/* 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 ap_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"
#include "apr_md5.h"
#if APR_HAVE_UNISTD_H
#include <unistd.h> /* for getpid() */
#endif
#ifdef __cplusplus
extern "C" {
#endif
#define AP_SLOTMEM_PROVIDER_GROUP "slotmem"
#define AP_SLOTMEM_PROVIDER_VERSION "0"
typedef unsigned int ap_slotmem_type_t;
/*
* Values for ap_slotmem_type_t::
*
* AP_SLOTMEM_TYPE_PERSIST: For transitory providers, persist
* the data on the file-system
*
* AP_SLOTMEM_TYPE_NOTMPSAFE:
*
* AP_SLOTMEM_TYPE_PREALLOC: Access to slots require they be grabbed 1st
*
* AP_SLOTMEM_TYPE_CLEARINUSE: If persisting, clear 'inuse' array before
* storing
*/
#define AP_SLOTMEM_TYPE_PERSIST (1 << 0)
#define AP_SLOTMEM_TYPE_NOTMPSAFE (1 << 1)
#define AP_SLOTMEM_TYPE_PREGRAB (1 << 2)
#define AP_SLOTMEM_TYPE_CLEARINUSE (1 << 3)
typedef struct ap_slotmem_instance_t ap_slotmem_instance_t;
/**
* callback function used for slotmem doall.
* @param mem is the memory associated with a worker.
* @param data is what is passed to slotmem.
* @param pool is pool used
* @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 ap_slotmem_provider_t {
/*
* Name of the provider method
*/
const char *name;
/**
* call the callback on all worker slots
* @param s ap_slotmem_instance_t to use.
* @param funct callback function to call for each element.
* @param data parameter for the callback function.
* @param pool is pool used
* @return APR_SUCCESS if all went well
*/
apr_status_t (* doall)(ap_slotmem_instance_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 inst where to store pointer to slotmem
* @param name 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 type type of slotmem.
* @param pool is pool used
* @return APR_SUCCESS if all went well
*/
apr_status_t (* create)(ap_slotmem_instance_t **inst, const char *name, apr_size_t item_size, unsigned int item_num, ap_slotmem_type_t type, apr_pool_t *pool);
/**
* attach to an existing slotmem.
* This would attach to shared memory, basically.
* @param inst where to store pointer to slotmem
* @param name 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
*/
apr_status_t (* attach)(ap_slotmem_instance_t **inst, const char *name, apr_size_t *item_size, unsigned int *item_num, apr_pool_t *pool);
/**
* get the memory ptr associated with this worker slot.
* @param s ap_slotmem_instance_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
*/
apr_status_t (* dptr)(ap_slotmem_instance_t *s, unsigned int item_id, void**mem);
/**
* get/read the data associated with this worker slot.
* @param s ap_slotmem_instance_t to use.
* @param item_id item to return for 0 to item_num
* @param dest address to store the data
* @param dest_len length of dataset to retrieve
* @return APR_SUCCESS if all went well
*/
apr_status_t (* get)(ap_slotmem_instance_t *s, unsigned int item_id, unsigned char *dest, apr_size_t dest_len);
/**
* put/write the data associated with this worker slot.
* @param s ap_slotmem_instance_t to use.
* @param item_id item to return for 0 to item_num
* @param src address of the data to store in the slot
* @param src_len length of dataset to store in the slot
* @return APR_SUCCESS if all went well
*/
apr_status_t (* put)(ap_slotmem_instance_t *slot, unsigned int item_id, unsigned char *src, apr_size_t src_len);
/**
* return number of slots allocated for this entry.
* @param s ap_slotmem_instance_t to use.
* @return number of slots
*/
unsigned int (* num_slots)(ap_slotmem_instance_t *s);
/**
* return number of free (not used) slots allocated for this entry.
* Valid for slots which are AP_SLOTMEM_TYPE_PREGRAB as well as
* any which use get/release.
* @param s ap_slotmem_instance_t to use.
* @return number of slots
*/
unsigned int (* num_free_slots)(ap_slotmem_instance_t *s);
/**
* return slot size allocated for this entry.
* @param s ap_slotmem_instance_t to use.
* @return size of slot
*/
apr_size_t (* slot_size)(ap_slotmem_instance_t *s);
/**
* grab (or alloc) a free slot
* @param s ap_slotmem_instance_t to use.
* @param item_id ptr to the available slot id and marked as in-use
* @return APR_SUCCESS if all went well
*/
apr_status_t (* grab)(ap_slotmem_instance_t *s, unsigned int *item_id);
/**
* release (or free) the slot associated with this item_id
* @param s ap_slotmem_instance_t to use.
* @param item_id slot id to free and mark as no longer in-use
* @return APR_SUCCESS if all went well
*/
apr_status_t (* release)(ap_slotmem_instance_t *s, unsigned int item_id);
/**
* forced grab (or alloc) a slot associated with this item_id
* @param s ap_slotmem_instance_t to use.
* @param item_id to the specified slot id and marked as in-use
* @return APR_SUCCESS if all went well
*/
apr_status_t (* fgrab)(ap_slotmem_instance_t *s, unsigned int item_id);
};
typedef struct ap_slotmem_provider_t ap_slotmem_provider_t;
#ifdef __cplusplus
}
#endif
#endif
/** @} */
