kiper220/mimalloc
1
0
Fork 0
mirror of https://github.com/microsoft/mimalloc.git synced 2025-07-06 19:38:41 +03:00
Code Issues Projects Releases Packages Wiki Activity Actions

stronger encoding of free lists using two keys per page

Browse source
This commit is contained in:
daan 2019-12-27 23:33:50 -08:00
parent ce02986d56
commit e3391d9a53
8 changed files with 83 additions and 50 deletions
Download patch file Download diff file Expand all files Collapse all files

17
include/mimalloc-types.h
View file

@ -191,7 +191,7 @@ typedef struct mi_page_s {
mi_block_t* free; // list of available free blocks (`malloc` allocates from this list)
#ifdef MI_ENCODE_FREELIST
uintptr_t cookie; // random cookie to encode the free lists
uintptr_t key[2]; // two random keys to encode the free lists (see `_mi_block_next`)
#endif
size_t used; // number of blocks in use (including blocks in `local_free` and `thread_free`)
@ -206,9 +206,9 @@ typedef struct mi_page_s {
struct mi_page_s* prev; // previous page owned by this thread with the same `block_size`
// improve page index calculation
// without padding: 10 words on 64-bit, 11 on 32-bit. Secure adds one word
#if (MI_INTPTR_SIZE==8 && defined(MI_ENCODE_FREELIST)) || (MI_INTPTR_SIZE==4 && !defined(MI_ENCODE_FREELIST))
void* padding[1]; // 12 words on 64-bit with cookie, 12 words on 32-bit plain
// without padding: 10 words on 64-bit, 11 on 32-bit. Secure adds two words
#if (MI_INTPTR_SIZE==4)
void* padding[1]; // 12/14 words on 32-bit plain
#endif
} mi_page_t;
@ -239,8 +239,8 @@ typedef struct mi_segment_s {
size_t capacity; // count of available pages (`#free + used`)
size_t segment_size;// for huge pages this may be different from `MI_SEGMENT_SIZE`
size_t segment_info_size; // space we are using from the first page for segment meta-data and possible guard pages.
uintptr_t cookie; // verify addresses in debug mode: `mi_ptr_cookie(segment) == segment->cookie`
uintptr_t cookie; // verify addresses in secure mode: `_mi_ptr_cookie(segment) == segment->cookie`
// layout like this to optimize access in `mi_free`
size_t page_shift; // `1 << page_shift` == the page sizes == `page->block_size * page->reserved` (unless the first page, then `-segment_info_size`).
volatile _Atomic(uintptr_t) thread_id; // unique id of the thread owning this segment
@ -289,8 +289,9 @@ struct mi_heap_s {
mi_page_queue_t pages[MI_BIN_FULL + 1]; // queue of pages for each size class (or "bin")
volatile _Atomic(mi_block_t*) thread_delayed_free;
uintptr_t thread_id; // thread this heap belongs too
uintptr_t cookie;
mi_random_ctx_t random; // random number used for secure allocation
uintptr_t cookie; // random cookie to verify pointers (see `_mi_ptr_cookie`)
uintptr_t key[2]; // twb random keys used to encode the `thread_delayed_free` list
mi_random_ctx_t random; // random number context used for secure allocation
size_t page_count; // total number of pages in the `pages` queues.
bool no_reclaim; // `true` if this heap should not reclaim abandoned pages
};