ART虚拟机之Trace原理（转）

adb shell kill -3 888 //可指定进程pid 

//[见小节2.2] ----- pid 888 at 2016-11-11 22:22:22 ----- Cmd line: system_server ABI: arm Build type: optimized //[见小节3.1] Zygote loaded classes=4113 post zygote classes=3239 //[见小节3.2] Intern table: 57550 strong; 9315 weak //共加载16动态库 [见小节3.3] JNI: CheckJNI is off; globals=2418 (plus 115 weak) Libraries: /system/lib/libandroid.so /system/lib/libandroid_servers.so /system/lib/libaudioeffect_jni.so /system/lib/libcompiler_rt.so /system/lib/libjavacrypto.so /system/lib/libjnigraphics.so /system/lib/libmedia_jni.so /system/lib/librs_jni.so /system/lib/libsechook.so /system/lib/libshell_jni.so /system/lib/libsoundpool.so /system/lib/libwebviewchromium_loader.so /system/lib/libwifi-service.so /vendor/lib/libalarmservice_jni.so /vendor/lib/liblocationservice.so libjavacore.so (16) //已分配堆内存大小40MB，其中29M已用，总分配207772个对象 [见小节3.4] Heap: 27% free, 29MB/40MB; 307772 objects ... //省略GC相关信息 //当前进程总99个线程[见小节3.5] DALVIK THREADS (99): //主线程调用栈[见小节3.6] "main" prio=5 tid=1 Native | group="main" sCount=1 dsCount=0 obj=0x75bd9fb0 self=0x5573d4f770 | sysTid=12078 nice=-2 cgrp=default sched=0/0 handle=0x7fa75fafe8 | state=S schedstat=( 5907843636 827600677 5112 ) utm=453 stm=137 core=0 HZ=100 | stack=0x7fd64ef000-0x7fd64f1000 stackSize=8MB | held mutexes= //内核栈[见小节3.6.2] kernel: __switch_to+0x70/0x7c kernel: SyS_epoll_wait+0x2a0/0x324 kernel: SyS_epoll_pwait+0xa4/0x120 kernel: cpu_switch_to+0x48/0x4c native: #00 pc 0000000000069be4 /system/lib64/libc.so (__epoll_pwait+8) native: #01 pc 000000000001cca4 /system/lib64/libc.so (epoll_pwait+32) native: #02 pc 000000000001ad74 /system/lib64/libutils.so (_ZN7android6Looper9pollInnerEi+144) native: #03 pc 000000000001b154 /system/lib64/libutils.so (_ZN7android6Looper8pollOnceEiPiS1_PPv+80) native: #04 pc 00000000000d4bc0 /system/lib64/libandroid_runtime.so (_ZN7android18NativeMessageQueue8pollOnceEP7_JNIEnvP8_jobjecti+48) native: #05 pc 000000000000082c /data/dalvik-cache/arm64/system@framework@boot.oat (Java_android_os_MessageQueue_nativePollOnce__JI+144) at android.os.MessageQueue.nativePollOnce(Native method) at android.os.MessageQueue.next(MessageQueue.java:323) at android.os.Looper.loop(Looper.java:135) at com.android.server.SystemServer.run(SystemServer.java:290) at com.android.server.SystemServer.main(SystemServer.java:175) at java.lang.reflect.Method.invoke!(Native method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:738) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:628) "Binder_1" prio=5 tid=8 Native | group="main" sCount=1 dsCount=0 obj=0x12c610a0 self=0x5573e5c750 | sysTid=12092 nice=0 cgrp=default sched=0/0 handle=0x7fa2743450 | state=S schedstat=( 796240075 863170759 3586 ) utm=50 stm=29 core=1 HZ=100 | stack=0x7fa2647000-0x7fa2649000 stackSize=1013KB | held mutexes= kernel: __switch_to+0x70/0x7c kernel: binder_thread_read+0xd78/0xeb0 kernel: binder_ioctl_write_read+0x178/0x24c kernel: binder_ioctl+0x2b0/0x5e0 kernel: do_vfs_ioctl+0x4a4/0x578 kernel: SyS_ioctl+0x5c/0x88 kernel: cpu_switch_to+0x48/0x4c native: #00 pc 0000000000069cd0 /system/lib64/libc.so (__ioctl+4) native: #01 pc 0000000000073cf4 /system/lib64/libc.so (ioctl+100) native: #02 pc 000000000002d6e8 /system/lib64/libbinder.so (_ZN7android14IPCThreadState14talkWithDriverEb+164) native: #03 pc 000000000002df3c /system/lib64/libbinder.so (_ZN7android14IPCThreadState20getAndExecuteCommandEv+24) native: #04 pc 000000000002e114 /system/lib64/libbinder.so (_ZN7android14IPCThreadState14joinThreadPoolEb+124) native: #05 pc 0000000000036c38 /system/lib64/libbinder.so (???) native: #06 pc 000000000001579c /system/lib64/libutils.so (_ZN7android6Thread11_threadLoopEPv+208) native: #07 pc 0000000000090598 /system/lib64/libandroid_runtime.so (_ZN7android14AndroidRuntime15javaThreadShellEPv+96) native: #08 pc 0000000000014fec /system/lib64/libutils.so (???) native: #09 pc 0000000000067754 /system/lib64/libc.so (_ZL15__pthread_startPv+52) native: #10 pc 000000000001c644 /system/lib64/libc.so (__start_thread+16) (no managed stack frames) ... //此处省略剩余的N个线程. 

实例：

"Binder_1" prio=5 tid=8 Native | group="main" sCount=1 dsCount=0 obj=0x12c610a0 self=0x5573e5c750 | sysTid=12092 nice=0 cgrp=default sched=0/0 handle=0x7fa2743450 | state=S schedstat=( 796240075 863170759 3586 ) utm=50 stm=29 core=1 HZ=100 | stack=0x7fa2647000-0x7fa2649000 stackSize=1013KB | held mutexes= 

解释：

1. 第一行：线程名（“Binder_1”）（如果带有daemon说明是守护线程，线程优先级（“prio=5”），线程内部id（“tid=8”），线程状态（“NATIVE”）。
2. 第二行: 线程所属的线程组 （“main”），线程挂起次数（“sCount=1”），用于调试的线程挂起次数（”dsCount=0“）, 当前线程关联的java线程对象（”obj=0x12c610a0“），该线程地址（“self=0x5573e5c750”）。
3. 第三行：线程真正意义上的tid（“sysTid=12092”），调度有优先级（“nice=0”）， 优先组属（“cgrp=default”），调度策略（sched=0/0）， 处理函数地址（“handle=0x7fa2743450”）
4. 第四行： 线程状态(S), 调度时间统计schedstat，线程用户态下使用的时间值(单位是jiffies）（“utm=50”）， 内核态下得调度时间值（“stm=20”），最后运行该线程的核（“core=1”）
5. 第五行：线程栈的地址区间(“0x7fa2647000-0x7fa2649000”)，以及栈的大小(“1013KB”)
6. 第六行：所持有的mutex类型，有独占锁exclusive和共享锁shared两类。

说明：

• CPU调度统计信息(schedstat)：通过读取节点/proc/[pid]/task/[tid]/schedstat
• CPU使用统计：通过读取节点/proc/self/task/[tid]/stat
• 内核栈：通过读取节点/proc/self/task/[tid]/stack
• jiffies系统的节拍数，该值是1/HZ，一般来说100HZ，也就意味着1jiffies = 10ms.
• 线程状态：除了Native，另外还有Running, Blocked等状态，进程没有依附的状态(not attached)

转自：http://gityuan.com/2016/11/26/art-trace/