Watchdog can get deadlocked on activity manager (0971a136) · Commits · e / os / android_frameworks_base

services/java/com/android/server/Watchdog.java

+16 −3

Original line number	Original line	Diff line number	Diff line
	@@ -425,7 +425,7 @@ public class Watchdog extends Thread {
	// First collect stack traces from all threads of the system process.		// First collect stack traces from all threads of the system process.
	// Then kill this process so that the system will restart.		// Then kill this process so that the system will restart.

	String name = (mCurrentMonitor != null) ?		final String name = (mCurrentMonitor != null) ?
	mCurrentMonitor.getClass().getName() : "null";		mCurrentMonitor.getClass().getName() : "null";
	EventLog.writeEvent(EventLogTags.WATCHDOG, name);		EventLog.writeEvent(EventLogTags.WATCHDOG, name);

	@@ -434,7 +434,8 @@ public class Watchdog extends Thread {
	if (mPhonePid > 0) pids.add(mPhonePid);		if (mPhonePid > 0) pids.add(mPhonePid);
	// Pass !waitedHalf so that just in case we somehow wind up here without having		// Pass !waitedHalf so that just in case we somehow wind up here without having
	// dumped the halfway stacks, we properly re-initialize the trace file.		// dumped the halfway stacks, we properly re-initialize the trace file.
	File stack = ActivityManagerService.dumpStackTraces(!waitedHalf, pids, null, null);		final File stack = ActivityManagerService.dumpStackTraces(
			!waitedHalf, pids, null, null);

	// Give some extra time to make sure the stack traces get written.		// Give some extra time to make sure the stack traces get written.
	// The system's been hanging for a minute, another second or two won't hurt much.		// The system's been hanging for a minute, another second or two won't hurt much.
	@@ -445,7 +446,19 @@ public class Watchdog extends Thread {
	dumpKernelStackTraces();		dumpKernelStackTraces();
	}		}

	mActivity.addErrorToDropBox("watchdog", null, null, null, name, null, stack, null);		// Try to add the error to the dropbox, but assuming that the ActivityManager
			// itself may be deadlocked. (which has happened, causing this statement to
			// deadlock and the watchdog as a whole to be ineffective)
			Thread dropboxThread = new Thread("watchdogWriteToDropbox") {
			public void run() {
			mActivity.addErrorToDropBox(
			"watchdog", null, null, null, name, null, stack, null);
			}
			};
			dropboxThread.start();
			try {
			dropboxThread.join(2000); // wait up to 2 seconds for it to return.
			} catch (InterruptedException ignored) {}

	// Only kill the process if the debugger is not attached.		// Only kill the process if the debugger is not attached.
	if (!Debug.isDebuggerConnected()) {		if (!Debug.isDebuggerConnected()) {