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| author | Ben Gamari <bgamari.foss@gmail.com> | 2013-01-28 11:15:08 -0500 |
|---|---|---|
| committer | Simon Marlow <marlowsd@gmail.com> | 2013-01-30 10:50:14 +0000 |
| commit | a23661d242e8dd55007c4aee8a053f35de7705bd (patch) | |
| tree | e55bb371b52998e870a252de8768aaf4d1de6849 /rts/StgMiscClosures.cmm | |
| parent | 658817bf1b44e9be8a3857c09aae086bef937720 (diff) | |
| download | haskell-a23661d242e8dd55007c4aee8a053f35de7705bd.tar.gz | |
STM: Only wake up once
Previously, threads blocked on an STM retry would be sent a wakeup
message each time an unpark was requested. This could result in the
accumulation of a large number of wake-up messages, which would slow
wake-up once the sleeping thread is finally scheduled.
Here, we introduce a new closure type, STM_AWOKEN, which marks a TSO
which has been sent a wake-up message, allowing us to send only one
wakeup.
Diffstat (limited to 'rts/StgMiscClosures.cmm')
| -rw-r--r-- | rts/StgMiscClosures.cmm | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/rts/StgMiscClosures.cmm b/rts/StgMiscClosures.cmm index 4341013d5d..28a41ad681 100644 --- a/rts/StgMiscClosures.cmm +++ b/rts/StgMiscClosures.cmm @@ -547,6 +547,18 @@ INFO_TABLE_CONSTR(stg_END_TSO_QUEUE,0,0,0,CONSTR_NOCAF_STATIC,"END_TSO_QUEUE","E CLOSURE(stg_END_TSO_QUEUE_closure,stg_END_TSO_QUEUE); /* ---------------------------------------------------------------------------- + STM_AWOKEN + + This is a static nullary constructor (like []) that we use to mark a + thread waiting on an STM wakeup + ------------------------------------------------------------------------- */ + +INFO_TABLE_CONSTR(stg_STM_AWOKEN,0,0,0,CONSTR_NOCAF_STATIC,"STM_AWOKEN","STM_AWOKEN") +{ foreign "C" barf("STM_AWOKEN object entered!") never returns; } + +CLOSURE(stg_STM_AWOKEN_closure,stg_STM_AWOKEN); + +/* ---------------------------------------------------------------------------- Arrays These come in two basic flavours: arrays of data (StgArrWords) and arrays of |