static void
put_request_buffer(arp_entry* entry, net_buffer* buffer)
{
net_buffer* requestBuffer = atomic_pointer_test_and_set(
&entry->request_buffer, buffer, (net_buffer*)NULL);
if (requestBuffer != NULL) {
// someone else took over ownership of the request buffer
gBufferModule->free(buffer);
}
}
static net_buffer*
get_request_buffer(arp_entry* entry)
{
net_buffer* buffer = entry->request_buffer;
if (buffer == NULL || buffer == kDeletedBuffer)
return NULL;
buffer = atomic_pointer_test_and_set(&entry->request_buffer,
(net_buffer*)NULL, buffer);
if (buffer == kDeletedBuffer)
return NULL;
return buffer;
}
// Record the sem_undo operation into our private fUndoList and
// the team undo_list. The only limit here is the memory needed
// for creating a new sem_undo structure.
int RecordUndo(short semaphoreNumber, short value)
{
// Look if there is already a record from the team caller
// for the same semaphore set
bool notFound = true;
Team *team = thread_get_current_thread()->team;
DoublyLinkedList<sem_undo>::Iterator iterator = fUndoList.GetIterator();
while (iterator.HasNext()) {
struct sem_undo *current = iterator.Next();
if (current->team == team) {
// Update its undo value
MutexLocker _(team->xsi_sem_context->lock);
int newValue = current->undo_values[semaphoreNumber] + value;
if (newValue > USHRT_MAX || newValue < -USHRT_MAX) {
TRACE_ERROR(("XsiSemaphoreSet::RecordUndo: newValue %d "
"out of range\n", newValue));
return ERANGE;
}
current->undo_values[semaphoreNumber] = newValue;
notFound = false;
TRACE(("XsiSemaphoreSet::RecordUndo: found record. Team = %d, "
"semaphoreSetID = %d, semaphoreNumber = %d, value = %d\n",
(int)team->id, fID, semaphoreNumber,
current->undo_values[semaphoreNumber]));
break;
}
}
if (notFound) {
// First sem_undo request from this team for this
// semaphore set
int16 *undoValues
= (int16 *)malloc(sizeof(int16) * fNumberOfSemaphores);
if (undoValues == NULL)
return B_NO_MEMORY;
struct sem_undo *request
= new(std::nothrow) sem_undo(this, team, undoValues);
if (request == NULL) {
free(undoValues);
return B_NO_MEMORY;
}
memset(request->undo_values, 0, sizeof(int16) * fNumberOfSemaphores);
request->undo_values[semaphoreNumber] = value;
// Check if it's the very first sem_undo request for this team
xsi_sem_context *context = atomic_pointer_get(&team->xsi_sem_context);
if (context == NULL) {
// Create the context
context = new(std::nothrow) xsi_sem_context;
if (context == NULL) {
free(request->undo_values);
delete request;
return B_NO_MEMORY;
}
// Since we don't hold any global lock, someone
// else could have been quicker than us, so we have
// to delete the one we just created and use the one
// in place.
if (atomic_pointer_test_and_set(&team->xsi_sem_context, context,
(xsi_sem_context *)NULL) != NULL)
delete context;
}
// Add the request to both XsiSemaphoreSet and team list
fUndoList.Add(request);
MutexLocker _(team->xsi_sem_context->lock);
team->xsi_sem_context->undo_list.Add(request);
TRACE(("XsiSemaphoreSet::RecordUndo: new record added. Team = %d, "
"semaphoreSetID = %d, semaphoreNumber = %d, value = %d\n",
(int)team->id, fID, semaphoreNumber, value));
}
return B_OK;
}
