From 5d52d9b64c21dcf77849866584744722f8121389 Mon Sep 17 00:00:00 2001 From: Simon Marlow Date: Mon, 29 Mar 2010 14:44:56 +0000 Subject: New implementation of BLACKHOLEs This replaces the global blackhole_queue with a clever scheme that enables us to queue up blocked threads on the closure that they are blocked on, while still avoiding atomic instructions in the common case. Advantages: - gets rid of a locked global data structure and some tricky GC code (replacing it with some per-thread data structures and different tricky GC code :) - wakeups are more prompt: parallel/concurrent performance should benefit. I haven't seen anything dramatic in the parallel benchmarks so far, but a couple of threading benchmarks do improve a bit. - waking up a thread blocked on a blackhole is now O(1) (e.g. if it is the target of throwTo). - less sharing and better separation of Capabilities: communication is done with messages, the data structures are strictly owned by a Capability and cannot be modified except by sending messages. - this change will utlimately enable us to do more intelligent scheduling when threads block on each other. This is what started off the whole thing, but it isn't done yet (#3838). I'll be documenting all this on the wiki in due course. --- rts/FrontPanel.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'rts/FrontPanel.c') diff --git a/rts/FrontPanel.c b/rts/FrontPanel.c index ebba4056fb..da42548eb8 100644 --- a/rts/FrontPanel.c +++ b/rts/FrontPanel.c @@ -662,8 +662,6 @@ residencyCensus( void ) type = Thunk; break; - case CAF_BLACKHOLE: - case EAGER_BLACKHOLE: case BLACKHOLE: /* case BLACKHOLE_BQ: FIXME: case does not exist */ size = sizeW_fromITBL(info); -- cgit v1.2.1