void*
mono_shared_area (void)
{
int fd;
int pid = getpid ();
/* we should allow the user to configure the size */
int size = mono_pagesize ();
char buf [128];
void *res;
SAreaHeader *header;
if (shared_area_disabled ()) {
if (!malloced_shared_area)
malloced_shared_area = malloc_shared_area (0);
/* get the pid here */
return malloced_shared_area;
}
/* perform cleanup of segments left over from dead processes */
mono_shared_area_instances_helper (NULL, 0, TRUE);
g_snprintf (buf, sizeof (buf), "/mono.%d", pid);
fd = shm_open (buf, O_CREAT|O_EXCL|O_RDWR, S_IRUSR|S_IWUSR|S_IRGRP);
if (fd == -1 && errno == EEXIST) {
/* leftover */
shm_unlink (buf);
fd = shm_open (buf, O_CREAT|O_EXCL|O_RDWR, S_IRUSR|S_IWUSR|S_IRGRP);
}
/* in case of failure we try to return a memory area anyway,
* even if it means the data can't be read by other processes
*/
if (fd == -1)
return malloc_shared_area (pid);
if (ftruncate (fd, size) != 0) {
shm_unlink (buf);
close (fd);
}
BEGIN_CRITICAL_SECTION;
res = mmap (NULL, size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
END_CRITICAL_SECTION;
if (res == MAP_FAILED) {
shm_unlink (buf);
close (fd);
return malloc_shared_area (pid);
}
/* we don't need the file descriptor anymore */
close (fd);
header = (SAreaHeader *) res;
header->size = size;
header->pid = pid;
header->stats_start = sizeof (SAreaHeader);
header->stats_end = sizeof (SAreaHeader);
mono_atexit (mono_shared_area_remove);
return res;
}
int
mono_shared_area_instances (void **array, int count)
{
return mono_shared_area_instances_helper (array, count, FALSE);
}
