예제 #1
0
파일: Evac.c 프로젝트: 23Skidoo/ghc
STATIC_INLINE GNUC_ATTR_HOT void
copy_tag(StgClosure **p, const StgInfoTable *info,
         StgClosure *src, nat size, nat gen_no, StgWord tag)
{
    StgPtr to, from;
    nat i;

    to = alloc_for_copy(size,gen_no);

    from = (StgPtr)src;
    to[0] = (W_)info;
    for (i = 1; i < size; i++) { // unroll for small i
        to[i] = from[i];
    }

//  if (to+size+2 < bd->start + BLOCK_SIZE_W) {
//      __builtin_prefetch(to + size + 2, 1);
//  }

#if defined(PARALLEL_GC)
    {
        const StgInfoTable *new_info;
        new_info = (const StgInfoTable *)cas((StgPtr)&src->header.info, (W_)info, MK_FORWARDING_PTR(to));
        if (new_info != info) {
#ifdef PROFILING
            // We copied this object at the same time as another
            // thread.  We'll evacuate the object again and the copy
            // we just made will be discarded at the next GC, but we
            // may have copied it after the other thread called
            // SET_EVACUAEE_FOR_LDV(), which would confuse the LDV
            // profiler when it encounters this closure in
            // processHeapClosureForDead.  So we reset the LDVW field
            // here.
            LDVW(to) = 0;
#endif
            return evacuate(p); // does the failed_to_evac stuff
        } else {
            *p = TAG_CLOSURE(tag,(StgClosure*)to);
        }
    }
#else
    src->header.info = (const StgInfoTable *)MK_FORWARDING_PTR(to);
    *p = TAG_CLOSURE(tag,(StgClosure*)to);
#endif

#ifdef PROFILING
    // We store the size of the just evacuated object in the LDV word so that
    // the profiler can guess the position of the next object later.
    // This is safe only if we are sure that no other thread evacuates
    // the object again, so we cannot use copy_tag_nolock when PROFILING.
    SET_EVACUAEE_FOR_LDV(from, size);
#endif
}
예제 #2
0
파일: Evac.c 프로젝트: 23Skidoo/ghc
STATIC_INLINE void
copy_tag_nolock(StgClosure **p, const StgInfoTable *info,
         StgClosure *src, nat size, nat gen_no, StgWord tag)
{
    StgPtr to, from;
    nat i;

    to = alloc_for_copy(size,gen_no);

    from = (StgPtr)src;
    to[0] = (W_)info;
    for (i = 1; i < size; i++) { // unroll for small i
        to[i] = from[i];
    }

    // if somebody else reads the forwarding pointer, we better make
    // sure there's a closure at the end of it.
    write_barrier();
    *p = TAG_CLOSURE(tag,(StgClosure*)to);
    src->header.info = (const StgInfoTable *)MK_FORWARDING_PTR(to);

//  if (to+size+2 < bd->start + BLOCK_SIZE_W) {
//      __builtin_prefetch(to + size + 2, 1);
//  }

#ifdef PROFILING
    // We store the size of the just evacuated object in the LDV word so that
    // the profiler can guess the position of the next object later.
    SET_EVACUAEE_FOR_LDV(from, size);
#endif
}
예제 #3
0
파일: Evac.c 프로젝트: Mikolaj/ghc
STATIC_INLINE GNUC_ATTR_HOT void
copy_tag(StgClosure **p, const StgInfoTable *info, 
         StgClosure *src, nat size, nat gen_no, StgWord tag)
{
    StgPtr to, from;
    nat i;

    to = alloc_for_copy(size,gen_no);
    
    from = (StgPtr)src;
    to[0] = (W_)info;
    for (i = 1; i < size; i++) { // unroll for small i
	to[i] = from[i];
    }

//  if (to+size+2 < bd->start + BLOCK_SIZE_W) {
//      __builtin_prefetch(to + size + 2, 1);
//  }

#if defined(PARALLEL_GC)
    {
        const StgInfoTable *new_info;
        new_info = (const StgInfoTable *)cas((StgPtr)&src->header.info, (W_)info, MK_FORWARDING_PTR(to));
        if (new_info != info) {
            return evacuate(p); // does the failed_to_evac stuff
        } else {
            *p = TAG_CLOSURE(tag,(StgClosure*)to);
        }
    }
#else
    src->header.info = (const StgInfoTable *)MK_FORWARDING_PTR(to);
    *p = TAG_CLOSURE(tag,(StgClosure*)to);
#endif

#ifdef PROFILING
    // We store the size of the just evacuated object in the LDV word so that
    // the profiler can guess the position of the next object later.
    SET_EVACUAEE_FOR_LDV(from, size);
#endif
}
예제 #4
0
파일: Evac.c 프로젝트: DJacquard/ghc
/* Special version of copy() for when we only want to copy the info
 * pointer of an object, but reserve some padding after it.  This is
 * used to optimise evacuation of TSOs.
 */
static bool
copyPart(StgClosure **p, StgClosure *src, uint32_t size_to_reserve,
         uint32_t size_to_copy, uint32_t gen_no)
{
    StgPtr to, from;
    uint32_t i;
    StgWord info;

#if defined(PARALLEL_GC)
spin:
        info = xchg((StgPtr)&src->header.info, (W_)&stg_WHITEHOLE_info);
        if (info == (W_)&stg_WHITEHOLE_info) {
#if defined(PROF_SPIN)
            whitehole_gc_spin++;
#endif
            busy_wait_nop();
            goto spin;
        }
    if (IS_FORWARDING_PTR(info)) {
        src->header.info = (const StgInfoTable *)info;
        evacuate(p); // does the failed_to_evac stuff
        return false;
    }
#else
    info = (W_)src->header.info;
#endif

    to = alloc_for_copy(size_to_reserve, gen_no);

    from = (StgPtr)src;
    to[0] = info;
    for (i = 1; i < size_to_copy; i++) { // unroll for small i
        to[i] = from[i];
    }

    write_barrier();
    src->header.info = (const StgInfoTable*)MK_FORWARDING_PTR(to);
    *p = (StgClosure *)to;

#if defined(PROFILING)
    // We store the size of the just evacuated object in the LDV word so that
    // the profiler can guess the position of the next object later.
    SET_EVACUAEE_FOR_LDV(from, size_to_reserve);
    // fill the slop
    if (size_to_reserve - size_to_copy > 0)
        LDV_FILL_SLOP(to + size_to_copy, (int)(size_to_reserve - size_to_copy));
#endif

    return true;
}