static void determine_min_nos_size(GC_Gen *gc, POINTER_SIZE_INT min_heap_size)
{
min_nos_size_bytes *= gc->_num_processors;
POINTER_SIZE_INT min_nos_size_threshold = min_heap_size>>5;
if(min_nos_size_bytes > min_nos_size_threshold)
min_nos_size_bytes = round_down_to_size(min_nos_size_threshold, SPACE_ALLOC_UNIT);
if(MIN_NOS_SIZE) min_nos_size_bytes = MIN_NOS_SIZE;
}
static Block_Header *get_next_dest_block(Mspace *mspace)
{
Block_Header *cur_dest_block;
if(next_block_for_dest) {
cur_dest_block = (Block_Header*)next_block_for_dest;
while(cur_dest_block->status == BLOCK_DEST) {
cur_dest_block = cur_dest_block->next;
if(!cur_dest_block) break;
}
next_block_for_dest = cur_dest_block;
} else {
cur_dest_block = set_next_block_for_dest(mspace);
}
unsigned int total_dest_counter = 0;
/*For LOS_Shrink: last_dest_block might point to a fake block*/
Block_Header *last_dest_block =
(Block_Header *)round_down_to_size((POINTER_SIZE_INT)(last_block_for_dest->base), GC_BLOCK_SIZE_BYTES);
for(; cur_dest_block <= last_dest_block; cur_dest_block = cur_dest_block->next) {
if(!cur_dest_block) return NULL;
if(cur_dest_block->status == BLOCK_DEST) {
continue;
}
if(cur_dest_block->dest_counter == 0 && cur_dest_block->src) {
cur_dest_block->status = BLOCK_DEST;
return cur_dest_block;
} else if(cur_dest_block->dest_counter == 1 && GC_BLOCK_HEADER(cur_dest_block->src) == cur_dest_block) {
return cur_dest_block;
} else if(cur_dest_block->dest_counter == 0 && !cur_dest_block->src) {
cur_dest_block->status = BLOCK_DEST;
} else {
total_dest_counter += cur_dest_block->dest_counter;
}
}
if(total_dest_counter)
return DEST_NOT_EMPTY;
return NULL;
}
void slide_compact_mspace(Collector* collector)
{
GC* gc = collector->gc;
Mspace* mspace = (Mspace*)gc_get_mos((GC_Gen*)gc);
Lspace* lspace = (Lspace*)gc_get_los((GC_Gen*)gc);
unsigned int num_active_collectors = gc->num_active_collectors;
/* Pass 1: **************************************************
*mark all live objects in heap, and save all the slots that
*have references that are going to be repointed.
*/
TRACE2("gc.process", "GC: collector["<<((POINTER_SIZE_INT)collector->thread_handle)<<"]: pass1: marking...");
unsigned int old_num = atomic_cas32( &num_marking_collectors, 0, num_active_collectors+1);
if(collect_is_fallback())
mark_scan_heap_for_fallback(collector);
else if(gc->tuner->kind != TRANS_NOTHING)
mark_scan_heap_for_space_tune(collector);
else
mark_scan_heap(collector);
old_num = atomic_inc32(&num_marking_collectors);
/* last collector's world here */
if( ++old_num == num_active_collectors ) {
if(!IGNORE_FINREF )
collector_identify_finref(collector);
#ifndef BUILD_IN_REFERENT
else {
gc_set_weakref_sets(gc);
gc_update_weakref_ignore_finref(gc);
}
#endif
gc_identify_dead_weak_roots(gc);
if( gc->tuner->kind != TRANS_NOTHING ) gc_compute_space_tune_size_after_marking(gc);
//assert(!(gc->tuner->tuning_size % GC_BLOCK_SIZE_BYTES));
/* prepare for next phase */
gc_init_block_for_collectors(gc, mspace);
#ifdef USE_32BITS_HASHCODE
if(collect_is_fallback())
fallback_clear_fwd_obj_oi_init(collector);
#endif
last_block_for_dest = NULL;
/* let other collectors go */
num_marking_collectors++;
}
while(num_marking_collectors != num_active_collectors + 1);
TRACE2("gc.process", "GC: collector["<<((POINTER_SIZE_INT)collector->thread_handle)<<"]: finish pass1 and start pass2: relocating mos&nos...");
/* Pass 2: **************************************************
assign target addresses for all to-be-moved objects */
atomic_cas32( &num_repointing_collectors, 0, num_active_collectors+1);
#ifdef USE_32BITS_HASHCODE
if(collect_is_fallback())
fallback_clear_fwd_obj_oi(collector);
#endif
mspace_compute_object_target(collector, mspace);
old_num = atomic_inc32(&num_repointing_collectors);
/*last collector's world here*/
if( ++old_num == num_active_collectors ) {
if(lspace->move_object) {
TRACE2("gc.process", "GC: collector["<<((POINTER_SIZE_INT)collector->thread_handle)<<"]: pass2: relocating los ...");
lspace_compute_object_target(collector, lspace);
}
gc->collect_result = gc_collection_result(gc);
if(!gc->collect_result) {
num_repointing_collectors++;
return;
}
gc_reset_block_for_collectors(gc, mspace);
gc_init_block_for_fix_repointed_refs(gc, mspace);
num_repointing_collectors++;
}
while(num_repointing_collectors != num_active_collectors + 1);
if(!gc->collect_result) return;
TRACE2("gc.process", "GC: collector["<<((POINTER_SIZE_INT)collector->thread_handle)<<"]: finish pass2 and start pass3: repointing...");
/* Pass 3: **************************************************
*update all references whose objects are to be moved
*/
old_num = atomic_cas32( &num_fixing_collectors, 0, num_active_collectors+1);
mspace_fix_repointed_refs(collector, mspace);
old_num = atomic_inc32(&num_fixing_collectors);
/*last collector's world here */
if( ++old_num == num_active_collectors ) {
lspace_fix_repointed_refs(collector, lspace);
gc_fix_rootset(collector, FALSE);
gc_init_block_for_sliding_compact(gc, mspace);
/*LOS_Shrink: This operation moves objects in LOS, and should be part of Pass 4
*lspace_sliding_compact is not binded with los shrink, we could slide compact los individually.
*So we use a flag lspace->move_object here, not tuner->kind == TRANS_FROM_LOS_TO_MOS.
*/
if(lspace->move_object) lspace_sliding_compact(collector, lspace);
/*The temp blocks for storing interim infomation is copied to the real place they should be.
*And the space of the blocks are freed, which is alloced in gc_space_tuner_init_fake_blocks_for_los_shrink.
*/
last_block_for_dest = (Block_Header *)round_down_to_size((POINTER_SIZE_INT)last_block_for_dest->base, GC_BLOCK_SIZE_BYTES);
if(gc->tuner->kind == TRANS_FROM_LOS_TO_MOS) gc_space_tuner_release_fake_blocks_for_los_shrink(gc);
num_fixing_collectors++;
}
while(num_fixing_collectors != num_active_collectors + 1);
TRACE2("gc.process", "GC: collector["<<((POINTER_SIZE_INT)collector->thread_handle)<<"]: finish pass3 and start pass4: moving...");
/* Pass 4: **************************************************
move objects */
atomic_cas32( &num_moving_collectors, 0, num_active_collectors);
mspace_sliding_compact(collector, mspace);
atomic_inc32(&num_moving_collectors);
while(num_moving_collectors != num_active_collectors);
TRACE2("gc.process", "GC: collector["<<((POINTER_SIZE_INT)collector->thread_handle)<<"]: finish pass4 and start pass 5: restoring obj_info...");
/* Pass 5: **************************************************
restore obj_info */
atomic_cas32( &num_restoring_collectors, 0, num_active_collectors+1);
collector_restore_obj_info(collector);
#ifdef USE_32BITS_HASHCODE
collector_attach_hashcode(collector);
#endif
old_num = atomic_inc32(&num_restoring_collectors);
if( ++old_num == num_active_collectors ) {
if(gc->tuner->kind != TRANS_NOTHING)
mspace_update_info_after_space_tuning(mspace);
num_restoring_collectors++;
}
while(num_restoring_collectors != num_active_collectors + 1);
/* Dealing with out of memory in mspace */
void* mspace_border = &mspace->blocks[mspace->free_block_idx - mspace->first_block_idx];
if( mspace_border > nos_boundary) {
atomic_cas32( &num_extending_collectors, 0, num_active_collectors);
mspace_extend_compact(collector);
atomic_inc32(&num_extending_collectors);
while(num_extending_collectors != num_active_collectors);
}
TRACE2("gc.process", "GC: collector["<<((POINTER_SIZE_INT)collector->thread_handle)<<"]: finish pass5 and done.");
return;
}
void lspace_reset_for_slide(Lspace* lspace)
{
GC* gc = lspace->gc;
Space_Tuner* tuner = gc->tuner;
POINTER_SIZE_INT trans_size = tuner->tuning_size;
POINTER_SIZE_INT new_fa_size = 0;
assert(!(trans_size%GC_BLOCK_SIZE_BYTES));
Mspace * mos=(Mspace*)((GC_Gen*)gc)->mos;
Fspace *nos = (Fspace*)((GC_Gen*)gc)->nos;
/* Reset the pool first because its info is useless now. */
free_area_pool_reset(lspace->free_pool);
/*Lspace collection in major collection must move object*/
assert(lspace->move_object);
switch(tuner->kind){
case TRANS_FROM_MOS_TO_LOS:{
//debug_minor_sweep
if(LOS_ADJUST_BOUNDARY ) {
Block* mos_first_block = ((Blocked_Space*)((GC_Gen*)gc)->mos)->blocks;
lspace->heap_end = (void*)mos_first_block;
assert(!(tuner->tuning_size % GC_BLOCK_SIZE_BYTES));
}else{
vm_commit_mem(lspace->heap_end, trans_size);
lspace->heap_end= (void*)((POINTER_SIZE_INT)lspace->heap_end + trans_size);
//fixme: need to add decommit in NOS
if(trans_size < nos->committed_heap_size) {
nos->free_block_idx=nos->first_block_idx;
blocked_space_shrink((Blocked_Space*)nos, trans_size);
} else {
POINTER_SIZE_INT mos_free_size= blocked_space_free_mem_size((Blocked_Space*)mos);
void *decommit_base=(void*)((POINTER_SIZE_INT)nos->heap_end-trans_size);
vm_decommit_mem(decommit_base,trans_size);
unsigned int reduced_mos_size = trans_size - nos->committed_heap_size;
unsigned int size=round_down_to_size(mos_free_size-reduced_mos_size,SPACE_ALLOC_UNIT);
unsigned int nos_size= mos_free_size - reduced_mos_size ;
if(nos_size<GC_BLOCK_SIZE_BYTES) nos_size=GC_BLOCK_SIZE_BYTES;
nos_size=round_up_to_size(nos_size, GC_BLOCK_SIZE_BYTES);
mos->num_managed_blocks -= (( mos_free_size )>>GC_BLOCK_SHIFT_COUNT);
mos->num_used_blocks = mos->free_block_idx-mos->first_block_idx;
mos->num_total_blocks=mos->num_managed_blocks;
mos->ceiling_block_idx -= (( mos_free_size )>>GC_BLOCK_SHIFT_COUNT);
assert(mos->num_used_blocks<=mos->num_managed_blocks);
void *start_address=(void*)&(mos->blocks[mos->num_managed_blocks]);
assert(start_address< decommit_base);
mos->heap_end = start_address;
mos->committed_heap_size = (POINTER_SIZE_INT) start_address - (POINTER_SIZE_INT) mos->heap_start;
nos_boundary = nos->heap_start = start_address;
nos->heap_end = decommit_base;
nos->committed_heap_size = nos->reserved_heap_size = (POINTER_SIZE_INT)decommit_base- (POINTER_SIZE_INT) start_address;
nos->num_total_blocks = nos->num_managed_blocks = nos_size>>GC_BLOCK_SHIFT_COUNT;
nos->free_block_idx=nos->first_block_idx=GC_BLOCK_INDEX_FROM(gc->heap_start,start_address);
nos->ceiling_block_idx=nos->first_block_idx+nos->num_managed_blocks-1;
nos->num_used_blocks = 0;
space_init_blocks((Blocked_Space*)nos);
}
}
new_fa_size = (POINTER_SIZE_INT)lspace->scompact_fa_end - (POINTER_SIZE_INT)lspace->scompact_fa_start + tuner->tuning_size;
Free_Area* fa = free_area_new(lspace->scompact_fa_start, new_fa_size);
if(new_fa_size >= GC_LOS_OBJ_SIZE_THRESHOLD) free_pool_add_area(lspace->free_pool, fa);
lspace->committed_heap_size += trans_size;
break;
}
case TRANS_FROM_LOS_TO_MOS:{
assert(lspace->move_object);
if(LOS_ADJUST_BOUNDARY ){
Block* mos_first_block = ((Blocked_Space*)((GC_Gen*)gc)->mos)->blocks;
assert( (POINTER_SIZE_INT)lspace->heap_end - trans_size == (POINTER_SIZE_INT)mos_first_block );
lspace->heap_end = (void*)mos_first_block;
}else{
void *p=(void*)((POINTER_SIZE_INT)lspace->heap_end - trans_size);
vm_decommit_mem(p, trans_size);
lspace->heap_end=p;
//fixme: need to add decommit in NOS
blocked_space_extend((Blocked_Space*)((GC_Gen*) gc)->nos, trans_size);
}
lspace->committed_heap_size -= trans_size;
/*LOS_Shrink: We don't have to scan lspace to build free pool when slide compact LOS*/
assert((POINTER_SIZE_INT)lspace->scompact_fa_end > (POINTER_SIZE_INT)lspace->scompact_fa_start + tuner->tuning_size);
new_fa_size = (POINTER_SIZE_INT)lspace->scompact_fa_end - (POINTER_SIZE_INT)lspace->scompact_fa_start - tuner->tuning_size;
Free_Area* fa = free_area_new(lspace->scompact_fa_start, new_fa_size);
if(new_fa_size >= GC_LOS_OBJ_SIZE_THRESHOLD) free_pool_add_area(lspace->free_pool, fa);
break;
}
default:{
assert(lspace->move_object);
assert(tuner->kind == TRANS_NOTHING);
assert(!tuner->tuning_size);
new_fa_size = (POINTER_SIZE_INT)lspace->scompact_fa_end - (POINTER_SIZE_INT)lspace->scompact_fa_start;
if(new_fa_size == 0) break;
Free_Area* fa = free_area_new(lspace->scompact_fa_start, new_fa_size);
if(new_fa_size >= GC_LOS_OBJ_SIZE_THRESHOLD) free_pool_add_area(lspace->free_pool, fa);
break;
}
}
// lspace->accumu_alloced_size = 0;
// lspace->last_alloced_size = 0;
lspace->period_surviving_size = (POINTER_SIZE_INT)lspace->scompact_fa_start - (POINTER_SIZE_INT)lspace->heap_start;
lspace->last_surviving_size = lspace->period_surviving_size;
lspace->survive_ratio = (float)lspace->accumu_alloced_size / (float)lspace->committed_heap_size;
los_boundary = lspace->heap_end;
}
/* This is the real function that decide tuning_size, because we have know the total size of living objects after "mark_scan_heap_for_space_tune". */
void gc_compute_space_tune_size_after_marking(GC *gc)
{
Blocked_Space* mspace = (Blocked_Space*)gc_get_mos((GC_Gen*)gc);
Blocked_Space* fspace = (Blocked_Space*)gc_get_nos((GC_Gen*)gc);
Lspace *lspace = (Lspace*)gc_get_los((GC_Gen*)gc);
Space_Tuner* tuner = gc->tuner;
POINTER_SIZE_INT max_tuning_size = 0;
POINTER_SIZE_INT non_los_size = mspace->committed_heap_size + fspace->committed_heap_size;
if(LOS_ADJUST_BOUNDARY)
gc_compute_live_object_size_after_marking(gc, non_los_size);
else {
unsigned int collector_num = gc->num_active_collectors;
POINTER_SIZE_INT reserve_size = collector_num <<(GC_BLOCK_SHIFT_COUNT+2);
los_live_obj_size = (POINTER_SIZE_INT) lspace->last_surviving_size + reserve_size;
non_los_live_obj_size = ((POINTER_SIZE_INT)(mspace->free_block_idx-mspace->first_block_idx)<<GC_BLOCK_SHIFT_COUNT)+reserve_size;
non_los_live_obj_size = round_up_to_size(non_los_live_obj_size, SPACE_ALLOC_UNIT);
}
check_tuning_size(gc);
/*We should assure that the non_los area is no less than min_none_los_size_bytes*/
POINTER_SIZE_INT max_tune_for_min_non_los = 0;
if(non_los_size > min_none_los_size_bytes)
max_tune_for_min_non_los = non_los_size - min_none_los_size_bytes;
POINTER_SIZE_INT max_tune_for_min_los = 0;
//debug_adjust
assert(lspace->committed_heap_size >= min_los_size_bytes);
max_tune_for_min_los = lspace->committed_heap_size - min_los_size_bytes;
/*Not force tune, LOS_Extend:*/
if(tuner->kind == TRANS_FROM_MOS_TO_LOS)
{
if (gc->committed_heap_size > lspace->committed_heap_size + non_los_live_obj_size){
max_tuning_size = gc->committed_heap_size - lspace->committed_heap_size - non_los_live_obj_size;
if(max_tuning_size > max_tune_for_min_non_los)
max_tuning_size = max_tune_for_min_non_los;
if( tuner->tuning_size > max_tuning_size)
tuner->tuning_size = max_tuning_size;
/*Round down so as not to break max_tuning_size*/
if(LOS_ADJUST_BOUNDARY)
tuner->tuning_size = round_down_to_size(tuner->tuning_size, GC_BLOCK_SIZE_BYTES);
else
tuner->tuning_size = round_down_to_size(tuner->tuning_size, SPACE_ALLOC_UNIT);
/*If tuning size is zero, we should reset kind to NOTHING, in case that gc_init_block_for_collectors relink the block list.*/
if(tuner->tuning_size == 0) tuner->kind = TRANS_NOTHING;
}else{
tuner->tuning_size = 0;
tuner->kind = TRANS_NOTHING;
}
}
/*Not force tune, LOS Shrink*/
else
{
if(lspace->committed_heap_size > los_live_obj_size){
max_tuning_size = lspace->committed_heap_size - los_live_obj_size;
if(max_tuning_size > max_tune_for_min_los)
max_tuning_size = max_tune_for_min_los;
if(tuner->tuning_size > max_tuning_size)
tuner->tuning_size = max_tuning_size;
/*Round down so as not to break max_tuning_size*/
if (LOS_ADJUST_BOUNDARY)
tuner->tuning_size = round_down_to_size(tuner->tuning_size, GC_BLOCK_SIZE_BYTES);
else
tuner->tuning_size = round_down_to_size(tuner->tuning_size, SPACE_ALLOC_UNIT);
if(tuner->tuning_size == 0) tuner->kind = TRANS_NOTHING;
}else{
/* this is possible because of the reservation in gc_compute_live_object_size_after_marking*/
tuner->tuning_size = 0;
tuner->kind = TRANS_NOTHING;
}
}
/*If the tuning strategy give a bigger tuning_size than failure size, we just follow the strategy and set noforce.*/
Boolean doforce = TRUE;
POINTER_SIZE_INT failure_size = lspace_get_failure_size((Lspace*)lspace);
if( (tuner->kind == TRANS_FROM_MOS_TO_LOS) && (!tuner->reverse) && (tuner->tuning_size > failure_size) )
doforce = FALSE;
if( (tuner->force_tune) && (doforce) )
compute_space_tune_size_for_force_tune(gc, max_tune_for_min_non_los);
return;
}
/* If this GC is caused by a LOS allocation failure, we set the "force_tune" flag.
* Attention1: The space tuning strategy will extend or shrink LOS according to the wasted memory size and allocation speed.
* If the strategy decide to shrink or the size extended is not large enough to hold the failed object, we set the "doforce" flag in
* function "gc_compute_space_tune_size_after_marking". And only if "force_tune" and "doforce" are both true, we decide the
* size of extention by this function.
* Attention2: The total heap size might extend in this function. */
static void compute_space_tune_size_for_force_tune(GC *gc, POINTER_SIZE_INT max_tune_for_min_non_los)
{
Space_Tuner* tuner = gc->tuner;
Lspace *lspace = (Lspace*)gc_get_los((GC_Gen*)gc);
Blocked_Space* fspace = (Blocked_Space*)gc_get_nos((GC_Gen*)gc);
POINTER_SIZE_INT max_tuning_size = 0;
POINTER_SIZE_INT failure_size = lspace->failure_size;
POINTER_SIZE_INT lspace_free_size = ( (lspace->committed_heap_size > los_live_obj_size) ? (lspace->committed_heap_size - los_live_obj_size) : (0) );
//debug_adjust
assert(!(lspace_free_size % KB));
assert(!(failure_size % KB));
if(lspace_free_size >= failure_size){
tuner->tuning_size = 0;
tuner->kind = TRANS_NOTHING;
}else{
tuner->tuning_size = failure_size -lspace_free_size;
/*We should assure that the tuning size is no more than the free space of non_los area*/
if( gc->committed_heap_size > lspace->committed_heap_size + non_los_live_obj_size )
max_tuning_size = gc->committed_heap_size - lspace->committed_heap_size - non_los_live_obj_size;
if(max_tuning_size > max_tune_for_min_non_los)
max_tuning_size = max_tune_for_min_non_los;
/*Round up to satisfy LOS alloc demand.*/
if(LOS_ADJUST_BOUNDARY) {
tuner->tuning_size = round_up_to_size(tuner->tuning_size, GC_BLOCK_SIZE_BYTES);
max_tuning_size = round_down_to_size(max_tuning_size, GC_BLOCK_SIZE_BYTES);
}else {
tuner->tuning_size = round_up_to_size(tuner->tuning_size, SPACE_ALLOC_UNIT);
max_tuning_size = round_down_to_size(max_tuning_size, SPACE_ALLOC_UNIT);
}
/*If the tuning size is too large, we did nothing and wait for the OOM of JVM*/
/*Fixme: if the heap size is not mx, we can extend the whole heap size*/
if(tuner->tuning_size > max_tuning_size){
tuner->tuning_size = round_up_to_size(tuner->tuning_size, SPACE_ALLOC_UNIT);
max_tuning_size = round_down_to_size(max_tuning_size, SPACE_ALLOC_UNIT);
//debug_adjust
assert(max_heap_size_bytes >= gc->committed_heap_size);
POINTER_SIZE_INT extend_heap_size = 0;
POINTER_SIZE_INT potential_max_tuning_size = max_tuning_size + max_heap_size_bytes - gc->committed_heap_size;
potential_max_tuning_size -= LOS_HEAD_RESERVE_FOR_HEAP_BASE;
//debug_adjust
assert(!(potential_max_tuning_size % SPACE_ALLOC_UNIT));
if(tuner->tuning_size > potential_max_tuning_size){
tuner->tuning_size = 0;
tuner->kind = TRANS_NOTHING;
}else{
/*We have tuner->tuning_size > max_tuning_size up there.*/
extend_heap_size = tuner->tuning_size - max_tuning_size;
blocked_space_extend(fspace, (unsigned int)extend_heap_size);
gc->committed_heap_size += extend_heap_size;
tuner->kind = TRANS_FROM_MOS_TO_LOS;
}
}
else
{
tuner->kind = TRANS_FROM_MOS_TO_LOS;
}
}
return;
}
/* FIXME:: In this algorithm, it assumes NOS is a full forward space.
Semispace GC's NOS has survivor_area. Need careful rethinking.
But this algorithm so far can be a good approximation. */
Boolean gc_compute_new_space_size(GC_Gen* gc, POINTER_SIZE_INT* mos_size, POINTER_SIZE_INT* nos_size)
{
Blocked_Space* nos = (Blocked_Space*)gc->nos;
Blocked_Space* mos = (Blocked_Space*)gc->mos;
Space* los = gc->los;
POINTER_SIZE_INT new_nos_size;
POINTER_SIZE_INT new_mos_size;
POINTER_SIZE_INT curr_nos_size = space_committed_size((Space*)nos);
// POINTER_SIZE_INT used_nos_size = nos_used_space_size((Space*)nos);
POINTER_SIZE_INT used_mos_size = mos_used_space_size((Space*)mos);
POINTER_SIZE_INT total_size; /* total_size is no-LOS spaces size */
#ifdef STATIC_NOS_MAPPING
total_size = max_heap_size_bytes - space_committed_size(los);
#else
POINTER_SIZE_INT curr_heap_commit_end;
if(LOS_ADJUST_BOUNDARY) {
curr_heap_commit_end=(POINTER_SIZE_INT)gc->heap_start + LOS_HEAD_RESERVE_FOR_HEAP_BASE + gc->committed_heap_size;
assert(curr_heap_commit_end > (POINTER_SIZE_INT)mos->heap_start);
total_size = curr_heap_commit_end - (POINTER_SIZE_INT)mos->heap_start;
}else {/*LOS_ADJUST_BOUNDARY else */
curr_heap_commit_end = (nos->committed_heap_size)? (POINTER_SIZE_INT) nos->heap_start + nos->committed_heap_size:
(POINTER_SIZE_INT) mos->heap_start+mos->committed_heap_size;
total_size = curr_heap_commit_end - (POINTER_SIZE_INT) mos->heap_start;
}
#endif
assert(total_size >= used_mos_size);
POINTER_SIZE_INT total_free = total_size - used_mos_size;
/*If total free is smaller than one block, there is no room for us to adjust*/
if(total_free < GC_BLOCK_SIZE_BYTES) return FALSE;
POINTER_SIZE_INT nos_reserve_size;
if( MOS_RESERVE_SIZE == 0){
/*To reserve some MOS space to avoid fallback situation.
*But we need ensure nos has at least one block.
*We have such fomula here:
*NOS_SIZE + NOS_SIZE * anti_fall_back_ratio + NOS_SIZE * survive_ratio = TOTAL_FREE*/
POINTER_SIZE_INT anti_fallback_size_in_mos;
float ratio_of_anti_fallback_size_to_nos = 0.25f;
anti_fallback_size_in_mos = (POINTER_SIZE_INT)(((float)total_free * ratio_of_anti_fallback_size_to_nos)/(1.0f + ratio_of_anti_fallback_size_to_nos + nos->survive_ratio));
if(anti_fallback_size_in_mos > DEFAULT_MOS_RESERVE_SIZE ){
/*If the computed anti_fallback_size_in_mos is too large, we reset it back to DEFAULT_MOS_RESERVE_SIZE .*/
anti_fallback_size_in_mos = DEFAULT_MOS_RESERVE_SIZE ;
/*Here, anti_fallback_size_in_mos must be smaller than TOTAL_FREE*/
nos_reserve_size = (POINTER_SIZE_INT)(((float)(total_free - anti_fallback_size_in_mos))/(1.0f + nos->survive_ratio));
}else{
nos_reserve_size = (POINTER_SIZE_INT)(((float)total_free)/(1.0f + ratio_of_anti_fallback_size_to_nos + nos->survive_ratio));
}
}else{
nos_reserve_size = total_free - MOS_RESERVE_SIZE;
}
/*NOS should not be zero, if there is only one block in non-los, i.e. in the former if sentence,
*if total_free = GC_BLOCK_SIZE_BYTES, then the computed nos_reserve_size is between zero
*and GC_BLOCK_SIZE_BYTES. In this case, we assign this block to NOS*/
if(nos_reserve_size <= GC_BLOCK_SIZE_BYTES) nos_reserve_size = GC_BLOCK_SIZE_BYTES;
#ifdef STATIC_NOS_MAPPING
if(nos_reserve_size > nos->reserved_heap_size) nos_reserve_size = nos->reserved_heap_size;
#endif
new_nos_size = round_down_to_size((POINTER_SIZE_INT)nos_reserve_size, GC_BLOCK_SIZE_BYTES);
if(gc->force_gen_mode){
new_nos_size = min_nos_size_bytes;
}
new_mos_size = total_size - new_nos_size;
#ifdef STATIC_NOS_MAPPING
if(new_mos_size > mos->reserved_heap_size) new_mos_size = mos->reserved_heap_size;
#endif
*nos_size = new_nos_size;
*mos_size = new_mos_size;
return TRUE;;
}
