/* *  *  $Id: bufferpool.h 327 2006-03-28 16:14:41Z shawill $ *   *  This file is part of Fenice * *  Fenice -- Open Media Server * *  Copyright (C) 2004 by *  *- Giampaolo Mancini <giampaolo.mancini@polito.it> *- Francesco Varano  <francesco.varano@polito.it> *- Marco Penno           <marco.penno@polito.it> *- Federico Ridolfo      <federico.ridolfo@polito.it> *- Eugenio Menegatti     <m.eu@libero.it> *- Stefano Cau *- Giuliano Emma *- Stefano Oldrini *  *  Fenice is free software; you can redistribute it and/or modify *  it under the terms of the GNU General Public License as published by *  the Free Software Foundation; either version 2 of the License, or *  (at your option) any later version. * *  Fenice is distributed in the hope that it will be useful, *  but WITHOUT ANY WARRANTY; without even the implied warranty of *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the *  GNU General Public License for more details. * *  You should have received a copy of the GNU General Public License *  along with Fenice; if not, write to the Free Software *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA *   * */  /* * Fenice's bufferpool is projected to support ONE AND ONLY ONE producer and many consumers. * Each consumer have it's own OMSConsumer structure that is NOT SHARED with others readers. * So the only struct that must be locked with mutexes is OMSBuffer. * */#ifndef _BUFFERPOOLH#define _BUFFERPOOLH#ifdef HAVE_CONFIG_H#include <config.h>#endif#include <fenice/types.h>#include <pthread.h>#include <stdlib.h>#include <stddef.h>#include <limits.h>#define omsbuff_min(x,y) ((x) < (y) ? (x) : (y))#define omsbuff_max(x,y) ((x) > (y) ? (x) : (y))#define OMSBUFF_MEM_PAGE 9#define OMSSLOT_DATASIZE 65000#define OMSBUFF_SHM_CTRLNAME "Buffer"#define OMSBUFF_SHM_SLOTSNAME "Slots"#define OMSBUFF_SHM_PAGE OMSBUFF_MEM_PAGE        /*共享內存的頁數*/   #ifndef PATH_MAX#define PATH_MAX 4096#endif#define OMSbuff_lock(buffer) pthread_mutex_lock(&buffer->control->syn)#define OMSbuff_unlock(buffer) pthread_mutex_unlock(&buffer->control->syn)typedef ptrdiff_t OMSSlotPtr;            /*long 類型變量*/                       #define OMSSLOT_COMMON  uint16 refs; \            uint64 slot_seq; /* monotone identifier of slot (NOT RTP seq) */ \            double timestamp; \            uint8 data[OMSSLOT_DATASIZE]; \            uint32 data_size; \            uint8 marker; \            ptrdiff_t next;typedef struct _OMSslot {    OMSSLOT_COMMON} OMSSlot;typedef struct _OMSControl {    uint16 refs;  /*共享緩存的消費者*/    uint32 nslots;    OMSSlotPtr write_pos; /*最后一次寫操作的位置*/    OMSSlotPtr valid_read_pos; /*新消費者的合法讀位置*/    pthread_mutex_t syn;        /*信號量*/} OMSControl;typedef enum {buff_local=0, buff_shm} OMSBufferType;/* * 緩沖區結構體 * 在通用的內存分配操作和共享內存操作下，指針有不同的含義 * 使用共享內存的情況下，緩沖指針是相對共享內存開頭的偏移量 * 在此情況下，兩個進程可以通過將mmap的返回值加入到地址中獲得絕對地址 * */typedef struct _OMSbuffer {    OMSBufferType type;                /*是否是共享內存*/    OMSControl *control;                 OMSSlot *slots;                        /*! Buffer head*/    uint32 known_slots; /*最后一個已知的slot個數，僅僅在共享內存緩沖區情況有用 */    char filename[PATH_MAX];} OMSBuffer;typedef struct _OMSconsumer {    OMSSlotPtr read_pos; /*! read position*/    OMSSlotPtr last_read_pos; /*! last read position . used for managing the slot addition*/    uint64 last_seq;    OMSBuffer *buffer;    int32 frames;    double firstts;} OMSConsumer;/*! This structure is usefull if you need to do some syncronization among different correlated buffers. * */typedef struct _OMSAggregate {    OMSBuffer *buffer;    struct _OMSAggregate *next;} OMSAggregate;/*API函數定義，聲明*/OMSBuffer *OMSbuff_new(uint32);OMSConsumer *OMSbuff_ref(OMSBuffer *);void OMSbuff_unref(OMSConsumer *);int32 OMSbuff_read(OMSConsumer *, uint32 *, uint8 *, uint8 *, uint32 *);OMSSlot *OMSbuff_getreader(OMSConsumer *);int32 OMSbuff_gotreader(OMSConsumer *);int32 OMSbuff_write(OMSBuffer *, uint64, uint32, uint8, uint8 *, uint32);OMSSlot *OMSbuff_getslot(OMSBuffer *);OMSSlot *OMSbuff_addpage(OMSBuffer *, OMSSlot *);//OMSSlot *OMSbuff_slotadd(OMSBuffer *, OMSSlot *);void OMSbuff_free(OMSBuffer *);int OMSbuff_isempty(OMSConsumer *);double OMSbuff_nextts(OMSConsumer *);/*Bufferpool 中的共享內存操作函數*/OMSBuffer *OMSbuff_shm_create(char *, uint32);OMSBuffer *OMSbuff_shm_map(char *);OMSSlot *OMSbuff_shm_addpage(OMSBuffer *);int OMSbuff_shm_remap(OMSBuffer *);#define OMSbuff_shm_refresh(oms_buffer)	    \(((oms_buffer->type == buff_shm) && (oms_buffer->known_slots != oms_buffer->control->nslots)) ? \OMSbuff_shm_remap(oms_buffer) : 0)int OMSbuff_shm_unmap(OMSBuffer *);int OMSbuff_shm_destroy(OMSBuffer *);/*IPC  名字*/char *fnc_ipc_name(const char *, const char *);// OMSSlotPtr manipulation#define OMStoSlot(b, p) ((p<0) ? NULL : (&b->slots[p])) // used when a pointer could be NULL, otherwise we'll use buffe->slots[index]#define OMStoSlotPtr(b, p) (p ? p - b->slots : -1)/*消費者集合之間的同步*/OMSAggregate *OMBbuff_aggregate(OMSAggregate *, OMSBuffer *);int OMSbuff_sync(OMSAggregate *);#ifdef ENABLE_DUMPBUFFvoid OMSbuff_dump(OMSConsumer *, OMSBuffer *);#else#define OMSbuff_dump(x, y)#endif#endif