/* +----------------------------------------------------------------------+ | PHP Version 6 | +----------------------------------------------------------------------+ | Copyright (c) 2006-2008 The PHP Group | +----------------------------------------------------------------------+ | This source file is subject to version 3.01 of the PHP license, | | that is bundled with this package in the file LICENSE, and is | | available through the world-wide-web at the following url: | | http://www.php.net/license/3_01.txt | | If you did not receive a copy of the PHP license and are unable to | | obtain it through the world-wide-web, please send a note to | | license@php.net so we can mail you a copy immediately. | +----------------------------------------------------------------------+ | Authors: Georg Richter | | Andrey Hristov | | Ulf Wendel | +----------------------------------------------------------------------+ */ /* $Id$ */ #include "php.h" #include "mysqlnd.h" #include "mysqlnd_priv.h" #include "mysqlnd_palloc.h" #define MYSQLND_SILENT #define MYSQLND_DONT_DUMP_STATS #define MYSQLND_ZVALS_MAX_CACHE 5000 #if A0 /* Caching zval allocator */ zval * mysqlnd_alloc_get_zval(MYSQLND_ZVAL_CACHE * const cache); void mysqlnd_alloc_zval_ptr_dtor(zval **zv, MYSQLND_ZVAL_CACHE * const cache); MYSQLND_ZVAL_CACHE* mysqlnd_alloc_init_cache(); MYSQLND_ZVAL_CACHE* mysqlnd_alloc_get_cache_reference(MYSQLND_ZVAL_CACHE *cache); void mysqlnd_alloc_free_cache_reference(MYSQLND_ZVAL_CACHE **cache); #endif /* The cache line is a big contiguous array of zval pointers. Because the CPU cache will cache starting from an address, and not before it, then we have to organize our structure according to this. Thus, if 'last_added' is valid pointer (not NULL) then last_added is increased. When zval is cached, if there is room, last_added is decreased and then the zval pointer will be assigned to it. This means that some positions may become hot points and stay in the cache. Imagine we have 5 pointers in a line 1. last_added = list_item->ptr_line + cache->max_items; 2. get_zval -> *last_added = NULL. Use MAKE_STD_ZVAL 3. get_zval -> *last_added = NULL. Use MAKE_STD_ZVAL 4. get_zval -> *last_added = NULL. Use MAKE_STD_ZVAL 0x0 0x0 0x0 0x0 0x0 --- empty_position, always 0x0 <-- last_added 5. free_zval -> if (free_items++ != max_items) {// we can add more *(--last_added) = zval_ptr; } (memory addresses increase downwards) 0x0 0x0 0x0 0x0 0xA <-- last_added --- 0x0 6. free_zval -> if (free_items++ != max_items) {// we can add more *(--last_added) = zval_ptr; } 0x0 0x0 0x0 0xB <-- last_added 0xA --- 0x0 7. free_zval -> if (free_items++ != max_items) {// we can add more *(--last_added) = zval_ptr; } 0x0 0x0 0xC <-- last_added 0xB 0xA --- 0x0 8. get_zval -> *last_added != NULL. -> p = *last_added; *last_added++ = NULL; 0x0 0x0 0x0 0xB <-- last_added 0xA --- 0x0 9. get_zval -> *last_added != NULL. -> p = *last_added; *last_added++ = NULL; 0x0 0x0 0x0 0x0 0xA <-- last_added --- 0x0 10. get_zval -> *last_added != NULL. -> p = *last_added; *last_added++ = NULL; 0x0 0x0 0x0 0x0 0x0 --- 0x0 <-- last_added */ zval * mysqlnd_alloc_get_zval(MYSQLND_ZVAL_CACHE * const cache) { zval *ret = NULL; #ifndef MYSQLND_SILENT php_printf("[mysqlnd_alloc_get_zval %p] *last_added=%p free_items=%d ", cache, cache? cache->free_list->last_added:NULL, cache->free_items); #endif if (cache) { if ((ret = *cache->free_list->last_added)) { *cache->free_list->last_added++ = NULL; --cache->free_items; ++cache->get_hits; } else { ++cache->get_misses; } } if (!ret) { ALLOC_ZVAL(ret); } INIT_PZVAL(ret); #ifndef MYSQLND_SILENT php_printf("ret=%p\n", ret); #endif return ret; } static void mysqlnd_alloc_cache_prealloc(MYSQLND_ZVAL_CACHE * const cache, unsigned int count) { zval *data; cache->free_items = count; while (count--) { MAKE_STD_ZVAL(data); ZVAL_NULL(data); #ifndef MYSQLND_SILENT php_printf("[mysqlnd_alloc_prealloc %p] items=%d data=%p\n", cache, cache->free_items, data); #endif *(--cache->free_list->last_added) = data; } } void mysqlnd_alloc_zval_ptr_dtor(zval **zv, MYSQLND_ZVAL_CACHE * const cache) { if (!cache || Z_REFCOUNT_PP(zv) > 1 || cache->max_items == cache->free_items) { #ifndef MYSQLND_SILENT php_printf("[mysqlnd_alloc_zval_ptr_dtor %p]1 last_added-1=%p *zv=%p\n", cache->free_list->last_added, *zv); #endif /* We can't cache zval's with refcount > 1 */ zval_ptr_dtor(zv); if (cache) { if (cache->max_items == cache->free_items) { ++cache->put_full_misses; } else { ++cache->put_refcount_misses; } } } else { /* refcount is 1 and there is place. Go, cache it! */ ++cache->free_items; zval_dtor(*zv); ZVAL_NULL(*zv); *(--cache->free_list->last_added) = *zv; ++cache->put_hits; } #ifndef MYSQLND_SILENT php_printf("[mysqlnd_alloc_zval_ptr_dtor %p] free_items=%d\n", cache, cache->free_items); #endif } MYSQLND_ZVAL_CACHE* mysqlnd_alloc_init_cache(void) { MYSQLND_ZVAL_CACHE *ret = ecalloc(1, sizeof(MYSQLND_ZVAL_CACHE)); #ifndef MYSQLND_SILENT php_printf("[mysqlnd_alloc_init_cache %p]\n", ret); #endif ret->max_items = MYSQLND_ZVALS_MAX_CACHE; ret->free_items = 0; ret->references = 1; /* Let's have always one, so we don't need to do a check in get_zval */ ret->free_list = ecalloc(1, sizeof(struct st_mysqlnd_zval_list)); /* One more for empty position of last_added */ ret->free_list->ptr_line = ecalloc(ret->max_items + 1, sizeof(zval *)); ret->free_list->last_added = ret->free_list->ptr_line + ret->max_items; mysqlnd_alloc_cache_prealloc(ret, (ret->max_items / 100) * 100); return ret; } MYSQLND_ZVAL_CACHE* mysqlnd_alloc_get_cache_reference(MYSQLND_ZVAL_CACHE *cache) { if (cache) { cache->references++; } return cache; } static void mysqlnd_alloc_free_cache(MYSQLND_ZVAL_CACHE *cache) { #ifndef MYSQLND_SILENT uint i = 0; php_printf("[mysqlnd_alloc_free_cache %p]\n", cache); #endif while (*cache->free_list->last_added) { #ifndef MYSQLND_SILENT php_printf("\t[free_item %d %p]\n", i++, *cache->free_list->last_added); #endif zval_ptr_dtor(cache->free_list->last_added); cache->free_list->last_added++; } #ifndef MYSQLND_DONT_DUMP_STATS php_printf("CACHE STATS:\n\tGET\n\t\tHITS:%lu\n\t\tMISSES=%lu\n\t\tHIT RATIO=%1.3f\n\t" "PUT\n\t\tHITS:%lu\n\t\tFULL_MISS=%lu\n\t\tREFC_MISS=%lu\n\t\tHIT RATIO=%1.3f\n\n", cache->get_hits, cache->get_misses, (1.0*cache->get_hits/(cache->get_hits + cache->get_misses)), cache->put_hits, cache->put_full_misses, cache->put_refcount_misses, (1.0 * cache->put_hits / (cache->put_hits + cache->put_full_misses + cache->put_refcount_misses))); #endif efree(cache->free_list->ptr_line); efree(cache->free_list); efree(cache); } void mysqlnd_alloc_free_cache_reference(MYSQLND_ZVAL_CACHE **cache) { #ifndef MYSQLND_SILENT php_printf("[mysqlnd_alloc_free_cache_reference %p] refs=%d\n", *cache, (*cache)->references); #endif if (*cache && --(*cache)->references == 0) { mysqlnd_alloc_free_cache(*cache); } *cache = NULL; } /* * Local variables: * tab-width: 4 * c-basic-offset: 4 * End: * vim600: noet sw=4 ts=4 fdm=marker * vim<600: noet sw=4 ts=4 */