sion_cache.c

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/****************************************************************************
**  SIONLIB     http://www.fz-juelich.de/jsc/sionlib                       **
*****************************************************************************
**  Copyright (c) 2008-2019                                                **
**  Forschungszentrum Juelich, Juelich Supercomputing Centre               **
**                                                                         **
**  See the file COPYRIGHT in the package base directory for details       **
****************************************************************************/
#define _XOPEN_SOURCE 700

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <assert.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>


#include "sion.h"
#include "sion_debug.h"
#include "sion_error_handler.h"
#include "sion_internal.h"
#include "sion_cache.h"


#if defined(_SION_LINUX)
#include <sys/mman.h>
#elif defined(_SION_AIX)
#elif defined(_SION_BGP)
#endif


int  _sion_cache_check_env(_sion_filedesc *sion_filedesc) {
  const char *t;
  int rc = SION_SUCCESS;

  t = _sion_getenv("SION_CACHESIZE");
  if(t) {
    sion_filedesc->usecache=1;
    sion_filedesc->cachesize=atoi(t);
    sion_filedesc->flag1 |= _SION_FLAG1_USECACHE;
  }
  DPRINTFP((2, "_sion_cache_check_env", -1, "usecache=%d cachesize=%d flag1=%d\n", sion_filedesc->usecache, sion_filedesc->cachesize, sion_filedesc->flag1));

  return (rc);
}


int  _sion_cache_init(_sion_filedesc *sion_filedesc) {
  int rc = SION_SUCCESS;

  /* allocation */
  if(sion_filedesc->usecache) {
    if(sion_filedesc->mode == SION_FILEMODE_WRITE) { 
#if defined(_SION_LINUX)
      rc=_sion_cache_create_linux(sion_filedesc);
#elif defined(_SION_AIX)
#elif defined(_SION_BGP)
#endif
    } else if(sion_filedesc->mode == SION_FILEMODE_READ) {
#if defined(_SION_LINUX)
      rc=_sion_cache_load_linux(sion_filedesc);
#elif defined(_SION_AIX)
#elif defined(_SION_BGP)
#endif
    } else {
      _sion_errorprint(SION_NOT_SUCCESS,_SION_ERROR_RETURN,"_sion_cache_init: unknown SION mode\n");
    }
  }

  return (rc);
}


int  _sion_cache_destroy(_sion_filedesc *sion_filedesc) {
  int rc = SION_SUCCESS;

  /* deallocation */
  if(sion_filedesc->usecache) {
#if defined(_SION_LINUX)
    rc=_sion_cache_destroy_linux(sion_filedesc);
#elif defined(_SION_AIX)
#elif defined(_SION_BGP)
#endif
  }

  return (rc);
}

int  _sion_cache_create_linux(_sion_filedesc *sion_filedesc) {
  int rc = SION_SUCCESS;

 /* #NODIST# */
#ifdef _SION_CACHE

#if defined(_SION_LINUX)
  int   shmfd;
  char* shmptr;  

  if(sion_filedesc->rank>0) sprintf(sion_filedesc->cachefn,"sion_%07d",sion_filedesc->rank);
  else                      sprintf(sion_filedesc->cachefn,"sion_%07d",0);

  /* creating the shared memory object    --  shm_open()  */
  shmfd = shm_open(sion_filedesc->cachefn, O_CREAT | O_EXCL | O_RDWR, S_IRWXU | S_IRWXG);
  if (shmfd < 0) {
    _sion_errorprint(SION_NOT_SUCCESS,_SION_ERROR_RETURN,"_sion_cache_create_linux: could not create segment\n");
  }
  DPRINTFP((2, "_sion_cache_create_linux", -1, "after shm_open %s shmfd=%d\n", sion_filedesc->cachefn, shmfd));
    
  /* adjusting mapped file size (make room for the whole segment to map)      --  ftruncate() */
  ftruncate(shmfd, sion_filedesc->cachesize);

  /* requesting the shared segment    --  mmap() */    
  shmptr = (char *)mmap(NULL, sion_filedesc->cachesize, PROT_READ | PROT_WRITE, MAP_SHARED, shmfd, 0);
  if (shmptr == NULL) {
    _sion_errorprint(SION_NOT_SUCCESS,_SION_ERROR_RETURN,"_sion_cache_create_linux: could not mmap segment\n");
  }
  DPRINTFP((2, "_sion_cache_create_linux", -1, "after mmap %d bytes\n", sion_filedesc->cachesize));
  
  sion_filedesc->cacheid=shmfd;
  sion_filedesc->cacheptr=shmptr;
#endif

#endif
 /* #NODIST# */
  return(rc);
}

int  _sion_cache_load_linux(_sion_filedesc *sion_filedesc) {
  int rc = SION_SUCCESS;
 /* #NODIST# */
#ifdef _SION_CACHE

#if defined(_SION_LINUX)
  int   shmfd;
  char* shmptr;  

  if(sion_filedesc->rank>0) sprintf(sion_filedesc->cachefn,"sion_%07d",sion_filedesc->rank);
  else                      sprintf(sion_filedesc->cachefn,"sion_%07d",0);

  /* creating the shared memory object    --  shm_open()  */
  shmfd = shm_open(sion_filedesc->cachefn, O_RDWR, S_IRWXU | S_IRWXG);
  if (shmfd < 0) {
    _sion_errorprint(SION_NOT_SUCCESS,_SION_ERROR_RETURN,"_sion_cache_losd_linux: could not load segment\n");
  }
  DPRINTFP((2, "_sion_cache_create_linux", -1, "after shm_open %s shmfd=%d\n", sion_filedesc->cachefn, shmfd));
    
  /* adjusting mapped file size (make room for the whole segment to map)      --  ftruncate() */
  ftruncate(shmfd, sion_filedesc->cachesize);

  /* requesting the shared segment    --  mmap() */    
  shmptr = (char *)mmap(NULL, sion_filedesc->cachesize, PROT_READ | PROT_WRITE, MAP_SHARED, shmfd, 0);
  if (shmptr == NULL) {
    _sion_errorprint(SION_NOT_SUCCESS,_SION_ERROR_RETURN,"_sion_cache_create_linux: could not mmap segment\n");
  }
  DPRINTFP((2, "_sion_cache_create_linux", -1, "after mmap %d bytes\n", sion_filedesc->cachesize));
  
  sion_filedesc->cacheid=shmfd;
  sion_filedesc->cacheptr=shmptr;
#endif

#endif
 /* #NODIST# */

  return(rc);
}


int  _sion_cache_destroy_linux(_sion_filedesc *sion_filedesc) {
  int rc = SION_SUCCESS;

 /* #NODIST# */
#ifdef _SION_CACHE

#if defined(_SION_LINUX)
  /* destroy shared memory object    --  shm_unlink()  */
  if (shm_unlink(sion_filedesc->cachefn) != 0) {
    _sion_errorprint(SION_NOT_SUCCESS,_SION_ERROR_RETURN,"_sion_cache_destroy_linux: could not destroy segment\n");
  }
  
  sion_filedesc->cacheid=-1;
  sion_filedesc->cacheptr=NULL;
#endif

#endif
 /* #NODIST# */

  return(rc);
}