首页 > 代码库 > Android4.4 framework分析——startService的创建过程
Android4.4 framework分析——startService的创建过程
我们常用context.startService()来启动一个service,下面来分析一下这个service的启动过程,下图是service启动的序列图:
step2,mBase.startService()中mBase定义为Context,它的真实实现是ContextImpl对象(看名字就知道是Context的实现类)。
step4,ActivityManagerNative.getDefault().startService()中ActivityManagerNative.getDefault()得到的是ActivityManagerService的代理对象ActivityManagerProxy。
step9,bringUpServiceLocked()中如果service所在进程(android:process属性中声明)已启动,则直接使用realStartServiceLocked()启动service,否则执行step10~step30先启动新进程,新进程的启动过程分析,可以查看Android应用程序进程启动过程的源代码分析 。
step18,mPendingServices.add()中会将这个要启动的service加入到mPendingServices这个待启动列表中,待新进程启动后会取出,在此时,step37中mPendingServices.get(i)。
step39,realStartServiceLocked()真的要启动service了。
step42,scheduleCreateService()要调用Service的onCreate创建service了。
step53,scheduleServiceArgs()调用Service的onStartCommand()执行service。
下面是ActivityThread的代码片段:
private class H extends Handler { public static final int LAUNCH_ACTIVITY = 100; public static final int PAUSE_ACTIVITY = 101; public static final int PAUSE_ACTIVITY_FINISHING= 102; public static final int STOP_ACTIVITY_SHOW = 103; public static final int STOP_ACTIVITY_HIDE = 104; public static final int SHOW_WINDOW = 105; public static final int HIDE_WINDOW = 106; public static final int RESUME_ACTIVITY = 107; public static final int SEND_RESULT = 108; public static final int DESTROY_ACTIVITY = 109; public static final int BIND_APPLICATION = 110; public static final int EXIT_APPLICATION = 111; public static final int NEW_INTENT = 112; public static final int RECEIVER = 113; public static final int CREATE_SERVICE = 114; public static final int SERVICE_ARGS = 115; public static final int STOP_SERVICE = 116; public static final int REQUEST_THUMBNAIL = 117; public static final int CONFIGURATION_CHANGED = 118; public static final int CLEAN_UP_CONTEXT = 119; public static final int GC_WHEN_IDLE = 120; public static final int BIND_SERVICE = 121; public static final int UNBIND_SERVICE = 122; public static final int DUMP_SERVICE = 123; public static final int LOW_MEMORY = 124; public static final int ACTIVITY_CONFIGURATION_CHANGED = 125; public static final int RELAUNCH_ACTIVITY = 126; public static final int PROFILER_CONTROL = 127; public static final int CREATE_BACKUP_AGENT = 128; public static final int DESTROY_BACKUP_AGENT = 129; public static final int SUICIDE = 130; public static final int REMOVE_PROVIDER = 131; public static final int ENABLE_JIT = 132; public static final int DISPATCH_PACKAGE_BROADCAST = 133; public static final int SCHEDULE_CRASH = 134; public static final int DUMP_HEAP = 135; public static final int DUMP_ACTIVITY = 136; public static final int SLEEPING = 137; public static final int SET_CORE_SETTINGS = 138; public static final int UPDATE_PACKAGE_COMPATIBILITY_INFO = 139; public static final int TRIM_MEMORY = 140; public static final int DUMP_PROVIDER = 141; public static final int UNSTABLE_PROVIDER_DIED = 142; public static final int REQUEST_ASSIST_CONTEXT_EXTRAS = 143; public static final int TRANSLUCENT_CONVERSION_COMPLETE = 144; public static final int INSTALL_PROVIDER = 145; String codeToString(int code) { if (DEBUG_MESSAGES) { switch (code) { case LAUNCH_ACTIVITY: return "LAUNCH_ACTIVITY"; case PAUSE_ACTIVITY: return "PAUSE_ACTIVITY"; case PAUSE_ACTIVITY_FINISHING: return "PAUSE_ACTIVITY_FINISHING"; case STOP_ACTIVITY_SHOW: return "STOP_ACTIVITY_SHOW"; case STOP_ACTIVITY_HIDE: return "STOP_ACTIVITY_HIDE"; case SHOW_WINDOW: return "SHOW_WINDOW"; case HIDE_WINDOW: return "HIDE_WINDOW"; case RESUME_ACTIVITY: return "RESUME_ACTIVITY"; case SEND_RESULT: return "SEND_RESULT"; case DESTROY_ACTIVITY: return "DESTROY_ACTIVITY"; case BIND_APPLICATION: return "BIND_APPLICATION"; case EXIT_APPLICATION: return "EXIT_APPLICATION"; case NEW_INTENT: return "NEW_INTENT"; case RECEIVER: return "RECEIVER"; case CREATE_SERVICE: return "CREATE_SERVICE"; case SERVICE_ARGS: return "SERVICE_ARGS"; case STOP_SERVICE: return "STOP_SERVICE"; case REQUEST_THUMBNAIL: return "REQUEST_THUMBNAIL"; case CONFIGURATION_CHANGED: return "CONFIGURATION_CHANGED"; case CLEAN_UP_CONTEXT: return "CLEAN_UP_CONTEXT"; case GC_WHEN_IDLE: return "GC_WHEN_IDLE"; case BIND_SERVICE: return "BIND_SERVICE"; case UNBIND_SERVICE: return "UNBIND_SERVICE"; case DUMP_SERVICE: return "DUMP_SERVICE"; case LOW_MEMORY: return "LOW_MEMORY"; case ACTIVITY_CONFIGURATION_CHANGED: return "ACTIVITY_CONFIGURATION_CHANGED"; case RELAUNCH_ACTIVITY: return "RELAUNCH_ACTIVITY"; case PROFILER_CONTROL: return "PROFILER_CONTROL"; case CREATE_BACKUP_AGENT: return "CREATE_BACKUP_AGENT"; case DESTROY_BACKUP_AGENT: return "DESTROY_BACKUP_AGENT"; case SUICIDE: return "SUICIDE"; case REMOVE_PROVIDER: return "REMOVE_PROVIDER"; case ENABLE_JIT: return "ENABLE_JIT"; case DISPATCH_PACKAGE_BROADCAST: return "DISPATCH_PACKAGE_BROADCAST"; case SCHEDULE_CRASH: return "SCHEDULE_CRASH"; case DUMP_HEAP: return "DUMP_HEAP"; case DUMP_ACTIVITY: return "DUMP_ACTIVITY"; case SLEEPING: return "SLEEPING"; case SET_CORE_SETTINGS: return "SET_CORE_SETTINGS"; case UPDATE_PACKAGE_COMPATIBILITY_INFO: return "UPDATE_PACKAGE_COMPATIBILITY_INFO"; case TRIM_MEMORY: return "TRIM_MEMORY"; case DUMP_PROVIDER: return "DUMP_PROVIDER"; case UNSTABLE_PROVIDER_DIED: return "UNSTABLE_PROVIDER_DIED"; case REQUEST_ASSIST_CONTEXT_EXTRAS: return "REQUEST_ASSIST_CONTEXT_EXTRAS"; case TRANSLUCENT_CONVERSION_COMPLETE: return "TRANSLUCENT_CONVERSION_COMPLETE"; case INSTALL_PROVIDER: return "INSTALL_PROVIDER"; } } return Integer.toString(code); } public void handleMessage(Message msg) { if (DEBUG_MESSAGES) Slog.v(TAG, ">>> handling: " + codeToString(msg.what)); switch (msg.what) { case LAUNCH_ACTIVITY: { Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "activityStart"); ActivityClientRecord r = (ActivityClientRecord)msg.obj; r.packageInfo = getPackageInfoNoCheck( r.activityInfo.applicationInfo, r.compatInfo); handleLaunchActivity(r, null); Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER); } break; case RELAUNCH_ACTIVITY: { Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "activityRestart"); ActivityClientRecord r = (ActivityClientRecord)msg.obj; handleRelaunchActivity(r); Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER); } break; case PAUSE_ACTIVITY: Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "activityPause"); handlePauseActivity((IBinder)msg.obj, false, msg.arg1 != 0, msg.arg2); maybeSnapshot(); Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER); break; case PAUSE_ACTIVITY_FINISHING: Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "activityPause"); handlePauseActivity((IBinder)msg.obj, true, msg.arg1 != 0, msg.arg2); Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER); break; case STOP_ACTIVITY_SHOW: Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "activityStop"); handleStopActivity((IBinder)msg.obj, true, msg.arg2); Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER); break; case STOP_ACTIVITY_HIDE: Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "activityStop"); handleStopActivity((IBinder)msg.obj, false, msg.arg2); Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER); break; case SHOW_WINDOW: Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "activityShowWindow"); handleWindowVisibility((IBinder)msg.obj, true); Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER); break; case HIDE_WINDOW: Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "activityHideWindow"); handleWindowVisibility((IBinder)msg.obj, false); Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER); break; case RESUME_ACTIVITY: Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "activityResume"); handleResumeActivity((IBinder)msg.obj, true, msg.arg1 != 0, true); Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER); break; case SEND_RESULT: Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "activityDeliverResult"); handleSendResult((ResultData)msg.obj); Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER); break; case DESTROY_ACTIVITY: Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "activityDestroy"); handleDestroyActivity((IBinder)msg.obj, msg.arg1 != 0, msg.arg2, false); Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER); break; case BIND_APPLICATION: Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "bindApplication"); AppBindData data = http://www.mamicode.com/(AppBindData)msg.obj;>这部分代码是ActivityThread的一个内部类H,里面定义了activity、service等启动、销毁等事件的响应,也就是说activity、service的启动、销毁都是在ActivityThread中进行的。
右键复制图片地址,在浏览器中打开即可查看大图。
未完待续,有不对的地方,请指正。
Android4.4 framework分析——startService的创建过程