/*
* stats_open
*
* Opens the resources needed for a stats object. After this call returns
* successfully, the stats object is ready for use.
*
* The resources allocated by stats_open must be freed by a corresponding
* call to stats_close().
*
* Returns:
* S_OK - success
* ERROR_INVALID_PARAMETERS - the stats object passed was not valid
*/
int stats_open(struct stats *stats)
{
int err;
if (!stats || stats->magic != STATS_MAGIC || stats->data != NULL)
return ERROR_INVALID_PARAMETERS;
assert(!lock_is_open(&stats->lock));
assert(!shared_memory_is_open(&stats->shmem));
assert(stats->data == NULL);
/* open the lock */
err = lock_open(&stats->lock);
if (err == S_OK)
{
/* acquire the lock to make the process of getting and initializing the shared memory atomic */
lock_acquire(&stats->lock);
/* open the shared memory */
err = shared_memory_open(&stats->shmem);
if (err == S_OK)
{
assert(shared_memory_size(&stats->shmem) == sizeof(struct stats_data));
assert(shared_memory_ptr(&stats->shmem) != NULL);
/* get the pointer to the shared memory and initialize it if this process created it */
stats->data = (struct stats_data *) shared_memory_ptr(&stats->shmem);
if (shared_memory_was_created(&stats->shmem))
{
stats_init_data(stats);
}
assert(stats->data->hdr.stats_magic == STATS_MAGIC);
}
lock_release(&stats->lock);
}
assert((err == S_OK && stats->data != NULL) || (err != S_OK && stats->data == NULL));
return err;
}
IPC_handle IPC_openSharedMemory(const IPC_str *name)
{
DEBUG_PRINT("%s( %s )\n", __FUNCTION__, name );
int mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
int oflags = O_RDWR;
ipc_handle_t h = NULL;
void *ipc_drv_handle = shared_memory_open(name, 0);
if(!ipc_drv_handle) {
goto do_exit;
}
h = allocate_ipc_object(name, IPC_typeSharedMem);
if(!h) {
goto do_unregister_shm;
}
h->ipc_user = ipc_drv_handle;
h->ipc_descr.ipc_shm = shm_open(h->ipc_name, oflags, mode);
if(h->ipc_descr.ipc_shm < 0) {
goto do_free_ipc_object;
}
DEBUG_PRINT("%s(): open shared memory - %s\n", __FUNCTION__, name);
return h;
do_free_ipc_object:
delete_ipc_object(h);
do_unregister_shm:
shared_memory_close(ipc_drv_handle);
do_exit:
return NULL;
}
IPC_handle IPC_createSharedMemory(const IPC_str *name, int size)
{
DEBUG_PRINT("%s( %s, 0x%x )\n", __FUNCTION__, name, size );
int mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
int oflags = O_RDWR | O_CREAT | O_EXCL;
ipc_handle_t h = NULL;
int res = -1;
void *ipc_drv_handle = shared_memory_open(name, size);
if(!ipc_drv_handle) {
goto do_exit;
}
h = allocate_ipc_object(name, IPC_typeSharedMem);
if(!h) {
goto do_unregister_shm;
return NULL;
}
h->ipc_user = ipc_drv_handle;
h->ipc_descr.ipc_shm = shm_open(h->ipc_name, oflags, mode);
if(h->ipc_descr.ipc_shm < 0) {
if(errno != EEXIST)
goto do_free_ipc_object;
h->ipc_descr.ipc_shm = shm_open(h->ipc_name, O_RDWR, mode);
if(h->ipc_descr.ipc_shm < 0)
goto do_free_ipc_object;
struct stat st_buf;
res = fstat(h->ipc_descr.ipc_shm, &st_buf);
if(res < 0)
goto do_free_ipc_object;
if(st_buf.st_size > 0) {
DEBUG_PRINT("%s(): open shared memory - %s\n", __FUNCTION__, name );
goto do_return_ipc_object;
}
res = ftruncate(h->ipc_descr.ipc_shm, size);
if(res < 0)
goto do_free_ipc_object;
DEBUG_PRINT("%s(): open and init shared memory - %s\n", __FUNCTION__, name );
goto do_return_ipc_object;
}
res = ftruncate(h->ipc_descr.ipc_shm, size);
if(res < 0)
goto do_free_ipc_object;
DEBUG_PRINT("%s(): create shared memory - %s\n", __FUNCTION__, name);
do_return_ipc_object:
h->ipc_size = size;
return h;
do_free_ipc_object:
delete_ipc_object(h);
do_unregister_shm:
shared_memory_close(ipc_drv_handle);
do_exit:
return NULL;
}