//DESCRIPTION: Initalize the slab object. This is an abstraction for a contiguous block of objects that can be index into using
//the id of the object. The slab works exclusively with mmap'd regions. Thus it takes a file descriptor and does an ftruncate if
//it needs to resize the region. Also, the slab is a homogenous storage device, so it only stores the same type (size) of objects
ObjectSlab * initObjectSlab(char * segmentName, void * initAddress, int sizeOfType, int slabIncrementSize){
ObjectSlab * slab = malloc(sizeof(ObjectSlab));
if (slab) {
int sizeInBytes=0;
openSharedMemory(slab,segmentName,&sizeInBytes);
if (slab->shm_fd == -1){
perror("creating shared memory segment failed");
return NULL;
}
if (sizeInBytes == 0){
sizeInBytes=slabIncrementSize * sizeOfType + sizeof(ObjectSlabHeader);
int result = ftruncate(slab->shm_fd, sizeInBytes); //make the file bigger
if (result==-1){
perror("An error occured when trying to truncate a file");
return NULL;
}
}
slab->objects = mapSharedMemory(slab, sizeInBytes, initAddress);
if (!slab->objects){
perror("failed to map the segment into the address space");
return NULL;
}
slab->slabIncrementSize = slabIncrementSize;
slab->sizeInObjects = (sizeInBytes - sizeof(ObjectSlabHeader))/sizeOfType;
slab->sizeOfType = sizeOfType;
}
return slab;
}
int SharedMemoryTracker::init()
{
OutputDebugString("Socket Tracker Init\n");
openSharedMemory();
return 0;
}
/**
* Creates/open a shared memory region
*
* The rootname will uniquely identify the shared memory region,
* and is valid across different JVM instance.
*
* The shared memory region should persist across process, until OS reboots
* or destroy call is being made.
*
* @param[in] portLibrary The port Library
* @param[out] handle This handle is required for further attach/destroy of the memory region
* @param[in] rootname Shared name for the region, which used to identify the region.
* @param[in] size Size of the region in bytes
* @param[in] perm permission for the region.
*
* @return
* \arg HYPORT_ERROR_SHMEM_OPFAILED Failure - Cannot open the shared memory region
* \arg HYPORT_INFO_SHMEM_OPENED Success - Existing memory region has been opened
* \arg HYPORT_INFO_SHMEM_CREATED Success - A new shared memory region has been created
*
*/
IDATA VMCALL
hyshmem_open (HyPortLibrary * portLibrary, struct hyshmem_handle **handle,
const char *rootname, I_32 size, I_32 perm)
{
/*TODO: Do we need the length to be longer? */
char controlFile[HYSH_MAXPATH];
IDATA retryCount, exist;
key_t fkey;
void *region;
int retry = RETRY_COUNT;
Trc_PRT_shmem_hyshmem_open_Entry (rootname, size, perm);
if (ensureDirectory (portLibrary) == FAILED)
{
portLibrary->error_set_last_error (portLibrary, errno,
HYPORT_ERROR_SHMEM_DATA_DIRECTORY_FAILED);
Trc_PRT_shmem_hyshmem_open_Exit3 ();
return HYPORT_ERROR_SHSEM_OPFAILED;
}
getControlFilePath (portLibrary, controlFile, HYSH_MAXPATH, rootname);
while (retry)
{
I_32 rc;
rc = portLibrary->file_attr (portLibrary, controlFile);
if (HyIsFile != rc)
{
Trc_PRT_shmem_hyshmem_open_Event1 (controlFile);
rc =
createSharedMemory (portLibrary, handle, controlFile, size, perm);
}
else
{
Trc_PRT_shmem_hyshmem_open_Event2 (controlFile);
rc = openSharedMemory (portLibrary, handle, controlFile);
}
switch (rc)
{
case RETRY:
Trc_PRT_shmem_hyshmem_open_Event3 (retry);
retry--;
usleep (100);
continue;
case FAILED:
Trc_PRT_shmem_hyshmem_open_Exit1 ();
return HYPORT_ERROR_SHMEM_OPFAILED;
default:
Trc_PRT_shmem_hyshmem_open_Exit (rc, *handle);
return rc;
}
}
/* max number of retry count reach, return failure */
portLibrary->file_unlink (portLibrary, controlFile);
Trc_PRT_shmem_hyshmem_open_Exit2 ();
return HYPORT_ERROR_SHMEM_OPFAILED;
}
