IssueTracker

- Steps to reproduce the problem (including sample code if appropriate).
1. doing monkey test a whole day.
2. restart device.

- What happened.
System main thread may happened watchdog timeout when GMS calling UsageStatsService.queryEvents
but costs too much, because activity / pause usage event too mush in daily usage event file.
(as attachemnt for daily event xml file sample run by monkey test)

//watchdog timeout should be happened in this time but because delayed by UsageStatsService.queryEvents called by GMS
10-31 09:56:14.017  1351  1351 W art     : Long monitor contention event with owner method=android.app.usage.UsageEvents com.android.server.usage.UsageStatsService.queryEvents(int, long, long) from UsageStatsService.java:720 waiters=1 for 91.896s

10-31 09:56:31.718  1351  1856 W Watchdog: *** WATCHDOG KILLING SYSTEM PROCESS: Blocked in handler on main thread (main)

//system server main-thread be blocked points
"main" prio=5 tid=1 Blocked
  | group="main" sCount=1 dsCount=0 obj=0x7323efa0 self=0xb8a5c328
  | sysTid=1351 nice=-2 cgrp=default sched=0/0 handle=0xb6f96b44
  | state=S schedstat=( 2593657022208 1661164362022 3429213 ) utm=183361 stm=76004 core=1 HZ=100
  | stack=0xbe653000-0xbe655000 stackSize=8MB
  | held mutexes=
  at com.android.server.usage.UsageStatsService$1.onDisplayChanged(UsageStatsService.java:271)
  - waiting to lock <0x0ccd17d8> (a java.lang.Object) held by thread 78
  at android.hardware.display.DisplayManagerGlobal$DisplayListenerDelegate.handleMessage(DisplayManagerGlobal.java:467)
  at android.os.Handler.dispatchMessage(Handler.java:102)
  at android.os.Looper.loop(Looper.java:168)
  at com.android.server.SystemServer.run(SystemServer.java:350)
  at com.android.server.SystemServer.main(SystemServer.java:235)
  at java.lang.reflect.Method.invoke!(Native method)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:797)
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:687)

…
"Binder_6" prio=5 tid=78 Runnable
  | group="main" sCount=0 dsCount=0 obj=0x138360a0 self=0xb9c35170
  | sysTid=1913 nice=0 cgrp=default sched=0/0 handle=0x9003c930
  | state=R schedstat=( 3550088585589 2264783707620 5548719 ) utm=290795 stm=64229 core=3 HZ=100
  | stack=0x8ff40000-0x8ff42000 stackSize=1014KB
  | held mutexes= "mutator lock"(shared held)
  at java.lang.String.equals(String.java:431)
  at org.kxml2.io.KXmlParser.getAttributeValue(KXmlParser.java:2038)
  at com.android.internal.util.XmlUtils.readLongAttribute(XmlUtils.java:1556)
  at com.android.server.usage.UsageStatsXmlV1.loadEvent(UsageStatsXmlV1.java:123)
  at com.android.server.usage.UsageStatsXmlV1.read(UsageStatsXmlV1.java:234)
  at com.android.server.usage.UsageStatsXml.read(UsageStatsXml.java:99)
  at com.android.server.usage.UsageStatsXml.read(UsageStatsXml.java:63)
  at com.android.server.usage.UsageStatsDatabase.queryUsageStats(UsageStatsDatabase.java:446)
  - locked <0x095d56bb> (a java.lang.Object)
  at com.android.server.usage.UserUsageStatsService.queryStats(UserUsageStatsService.java:315)
  at com.android.server.usage.UserUsageStatsService.queryEvents(UserUsageStatsService.java:351)
  at com.android.server.usage.UsageStatsService.queryEvents(UsageStatsService.java:728)
  - locked <0x0ccd17d8> (a java.lang.Object)
  at com.android.server.usage.UsageStatsService$BinderService.queryEvents(UsageStatsService.java:1216)
  at android.app.usage.IUsageStatsManager$Stub.onTransact(IUsageStatsManager.java:103)
  at android.os.Binder.execTransact(Binder.java:461)



----- pid 10800 at 2015-10-31 09:56:36 -----
Cmd line: com.google.process.gapps
…
"IntentService[LockboxService]" prio=5 tid=41 Native
  | group="main" sCount=1 dsCount=0 obj=0x13cc9ac0 self=0xba43aea8
  | sysTid=19170 nice=0 cgrp=default sched=0/0 handle=0x98afa930
  | state=S schedstat=( 1934023469 775424381 1191 ) utm=170 stm=23 core=3 HZ=100
  | stack=0x989f8000-0x989fa000 stackSize=1038KB
  | held mutexes=
  native: #00 pc 00043a24  /system/lib/libc.so (__ioctl+8)
  native: #01 pc 00049e99  /system/lib/libc.so (ioctl+14)
  native: #02 pc 0001ead9  /system/lib/libbinder.so (android::IPCThreadState::talkWithDriver(bool)+132)
  native: #03 pc 0001f217  /system/lib/libbinder.so (android::IPCThreadState::waitForResponse(android::Parcel*, int*)+38)
  native: #04 pc 0001f463  /system/lib/libbinder.so (android::IPCThreadState::transact(int, unsigned int, android::Parcel const&, android::Parcel*, unsigned int)+274)
  native: #05 pc 0001a0bb  /system/lib/libbinder.so (android::BpBinder::transact(unsigned int, android::Parcel const&, android::Parcel*, unsigned int)+30)
  native: #06 pc 0008fef9  /system/lib/libandroid_runtime.so (android_os_BinderProxy_transact(_JNIEnv*, _jobject*, int, _jobject*, _jobject*, int)+280)
  native: #07 pc 73235819  /data/dalvik-cache/arm/system@framework@boot.oat (Java_android_os_BinderProxy_transactNative__ILandroid_os_Parcel_2Landroid_os_Parcel_2I+140)
  at android.os.BinderProxy.transactNative(Native method)
  at android.os.BinderProxy.transact(Binder.java:511)
  at android.app.usage.IUsageStatsManager$Stub$Proxy.queryEvents(IUsageStatsManager.java:232)
  at android.app.usage.UsageStatsManager.queryEvents(UsageStatsManager.java:182)

  at com.google.android.gms.lockbox.a.f.a(SourceFile:73)
  at com.google.android.gms.lockbox.LockboxService.a(SourceFile:187)
  at com.google.android.gms.lockbox.LockboxService.onHandleIntent(SourceFile:141)
  at android.app.IntentService$ServiceHandler.handleMessage(IntentService.java:66)
  at android.os.Handler.dispatchMessage(Handler.java:102)
  at android.os.Looper.loop(Looper.java:168)
  at android.os.HandlerThread.run(HandlerThread.java:61)
…
proc 10800
  thread 19170: l 10
    outgoing transaction 144717221: d8932480 from 10800:19170 to 1351:1913 code 3 flags 10 pri 0 r1 node 3229 size 152:0 data c940058c



- What you think the correct behavior should be.
UsageStatsService.onDisplayChanged callback should be executed in another thread instead in system main thread.

-- OS version
android 6.0