vmware9u盘启动-(vmwareu盘启动教程)

线程池 优化Zygote 启动

Zygote 启动优化实质：

使我们的进程最大限度的抢占CPU

经过一系列初始化后，在ZygoteInit类中 forkSystemServer,为启动SystemServer 做准备。ZygoteInit.java代码路径如下：alps\frameworks\base\core\java\com\android\internal\os\ZygoteInit.java

/** * Prepare the arguments and forks for the system server process. * * Returns an {@code Runnable} that provides an entrypoint into system_server code in the * child process, and {@code null} in the parent. */ private static Runnable forkSystemServer(String abiList, String socketName, ZygoteServer zygoteServer) { long capabilities = posixCapabilitiesAsBits( OsConstants.CAP_IPC_LOCK, OsConstants.CAP_KILL, OsConstants.CAP_NET_ADMIN, OsConstants.CAP_NET_BIND_SERVICE, OsConstants.CAP_NET_BROADCAST, OsConstants.CAP_NET_RAW, OsConstants.CAP_SYS_MODULE, OsConstants.CAP_SYS_NICE, OsConstants.CAP_SYS_PTRACE, OsConstants.CAP_SYS_TIME, OsConstants.CAP_SYS_TTY_CONFIG, OsConstants.CAP_WAKE_ALARM, OsConstants.CAP_BLOCK_SUSPEND ); /* Containers run without some capabilities, so drop any caps that are not available. */ StructCapUserHeader header = new StructCapUserHeader( OsConstants._LINUX_CAPABILITY_VERSION_3, 0); StructCapUserData[] data; try { data = Os.capget(header); } catch (ErrnoException ex) { throw new RuntimeException(\"Failed to capget()\", ex); } capabilities &= ((long) data[0].effective) | (((long) data[1].effective) << 32); /* Hardcoded command line to start the system server */ String args[] = { \"--setuid=1000\", \"--setgid=1000\", /// M: [Wi-Fi Hotspot Manager] system_server add dhcp (1014) group to access /// \"/data/misc/dhcp/dnsmasq.leases\" \"--setgroups=1001,1002,1003,1004,1005,1006,1007,1008,1009,1010,1014,1018,1021,1023,\" + \"1024,1032,1065,3001,3002,3003,3006,3007,3009,3010\", \"--capabilities=\" + capabilities + \",\" + capabilities, \"--nice-name=system_server\", \"--runtime-args\", \"--target-sdk-version=\" + VMRuntime.SDK_VERSION_CUR_DEVELOPMENT, \"com.android.server.SystemServer\", }; ZygoteConnection.Arguments parsedArgs = null; int pid; try { parsedArgs = new ZygoteConnection.Arguments(args); ZygoteConnection.applyDebuggerSystemProperty(parsedArgs); ZygoteConnection.applyInvokeWithSystemProperty(parsedArgs); boolean profileSystemServer = SystemProperties.getBoolean( \"dalvik.vm.profilesystemserver\", false); if (profileSystemServer) { parsedArgs.runtimeFlags |= Zygote.PROFILE_SYSTEM_SERVER; } /* Request to fork the system server process */ pid = Zygote.forkSystemServer( parsedArgs.uid, parsedArgs.gid, parsedArgs.gids, parsedArgs.runtimeFlags, null, parsedArgs.permittedCapabilities, parsedArgs.effectiveCapabilities); } catch (IllegalArgumentException ex) { throw new RuntimeException(ex); } /* For child process */ if (pid == 0) { if (hasSecondZygote(abiList)) { waitForSecondaryZygote(socketName); } zygoteServer.closeServerSocket(); return handleSystemServerProcess(parsedArgs); } return null; }
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