From a1e3066e066f0f75da361f881b2f3198e0aada5f Mon Sep 17 00:00:00 2001 From: Simon Marlow Date: Tue, 6 Mar 2007 14:27:32 +0000 Subject: [PATCH] THREADED_RTS: use cas() when claiming thunks I guess I forgot to do this the first time around; the upshot is that there could be some uncaught duplication of work on a multiprocessor (but unlikely). --- rts/ThreadPaused.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/rts/ThreadPaused.c b/rts/ThreadPaused.c index e76d70f..5b64f76 100644 --- a/rts/ThreadPaused.c +++ b/rts/ThreadPaused.c @@ -178,6 +178,8 @@ threadPaused(Capability *cap, StgTSO *tso) { StgClosure *frame; StgRetInfoTable *info; + const StgInfoTable *bh_info; + const StgInfoTable *cur_bh_info USED_IF_THREADS; StgClosure *bh; StgPtr stack_end; nat words_to_squeeze = 0; @@ -212,8 +214,13 @@ threadPaused(Capability *cap, StgTSO *tso) SET_INFO(frame, (StgInfoTable *)&stg_marked_upd_frame_info); bh = ((StgUpdateFrame *)frame)->updatee; + bh_info = bh->header.info; - if (closure_IND(bh) || bh->header.info == &stg_BLACKHOLE_info) { +#ifdef THREADED_RTS + retry: +#endif + if (closure_flags[INFO_PTR_TO_STRUCT(bh_info)->type] & _IND + || bh_info == &stg_BLACKHOLE_info) { debugTrace(DEBUG_squeeze, "suspending duplicate work: %ld words of stack", (long)((StgPtr)frame - tso->sp)); @@ -246,7 +253,20 @@ threadPaused(Capability *cap, StgTSO *tso) // We pretend that bh is now dead. LDV_recordDead_FILL_SLOP_DYNAMIC((StgClosure *)bh); #endif + +#ifdef THREADED_RTS + cur_bh_info = (const StgInfoTable *) + cas((StgVolatilePtr)&bh->header.info, + (StgWord)bh_info, + (StgWord)&stg_BLACKHOLE_info); + + if (cur_bh_info != bh_info) { + bh_info = cur_bh_info; + goto retry; + } +#else SET_INFO(bh,&stg_BLACKHOLE_info); +#endif // We pretend that bh has just been created. LDV_RECORD_CREATE(bh); -- 1.7.10.4