What are the advantages/disadvantages of a game loop on a separate thread?

In the Android examples, like LunarLander, and many other tutorials written on blogs across the net, game loops almost always run a separate thread to call the state updating and rendering parts of the game.

Why is this? What are the advantages and disadvantages? The only reason I can think of is just to keep the app responsive to input such as if the user presses the menu or back buttons. Other than that, the game just has to chug along in update/render cycles as fast as it can.

I'm aware this is a good reason, although one would hope开发者_运维百科 that if one's game is running at a decent frame rate, the app would remain responsive enough. But, are there any other reasons?

On the other hand, I imagine it would create more headache accessing game resources, for example a game object manager or the sound system, which may live on a separate thread.

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On Lunar lander and other android apps - it is important to have your surface view run on a separate thread, so that the android OS does not kill it for any long running processes. Android keeps the main UI thread - used for the menu and home buttons among other things - avaiable to recveive user input at all times. If you app causes the main thread to slow down, the OS will kill your thread and end you game.

So running your game loop off of the Surface View thread lets you game run as fast as it can when it has focus, but it also makes it possible for android to interrupt it whenever it needs to, for instance when a call come in, or the user presses the home button.