root/sapi/fpm/fpm/fpm_shm.c

DEFINITIONS

1. fpm_shm_alloc
2. fpm_shm_free
3. fpm_shm_get_size_allocated

   1 
   2         /* $Id: fpm_shm.c,v 1.3 2008/05/24 17:38:47 anight Exp $ */
   3         /* (c) 2007,2008 Andrei Nigmatulin, Jerome Loyet */
   4 
   5 #include <sys/mman.h>
   6 #include <errno.h>
   7 #include <string.h>
   8 
   9 #include "fpm_shm.h"
  10 #include "zlog.h"
  11 
  12 
  13 /* MAP_ANON is deprecated, but not in macosx */
  14 #if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
  15 #define MAP_ANONYMOUS MAP_ANON
  16 #endif
  17 
  18 static size_t fpm_shm_size = 0;
  19 
  20 void *fpm_shm_alloc(size_t size) /* {{{ */
  21 {
  22         void *mem;
  23 
  24         mem = mmap(0, size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0);
  25 
  26 #ifdef MAP_FAILED
  27         if (mem == MAP_FAILED) {
  28                 zlog(ZLOG_SYSERROR, "unable to allocate %zu bytes in shared memory: %s", size, strerror(errno));
  29                 return NULL;
  30         }
  31 #endif
  32 
  33         if (!mem) {
  34                 zlog(ZLOG_SYSERROR, "unable to allocate %zu bytes in shared memory", size);
  35                 return NULL;
  36         }
  37 
  38         memset(mem, 0, size);
  39         fpm_shm_size += size;
  40         return mem;
  41 }
  42 /* }}} */
  43 
  44 int fpm_shm_free(void *mem, size_t size) /* {{{ */
  45 {
  46         if (!mem) {
  47                 zlog(ZLOG_ERROR, "mem is NULL");
  48                 return 0;
  49         }
  50 
  51         if (munmap(mem, size) == -1) {
  52                 zlog(ZLOG_SYSERROR, "Unable to free shm");
  53                 return 0;
  54         }
  55 
  56         if (fpm_shm_size - size > 0) {
  57                 fpm_shm_size -= size;
  58         } else {
  59                 fpm_shm_size = 0;
  60         }
  61 
  62         return 1;
  63 }
  64 /* }}} */
  65 
  66 size_t fpm_shm_get_size_allocated() /* {{{*/
  67 {
  68         return fpm_shm_size;
  69 }
  70 /* }}} */