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. --- utils/genapply/GenApply.hs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'utils') diff --git a/utils/genapply/GenApply.hs b/utils/genapply/GenApply.hs index 765bfb3be6..16d33940fb 100644 --- a/utils/genapply/GenApply.hs +++ b/utils/genapply/GenApply.hs @@ -564,8 +564,8 @@ genApply regstatus args = -- else: text "case AP,", text " AP_STACK,", - text " CAF_BLACKHOLE,", text " BLACKHOLE,", + text " WHITEHOLE,", text " THUNK,", text " THUNK_1_0,", text " THUNK_0_1,", -- cgit v1.2.1