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| author | Simon Marlow <marlowsd@gmail.com> | 2010-03-29 14:44:56 +0000 |
|---|---|---|
| committer | Simon Marlow <marlowsd@gmail.com> | 2010-03-29 14:44:56 +0000 |
| commit | 5d52d9b64c21dcf77849866584744722f8121389 (patch) | |
| tree | 25aeafc9b761e73714c24ae414c0b1c41765c99f /rts/ClosureFlags.c | |
| parent | 79957d77c1bff767f1041d3fabdeb94d92a52878 (diff) | |
| download | haskell-5d52d9b64c21dcf77849866584744722f8121389.tar.gz | |
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.
Diffstat (limited to 'rts/ClosureFlags.c')
| -rw-r--r-- | rts/ClosureFlags.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/rts/ClosureFlags.c b/rts/ClosureFlags.c index 358cb40ed3..cebd124dd2 100644 --- a/rts/ClosureFlags.c +++ b/rts/ClosureFlags.c @@ -62,8 +62,8 @@ StgWord16 closure_flags[] = { [UPDATE_FRAME] = ( _BTM ), [CATCH_FRAME] = ( _BTM ), [STOP_FRAME] = ( _BTM ), - [CAF_BLACKHOLE] = ( _BTM|_NS| _UPT ), [BLACKHOLE] = ( _NS| _UPT ), + [BLOCKING_QUEUE] = ( _NS| _MUT|_UPT ), [MVAR_CLEAN] = (_HNF| _NS| _MUT|_UPT ), [MVAR_DIRTY] = (_HNF| _NS| _MUT|_UPT ), [ARR_WORDS] = (_HNF| _NS| _UPT ), |