Handle spurious wakeups properly.

Handle spurious wakeups properly.
Committed: https://code.google.com/p/dart/source/detail?r=781

[turnidge, 2011-10-26 17:40:07]

I may change this later to try to hide the spurious wakeup from the caller.  I
would need to keep a separate timer if we wanted to respect the timeout
properly.  For now, I am going to fix the crash by guarding in the caller while
I consider.

[siva, 2011-10-26 18:36:27]

LGTM.

We should also document the DeQueue method in message_queue.h clearly stating
that this method will return a NULL message when a timeout or spurious wake ups
happen and it is the responsibility of the caller to deal with NULL.

We also need to check for validity of the millis argument to DeQueue (for
instance if -1 is passed I think we get some weird behaviour).

[turnidge, 2011-10-26 20:46:59]

Updated the docs for the function.  Added an assert for negative timeouts.

On 2011/10/26 18:36:27, asiva wrote:
> LGTM.
> 
> We should also document the DeQueue method in message_queue.h clearly stating
> that this method will return a NULL message when a timeout or spurious wake
ups
> happen and it is the responsibility of the caller to deal with NULL.
> 
> We also need to check for validity of the millis argument to DeQueue (for
> instance if -1 is passed I think we get some weird behaviour).