SWT／ANR问题－－Native方法执行时间过长导致SWT

1.确认问题时间点：

02-12 17:26:02.574534  1159  3442 E Watchdog: **SWT happen **Blocked in handler on ui thread (android.ui)

2.查找对应时间段内两次trace是一致的，都如下（下图只截取了其中一个时间点的backtrace）：

从system_server blocked的thread入手分析，此题是android.ui

"android.ui" prio=5 tid=13 Native
  | group="main" sCount=1 dsCount=0 flags=1 obj=0x15995758 self=0x799c9ec000
  | sysTid=1287 nice=-2 cgrp=default sched=0/0 handle=0x797dc384f0
  | state=S schedstat=( 183148434550 114009689792 565633 ) utm=11764 stm=6550 core=5 HZ=100
  | stack=0x797db35000-0x797db37000 stackSize=1041KB
  | held mutexes=
  kernel: __switch_to+0xc0/0xcc
  kernel: futex_wait_queue_me+0xc4/0x12c