android ctl.start

通过控制ctl.start和ctl.stop这两个属性，可以控制init.rc文件中定义的各种service。

如启动与关闭adb服务

    frameworks\base\services\core\java\com\android\server\adb\AdbService.java

    private void startAdbd() {

        SystemProperties.set(CTL_START, ADBD);

    }

    private void stopAdbd() {

        if (!mIsAdbUsbEnabled && !mIsAdbWifiEnabled) {

            SystemProperties.set(CTL_STOP, ADBD);

        }

    }

如android开机动画的启动和停止同样也是

SystemProperties.set("ctl.start", "bootanim");

java

SystemProperties.set("ctl.start", "service_name");

shell ：

setprop ctl.start service_name

setprop ctl.stop service_name

JNI:

property_set("ctl.start", service_name);

property_set("ctl.stop", service_name);

我们经常使用adb shell stop ,start命令来重启framework，我们来看下其代码

是在system/core/toolbox下面,原理很简单就是利用ctl属性来控制进程。

start.c
#include
#include
#include
#include
int start_main(int argc, char *argv[])
{
    if(argc > 1) {
        property_set("ctl.start", argv[1]);
    } else {
    /* defaults to starting the common services stopped by stop.c */
        property_set("ctl.start", "netd");
        property_set("ctl.start", "surfaceflinger");
        property_set("ctl.start", "zygote");
        property_set("ctl.start", "zygote_secondary");
    }
    return 0;
}

stop.c
#include
#include
#include
int stop_main(int argc, char *argv[])
{
    if(argc > 1) {
        property_set("ctl.stop", argv[1]);
    } else{
        /* defaults to stopping the common services */
        property_set("ctl.stop", "zygote_secondary");
        property_set("ctl.stop", "zygote");
        property_set("ctl.stop", "surfaceflinger");
        property_set("ctl.stop", "netd");
    }
    return 0;
}