cvs: ZendEngine2 / zend_mm.c zend_mm.h

andi Mon Dec 9 03:14:01 2002 EDT Modified files: /ZendEngine2 zend_mm.c zend_mm.h Log: - First attempt to improve memory manager during realloc()'s Index: ZendEngine2/zend_mm.c diff -u ZendEngine2/zend_mm.c:1.14 ZendEngine2/zend_mm.c:1.15 --- ZendEngine2/zend_mm.c:1.14 Wed Aug 7 10:47:41 2002 +++ ZendEngine2/zend_mm.c Mon Dec 9 03:14:00 2002 @@ -57,6 +57,7 @@ #define ZEND_MM_ALIGNED_FREE_HEADER_SIZE ZEND_MM_ALIGNED_SIZE(sizeof(zend_mm_free_block)) #define ZEND_MM_ALIGNED_SEGMENT_SIZE ZEND_MM_ALIGNED_SIZE(sizeof(zend_mm_segment)) +#define ZEND_MM_ALIGNED_MAX_HEADER_SIZE MAX(ZEND_MM_ALIGNED_HEADER_SIZE, ZEND_MM_ALIGNED_FREE_HEADER_SIZE) /* Memory calculations */ #define ZEND_MM_BLOCK_AT(blk, offset) ((zend_mm_block *) (((char *) (blk))+(offset))) @@ -152,14 +153,15 @@ block_size -= ZEND_MM_ALIGNED_SEGMENT_SIZE; mm_block = (zend_mm_free_block *) ((char *) segment + ZEND_MM_ALIGNED_SEGMENT_SIZE); - mm_block->size = block_size - ZEND_MM_ALIGNED_FREE_HEADER_SIZE; /* keep one guard block in the end */ + mm_block->size = block_size - ZEND_MM_ALIGNED_HEADER_SIZE; /* keep one guard block in the end */ mm_block->type = ZEND_MM_FREE_BLOCK; mm_block->prev_size = 0; /* Size is always at least ZEND_MM_ALIGNED_HEADER_SIZE big (>0) so 0 is OK */ /* setup guard block */ guard_block = ZEND_MM_BLOCK_AT(mm_block, mm_block->size); guard_block->type = ZEND_MM_USED_BLOCK; - guard_block->size = ZEND_MM_ALIGNED_FREE_HEADER_SIZE; + guard_block->size = ZEND_MM_ALIGNED_HEADER_SIZE; + guard_block->guard_block = 1; guard_block->prev_size = mm_block->size; ZEND_MM_DEBUG(("Setup guard block at 0x%0.8X\n", guard_block)); @@ -231,9 +233,9 @@ zend_mm_finished_searching_for_block: if (!best_fit) { - if (true_size > (heap->block_size - ZEND_MM_ALIGNED_SEGMENT_SIZE - ZEND_MM_ALIGNED_FREE_HEADER_SIZE)) { + if (true_size > (heap->block_size - ZEND_MM_ALIGNED_SEGMENT_SIZE - ZEND_MM_ALIGNED_HEADER_SIZE)) { /* Make sure we add a memory block which is big enough */ - zend_mm_add_memory_block(heap, true_size + ZEND_MM_ALIGNED_SEGMENT_SIZE + ZEND_MM_ALIGNED_FREE_HEADER_SIZE); + zend_mm_add_memory_block(heap, true_size + ZEND_MM_ALIGNED_SEGMENT_SIZE + ZEND_MM_ALIGNED_HEADER_SIZE); } else { zend_mm_add_memory_block(heap, heap->block_size); } @@ -242,6 +244,7 @@ /* mark as used */ best_fit->type = ZEND_MM_USED_BLOCK; + ((zend_mm_block *) best_fit)->guard_block = 0; /* remove from free list */ zend_mm_remove_from_free_list(heap, best_fit); @@ -257,7 +260,7 @@ zend_mm_block *mm_block = ZEND_MM_HEADER_OF(p); zend_mm_block *prev_block, *next_block; - if (mm_block->type!=ZEND_MM_USED_BLOCK) { + if (mm_block->type != ZEND_MM_USED_BLOCK) { /* error */ return; } @@ -299,6 +302,34 @@ } next_block = ZEND_MM_BLOCK_AT(mm_block, mm_block->size); + + if ((mm_block->prev_size == 0) && (next_block->type == ZEND_MM_USED_BLOCK) && + (next_block->guard_block)) { + zend_mm_segment *segment = (zend_mm_segment *) ((char *)mm_block - ZEND_MM_ALIGNED_SEGMENT_SIZE); + zend_mm_segment *segment_copy = segment; + zend_mm_block *guard_block; + size_t realloc_to_size; + + /* segment size, size of block and size of guard block */ + realloc_to_size = ZEND_MM_ALIGNED_SEGMENT_SIZE+true_size+ZEND_MM_ALIGNED_HEADER_SIZE; + segment = realloc(segment, realloc_to_size); + if (segment != segment_copy) { + /* The segment moved. Fix the segment list */ + fprintf(stderr, "Segment moved! This is not handled right now\n"); + exit(1); + } + + mm_block->size = true_size; + + /* setup guard block */ + guard_block = ZEND_MM_BLOCK_AT(mm_block, mm_block->size); + guard_block->type = ZEND_MM_USED_BLOCK; + guard_block->size = ZEND_MM_ALIGNED_HEADER_SIZE; + guard_block->guard_block = 1; + guard_block->prev_size = mm_block->size; + + return ZEND_MM_DATA_OF(mm_block); + } if (next_block->type != ZEND_MM_FREE_BLOCK || (mm_block->size + next_block->size < true_size)) { void *ptr; Index: ZendEngine2/zend_mm.h diff -u ZendEngine2/zend_mm.h:1.8 ZendEngine2/zend_mm.h:1.9 --- ZendEngine2/zend_mm.h:1.8 Wed Jun 26 10:24:23 2002 +++ ZendEngine2/zend_mm.h Mon Dec 9 03:14:00 2002 @@ -32,6 +32,7 @@ unsigned int size : 31; unsigned int type : 1; size_t prev_size; + unsigned int guard_block : 1; } zend_mm_block; typedef struct _zend_mm_free_block {