static void
thread_static( StgClosure* p )
{
const StgInfoTable *info;
// keep going until we've threaded all the objects on the linked
// list...
while (p != END_OF_STATIC_LIST) {
info = get_itbl(p);
switch (info->type) {
case IND_STATIC:
thread(&((StgInd *)p)->indirectee);
p = *IND_STATIC_LINK(p);
continue;
case THUNK_STATIC:
p = *THUNK_STATIC_LINK(p);
continue;
case FUN_STATIC:
p = *FUN_STATIC_LINK(p);
continue;
case CONSTR_STATIC:
p = *STATIC_LINK(info,p);
continue;
default:
barf("thread_static: strange closure %d", (int)(info->type));
}
}
}
/*
Check the static objects list.
*/
void
checkStaticObjects ( StgClosure* static_objects )
{
StgClosure *p = static_objects;
const StgInfoTable *info;
while (p != END_OF_STATIC_OBJECT_LIST) {
p = UNTAG_STATIC_LIST_PTR(p);
checkClosure(p);
info = get_itbl(p);
switch (info->type) {
case IND_STATIC:
{
const StgClosure *indirectee;
indirectee = UNTAG_CONST_CLOSURE(((StgIndStatic *)p)->indirectee);
ASSERT(LOOKS_LIKE_CLOSURE_PTR(indirectee));
ASSERT(LOOKS_LIKE_INFO_PTR((StgWord)indirectee->header.info));
p = *IND_STATIC_LINK((StgClosure *)p);
break;
}
case THUNK_STATIC:
p = *THUNK_STATIC_LINK((StgClosure *)p);
break;
case FUN_STATIC:
p = *STATIC_LINK(info,(StgClosure *)p);
break;
case CONSTR:
case CONSTR_NOCAF:
case CONSTR_1_0:
case CONSTR_2_0:
case CONSTR_1_1:
p = *STATIC_LINK(info,(StgClosure *)p);
break;
default:
barf("checkStaticObjetcs: strange closure %p (%s)",
p, info_type(p));
}
}
}
/*
Check the static objects list.
*/
void
checkStaticObjects ( StgClosure* static_objects )
{
StgClosure *p = static_objects;
StgInfoTable *info;
while (p != END_OF_STATIC_LIST) {
checkClosure(p);
info = get_itbl(p);
switch (info->type) {
case IND_STATIC:
{
StgClosure *indirectee = UNTAG_CLOSURE(((StgIndStatic *)p)->indirectee);
ASSERT(LOOKS_LIKE_CLOSURE_PTR(indirectee));
ASSERT(LOOKS_LIKE_INFO_PTR((StgWord)indirectee->header.info));
p = *IND_STATIC_LINK((StgClosure *)p);
break;
}
case THUNK_STATIC:
p = *THUNK_STATIC_LINK((StgClosure *)p);
break;
case FUN_STATIC:
p = *FUN_STATIC_LINK((StgClosure *)p);
break;
case CONSTR_STATIC:
p = *STATIC_LINK(info,(StgClosure *)p);
break;
default:
barf("checkStaticObjetcs: strange closure %p (%s)", p,
#ifndef HaLVM_TARGET_OS
info_type(p)
#else
"[HaLVM has no info_type()]"
#endif
);
}
}
}
REGPARM1 GNUC_ATTR_HOT void
evacuate(StgClosure **p)
{
bdescr *bd = NULL;
nat gen_no;
StgClosure *q;
const StgInfoTable *info;
StgWord tag;
q = *p;
loop:
/* The tag and the pointer are split, to be merged after evacing */
tag = GET_CLOSURE_TAG(q);
q = UNTAG_CLOSURE(q);
ASSERTM(LOOKS_LIKE_CLOSURE_PTR(q), "invalid closure, info=%p", q->header.info);
if (!HEAP_ALLOCED_GC(q)) {
if (!major_gc) return;
info = get_itbl(q);
switch (info->type) {
case THUNK_STATIC:
if (info->srt_bitmap != 0) {
evacuate_static_object(THUNK_STATIC_LINK((StgClosure *)q), q);
}
return;
case FUN_STATIC:
if (info->srt_bitmap != 0) {
evacuate_static_object(FUN_STATIC_LINK((StgClosure *)q), q);
}
return;
case IND_STATIC:
/* If q->saved_info != NULL, then it's a revertible CAF - it'll be
* on the CAF list, so don't do anything with it here (we'll
* scavenge it later).
*/
evacuate_static_object(IND_STATIC_LINK((StgClosure *)q), q);
return;
case CONSTR_STATIC:
evacuate_static_object(STATIC_LINK(info,(StgClosure *)q), q);
return;
case CONSTR_NOCAF_STATIC:
/* no need to put these on the static linked list, they don't need
* to be scavenged.
*/
return;
default:
barf("evacuate(static): strange closure type %d", (int)(info->type));
}
}
bd = Bdescr((P_)q);
if ((bd->flags & (BF_LARGE | BF_MARKED | BF_EVACUATED)) != 0) {
// pointer into to-space: just return it. It might be a pointer
// into a generation that we aren't collecting (> N), or it
// might just be a pointer into to-space. The latter doesn't
// happen often, but allowing it makes certain things a bit
// easier; e.g. scavenging an object is idempotent, so it's OK to
// have an object on the mutable list multiple times.
if (bd->flags & BF_EVACUATED) {
// We aren't copying this object, so we have to check
// whether it is already in the target generation. (this is
// the write barrier).
if (bd->gen_no < gct->evac_gen_no) {
gct->failed_to_evac = rtsTrue;
TICK_GC_FAILED_PROMOTION();
}
return;
}
/* evacuate large objects by re-linking them onto a different list.
*/
if (bd->flags & BF_LARGE) {
evacuate_large((P_)q);
return;
}
/* If the object is in a gen that we're compacting, then we
* need to use an alternative evacuate procedure.
*/
if (!is_marked((P_)q,bd)) {
mark((P_)q,bd);
push_mark_stack((P_)q);
}
return;
}
gen_no = bd->dest_no;
info = q->header.info;
if (IS_FORWARDING_PTR(info))
{
/* Already evacuated, just return the forwarding address.
* HOWEVER: if the requested destination generation (gct->evac_gen) is
* older than the actual generation (because the object was
* already evacuated to a younger generation) then we have to
* set the gct->failed_to_evac flag to indicate that we couldn't
* manage to promote the object to the desired generation.
*/
/*
* Optimisation: the check is fairly expensive, but we can often
* shortcut it if either the required generation is 0, or the
* current object (the EVACUATED) is in a high enough generation.
* We know that an EVACUATED always points to an object in the
* same or an older generation. gen is the lowest generation that the
* current object would be evacuated to, so we only do the full
* check if gen is too low.
*/
StgClosure *e = (StgClosure*)UN_FORWARDING_PTR(info);
*p = TAG_CLOSURE(tag,e);
if (gen_no < gct->evac_gen_no) { // optimisation
if (Bdescr((P_)e)->gen_no < gct->evac_gen_no) {
gct->failed_to_evac = rtsTrue;
TICK_GC_FAILED_PROMOTION();
}
}
return;
}
switch (INFO_PTR_TO_STRUCT(info)->type) {
case WHITEHOLE:
goto loop;
// For ints and chars of low value, save space by replacing references to
// these with closures with references to common, shared ones in the RTS.
//
// * Except when compiling into Windows DLLs which don't support cross-package
// data references very well.
//
case CONSTR_0_1:
{
#if defined(COMPILING_WINDOWS_DLL)
copy_tag_nolock(p,info,q,sizeofW(StgHeader)+1,gen_no,tag);
#else
StgWord w = (StgWord)q->payload[0];
if (info == Czh_con_info &&
// unsigned, so always true: (StgChar)w >= MIN_CHARLIKE &&
(StgChar)w <= MAX_CHARLIKE) {
*p = TAG_CLOSURE(tag,
(StgClosure *)CHARLIKE_CLOSURE((StgChar)w)
);
}
else if (info == Izh_con_info &&
(StgInt)w >= MIN_INTLIKE && (StgInt)w <= MAX_INTLIKE) {
*p = TAG_CLOSURE(tag,
(StgClosure *)INTLIKE_CLOSURE((StgInt)w)
);
}
else {
copy_tag_nolock(p,info,q,sizeofW(StgHeader)+1,gen_no,tag);
}
#endif
return;
}
case FUN_0_1:
case FUN_1_0:
case CONSTR_1_0:
copy_tag_nolock(p,info,q,sizeofW(StgHeader)+1,gen_no,tag);
return;
case THUNK_1_0:
case THUNK_0_1:
copy(p,info,q,sizeofW(StgThunk)+1,gen_no);
return;
case THUNK_1_1:
case THUNK_2_0:
case THUNK_0_2:
#ifdef NO_PROMOTE_THUNKS
#error bitrotted
#endif
copy(p,info,q,sizeofW(StgThunk)+2,gen_no);
return;
case FUN_1_1:
case FUN_2_0:
case FUN_0_2:
case CONSTR_1_1:
case CONSTR_2_0:
copy_tag_nolock(p,info,q,sizeofW(StgHeader)+2,gen_no,tag);
return;
case CONSTR_0_2:
copy_tag_nolock(p,info,q,sizeofW(StgHeader)+2,gen_no,tag);
return;
case THUNK:
copy(p,info,q,thunk_sizeW_fromITBL(INFO_PTR_TO_STRUCT(info)),gen_no);
return;
case FUN:
case CONSTR:
copy_tag_nolock(p,info,q,sizeW_fromITBL(INFO_PTR_TO_STRUCT(info)),gen_no,tag);
return;
case BLACKHOLE:
{
StgClosure *r;
const StgInfoTable *i;
r = ((StgInd*)q)->indirectee;
if (GET_CLOSURE_TAG(r) == 0) {
i = r->header.info;
if (IS_FORWARDING_PTR(i)) {
r = (StgClosure *)UN_FORWARDING_PTR(i);
i = r->header.info;
}
if (i == &stg_TSO_info
|| i == &stg_WHITEHOLE_info
|| i == &stg_BLOCKING_QUEUE_CLEAN_info
|| i == &stg_BLOCKING_QUEUE_DIRTY_info) {
copy(p,info,q,sizeofW(StgInd),gen_no);
return;
}
ASSERT(i != &stg_IND_info);
}
q = r;
*p = r;
goto loop;
}
case MUT_VAR_CLEAN:
case MUT_VAR_DIRTY:
case MVAR_CLEAN:
case MVAR_DIRTY:
case TVAR:
case BLOCKING_QUEUE:
case WEAK:
case PRIM:
case MUT_PRIM:
copy(p,info,q,sizeW_fromITBL(INFO_PTR_TO_STRUCT(info)),gen_no);
return;
case BCO:
copy(p,info,q,bco_sizeW((StgBCO *)q),gen_no);
return;
case THUNK_SELECTOR:
eval_thunk_selector(p, (StgSelector *)q, rtsTrue);
return;
case IND:
// follow chains of indirections, don't evacuate them
q = ((StgInd*)q)->indirectee;
*p = q;
goto loop;
case RET_BCO:
case RET_SMALL:
case RET_BIG:
case UPDATE_FRAME:
case UNDERFLOW_FRAME:
case STOP_FRAME:
case CATCH_FRAME:
case CATCH_STM_FRAME:
case CATCH_RETRY_FRAME:
case ATOMICALLY_FRAME:
// shouldn't see these
barf("evacuate: stack frame at %p\n", q);
case PAP:
copy(p,info,q,pap_sizeW((StgPAP*)q),gen_no);
return;
case AP:
copy(p,info,q,ap_sizeW((StgAP*)q),gen_no);
return;
case AP_STACK:
copy(p,info,q,ap_stack_sizeW((StgAP_STACK*)q),gen_no);
return;
case ARR_WORDS:
// just copy the block
copy(p,info,q,arr_words_sizeW((StgArrBytes *)q),gen_no);
return;
case MUT_ARR_PTRS_CLEAN:
case MUT_ARR_PTRS_DIRTY:
case MUT_ARR_PTRS_FROZEN:
case MUT_ARR_PTRS_FROZEN0:
// just copy the block
copy(p,info,q,mut_arr_ptrs_sizeW((StgMutArrPtrs *)q),gen_no);
return;
case SMALL_MUT_ARR_PTRS_CLEAN:
case SMALL_MUT_ARR_PTRS_DIRTY:
case SMALL_MUT_ARR_PTRS_FROZEN:
case SMALL_MUT_ARR_PTRS_FROZEN0:
// just copy the block
copy(p,info,q,small_mut_arr_ptrs_sizeW((StgSmallMutArrPtrs *)q),gen_no);
return;
case TSO:
copy(p,info,q,sizeofW(StgTSO),gen_no);
return;
case STACK:
{
StgStack *stack = (StgStack *)q;
/* To evacuate a small STACK, we need to adjust the stack pointer
*/
{
StgStack *new_stack;
StgPtr r, s;
rtsBool mine;
mine = copyPart(p,(StgClosure *)stack, stack_sizeW(stack),
sizeofW(StgStack), gen_no);
if (mine) {
new_stack = (StgStack *)*p;
move_STACK(stack, new_stack);
for (r = stack->sp, s = new_stack->sp;
r < stack->stack + stack->stack_size;) {
*s++ = *r++;
}
}
return;
}
}
case TREC_CHUNK:
copy(p,info,q,sizeofW(StgTRecChunk),gen_no);
return;
default:
barf("evacuate: strange closure type %d", (int)(INFO_PTR_TO_STRUCT(info)->type));
}
barf("evacuate");
}
//
// Check whether we can unload any object code. This is called at the
// appropriate point during a GC, where all the heap data is nice and
// packed together and we have a linked list of the static objects.
//
// The check involves a complete heap traversal, but you only pay for
// this (a) when you have called unloadObj(), and (b) at a major GC,
// which is much more expensive than the traversal we're doing here.
//
void checkUnload (StgClosure *static_objects)
{
nat g, n;
HashTable *addrs;
StgClosure* p;
const StgInfoTable *info;
ObjectCode *oc, *prev, *next;
gen_workspace *ws;
StgClosure* link;
if (unloaded_objects == NULL) return;
ACQUIRE_LOCK(&linker_unloaded_mutex);
// Mark every unloadable object as unreferenced initially
for (oc = unloaded_objects; oc; oc = oc->next) {
IF_DEBUG(linker, debugBelch("Checking whether to unload %" PATH_FMT "\n",
oc->fileName));
oc->referenced = rtsFalse;
}
addrs = allocHashTable();
for (p = static_objects; p != END_OF_STATIC_OBJECT_LIST; p = link) {
p = UNTAG_STATIC_LIST_PTR(p);
checkAddress(addrs, p);
info = get_itbl(p);
link = *STATIC_LINK(info, p);
}
// CAFs on revertible_caf_list are not on static_objects
for (p = (StgClosure*)revertible_caf_list;
p != END_OF_CAF_LIST;
p = ((StgIndStatic *)p)->static_link) {
p = UNTAG_STATIC_LIST_PTR(p);
checkAddress(addrs, p);
}
for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
searchHeapBlocks (addrs, generations[g].blocks);
searchHeapBlocks (addrs, generations[g].large_objects);
for (n = 0; n < n_capabilities; n++) {
ws = &gc_threads[n]->gens[g];
searchHeapBlocks(addrs, ws->todo_bd);
searchHeapBlocks(addrs, ws->part_list);
searchHeapBlocks(addrs, ws->scavd_list);
}
}
#ifdef PROFILING
/* Traverse the cost centre tree, calling checkAddress on each CCS/CC */
searchCostCentres(addrs, CCS_MAIN);
/* Also check each cost centre in the CC_LIST */
CostCentre *cc;
for (cc = CC_LIST; cc != NULL; cc = cc->link) {
checkAddress(addrs, cc);
}
#endif /* PROFILING */
// Look through the unloadable objects, and any object that is still
// marked as unreferenced can be physically unloaded, because we
// have no references to it.
prev = NULL;
for (oc = unloaded_objects; oc; oc = next) {
next = oc->next;
if (oc->referenced == 0) {
if (prev == NULL) {
unloaded_objects = oc->next;
} else {
prev->next = oc->next;
}
IF_DEBUG(linker, debugBelch("Unloading object file %" PATH_FMT "\n",
oc->fileName));
freeObjectCode(oc);
} else {
IF_DEBUG(linker, debugBelch("Object file still in use: %"
PATH_FMT "\n", oc->fileName));
prev = oc;
}
}
freeHashTable(addrs, NULL);
RELEASE_LOCK(&linker_unloaded_mutex);
}
//
// Check whether we can unload any object code. This is called at the
// appropriate point during a GC, where all the heap data is nice and
// packed together and we have a linked list of the static objects.
//
// The check involves a complete heap traversal, but you only pay for
// this (a) when you have called unloadObj(), and (b) at a major GC,
// which is much more expensive than the traversal we're doing here.
//
void checkUnload (StgClosure *static_objects)
{
nat g, n;
HashTable *addrs;
StgClosure* p;
const StgInfoTable *info;
ObjectCode *oc, *prev, *next;
gen_workspace *ws;
StgClosure* link;
if (unloaded_objects == NULL) return;
// Mark every unloadable object as unreferenced initially
for (oc = unloaded_objects; oc; oc = oc->next) {
IF_DEBUG(linker, debugBelch("Checking whether to unload %" PATH_FMT "\n",
oc->fileName));
oc->referenced = rtsFalse;
}
addrs = allocHashTable();
for (p = static_objects; p != END_OF_STATIC_LIST; p = link) {
checkAddress(addrs, p);
info = get_itbl(p);
link = *STATIC_LINK(info, p);
}
for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
searchHeapBlocks (addrs, generations[g].blocks);
searchHeapBlocks (addrs, generations[g].large_objects);
for (n = 0; n < n_capabilities; n++) {
ws = &gc_threads[n]->gens[g];
searchHeapBlocks(addrs, ws->todo_bd);
searchHeapBlocks(addrs, ws->part_list);
searchHeapBlocks(addrs, ws->scavd_list);
}
}
// Look through the unloadable objects, and any object that is still
// marked as unreferenced can be physically unloaded, because we
// have no references to it.
prev = NULL;
for (oc = unloaded_objects; oc; prev = oc, oc = next) {
next = oc->next;
if (oc->referenced == 0) {
if (prev == NULL) {
unloaded_objects = oc->next;
} else {
prev->next = oc->next;
}
IF_DEBUG(linker, debugBelch("Unloading object file %" PATH_FMT "\n",
oc->fileName));
freeObjectCode(oc);
} else {
IF_DEBUG(linker, debugBelch("Object file still in use: %"
PATH_FMT "\n", oc->fileName));
}
}
freeHashTable(addrs, NULL);
}
static void
scavenge_static(void)
{
StgClosure* p;
const StgInfoTable *info;
debugTrace(DEBUG_gc, "scavenging static objects");
/* Always evacuate straight to the oldest generation for static
* objects */
gct->evac_gen_no = oldest_gen->no;
/* keep going until we've scavenged all the objects on the linked
list... */
while (1) {
/* get the next static object from the list. Remember, there might
* be more stuff on this list after each evacuation...
* (static_objects is a global)
*/
p = gct->static_objects;
if (p == END_OF_STATIC_LIST) {
break;
}
ASSERT(LOOKS_LIKE_CLOSURE_PTR(p));
info = get_itbl(p);
/*
if (info->type==RBH)
info = REVERT_INFOPTR(info); // if it's an RBH, look at the orig closure
*/
// make sure the info pointer is into text space
/* Take this object *off* the static_objects list,
* and put it on the scavenged_static_objects list.
*/
gct->static_objects = *STATIC_LINK(info,p);
*STATIC_LINK(info,p) = gct->scavenged_static_objects;
gct->scavenged_static_objects = p;
switch (info -> type) {
case IND_STATIC:
{
StgInd *ind = (StgInd *)p;
evacuate(&ind->indirectee);
/* might fail to evacuate it, in which case we have to pop it
* back on the mutable list of the oldest generation. We
* leave it *on* the scavenged_static_objects list, though,
* in case we visit this object again.
*/
if (gct->failed_to_evac) {
gct->failed_to_evac = rtsFalse;
recordMutableGen_GC((StgClosure *)p,oldest_gen->no);
}
break;
}
case THUNK_STATIC:
scavenge_thunk_srt(info);
break;
case FUN_STATIC:
scavenge_fun_srt(info);
break;
case CONSTR_STATIC:
{
StgPtr q, next;
next = (P_)p->payload + info->layout.payload.ptrs;
// evacuate the pointers
for (q = (P_)p->payload; q < next; q++) {
evacuate((StgClosure **)q);
}
break;
}
default:
barf("scavenge_static: strange closure %d", (int)(info->type));
}
ASSERT(gct->failed_to_evac == rtsFalse);
}
}
