/* Add an operation to the queue for tile @index
* Note: if an operation affects more than one tile, it must be added once per tile.
*
* Concurrency: This function is not thread-safe on the same @self instance. */
void
operation_queue_add(OperationQueue *self, TileIndex index, OperationDataDrawDab *op)
{
while (!tile_map_contains(self->tile_map, index)) {
#ifdef HEAVY_DEBUG
operation_queue_resize(self, self->tile_map->size+1);
#else
operation_queue_resize(self, self->tile_map->size*2);
#endif
}
Fifo **queue_pointer = (Fifo **)tile_map_get(self->tile_map, index);
Fifo *op_queue = *queue_pointer;
if (op_queue == NULL) {
// Lazy initialization
op_queue = fifo_new();
*queue_pointer = op_queue;
}
if (fifo_peek_first(op_queue) == NULL) {
// Critical section, not thread-safe
if (!(self->dirty_tiles_n < self->tile_map->size*2*self->tile_map->size*2)) {
// Prune duplicate tiles that cause us to almost exceed max
self->dirty_tiles_n = remove_duplicate_tiles(self->dirty_tiles, self->dirty_tiles_n);
}
assert(self->dirty_tiles_n < self->tile_map->size*2*self->tile_map->size*2);
self->dirty_tiles[self->dirty_tiles_n++] = index;
}
fifo_push(op_queue, (void *)op);
}
/* Pop an operation off the queue for tile @index
* The user of this function is reponsible for freeing the result using free()
*
* Concurrency: This function is reentrant (and lock-free) on different @index */
OperationDataDrawDab *
operation_queue_pop(OperationQueue *self, TileIndex index)
{
OperationDataDrawDab *op = NULL;
if (!tile_map_contains(self->tile_map, index)) {
return NULL;
}
Fifo **queue_pointer = tile_map_get(self->tile_map, index);
Fifo *op_queue = *queue_pointer;
if (!op_queue) {
return NULL;
}
op = fifo_pop(op_queue);
if (!op) {
// Queue empty
fifo_free(op_queue, operation_delete_func);
*queue_pointer = NULL;
return NULL;
} else {
assert(op != NULL);
return op;
}
}
OperationDataDrawDab *
operation_queue_peek_last(OperationQueue *self, TileIndex index) {
if (!tile_map_contains(self->tile_map, index)) {
return NULL;
}
Fifo *op_queue = (Fifo *)*tile_map_get(self->tile_map, index);
return (!op_queue) ? NULL : (OperationDataDrawDab *)fifo_peek_last(op_queue);
}