Android Training Course (35)

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In the init. rc file, you can see the following services loaded:

Service zygote/system/bin/app_process-Xzygote/system/bin -- zygote -- start-system-server

Socket zygote stream 666

Onrestart write/sys/android_power/request_state wake

Onrestart write/sys/power/state on

Onrestart restart media

The code of the zygote service is in the directory:

Android-2.0/frameworks/base/cmds/app_process

 

The zygote service is mainly used to create a service listening user's command and create an application program to run according to the user's command.

Its main entry function code is as follows:

Int main (int argc, const char * const argv [])

{

// These are global variables in ProcessState. cpp

MArgC = argc;

MArgV = argv;

MArgLen = 0;

For (int I = 0; I <argc; I ++ ){

MArgLen + = strlen (argv [I]) + 1;

}

MArgLen --;

AppRuntime runtime;

Create a JAVA Runtime Library object.

Const char * arg;

Const char * argv0;

Argv0 = argv [0];

// Process command line arguments

// Ignore argv [0]

Argc --;

Argv ++;

// Everything up to -- or first non-arg goes to the vm

Int I = runtime. addVmArguments (argc, argv );

Add command line parameters here.

// Next arg is parent directory

If (I <argc ){

Runtime. mParentDir = argv [I ++];

}

// Next arg is startup classname or "-- zygote"

If (I <argc ){

Arg = argv [I ++];

If (0 = strcmp ("-- zygote", arg )){

Bool startSystemServer = (I <argc )?

Strcmp (argv [I], "-- start-system-server") = 0: false;

SetArgv0 (argv0, "zygote ");

Set_process_name ("zygote ");

Runtime. start ("com. android. internal. OS. ZygoteInit ",

StartSystemServer );

Create a java vm Based on the command line parameters. Run the VM from com. android. internal. OS. ZygoteInit and start all JAVA services.

} Else {

Set_process_name (argv0 );

Runtime. mClassName = arg;

// Remainder of args get passed to startup class main ()

Runtime. mArgC = argc-I;

Runtime. mArgV = argv + I;

LOGV ("App process is starting with pid = % d, class = % s .",

Getpid (), runtime. getClassName ());

Runtime. start ();

}

} Else {

LOG_ALWAYS_FATAL ("app_process: no class name or -- zygote supplied .");

Fprintf (stderr, "Error: no class name or -- zygote supplied .");

App_usage ();

Return 10;

}

}