Usage of ActivityManager

I have a quick question about the usage of ActivityManager.

I've looked at the source code and read through it and as expectedly, it gave info about how it worked.

However, I am interested in at what place(s) in Android OS uses this activity to actually manage activities.

For example, when an activity starts, Android will keep track of activities using the ActivityManage开发者_开发百科r's method and I want to find out where that happens.

This is a list for all the places in the code who contain ActivityManager. Note that most of them do not refer to the ActivityManager that is offered by the SDK but rather the ActivityManagerNative that i think it kind of a 'gateway' to the native code.