slotmem.h revision f4c04690e8c0af5cdd3ec59cf5b31f0561fd4ed0
/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef SLOTMEM_H
#define SLOTMEM_H
/* Memory handler for a shared memory divided in slot.
*/
/**
* @file slotmem.h
* @brief Memory Slot Extension Storage Module for Apache
*
* @defgroup MEM mem
* @ingroup APACHE_MODS
* @{
*/
#include "httpd.h"
#include "http_config.h"
#include "http_log.h"
#include "ap_provider.h"
#include "apr.h"
#include "apr_strings.h"
#include "apr_pools.h"
#include "apr_shm.h"
#include "apr_global_mutex.h"
#include "apr_file_io.h"
#ifdef AP_NEED_SET_MUTEX_PERMS
#include "unixd.h"
#endif
#if APR_HAVE_UNISTD_H
#include <unistd.h> /* for getpid() */
#endif
#define SLOTMEM_STORAGE "slotmem"
typedef struct ap_slotmem ap_slotmem_t;
struct ap_slotmem {
char *name; /* per segment name */
void *shm; /* ptr to memory segment (apr_shm_t *) */
void *base; /* data set start */
apr_size_t size; /* size of each memory slot */
int num; /* number of mem slots */
apr_pool_t *gpool; /* per segment global pool */
apr_global_mutex_t *smutex; /* mutex */
void *context; /* general purpose storage */
struct ap_slotmem *next; /* location of next allocated segment */
};
/**
* callback function used for slotmem.
* @param mem is the memory associated with a worker.
* @param data is what is passed to slotmem.
* @param pool is pool used to create scoreboard
* @return APR_SUCCESS if all went well
*/
typedef apr_status_t ap_slotmem_callback_fn_t(void* mem, void *data, apr_pool_t *pool);
struct slotmem_storage_method {
/**
* call the callback on all worker slots
* @param s ap_slotmem_t to use.
* @param funct callback function to call for each element.
* @param data parameter for the callback function.
* @param pool is pool used to create scoreboard
* @return APR_SUCCESS if all went well
*/
AP_DECLARE(apr_status_t) (* slotmem)(ap_slotmem_t *s, ap_slotmem_callback_fn_t *func, void *data, apr_pool_t *pool);
/**
* create a new slotmem with each item size is item_size.
* This would create shared memory, basically.
* @param pointer to store the address of the scoreboard.
* @param name is a key used for debugging and in mod_status output or allow another process to share this space.
* @param item_size size of each item
* @param item_num number of item to create.
* @param pool is pool used to create scoreboard
* @return APR_SUCCESS if all went well
*/
AP_DECLARE(apr_status_t) (* ap_slotmem_create)(ap_slotmem_t **new, const char *name, apr_size_t item_size, int item_num, apr_pool_t *pool);
/**
* attach to an existing slotmem.
* This would attach to shared memory, basically.
* @param pointer to store the address of the scoreboard.
* @param name is a key used for debugging and in mod_status output or allow another process to share this space.
* @param item_size size of each item
* @param item_num max number of item.
* @param pool is pool to memory allocate.
* @return APR_SUCCESS if all went well
*/
AP_DECLARE(apr_status_t) (* ap_slotmem_attach)(ap_slotmem_t **new, const char *name, apr_size_t *item_size, int *item_num, apr_pool_t *pool);
/**
* get the memory associated with this worker slot.
* @param s ap_slotmem_t to use.
* @param item_id item to return for 0 to item_num
* @param mem address to store the pointer to the slot
* @return APR_SUCCESS if all went well
*/
AP_DECLARE(apr_status_t) (* ap_slotmem_mem)(ap_slotmem_t *s, int item_id, void**mem);
/**
* lock the memory segment
* NOTE: All slots share the same mutex
* @param s ap_slotmem_t to use
* @return APR_SUCCESS if all went well
*/
AP_DECLARE(apr_status_t) (* ap_slotmem_lock)(ap_slotmem_t *s);
/**
* unlock the memory segment
* NOTE: All slots share the same mutex
* @param s ap_slotmem_t to use.
* @return APR_SUCCESS if all went well
*/
AP_DECLARE(apr_status_t) (* ap_slotmem_unlock)(ap_slotmem_t *s);
};
typedef struct slotmem_storage_method slotmem_storage_method;
#endif /*SLOTMEM_H*/