic an AMS synchronous call by passing a message to AMS and wait for AMS
		// to notify us that the task has completed.
		// TODO(b/80414790) look into further untangling for the situation where the
		// caller is on the same thread as the handler we are posting to.
		synchronized (mService.mGlobalLock) {
		// Post message to AMS.
		final Message msg = PooledLambda.obtainMessage(
		ActivityManagerInternal::setDebugFlagsForStartingActivity,
		mService.mAmInternal, aInfo, startFlags, profilerInfo,
		mService.mGlobalLock);
		mService.mH.sendMessage(msg);
		try {
		mService.mGlobalLock.wait();
		} catch (InterruptedException ignore) {

		}
		}
		}
		}
		final String intentLaunchToken = intent.getLaunchToken();