STATIC_INLINE StgInd *
lockCAF (StgRegTable *reg, StgIndStatic *caf)
{
const StgInfoTable *orig_info;
Capability *cap = regTableToCapability(reg);
StgInd *bh;
orig_info = caf->header.info;
#ifdef THREADED_RTS
const StgInfoTable *cur_info;
if (orig_info == &stg_IND_STATIC_info ||
orig_info == &stg_WHITEHOLE_info) {
// already claimed by another thread; re-enter the CAF
return NULL;
}
cur_info = (const StgInfoTable *)
cas((StgVolatilePtr)&caf->header.info,
(StgWord)orig_info,
(StgWord)&stg_WHITEHOLE_info);
if (cur_info != orig_info) {
// already claimed by another thread; re-enter the CAF
return NULL;
}
// successfully claimed by us; overwrite with IND_STATIC
#endif
// For the benefit of revertCAFs(), save the original info pointer
caf->saved_info = orig_info;
// Allocate the blackhole indirection closure
bh = (StgInd *)allocate(cap, sizeofW(*bh));
SET_HDR(bh, &stg_CAF_BLACKHOLE_info, caf->header.prof.ccs);
bh->indirectee = (StgClosure *)cap->r.rCurrentTSO;
caf->indirectee = (StgClosure *)bh;
write_barrier();
SET_INFO((StgClosure*)caf,&stg_IND_STATIC_info);
return bh;
}
StgInt
newSpark (StgRegTable *reg, StgClosure *p)
{
Capability *cap = regTableToCapability(reg);
SparkPool *pool = cap->sparks;
/* I am not sure whether this is the right thing to do.
* Maybe it is better to exploit the tag information
* instead of throwing it away?
*/
p = UNTAG_CLOSURE(p);
if (closure_SHOULD_SPARK(p)) {
pushWSDeque(pool,p);
cap->sparks_created++;
} else {
cap->sparks_dud++;
}
return 1;
}
/*
This is the write barrier for MVARs. An MVAR_CLEAN objects is not
on the mutable list; a MVAR_DIRTY is. When written to, a
MVAR_CLEAN turns into a MVAR_DIRTY and is put on the mutable list.
The check for MVAR_CLEAN is inlined at the call site for speed,
this really does make a difference on concurrency-heavy benchmarks
such as Chaneneos and cheap-concurrency.
*/
void
dirty_MVAR(StgRegTable *reg, StgClosure *p)
{
recordClosureMutated(regTableToCapability(reg),p);
}