::Android Framework:: Which is first runner, zygote or dalvik?

I have a question involving the Android framework.

Every boot sequence shown on the Internet or in books shows the flow starting from zygote to dalvik as follows.

![Android Boot Sequence Image][1]

However, according to my code research, init processor runs `app_process(app_main.cpp)` before loading zygote like this :

[init.rc] :

service zygote **/system/bin/app_process** -Xzygote /system/bin --zygote --start-system-server

Because `zygote(ZygoteInit.java)` is java file(a kind of class), it needs the dalvik virtual machine to be executed so `app_process(app_main.cpp)` initializes dalvik machine and makes it ready for start.

And then loads `ZygoteInit.java` via dalvik.

Thus, zygote actually run.

It seems to me that the process which initializes and loads dalvik is not zygote but app_process and zygote is under dalvik because it is composed of java code.

**The only thing that makes me doubt this is some code in app_main.cpp.**

Watching `main` function in `app_main.cpp` file, you can find some lines as below :

[app_main.cpp] :

if (niceName && *niceName) {

setArgv0(argv0, niceName);

**set_process_name(niceName);**

}

`niceName` is pointing to the string `"zygote"`.

That means `app_process` is changed to zygote process using the `set_process_name()` function. If it is true, everything is OK. But I don't know what the fact is.

Anyone make me sure of what is first.

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[1]:

Dalvik is shipped on Android as a loadable library. `app_process` links with that library, and uses it. As such `app_process` starts a Dalvik VM within its own process.

The Zygote is just a special case of this.

So, to more directly answer your question: During a typical start-up, the first Dalvik VM to run is one that is spawned within an `app_process` process, and it is passed arguments which cause it to become the Zygote process of the running system.