tree b5faf2c76e83a21df1b6fe61e4d71664e4d02047
parent 5b48229b7406b2d80c189a978d71eda877ef36fc
author Dianne Hackborn <hackbod@google.com> 1368224608 -0700
committer Dianne Hackborn <hackbod@google.com> 1368493314 -0700

Improve watchdog error reporting.

We now keep track of all the threads that are stopped, and
print stacks for all of them.  Also more threads are now adding
themselves to the watchdog.

Unfortunately the stack we get from threads is far less useful
than the stacks from the ANR report, because these don't include
any information about the lock the thread is blocked on and what
thread is holding that lock.  For example, here is a test of the
log output from causing a hang in the system process:

W/Watchdog( 5205): *** WATCHDOG KILLING SYSTEM PROCESS: com.android.server.am.ActivityManagerService, main thread
W/Watchdog( 5205): foreground thread stack trace:
W/Watchdog( 5205):     at com.android.server.am.ActivityManagerService.monitor(ActivityManagerService.java:14333)
W/Watchdog( 5205):     at com.android.server.Watchdog$HandlerChecker.run(Watchdog.java:142)
W/Watchdog( 5205):     at android.os.Handler.handleCallback(Handler.java:730)
W/Watchdog( 5205):     at android.os.Handler.dispatchMessage(Handler.java:92)
W/Watchdog( 5205):     at android.os.Looper.loop(Looper.java:137)
W/Watchdog( 5205):     at android.os.HandlerThread.run(HandlerThread.java:61)
W/Watchdog( 5205): main thread stack trace:
W/Watchdog( 5205):     at com.android.server.am.ActivityManagerService.broadcastIntent(ActivityManagerService.java:12252)
W/Watchdog( 5205):     at android.app.ContextImpl.sendBroadcastAsUser(ContextImpl.java:1158)
W/Watchdog( 5205):     at com.android.server.DropBoxManagerService$3.handleMessage(DropBoxManagerService.java:161)
W/Watchdog( 5205):     at android.os.Handler.dispatchMessage(Handler.java:99)
W/Watchdog( 5205):     at android.os.Looper.loop(Looper.java:137)
W/Watchdog( 5205):     at com.android.server.ServerThread.initAndLoop(SystemServer.java:1050)
W/Watchdog( 5205):     at com.android.server.SystemServer.init2(SystemServer.java:1125)
W/Watchdog( 5205):     at com.android.server.SystemServer.init1(Native Method)
W/Watchdog( 5205):     at com.android.server.SystemServer.main(SystemServer.java:1116)
W/Watchdog( 5205):     at java.lang.reflect.Method.invokeNative(Native Method)
W/Watchdog( 5205):     at java.lang.reflect.Method.invoke(Method.java:525)
W/Watchdog( 5205):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:774)
W/Watchdog( 5205):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:590)
W/Watchdog( 5205):     at dalvik.system.NativeStart.main(Native Method)
I/Process ( 5205): Sending signal. PID: 5205 SIG: 9

Change-Id: I8ff9892d8d072d8dc599a73de4bdb75e3b1a6e97