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/* -----------------------------------------------------------------------------
*
* (c) The GHC Team, 1998-2013
*
* Performing updates.
*
* ---------------------------------------------------------------------------*/
#pragma once
#if !defined(CMINUSMINUS)
#include "BeginPrivate.h"
#endif
/* -----------------------------------------------------------------------------
Updates
-------------------------------------------------------------------------- */
/* LDV profiling:
* After all, we do *NOT* need to call LDV_RECORD_CREATE() for IND
* closures because they are inherently used. But, it corrupts
* the invariants that every closure keeps its creation time in the profiling
* field. So, we call LDV_RECORD_CREATE().
*/
/*
* We have two versions of this macro (sadly), one for use in C-- code,
* and the other for C.
*
* The and_then argument is a performance hack so that we can paste in
* the continuation code directly. It helps shave a couple of
* instructions off the common case in the update code, which is
* worthwhile (the update code is often part of the inner loop).
*/
#if defined(CMINUSMINUS)
#define UPDATE_FRAME_FIELDS(w_,p_,info_ptr,ccs,p2,updatee) \
w_ info_ptr, \
PROF_HDR_FIELDS(w_,ccs,p2) \
p_ updatee
/*
* Getting the memory barriers correct here is quite tricky. Essentially
* the write barrier ensures that any writes to the new indirectee are visible
* before we introduce the indirection.
* See Note [Heap memory barriers] in SMP.h.
*/
#define updateWithIndirection(p1, p2, and_then) \
W_ bd; \
\
prim_write_barrier; \
bd = Bdescr(p1); \
if (bdescr_gen_no(bd) != 0 :: bits16) { \
IF_NONMOVING_WRITE_BARRIER_ENABLED { \
ccall updateRemembSetPushThunk_(BaseReg, p1 "ptr"); \
} \
recordMutableCap(p1, TO_W_(bdescr_gen_no(bd))); \
TICK_UPD_OLD_IND(); \
} else { \
TICK_UPD_NEW_IND(); \
} \
OVERWRITING_CLOSURE(p1); \
StgInd_indirectee(p1) = p2; \
prim_write_barrier; \
SET_INFO(p1, stg_BLACKHOLE_info); \
LDV_RECORD_CREATE(p1); \
and_then;
#else /* !CMINUSMINUS */
INLINE_HEADER void updateWithIndirection (Capability *cap,
StgClosure *p1,
StgClosure *p2)
{
ASSERT( (P_)p1 != (P_)p2 );
/* not necessarily true: ASSERT( !closure_IND(p1) ); */
/* occurs in RaiseAsync.c:raiseAsync() */
/* See Note [Heap memory barriers] in SMP.h */
bdescr *bd = Bdescr((StgPtr)p1);
if (bd->gen_no != 0) {
IF_NONMOVING_WRITE_BARRIER_ENABLED {
updateRemembSetPushThunk(cap, (StgThunk*)p1);
}
recordMutableCap(p1, cap, bd->gen_no);
TICK_UPD_OLD_IND();
} else {
TICK_UPD_NEW_IND();
}
OVERWRITING_CLOSURE(p1);
RELEASE_STORE(&((StgInd *)p1)->indirectee, p2);
SET_INFO_RELEASE(p1, &stg_BLACKHOLE_info);
LDV_RECORD_CREATE(p1);
}
#endif /* CMINUSMINUS */
#if !defined(CMINUSMINUS)
#include "EndPrivate.h"
#endif
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