root/sapi/fpm/fpm/fpm_shm.c

DEFINITIONS

1. fpm_shm_alloc
2. fpm_shm_free
3. fpm_shm_get_size_allocated

        /* $Id: fpm_shm.c,v 1.3 2008/05/24 17:38:47 anight Exp $ */
        /* (c) 2007,2008 Andrei Nigmatulin, Jerome Loyet */

#include <sys/mman.h>
#include <errno.h>
#include <string.h>

#include "fpm_shm.h"
#include "zlog.h"


/* MAP_ANON is deprecated, but not in macosx */
#if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
#define MAP_ANONYMOUS MAP_ANON
#endif

static size_t fpm_shm_size = 0;

void *fpm_shm_alloc(size_t size) /* {{{ */
{
        void *mem;

        mem = mmap(0, size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0);

#ifdef MAP_FAILED
        if (mem == MAP_FAILED) {
                zlog(ZLOG_SYSERROR, "unable to allocate %zu bytes in shared memory: %s", size, strerror(errno));
                return NULL;
        }
#endif

        if (!mem) {
                zlog(ZLOG_SYSERROR, "unable to allocate %zu bytes in shared memory", size);
                return NULL;
        }

        memset(mem, 0, size);
        fpm_shm_size += size;
        return mem;
}
/* }}} */

int fpm_shm_free(void *mem, size_t size) /* {{{ */
{
        if (!mem) {
                zlog(ZLOG_ERROR, "mem is NULL");
                return 0;
        }

        if (munmap(mem, size) == -1) {
                zlog(ZLOG_SYSERROR, "Unable to free shm");
                return 0;
        }

        if (fpm_shm_size - size > 0) {
                fpm_shm_size -= size;
        } else {
                fpm_shm_size = 0;
        }

        return 1;
}
/* }}} */

size_t fpm_shm_get_size_allocated() /* {{{*/
{
        return fpm_shm_size;
}
/* }}} */