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shmem.hh

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/*************************************************************************
* File: shmem.hh                                                         *
* Authors: Fred Proctor, Will Shackleford                                *
* Purpose: C++ Header file for the Communication Management System (CMS).*
*          Includes:                                                     *
*                    1. class SHMEM.                                     *
* Notes: The class SHMEM should be used by procedures accessing a shared *
*  memory buffer on the same processor.                                  *
*************************************************************************/

#ifndef SHMEM_HH
#define SHMEM_HH

/* Include Files */
#include "rcs_defs.hh"          /* EXTERN_C_STD_HEADERS  */

#ifdef EXTERN_C_STD_HEADERS
extern "C"
{
#endif

#ifndef UNDER_CE
#include <stdio.h>              /* NULL */
#include <stddef.h>             /* size_t */
#endif

#ifndef _WINDOWS
#include <sys/types.h>          /* key_t */
#endif

#ifdef EXTERN_C_STD_HEADERS
}
#endif

#ifndef KEY_T_DEFINED

#ifdef VXWORKS
typedef int key_t;              /* key_t is not defined in VxWorks or  Windows -- do
                                   it here, and it should be visible
                                   throughout all the shared mem code */
#endif

#ifdef WIN32
typedef long key_t;
#endif

#endif


#include "cms.hh"               /* class CMS */
#include "shm.hh"               /* class RCS_SHAREDMEM */
#include "memsem.hh"            /* struct mem_access_object */
// #include "sem.hh"            /* class RCS_SEMAPHORE */

/* Class Definitions */

class SHMEM:public CMS
{
public:
  SHMEM (char *name, long size, int neutral, key_t key, int m = 0);
    SHMEM (char *bufline, char *procline, int set_to_server = 0,
           int set_to_master = 0);
    virtual ~ SHMEM ();

  CMS_STATUS main_access (void *_local);

private:

  /* data buffer stuff */
  int fast_mode;
#ifdef VXWORKS
  virtual CMS_STATUS read ();   /* Read from  buffer. */
  virtual CMS_STATUS peek ();   /* Read without setting flag. */
  virtual CMS_STATUS write (void *user_data);   /* Write to buffer. */
  virtual CMS_STATUS write_if_read (void *user_data);   /* Write to buffer. */
#endif
  int open ();                  /* get shared mem and sem */
  int close ();                 /* detach from shared mem and sem */
  key_t key;                    /* key for shared mem and sem */
  key_t bsem_key;               // key for blocking semaphore
  int second_read;              // true only if the first read returned no new data
  RCS_SHAREDMEM *shm;           /* shared memory */
  RCS_SEMAPHORE *sem;           /* semaphore */
  int master;                   /* Is this process responsible for */
  /* clearing memory & semaphores? */
  double sem_delay;             /* Time to wait between polling the semaphore. */
  struct mem_access_object mao; /* passed to mem_get_access()  */
  enum SHMEM_MUTEX_TYPE
  {
    NO_MUTEX,
    MAO_MUTEX,
    MAO_MUTEX_W_OS_SEM,
    OS_SEM_MUTEX,
    NO_INTERRUPTS_MUTEX,
    NO_SWITCHING_MUTEX
  };

  int use_os_sem;
  int use_os_sem_only;

  SHMEM_MUTEX_TYPE mutex_type;
  void *shm_addr_offset;

#ifdef WIN32
  HANDLE bsem;
#else
  RCS_SEMAPHORE *bsem;          // blocking semaphore
#endif
  int autokey_table_size;

};

#endif /* !SHMEM_HH */

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