--- libev/ev.pod 2007/12/08 15:30:30 1.76 +++ libev/ev.pod 2007/12/08 22:11:14 1.77 @@ -488,8 +488,9 @@ Here are the gory details of what C does: + - Before the first iteration, call any pending watchers. * If there are no active watchers (reference count is zero), return. - - Queue prepare watchers and then call all outstanding watchers. + - Queue all prepare watchers and then call all outstanding watchers. - If we have been forked, recreate the kernel state. - Update the kernel state with all outstanding changes. - Update the "event loop time". @@ -1483,6 +1484,16 @@ loop from blocking if lower-priority coroutines are active, thus mapping low-priority coroutines to idle/background tasks). +It is recommended to give C watchers highest (C) +priority, to ensure that they are being run before any other watchers +after the poll. Also, C watchers (and C watchers, +too) should not activate ("feed") events into libev. While libev fully +supports this, they will be called before other C watchers did +their job. As C watchers are often used to embed other event +loops those other event loops might be in an unusable state until their +C watcher ran (always remind yourself to coexist peacefully with +others). + =over 4 =item ev_prepare_init (ev_prepare *, callback)