RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 16:08:10 +00:00
Code Issues Activity Actions

LibC: Store empty malloc blocks in an array instead of a linked list

Browse source
This commit is contained in:
Sergey Bugaev 2019-12-17 22:55:19 +03:00 • committed by Andreas Kling
parent 0d6f186397
commit 1ad5568759
1 changed files with 7 additions and 8 deletions
Download patch file Download diff file Expand all files Collapse all files

15
Libraries/LibC/malloc.cpp
View file

@ -25,8 +25,8 @@ static LibThread::Lock& malloc_lock()
return *reinterpret_cast<LibThread::Lock*>(&lock_storage); return *reinterpret_cast<LibThread::Lock*>(&lock_storage);
} }
static const int number_of_chunked_blocks_to_keep_around_per_size_class = 32; constexpr int number_of_chunked_blocks_to_keep_around_per_size_class = 32;
static const int number_of_big_blocks_to_keep_around_per_size_class = 8; constexpr int number_of_big_blocks_to_keep_around_per_size_class = 8;
static bool s_log_malloc = false; static bool s_log_malloc = false;
static bool s_scrub_malloc = true; static bool s_scrub_malloc = true;
@ -89,7 +89,8 @@ struct ChunkedBlock : public CommonHeader
struct Allocator { struct Allocator {
size_t size { 0 }; size_t size { 0 };
size_t block_count { 0 }; size_t block_count { 0 };
ChunkedBlock* empty_block_queue { nullptr }; size_t empty_block_count { 0 };
ChunkedBlock* empty_blocks[number_of_chunked_blocks_to_keep_around_per_size_class] { nullptr };
InlineLinkedList<ChunkedBlock> usable_blocks; InlineLinkedList<ChunkedBlock> usable_blocks;
InlineLinkedList<ChunkedBlock> full_blocks; InlineLinkedList<ChunkedBlock> full_blocks;
}; };
@ -182,14 +183,13 @@ void* malloc(size_t size)
break; break;
} }
if (!block && allocator->empty_block_queue) { if (!block && allocator->empty_block_count) {
block = allocator->empty_block_queue; block = allocator->empty_blocks[--allocator->empty_block_count];
int rc = mprotect(block, PAGE_SIZE, PROT_READ | PROT_WRITE); int rc = mprotect(block, PAGE_SIZE, PROT_READ | PROT_WRITE);
if (rc < 0) { if (rc < 0) {
perror("mprotect"); perror("mprotect");
ASSERT_NOT_REACHED(); ASSERT_NOT_REACHED();
} }
allocator->empty_block_queue = block->m_next;
char buffer[64]; char buffer[64];
snprintf(buffer, sizeof(buffer), "malloc: ChunkedBlock(%zu) (reused)", good_size); snprintf(buffer, sizeof(buffer), "malloc: ChunkedBlock(%zu) (reused)", good_size);
set_mmap_name(block, PAGE_SIZE, buffer); set_mmap_name(block, PAGE_SIZE, buffer);
@ -288,8 +288,7 @@ void free(void* ptr)
dbgprintf("Keeping block %p around for size class %u\n", block, good_size); dbgprintf("Keeping block %p around for size class %u\n", block, good_size);
#endif #endif
allocator->usable_blocks.remove(block); allocator->usable_blocks.remove(block);
block->m_next = allocator->empty_block_queue; allocator->empty_blocks[allocator->empty_block_count++] = block;
allocator->empty_block_queue = block;
char buffer[64]; char buffer[64];
snprintf(buffer, sizeof(buffer), "malloc: ChunkedBlock(%zu) (free)", good_size); snprintf(buffer, sizeof(buffer), "malloc: ChunkedBlock(%zu) (free)", good_size);
set_mmap_name(block, PAGE_SIZE, buffer); set_mmap_name(block, PAGE_SIZE, buffer);