Anr problem - camera related debug

Generally speaking ,ANR Related issues , Need to combine ANR Occurs when trace file （ It can be downloaded from /data/anr Obtained under directory ）, analysis logcat Of log. Here are two camera related ANR Examples of problem analysis .

problem 1：

【 Problem description 】stopPreview Get stuck , Lead to ANR

from logcat log You can see 'stopPreview(): E' Not followed 'stopPreview(): X' Led to ANR
Happen ：
01-03 01:55:49.724 8466 8476 D QCamera2HWI: int qcamera::
QCamera2HardwareInterface::stopPreview(): E
01-03 01:57:34.894 1431 1450 E ActivityManager: ANR in com.android.camera (
com.android.camera/.CameraActivity)
Let's check trace file . Usually camera related ANR, We will first check mediaserver Of call stack
. stay trace Search for 'camera' See if there is anything suspicious . We found that stopPreview
Is when the card is waiting for a thread to end ：
"Binder_2" sysTid=8476

#00 pc 0000f9b8 /system/lib/libc.so (syscall+28)
#01 pc 000138b3 /system/lib/libc.so (pthread_join+90)
#02 pc 00029e1b /system/lib/hw/camera.msm8916.so (qcamera::QCameraCmdThread::exit()+46)
#03