Android13 Service startForeground流程分析

Service的startForeground用于将服务设置为前台服务，代码如下：

//frameworks/base/core/java/android/app/Service.java
public abstract class Service extends ContextWrapper implements ComponentCallbacks2,
        ContentCaptureManager.ContentCaptureClient {
    private IActivityManager mActivityManager = null;
    public final void startForeground(int id, Notification notification) {
        try {
            mActivityManager.setServiceForeground(
                    new ComponentName(this, mClassName), mToken, id,
                    notification, 0, FOREGROUND_SERVICE_TYPE_MANIFEST);
            clearStartForegroundServiceStackTrace();
        } catch (RemoteException ex) {
        }
    }
}

上面方法主要处理如下：

1、调用IActivityManager的setServiceForeground方法。

2、调用clearStartForegroundServiceStackTrace方法。

下面分别进行分析：

ActivityManagerService setServiceForeground

调用IActivityManager的setServiceForeground方法，IActivityMana