函数buf_pool_init
/********************************************************************//** Creates the buffer pool. @return DB_SUCCESS if success, DB_ERROR if not enough memory or error */ UNIV_INTERN ulint buf_pool_init( /*==========*/ ulint total_size, /*!< in: size of the total pool in bytes */ ulint n_instances) /*!< in: number of instances */ { ulint i;
//n_instances 一般为1 const ulint size = total_size / n_instances; ut_ad(n_instances > 0); ut_ad(n_instances <= MAX_BUFFER_POOLS); //#define MAX_BUFFER_POOLS (1 << MAX_BUFFER_POOLS_BITS) 1<<6 ut_ad(n_instances == srv_buf_pool_instances); /* We create an extra buffer pool instance, this instance is used for flushing the flush lists, to keep track of n_flush for all the buffer pools and also used as a waiting object during flushing. */
//UNIV_INTERN buf_pool_t* buf_pool_ptr; 通过heap heap = mem_heap_create_func(n, MEM_HEAP_DYNAMIC, file_name, line); 实现 详见 buf_pool_ptr = mem_zalloc(n_instances * sizeof *buf_pool_ptr); for (i = 0; i < n_instances; i++) { buf_pool_t* ptr = &buf_pool_ptr[i]; if (buf_pool_init_instance(ptr, size, i) != DB_SUCCESS) { //详见 /* Free all the instances created so far. */ buf_pool_free(i); return(DB_ERROR); } } buf_pool_set_sizes(); buf_LRU_old_ratio_update(100 * 3/ 8, FALSE); btr_search_sys_create(buf_pool_get_curr_size() / sizeof(void*) / 64); return(DB_SUCCESS); }