mirrors/mimalloc
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

use atomic read/write on the page->heap field where concurrent interaction is possible

Browse Source
This commit is contained in:
Daan Leijen 2019-11-20 13:19:17 -08:00
parent 94bfb47725
commit 4d4a2885f5
3 changed files with 18 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/alloc.c
View File

@ -235,7 +235,7 @@ static mi_decl_noinline void _mi_free_block_mt(mi_page_t* page, mi_block_t* bloc
}
else {
// racy read on `heap`, but ok because MI_DELAYED_FREEING is set (see `mi_heap_delete` and `mi_heap_collect_abandon`)
mi_heap_t* heap = page->heap;
mi_heap_t* heap = (mi_heap_t*)mi_atomic_read_ptr(mi_atomic_cast(void*, &page->heap));
mi_assert_internal(heap != NULL);
if (heap != NULL) {
// add to the delayed free list of this heap. (do this atomically as the lock only protects heap memory validity)

6
src/page-queue.c
View File

@ -260,7 +260,7 @@ static void mi_page_queue_remove(mi_page_queue_t* queue, mi_page_t* page) {
page->heap->page_count--;
page->next = NULL;
page->prev = NULL;
page->heap = NULL;
mi_atomic_write_ptr(mi_atomic_cast(void*, &page->heap), NULL);
mi_page_set_in_full(page,false);
}
@ -274,7 +274,7 @@ static void mi_page_queue_push(mi_heap_t* heap, mi_page_queue_t* queue, mi_page_
(mi_page_is_in_full(page) && mi_page_queue_is_full(queue)));
mi_page_set_in_full(page, mi_page_queue_is_full(queue));
page->heap = heap;
mi_atomic_write_ptr(mi_atomic_cast(void*, &page->heap), heap);
page->next = queue->first;
page->prev = NULL;
if (queue->first != NULL) {
@ -338,7 +338,7 @@ size_t _mi_page_queue_append(mi_heap_t* heap, mi_page_queue_t* pq, mi_page_queue
// set append pages to new heap and count
size_t count = 0;
for (mi_page_t* page = append->first; page != NULL; page = page->next) {
page->heap = heap;
mi_atomic_write_ptr(mi_atomic_cast(void*, &page->heap), heap);
count++;
}

21
src/page.c
View File

@ -343,18 +343,24 @@ void _mi_page_abandon(mi_page_t* page, mi_page_queue_t* pq) {
mi_assert_internal(pq == mi_page_queue_of(page));
mi_assert_internal(page->heap != NULL);
_mi_page_use_delayed_free(page,MI_NEVER_DELAYED_FREE);
#if MI_DEBUG > 1
mi_heap_t* pheap = (mi_heap_t*)mi_atomic_read_ptr(mi_atomic_cast(void*, &page->heap));
#endif
// remove from our page list
mi_segments_tld_t* segments_tld = &page->heap->tld->segments;
mi_page_queue_remove(pq, page);
// page is no longer associated with our heap
mi_atomic_write_ptr(mi_atomic_cast(void*, &page->heap), NULL);
#if MI_DEBUG>1
// check there are no references left..
for (mi_block_t* block = (mi_block_t*)page->heap->thread_delayed_free; block != NULL; block = mi_block_nextx(page->heap->cookie,block)) {
for (mi_block_t* block = (mi_block_t*)pheap->thread_delayed_free; block != NULL; block = mi_block_nextx(pheap->cookie, block)) {
mi_assert_internal(_mi_ptr_page(block) != page);
}
#endif
// and then remove from our page list
mi_segments_tld_t* segments_tld = &page->heap->tld->segments;
mi_page_queue_remove(pq, page);
// and abandon it
mi_assert_internal(page->heap == NULL);
_mi_segment_page_abandon(page,segments_tld);
@ -755,7 +761,8 @@ static mi_page_t* mi_huge_page_alloc(mi_heap_t* heap, size_t size) {
mi_assert_internal(_mi_page_segment(page)->page_kind==MI_PAGE_HUGE);
mi_assert_internal(_mi_page_segment(page)->used==1);
mi_assert_internal(_mi_page_segment(page)->thread_id==0); // abandoned, not in the huge queue
page->heap = NULL;
mi_atomic_write_ptr(mi_atomic_cast(void*, &page->heap), NULL);
if (page->block_size > MI_HUGE_OBJ_SIZE_MAX) {
_mi_stat_increase(&heap->tld->stats.giant, block_size);
_mi_stat_counter_increase(&heap->tld->stats.giant_count, 1);