Android11系统源码分析：从binder trace视角看Activity冷启动
目录
- Android11系统源码分析：从binder trace视角看Activity冷启动
- 一、 流程与TRACE
- 二、问题：冷启动bindpplication之前无法抓binder trace
- 三、总结
结论先行关注主干流程，不分析细节、由来。进程间ipc流程看binder trace，进程内流程借助AS断点。
一、 流程与TRACE
1.1、Launcher-- startActivity --> ATMS
1223 Traces for process: com.android.launcher3
1519 Count: 1
1520 Trace: java.lang.Throwable
1521 at android.os.BinderProxy.transact(BinderProxy.java:519)
1522 at android.app.IActivityTaskManager$Stub$Proxy.startActivity(IActivityTaskManager.java:3692)
1523 at android.app.Instrumentation.execStartActivity(Instrumentation.java:1723)
1524 at android.app.Activity.startActivityForResult(Activity.java:5320)
1525 at com.android.launcher3.Launcher.startActivityForResult(Launcher.java:1582)
1526 at com.android.launcher3.BaseQuickstepLauncher.startActivityForResult(BaseQuickstepLauncher.java:160)
1527 at android.app.Activity.startActivity(Activity.java:5660)
1528 at com.android.launcher3.BaseDraggingActivity.startActivitySafely(BaseDraggingActivity.java:182)
1529 at com.android.launcher3.Launcher.startActivitySafely(Launcher.java:1907)
1530 at com.android.launcher3.uioverrides.QuickstepLauncher.startActivitySafely(QuickstepLauncher.java:137)
1531 at com.android.launcher3.touch.ItemClickHandler.startAppShortcutOrInfoActivity(ItemClickHandler.java:285)
1532 at com.android.launcher3.touch.ItemClickHandler.onClick(ItemClickHandler.java:99)
1533 at com.android.launcher3.touch.ItemClickHandler.lambda$getInstance$0(ItemClickHandler.java:80)
1534 at com.android.launcher3.touch.-$$Lambda$ItemClickHandler$_rHy-J5yxnvGlFKWSh6CdrSf-lA.onClick(Unknown Source:2)
1535 at android.view.View.performClick(View.java:7448)
1536 at android.view.View.performClickInternal(View.java:7425)
1537 at android.view.View.access$3600(View.java:810)
1538 at android.view.View$PerformClick.run(View.java:28305)
1539 at android.os.Handler.handleCallback(Handler.java:938)
1540 at android.os.Handler.dispatchMessage(Handler.java:99)
1541 at android.os.Looper.loop(Looper.java:223)
1542 at android.app.ActivityThread.main(ActivityThread.java:7672)
1543 at java.lang.reflect.Method.invoke(Native Method)
1544 at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
1545 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
1.2、ATMS -- startPausing --> Launcher
3 Traces for process: system
159 Count: 1
160 Trace: java.lang.Throwable
161 at android.os.BinderProxy.transact(BinderProxy.java:519)
162 at android.app.IApplicationThread$Stub$Proxy.scheduleTransaction(IApplicationThread.java:2504)
163 at android.app.servertransaction.ClientTransaction.schedule(ClientTransaction.java:136)
164 at com.android.server.wm.ClientLifecycleManager.scheduleTransaction(ClientLifecycleManager.java:47)
165 at com.android.server.wm.ClientLifecycleManager.scheduleTransaction(ClientLifecycleManager.java:69)
166 at com.android.server.wm.ActivityStack.startPausingLocked(ActivityStack.java:1105)
167 at com.android.server.wm.TaskDisplayArea.pauseBackStacks(TaskDisplayArea.java:1200)
168 at com.android.server.wm.ActivityStack.resumeTopActivityInnerLocked(ActivityStack.java:1658)
169 at com.android.server.wm.ActivityStack.resumeTopActivityUncheckedLocked(ActivityStack.java:1507)
170 at com.android.server.wm.RootWindowContainer.resumeFocusedStacksTopActivities(RootWindowContainer.java:2306)
171 at com.android.server.wm.ActivityStarter.startActivityInner(ActivityStarter.java:1733)
172 at com.android.server.wm.ActivityStarter.startActivityUnchecked(ActivityStarter.java:1522)
173 at com.android.server.wm.ActivityStarter.executeRequest(ActivityStarter.java:1186)
174 at com.android.server.wm.ActivityStarter.execute(ActivityStarter.java:669)
175 at com.android.server.wm.ActivityTaskManagerService.startActivityAsUser(ActivityTaskManagerService.java:1096)
176 at com.android.server.wm.ActivityTaskManagerService.startActivityAsUser(ActivityTaskManagerService.java:1068)
177 at com.android.server.wm.ActivityTaskManagerService.startActivity(ActivityTaskManagerService.java:1043)
178 at android.app.IActivityTaskManager$Stub.onTransact(IActivityTaskManager.java:1422)
179 at android.os.Binder.execTransactInternal(Binder.java:1154)
180 at android.os.Binder.execTransact(Binder.java:1123)
1.3、Launcher -- activityPaused --> ATMS
1223 Traces for process: com.android.launcher3
1475 Count: 1
1476 Trace: java.lang.Throwable
1477 at android.os.BinderProxy.transact(BinderProxy.java:519)
1478 at android.app.IActivityTaskManager$Stub$Proxy.activityPaused(IActivityTaskManager.java:4368)
1479 at android.app.servertransaction.PauseActivityItem.postExecute(PauseActivityItem.java:64)
1480 at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:177)
1481 at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
1482 at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
1483 at android.os.Handler.dispatchMessage(Handler.java:106)
1484 at android.os.Looper.loop(Looper.java:223)
1485 at android.app.ActivityThread.main(ActivityThread.java:7672)
1486 at java.lang.reflect.Method.invoke(Native Method)
1487 at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
1488 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
1.4、ATMS --> zygote fork APP
该阶段，没有体现在binder trace上。因为system_server进程使用socket通信到zygote进程，完成的fork。下面的调用栈用AS断点然后Get Thread dump得来。
就system_server进程沟通zygote的过程，分成了三个线程三段代码。binder线程收消息，display线程收集参数，ActivityManager:procStart线程真正沟通zygote，write，flush发出启动参数。
第一段：ATMS#startProcessAsync
"Binder:497_6@24045" prio=5 tid=0x76 nid=NA runnable
java.lang.Thread.State: RUNNABLE
blocks android.display@24072
blocks android.anim@24073
at com.android.server.wm.ActivityTaskManagerService.startProcessAsync(ActivityTaskManagerService.java:5612)
at com.android.server.wm.ActivityStack.resumeTopActivityInnerLocked(ActivityStack.java:1680)
at com.android.server.wm.ActivityStack.resumeTopActivityUncheckedLocked(ActivityStack.java:1507)
at com.android.server.wm.RootWindowContainer.resumeFocusedStacksTopActivities(RootWindowContainer.java:2306)
at com.android.server.wm.ActivityStarter.startActivityInner(ActivityStarter.java:1733)
at com.android.server.wm.ActivityStarter.startActivityUnchecked(ActivityStarter.java:1522)
at com.android.server.wm.ActivityStarter.executeRequest(ActivityStarter.java:1186)
at com.android.server.wm.ActivityStarter.execute(ActivityStarter.java:669)
- locked <0x5e78> (a com.android.server.wm.WindowManagerGlobalLock)
at com.android.server.wm.ActivityTaskManagerService.startActivityAsUser(ActivityTaskManagerService.java:1096)
at com.android.server.wm.ActivityTaskManagerService.startActivityAsUser(ActivityTaskManagerService.java:1068)
at com.android.server.wm.ActivityTaskManagerService.startActivity(ActivityTaskManagerService.java:1043)
at android.app.IActivityTaskManager$Stub.onTransact(IActivityTaskManager.java:1422)
at android.os.Binder.execTransactInternal(Binder.java:1154)
at android.os.Binder.execTransact(Binder.java:1123)
第二段：ProcessList#startProcessLocked
"android.display@24057" prio=5 tid=0x16 nid=NA runnable
java.lang.Thread.State: RUNNABLE
blocks main@24228
blocks android.fg@24238
blocks ActivityManager@24245
blocks AlarmManager@24270
at com.android.server.am.ProcessList.startProcessLocked(ProcessList.java:1994)
at com.android.server.am.ProcessList.startProcessLocked(ProcessList.java:1943)
at com.android.server.am.ProcessList.startProcessLocked(ProcessList.java:2319)
at com.android.server.am.ProcessList.startProcessLocked(ProcessList.java:2441)
at com.android.server.am.ActivityManagerService.startProcessLocked(ActivityManagerService.java:3154)
at com.android.server.am.ActivityManagerService$LocalService.startProcess(ActivityManagerService.java:19627)
- locked <0x5e11> (a com.android.server.am.ActivityManagerService)
at com.android.server.wm.-$$Lambda$qMFJUmfG50ZSjk7Tac67xBia0d4.accept(lambda:-1)
at com.android.internal.util.function.pooled.PooledLambdaImpl.doInvoke(PooledLambdaImpl.java:360)
at com.android.internal.util.function.pooled.PooledLambdaImpl.invoke(PooledLambdaImpl.java:201)
at com.android.internal.util.function.pooled.OmniFunction.run(OmniFunction.java:97)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:223)
at android.os.HandlerThread.run(HandlerThread.java:67)
at com.android.server.ServiceThread.run(ServiceThread.java:44)
第三段：ZygoteProcess#attemptZygoteSendArgsAndGetResult
"ActivityManager:procStart@24043" prio=5 tid=0x1c nid=NA runnable
java.lang.Thread.State: RUNNABLE
at android.os.ZygoteProcess.attemptZygoteSendArgsAndGetResult(ZygoteProcess.java:470)
at android.os.ZygoteProcess.zygoteSendArgsAndGetResult(ZygoteProcess.java:460)
at android.os.ZygoteProcess.startViaZygote(ZygoteProcess.java:795)
- locked <0x5e7f> (a java.lang.Object)
at android.os.ZygoteProcess.start(ZygoteProcess.java:372)
at android.os.Process.start(Process.java:649)
at com.android.server.am.ProcessList.startProcess(ProcessList.java:2296)
at com.android.server.am.ProcessList.handleProcessStart(ProcessList.java:2055)
at com.android.server.am.ProcessList.lambda$startProcessLocked$0$ProcessList(ProcessList.java:1991)
at com.android.server.am.-$$Lambda$ProcessList$jjoaAPSQT_weAnGqu0R0SCcvKqw.run(lambda:-1)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:223)
at android.os.HandlerThread.run(HandlerThread.java:67)
at com.android.server.ServiceThread.run(ServiceThread.java:44)
1.5、APP -- attachApplication --> ATMS
1548 Traces for process: com.example.myapplication
1757 Count: 1
1758 Trace: java.lang.Throwable
1759 at android.os.BinderProxy.transact(BinderProxy.java:519)
1760 at android.app.IActivityManager$Stub$Proxy.attachApplication(IActivityManager.java:5628)
1761 at android.app.ActivityThread.attach(ActivityThread.java:7346)
1762 at android.app.ActivityThread.main(ActivityThread.java:7659)
1763 at java.lang.reflect.Method.invoke(Native Method)
1764 at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
1765 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
1.6、ATMS -- bindApplication --> APP
system_server进程发起端的调用栈
3 Traces for process: system
323 Count: 1
324 Trace: java.lang.Throwable
325 at android.os.BinderProxy.transact(BinderProxy.java:519)
326 at android.app.IApplicationThread$Stub$Proxy.bindApplication(IApplicationThread.java:1513)
327 at com.android.server.am.ActivityManagerService.attachApplicationLocked(ActivityManagerService.java:5318)
328 at com.android.server.am.ActivityManagerService.attachApplication(ActivityManagerService.java:5442)
329 at android.app.IActivityManager$Stub.onTransact(IActivityManager.java:2336)
330 at com.android.server.am.ActivityManagerService.onTransact(ActivityManagerService.java:2867)
331 at android.os.Binder.execTransactInternal(Binder.java:1154)
332 at android.os.Binder.execTransact(Binder.java:1123)
1.7、ATMS -- realStartActivity --> APP
3 Traces for process: system
118 Count: 1
119 Trace: java.lang.Throwable
120 at android.os.BinderProxy.transact(BinderProxy.java:519)
121 at android.app.IApplicationThread$Stub$Proxy.scheduleTransaction(IApplicationThread.java:2504)
122 at android.app.servertransaction.ClientTransaction.schedule(ClientTransaction.java:136)
123 at com.android.server.wm.ClientLifecycleManager.scheduleTransaction(ClientLifecycleManager.java:47)
124 at com.android.server.wm.ActivityStackSupervisor.realStartActivityLocked(ActivityStackSupervisor.java:868)
125 at com.android.server.wm.RootWindowContainer.startActivityForAttachedApplicationIfNeeded(RootWindowContainer.java:1972)
126 at com.android.server.wm.RootWindowContainer.lambda$5fbF65VSmaJkPHxEhceOGTat7JE(Unknown Source:0)
127 at com.android.server.wm.-$$Lambda$RootWindowContainer$5fbF65VSmaJkPHxEhceOGTat7JE.apply(Unknown Source:8)
128 at com.android.internal.util.function.pooled.PooledLambdaImpl.doInvoke(PooledLambdaImpl.java:315)
129 at com.android.internal.util.function.pooled.PooledLambdaImpl.invoke(PooledLambdaImpl.java:201)
130 at com.android.internal.util.function.pooled.OmniFunction.apply(OmniFunction.java:78)
131 at com.android.server.wm.ActivityRecord.forAllActivities(ActivityRecord.java:3637)
132 at com.android.server.wm.WindowContainer.forAllActivities(WindowContainer.java:1331)
133 at com.android.server.wm.WindowContainer.forAllActivities(WindowContainer.java:1324)
134 at com.android.server.wm.RootWindowContainer.attachApplication(RootWindowContainer.java:1949)
135 at com.android.server.wm.ActivityTaskManagerService$LocalService.attachApplication(ActivityTaskManagerService.java:6888)
136 at com.android.server.am.ActivityManagerService.attachApplicationLocked(ActivityManagerService.java:5362)
137 at com.android.server.am.ActivityManagerService.attachApplication(ActivityManagerService.java:5442)
138 at android.app.IActivityManager$Stub.onTransact(IActivityManager.java:2336)
139 at com.android.server.am.ActivityManagerService.onTransact(ActivityManagerService.java:2867)
140 at android.os.Binder.execTransactInternal(Binder.java:1154)
141 at android.os.Binder.execTransact(Binder.java:1123)
1.8、APP生命周期
onCreate
"main@15764" prio=5 tid=0x2 nid=NA runnable
java.lang.Thread.State: RUNNABLE
at com.example.myapplication.MainActivity3.onCreate(MainActivity3.java:12)
at android.app.Activity.performCreate(Activity.java:8000)
at android.app.Activity.performCreate(Activity.java:7984)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3404)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3595)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7672)
at java.lang.reflect.Method.invoke(Method.java:-1)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
onStart
"main@15764" prio=5 tid=0x2 nid=NA runnable
java.lang.Thread.State: RUNNABLE
at android.app.Activity.onStart(Activity.java:1829)
at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1435)
at android.app.Activity.performStart(Activity.java:8024)
at android.app.ActivityThread.handleStartActivity(ActivityThread.java:3457)
at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:221)
at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:201)
at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:173)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7672)
at java.lang.reflect.Method.invoke(Method.java:-1)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
onResume
"main@15764" prio=5 tid=0x2 nid=NA runnable
java.lang.Thread.State: RUNNABLE
at android.app.Activity.onResume(Activity.java:1905)
at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1456)
at android.app.Activity.performResume(Activity.java:8135)
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:4428)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:4470)
at android.app.servertransaction.ResumeActivityItem.execute(ResumeActivityItem.java:52)
at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:176)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7672)
at java.lang.reflect.Method.invoke(Method.java:-1)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
到此，Activity冷启动流程结束，下面是额外补充
onPause
"main@15801" prio=5 tid=0x2 nid=NA runnable
java.lang.Thread.State: RUNNABLE
at android.app.Activity.onPause(Activity.java:2347)
at android.app.Activity.performPause(Activity.java:8174)
at android.app.Instrumentation.callActivityOnPause(Instrumentation.java:1510)
at android.app.ActivityThread.performPauseActivityIfNeeded(ActivityThread.java:4729)
at android.app.ActivityThread.performPauseActivity(ActivityThread.java:4690)
at android.app.ActivityThread.handlePauseActivity(ActivityThread.java:4641)
at android.app.servertransaction.PauseActivityItem.execute(PauseActivityItem.java:46)
at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:176)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7672)
at java.lang.reflect.Method.invoke(Method.java:-1)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
onStop
"main@15801" prio=5 tid=0x2 nid=NA runnable
java.lang.Thread.State: RUNNABLE
at android.app.Activity.onStop(Activity.java:2589)
at android.app.Instrumentation.callActivityOnStop(Instrumentation.java:1476)
at android.app.Activity.performStop(Activity.java:8215)
at android.app.ActivityThread.callActivityOnStop(ActivityThread.java:4844)
at android.app.ActivityThread.performStopActivityInner(ActivityThread.java:4823)
at android.app.ActivityThread.handleStopActivity(ActivityThread.java:4897)
at android.app.servertransaction.StopActivityItem.execute(StopActivityItem.java:40)
at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:176)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7672)
at java.lang.reflect.Method.invoke(Method.java:-1)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
onRestart
"main@15801" prio=5 tid=0x2 nid=NA runnable
java.lang.Thread.State: RUNNABLE
at android.app.Activity.onRestart(Activity.java:1862)
at android.app.Instrumentation.callActivityOnRestart(Instrumentation.java:1445)
at android.app.Activity.performRestart(Activity.java:8102)
at android.app.ActivityThread.performRestartActivity(ActivityThread.java:4932)
at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:243)
at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:201)
at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:173)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7672)
at java.lang.reflect.Method.invoke(Method.java:-1)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
1.9、activityIdle
启动后，在app进程消息队列空闲时，会触发idle。
1548 Traces for process: com.example.myapplication
1929 Count: 1
1930 Trace: java.lang.Throwable
1931 at android.os.BinderProxy.transact(BinderProxy.java:519)
1932 at android.app.IActivityTaskManager$Stub$Proxy.activityIdle(IActivityTaskManager.java:4314)
1933 at android.app.ActivityThread$Idler.queueIdle(ActivityThread.java:2113)
1934 at android.os.MessageQueue.next(MessageQueue.java:404)
1935 at android.os.Looper.loop(Looper.java:183)
1936 at android.app.ActivityThread.main(ActivityThread.java:7672)
1937 at java.lang.reflect.Method.invoke(Native Method)
1938 at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
1939 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
二、问题：冷启动bindpplication之前无法抓binder trace
App进程刚起来时加个属性同步下。ActivityThread.java、ActivityManagerService.java
frameworks/base$ git diff core/java/android/app/ActivityThread.java
diff --git a/core/java/android/app/ActivityThread.java b/core/java/android/app/ActivityThread.java
index b47d44d60790..0eca8ddf993c 100644
--- a/core/java/android/app/ActivityThread.java
+++ b/core/java/android/app/ActivityThread.java
@@ -7610,6 +7617,11 @@ public final class ActivityThread extends ClientTransactionHandler {
public static void main(String[] args) {
Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "ActivityThreadMain");
+ //set binder tracing
+ boolean enable = "1".equals(SystemProperties.get("sys.appboot.bindertracing"));
+ if (( Build.IS_DEBUGGABLE) && enable) {
+ Binder.enableTracing();
+ }
// Install selective syscall interception
AndroidOs.install();
----------------------------------------------------------------------------
frameworks/base$ git diff services/core/java/com/android/server/am/ActivityManagerService.java
diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index 3f4878e38029..13c3ff601ba6 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -18862,6 +18862,7 @@ public class ActivityManagerService extends IActivityManager.Stub
Log.v(TAG, "Process disappared");
}
}
+ SystemProperties.set("sys.appboot.bindertracing","1");
return true;
}
}
@@ -18869,6 +18870,7 @@ public class ActivityManagerService extends IActivityManager.Stub
public boolean stopBinderTrackingAndDump(ParcelFileDescriptor fd) throws RemoteException {
try {
synchronized (this) {
+ SystemProperties.set("sys.appboot.bindertracing","0");
mBinderTransactionTrackingEnabled = false;
// TODO: hijacking SET_ACTIVITY_WATCHER, but should be changed to its own
// permission (same as profileControl).
1.5小节的trace就是靠这个抓到的。
三、总结
一张图展示大致流程，12个阶段。
-
本文只贴了调用栈，展示发生了什么。关于为什么，关于细节，要去断点读代码，读博客，读书。
-
本文关注了进程、生命周期相关的操作，activity显示流程本文没有体现。
-
am trace-ipc展示跨进程脉络，AS断点探索进程内流程。
-
我抓的一份binder trace。example-app-cold-start-binder.trace