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better padding implementation, more precise statistics

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daan 2020-01-31 20:34:24 -08:00
parent 8422ab125d
commit 68112a2751
7 changed files with 89 additions and 65 deletions
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12
include/mimalloc-internal.h
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@ -310,8 +310,10 @@ static inline uintptr_t _mi_ptr_cookie(const void* p) {
----------------------------------------------------------- */
static inline mi_page_t* _mi_heap_get_free_small_page(mi_heap_t* heap, size_t size) {
mi_assert_internal(size <= MI_SMALL_SIZE_MAX);
return heap->pages_free_direct[_mi_wsize_from_size(size)];
mi_assert_internal(size <= (MI_SMALL_SIZE_MAX + MI_PADDING_SIZE));
const size_t idx = _mi_wsize_from_size(size);
mi_assert_internal(idx < MI_PAGES_DIRECT);
return heap->pages_free_direct[idx];
}
// Get the page belonging to a certain size class
@ -375,6 +377,12 @@ static inline size_t mi_page_block_size(const mi_page_t* page) {
}
}
// Get the client usable block size of a page (without padding etc)
static inline size_t mi_page_usable_block_size(const mi_page_t* page) {
return mi_page_block_size(page) - MI_PADDING_SIZE;
}
// Thread free access
static inline mi_block_t* mi_page_thread_free(const mi_page_t* page) {
return (mi_block_t*)(mi_atomic_read_relaxed(&page->xthread_free) & ~3);

28
include/mimalloc-types.h
View file

@ -54,16 +54,17 @@ terms of the MIT license. A copy of the license can be found in the file
#define MI_ENCODE_FREELIST 1
#endif
// Reserve extra padding at the end of each block; must be a multiple of `2*sizeof(intptr_t)`!
// Reserve extra padding at the end of each block to be more resilient against heap block overflows.
// If free lists are encoded, the padding is checked if it was modified on free.
#if (!defined(MI_PADDING) && (MI_SECURE>=3 || MI_DEBUG>=1))
#define MI_PADDING
#define MI_PADDING
#endif
// The padding size must be at least `sizeof(intptr_t)`!
#if defined(MI_PADDING)
#define MI_PADDING_SIZE (2*sizeof(intptr_t))
#define MI_PADDING_WSIZE 1
#else
#define MI_PADDING_SIZE 0
#define MI_PADDING_WSIZE 0
#endif
@ -94,11 +95,13 @@ terms of the MIT license. A copy of the license can be found in the file
#define MI_INTPTR_SIZE (1<<MI_INTPTR_SHIFT)
#define MI_INTPTR_BITS (MI_INTPTR_SIZE*8)
#define MI_PADDING_SIZE (MI_PADDING_WSIZE * MI_INTPTR_SIZE)
#define KiB ((size_t)1024)
#define MiB (KiB*KiB)
#define GiB (MiB*KiB)
// ------------------------------------------------------
// Main internal data-structures
// ------------------------------------------------------
@ -306,19 +309,20 @@ typedef struct mi_random_cxt_s {
int output_available;
} mi_random_ctx_t;
#define MI_PAGES_DIRECT (MI_SMALL_WSIZE_MAX + MI_PADDING_WSIZE + 1)
// A heap owns a set of pages.
struct mi_heap_s {
mi_tld_t* tld;
mi_page_t* pages_free_direct[MI_SMALL_WSIZE_MAX + 2]; // optimize: array where every entry points a page with possibly free blocks in the corresponding queue for that size.
mi_page_queue_t pages[MI_BIN_FULL + 1]; // queue of pages for each size class (or "bin")
mi_page_t* pages_free_direct[MI_PAGES_DIRECT]; // optimize: array where every entry points a page with possibly free blocks in the corresponding queue for that size.
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; // 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
uintptr_t thread_id; // thread this heap belongs too
uintptr_t cookie; // random cookie to verify pointers (see `_mi_ptr_cookie`)
uintptr_t key[2]; // two 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
};