Android finding a deadlock

2020-07-20 02:32发布

问题:

I am getting an ANR sometimes when I run my Android service. I suspect it is happening because of a deadlock.

Is there an easy way to monitor deadlock in Android or Eclipse. Such as a utility to show which thread hold which lock etc.?

And is there a way to figure out a deadlock by looking at traces.txt file?

My ddms log looks like this at the time of crash

02-15 18:09:01.046: INFO/Process(90): Sending signal. PID: 450 SIG: 3
02-15 18:09:01.046: INFO/dalvikvm(450): threadid=3: reacting to signal 3
02-15 18:09:01.056: INFO/dalvikvm(450): Wrote stack traces to '/data/anr/traces.txt'
02-15 18:09:01.076: INFO/Process(90): Sending signal. PID: 10548 SIG: 9
02-15 18:09:01.076: ERROR/ActivityManager(90): ANR in com.abc.cm.core
02-15 18:09:01.076: ERROR/ActivityManager(90): Reason: Executing service com.abc.cm.core/.WorkOrderManager
02-15 18:09:01.076: ERROR/ActivityManager(90): Load: 1.46 / 1.16 / 1.05
02-15 18:09:01.076: ERROR/ActivityManager(90): CPU usage from 19462ms to 1067ms ago:
02-15 18:09:01.076: ERROR/ActivityManager(90):   abc.cm.core: 13% = 12% user + 1% kernel / faults: 1360 minor
02-15 18:09:01.076: ERROR/ActivityManager(90):   mmcqd: 4% = 0% user + 4% kernel
02-15 18:09:01.076: ERROR/ActivityManager(90):   system_server: 3% = 2% user + 1% kernel / faults: 473 minor
02-15 18:09:01.076: ERROR/ActivityManager(90):   zygote: 2% = 2% user + 0% kernel / faults: 90 minor
02-15 18:09:01.076: ERROR/ActivityManager(90):   adbd: 1% = 0% user + 1% kernel / faults: 1042 minor
02-15 18:09:01.076: ERROR/ActivityManager(90):   m.abc.unten: 0% = 0% user + 0% kernel / faults: 203 minor
02-15 18:09:01.076: ERROR/ActivityManager(90):   ndroid.launcher: 0% = 0% user + 0% kernel / faults: 802 minor
02-15 18:09:01.076: ERROR/ActivityManager(90):   droid.wallpaper: 0% = 0% user + 0% kernel / faults: 109 minor
02-15 18:09:01.076: ERROR/ActivityManager(90):   ndroid.settings: 0% = 0% user + 0% kernel / faults: 44 minor
02-15 18:09:01.076: ERROR/ActivityManager(90):   dhd_dpc: 0% = 0% user + 0% kernel
02-15 18:09:01.076: ERROR/ActivityManager(90):   events/0: 0% = 0% user + 0% kernel
02-15 18:09:01.076: ERROR/ActivityManager(90):   logcat: 0% = 0% user + 0% kernel
02-15 18:09:01.076: ERROR/ActivityManager(90):  +andisk.api.test: 0% = 0% user + 0% kernel
02-15 18:09:01.076: ERROR/ActivityManager(90):  +iTestFwService1: 0% = 0% user + 0% kernel
02-15 18:09:01.076: ERROR/ActivityManager(90):  +sh: 0% = 0% user + 0% kernel
02-15 18:09:01.076: ERROR/ActivityManager(90): TOTAL: 40% = 23% user + 16% kernel + 0% iowait + 0% softirq
02-15 18:09:01.096: INFO/ActivityManager(90): Process com.abc.cm.core (pid 10548) has died.

回答1:

fixing deadlocks on any platform is hard. the only way I know on android is to add some logging (eg using Log.d) before and after each lock/unlock/otherExpensiveFunctions