SWT / anr problem - anr/je causes SWT

The problem background ：

perform monkey test , The mobile phone test report appears 2 Time swt Report errors , The preliminary analysis is dump trace Stuck without return , cause swt

The analysis process ：

Get SWT db, see __exp_main.txt：

Trigger time:[2018-11-21 17:30:08.126598] pid:1012

Backtrace: 
Time: 2018-11-21 17:30:07
Process: system_server
Subject: Blocked in handler on ActivityManager (ActivityManager)

Let's see ActivityManager What happened? , You want to search SWT_JBT_TRACES Inside ActivityManager thread, from __exp_main.txt find ActivityManager Corresponding tid 1026.

look for SWT Several calls to the stack around time , Look for deadlocks or slow responses , Search for keywords sysTid=1026, Have found 3 Pen to record ：

----- pid 1012 at 2018-11-21 17:29:40 -----
Cmd line: system_server
......
"ActivityManager" prio=5 tid=11 Native
 | group="main" sCount=1 dsCount=0 flags=1 obj=0x12e02050 self=0x7238f3d800
 | sysTid=1026 nice=-2 cgrp=default sched=0/0 handle=0x722844c4f0
 | state=S schedstat