App进程创建代码分析（基于Android 14）

开机阶段

\frameworks\base\core\java\com\android\internal\os\ZygoteInit.java
    public static void main(String[] argv) {
    .......
                zygoteServer = new ZygoteServer(isPrimaryZygote);
           //执行创建SystemServer进程流程
            if (startSystemServer) {
                Runnable r = forkSystemServer(abiList, zygoteSocketName, zygoteServer);

                // {@code r == null} in the parent (zygote) process, and {@code r != null} in the
                // child (system_server) process.
                if (r != null) {
                    r.run();
                    return;
                }
            }


            // The select loop returns early in the child process after a fork and
            // loops forever in the zygote.
            //调用runSelectLoop方法，开启loop循环，为后面fork子进程做准备
            caller = zygoteServer.runSelectLoop(abiList);

点击桌面启动一个进程（pid:5636 包名：com.example.test111）

调用到AMS的startProcess方法

frameworks\base\services\core\java\com\android\server\am\ActivityManagerService.java
        @Override
        public void startProcess(String processName, ApplicationInfo info, boolean knownToBeDead,
                boolean isTop, String hostingType, ComponentName hostingName) {
           
                synchronized (ActivityManagerService.this) {
                
                    startProcessLocked(processName, info, knownToBeDead, 0 /* intentFlags */,
                            new HostingRecord(hostingType, hostingName, isTop),
                            ZYGOTE_POLICY_FLAG_LATENCY_SENSITIVE, false /* allowWhileBooting */,
                            false /* isolated */);
                }
            } finally {
                Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER);
            }
        }
       
      @GuardedBy("this")
    final ProcessRecord startProcessLocked(String processName,
            ApplicationInfo info, boolean knownToBeDead, int intentFlags,
            HostingRecord hostingRecord, int zygotePolicyFlags, boolean allowWhileBooting,
            boolean isolated) {
        return mProcessList.startProcessLocked(processName, info, knownToBeDead, intentFlags,
                hostingRecord, zygotePolicyFlags, allowWhileBooting, isolated, 0 /* isolatedUid */,
                false /* isSdkSandbox */, 0 /* sdkSandboxClientAppUid */,
                null /* sdkSandboxClientAppPackage */,
                null /* ABI override */, null /* entryPoint */,
                null /* entryPointArgs */, null /* crashHandler */);
    }

调用到ProcessList.java的startProcessLocked方法

frameworks\base\services\core\java\com\android\server\am\ProcessList.java
    @GuardedBy("mService")
    ProcessRecord startProcessLocked(String processName, ApplicationInfo info,
            boolean knownToBeDead, int intentFlags, HostingRecord hostingRecord,
            int zygotePolicyFlags, boolean allowWhileBooting, boolean isolated, int isolatedUid,
            boolean isSdkSandbox, int sdkSandboxUid, String sdkSandboxClientAppPackage,
            String abiOverride, String entryPoint, String[] entryPointArgs, Runnable crashHandler) {

		
        long startTime = SystemClock.uptimeMillis();
        ProcessRecord app;
        if (!isolated) {
        //通过包名获取ProcessRecord
            app = getProcessRecordLocked(processName, info.uid);
          ......
          //app获取为null
          
          if (app == null) {
			
			if("com.example.test111".equals(processName)){
			       Log.i("XXXX","ProcessList newProcessRecordLocked here");
		    }
            //通过包名创建一个新的ProcessRecord对象
            app = newProcessRecordLocked(info, processName, isolated, isolatedUid, isSdkSandbox,
              ......
                      
                      final boolean success =
                startProcessLocked(app, hostingRecord, zygotePolicyFlags, abiOverride);
                return success ? app : null;
        } 
            @GuardedBy("mService")
    boolean startProcessLocked(HostingRecord hostingRecord, String entryPoint, ProcessRecord app,
            int uid, int[] gids, int runtimeFlags, int zygotePolicyFlags, int mountExternal,
            String seInfo, String requiredAbi, String instructionSet, String invokeWith,
            long startUptime, long startElapsedTime) {
        .......
          try {
			.......
                final Process.ProcessStartResult startResult = startProcess(hostingRecord,
                        entryPoint, app,
                        uid, gids, runtimeFlags, zygotePolicyFlags, mountExternal, seInfo,
                        requiredAbi, instructionSet, invokeWith, startUptime);
                handleProcessStartedLocked(app, startResult.pid, startResult.usingWrapper,
                        startSeq, false);
                UnionManagerServiceFactory.getInstance().getUnionLocalService().preforkStart(app.processName);
                ......
                
         private Process.ProcessStartResult startProcess(HostingRecord hostingRecord, String entryPoint,
            ProcessRecord app, int uid, int[] gids, int runtimeFlags, int zygotePolicyFlags,
            int mountExternal, String seInfo, String requiredAbi, String instructionSet,
            String invokeWith, long startTime) {
            ......
            //一大堆判断app的信息：hasAppStorage  targetPackagesList usesWebviewZygote
            ......
             regularZygote = true;
             	
                    startResult = Process.start(entryPoint,
                        app.processName, uid, uid, gids, runtimeFlags, mountExternal,
                        app.info.targetSdkVersion, seInfo, requiredAbi, instructionSet,
                        app.info.dataDir, invokeWith, app.info.packageName, zygotePolicyFlags,
                        isTopApp, app.getDisabledCompatChanges(), pkgDataInfoMap,
                        allowlistedAppDataInfoMap, bindMountAppsData, bindMountAppStorageDirs,
                        new String[]{PROC_START_SEQ_IDENT + app.getStartSeq()});
                // By now the process group should have been created by zygote.
                app.mProcessGroupCreated = true;
                .......
                return startResult;
                ......
                }

调用到Process的start方法，创建了一个ZygoteProcess对象并调用start方法

frameworks\base\core\java\android\os\Process.java
    public static ProcessStartResult start(
    .....){
           return ZYGOTE_PROCESS.start(processClass, niceName, uid, gid, gids,
                    runtimeFlags, mountExternal, targetSdkVersion, seInfo,
                    abi, instructionSet, appDataDir, invokeWith, packageName,
                    zygotePolicyFlags, isTopApp, disabledCompatChanges,
                    pkgDataInfoMap, whitelistedDataInfoMap, bindMountAppsData,
                    bindMountAppStorageDirs, zygoteArgs);
    }
        public static final ZygoteProcess ZYGOTE_PROCESS = new ZygoteProcess();

frameworks\base\core\java\android\os\ZygoteProcess.java
public final Process.ProcessStartResult start(......){
.......
 try {
            return startViaZygote(processClass, niceName, uid, gid, gids,
                    runtimeFlags, mountExternal, targetSdkVersion, seInfo,
                    abi, instructionSet, appDataDir, invokeWith, /*startChildZygote=*/ false,
                    packageName, zygotePolicyFlags, isTopApp, disabledCompatChanges,
                    pkgDataInfoMap, allowlistedDataInfoList, bindMountAppsData,
                    bindMountAppStorageDirs, zygoteArgs);
        } catch (ZygoteStartFailedEx ex) {
            Log.e(LOG_TAG,
                    "Starting VM proce