Re: [Qemu-devel] [RFC][PATCH 05/12] coroutine: Add coroutines

[Stefan Hajnoczi]

On Wed, Jan 26, 2011 at 05:29:23PM +0200, Avi Kivity wrote:
> On 01/22/2011 11:29 AM, Stefan Hajnoczi wrote:
> >Add functions to create coroutines and transfer control into a coroutine
> >and back out again.
> >
> >
> >+
> >+struct Coroutine {
> >+    struct coroutine co;
> >+};
> >+
> >
> >+/**
> >+ * Coroutine entry point
> >+ *
> >+ * When the coroutine is entered for the first time, opaque is passed in as 
> >an
> >+ * argument.
> >+ *
> >+ * When this function returns, the coroutine is destroyed automatically and 
> >the
> >+ * return value is passed back to the caller who last entered the coroutine.
> >+ */
> >+typedef void * coroutine_fn CoroutineEntry(void *opaque);
> 
> The more modern style is to use the Coroutine structure as argument,
> and let the coroutine function use container_of() to obtain access
> to its own data structures.  Similarly it can store any return value
> there, avoiding casts to and from void pointers.

Yes, container_of() would be nice but we need to be careful to support
pooling Coroutine structs.  Or maybe just pool the mmaped stacks.

Stefan