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22 * @file testbed/testbed_api_operations.c
23 * @brief functions to manage operation queues
24 * @author Christian Grothoff
25 * @author Sree Harsha Totakura
29 #include "testbed_api_operations.h"
33 * An entry in the operation queue
38 * The next DLL pointer
40 struct QueueEntry *next;
43 * The prev DLL pointer
45 struct QueueEntry *prev;
48 * The operation this entry holds
50 struct GNUNET_TESTBED_Operation *op;
53 * How many units of resources does the operation need
60 * Queue of operations where we can only support a certain
61 * number of concurrent operations of a particular type.
66 * DLL head for the wait queue. Operations which are waiting for this
67 * operation queue are put here
69 struct QueueEntry *wq_head;
72 * DLL tail for the wait queue.
74 struct QueueEntry *wq_tail;
77 * DLL head for the ready queue. Operations which are in this operation queue
78 * and are in ready state are put here
80 struct QueueEntry *rq_head;
83 * DLL tail for the ready queue
85 struct QueueEntry *rq_tail;
88 * DLL head for the active queue. Operations which are in this operation
89 * queue and are currently active are put here
91 struct QueueEntry *aq_head;
94 * DLL tail for the active queue.
96 struct QueueEntry *aq_tail;
99 * DLL head for the inactive queue. Operations which are inactive and can be
100 * evicted if the queues it holds are maxed out and another operation begins
103 struct QueueEntry *nq_head;
106 * DLL tail for the inactive queue.
108 struct QueueEntry *nq_tail;
111 * Number of operations that are currently active in this queue.
116 * Max number of operations which can be active at any time in this queue
118 unsigned int max_active;
129 * The operation is just created and is in initial state
134 * The operation is currently waiting for resources
139 * The operation is ready to be started
144 * The operation has started and is active
149 * The operation is inactive. It still holds resources on the operation
150 * queues. However, this operation will be evicted when another operation
151 * requires resources from the maxed out queues this operation is holding
159 * An entry in the ready queue (implemented as DLL)
161 struct ReadyQueueEntry
166 struct ReadyQueueEntry *next;
171 struct ReadyQueueEntry *prev;
174 * The operation associated with this entry
176 struct GNUNET_TESTBED_Operation *op;
181 * Opaque handle to an abstract operation to be executed by the testing framework.
183 struct GNUNET_TESTBED_Operation
186 * Function to call when we have the resources to begin the operation.
188 OperationStart start;
191 * Function to call to clean up after the operation (which may or may
192 * not have been started yet).
194 OperationRelease release;
197 * Closure for callbacks.
202 * Array of operation queues this Operation belongs to.
204 struct OperationQueue **queues;
207 * Array of operation queue entries corresponding to this operation in
208 * operation queues for this operation
210 struct QueueEntry **qentries;
213 * Array of number of resources an operation need from each queue. The numbers
214 * in this array should correspond to the queues array
219 * Entry corresponding to this operation in ready queue. Will be NULL if the
220 * operation is not marked as READY
222 struct ReadyQueueEntry *rq_entry;
225 * Number of queues in the operation queues array
227 unsigned int nqueues;
230 * The state of the operation
232 enum OperationState state;
237 * DLL head for the ready queue
239 struct ReadyQueueEntry *rq_head;
242 * DLL tail for the ready queue
244 struct ReadyQueueEntry *rq_tail;
247 * The id of the task to process the ready queue
249 GNUNET_SCHEDULER_TaskIdentifier process_rq_task_id;
253 * Removes a queue entry of an operation from one of the operation queues' lists
254 * depending on the state of the operation
256 * @param op the operation whose entry has to be removed
257 * @param index the index of the entry in the operation's array of queue entries
260 remove_queue_entry (struct GNUNET_TESTBED_Operation *op, unsigned int index)
262 struct OperationQueue *opq;
263 struct QueueEntry *entry;
265 opq = op->queues[index];
266 entry = op->qentries[index];
272 case OP_STATE_WAITING:
273 GNUNET_CONTAINER_DLL_remove (opq->wq_head, opq->wq_tail, entry);
276 GNUNET_CONTAINER_DLL_remove (opq->rq_head, opq->rq_tail, entry);
278 case OP_STATE_ACTIVE:
279 GNUNET_CONTAINER_DLL_remove (opq->aq_head, opq->aq_tail, entry);
281 case OP_STATE_INACTIVE:
282 GNUNET_CONTAINER_DLL_remove (opq->nq_head, opq->nq_tail, entry);
289 * Changes the state of the operation while moving its associated queue entries
290 * in the operation's operation queues
292 * @param op the operation whose state has to be changed
293 * @param state the state the operation should have. It cannot be OP_STATE_INIT
296 change_state (struct GNUNET_TESTBED_Operation *op, enum OperationState state)
298 struct QueueEntry *entry;
299 struct OperationQueue *opq;
303 GNUNET_assert (OP_STATE_INIT != state);
304 GNUNET_assert (NULL != op->queues);
305 GNUNET_assert (NULL != op->nres);
306 GNUNET_assert ((OP_STATE_INIT == op->state) || (NULL != op->qentries));
307 GNUNET_assert (op->state != state);
308 for (cnt = 0; cnt < op->nqueues; cnt++)
310 if (OP_STATE_INIT == op->state)
312 entry = GNUNET_malloc (sizeof (struct QueueEntry));
314 entry->nres = op->nres[cnt];
316 GNUNET_array_append (op->qentries, s, entry);
320 entry = op->qentries[cnt];
321 remove_queue_entry (op, cnt);
323 opq = op->queues[cnt];
329 case OP_STATE_WAITING:
330 GNUNET_CONTAINER_DLL_insert_tail (opq->wq_head, opq->wq_tail, entry);
333 GNUNET_CONTAINER_DLL_insert_tail (opq->rq_head, opq->rq_tail, entry);
335 case OP_STATE_ACTIVE:
336 GNUNET_CONTAINER_DLL_insert_tail (opq->aq_head, opq->aq_tail, entry);
338 case OP_STATE_INACTIVE:
339 GNUNET_CONTAINER_DLL_insert_tail (opq->nq_head, opq->nq_tail, entry);
348 * Removes an operation from the ready queue. Also stops the 'process_rq_task'
349 * if the given operation is the last one in the queue.
351 * @param op the operation to be removed
354 rq_remove (struct GNUNET_TESTBED_Operation *op)
356 GNUNET_assert (NULL != op->rq_entry);
357 GNUNET_CONTAINER_DLL_remove (rq_head, rq_tail, op->rq_entry);
358 GNUNET_free (op->rq_entry);
360 if ( (NULL == rq_head) && (GNUNET_SCHEDULER_NO_TASK != process_rq_task_id) )
362 GNUNET_SCHEDULER_cancel (process_rq_task_id);
363 process_rq_task_id = GNUNET_SCHEDULER_NO_TASK;
369 * Processes the ready queue by calling the operation start callback of the
370 * operation at the head. The operation is then removed from the queue. The
371 * task is scheduled to run again immediately until no more operations are in
375 * @param tc scheduler task context. Not used.
378 process_rq_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
380 struct GNUNET_TESTBED_Operation *op;
382 process_rq_task_id = GNUNET_SCHEDULER_NO_TASK;
383 GNUNET_assert (NULL != rq_head);
384 GNUNET_assert (NULL != (op = rq_head->op));
387 process_rq_task_id = GNUNET_SCHEDULER_add_now (&process_rq_task, NULL);
388 change_state (op, OP_STATE_ACTIVE);
389 if (NULL != op->start)
390 op->start (op->cb_cls);
395 * Adds the operation to the ready queue and starts the 'process_rq_task'
397 * @param op the operation to be queued
400 rq_add (struct GNUNET_TESTBED_Operation *op)
402 struct ReadyQueueEntry *rq_entry;
404 GNUNET_assert (NULL == op->rq_entry);
405 rq_entry = GNUNET_malloc (sizeof (struct ReadyQueueEntry));
407 GNUNET_CONTAINER_DLL_insert_tail (rq_head, rq_tail, rq_entry);
408 op->rq_entry = rq_entry;
409 if (GNUNET_SCHEDULER_NO_TASK == process_rq_task_id)
410 process_rq_task_id = GNUNET_SCHEDULER_add_now (&process_rq_task, NULL);
415 * Checks if the given operation queue is empty or not
417 * @param opq the operation queue
418 * @return GNUNET_YES if the given operation queue has no operations; GNUNET_NO
422 is_queue_empty (struct OperationQueue *opq)
424 if ( (NULL != opq->wq_head)
425 || (NULL != opq->rq_head)
426 || (NULL != opq->aq_head)
427 || (NULL != opq->nq_head) )
434 * Checks if the given operation queue has enough resources to provide for the
435 * operation of the given queue entry. It also checks if any inactive
436 * operations are to be released in order to accommodate the needed resources
437 * and returns them as an array.
439 * @param opq the operation queue to check for resource accommodation
440 * @param entry the operation queue entry whose operation's resources are to be
442 * @param ops_ pointer to return the array of operations which are to be released
443 * in order to accommodate the new operation. Can be NULL
444 * @param n_ops_ the number of operations in ops_
445 * @return GNUNET_YES if the given entry's operation can be accommodated in this
446 * queue. GNUNET_NO if it cannot be accommodated; ops_ and n_ops_ will
447 * be set to NULL and 0 respectively.
450 decide_capacity (struct OperationQueue *opq,
451 struct QueueEntry *entry,
452 struct GNUNET_TESTBED_Operation ***ops_,
453 unsigned int *n_ops_)
455 struct QueueEntry **evict_entries;
456 struct GNUNET_TESTBED_Operation **ops;
457 struct GNUNET_TESTBED_Operation *op;
459 unsigned int n_evict_entries;
464 GNUNET_assert (NULL != (op = entry->op));
465 GNUNET_assert (0 < (need = entry->nres));
468 evict_entries = NULL;
471 if (opq->active > opq->max_active)
473 need += opq->active - opq->max_active;
477 if ((opq->active + need) <= opq->max_active)
479 deficit = need - (opq->max_active - opq->active);
480 for (entry = opq->nq_head;
481 (0 < deficit) && (NULL != entry);
484 GNUNET_array_append (evict_entries, n_evict_entries, entry);
485 deficit -= entry->nres;
492 for (n_ops = 0; n_ops < n_evict_entries;)
494 op = evict_entries[n_ops]->op;
495 GNUNET_array_append (ops, n_ops, op); /* increments n-ops */
499 GNUNET_free_non_null (evict_entries);
500 if (NULL != ops_) *ops_ = ops;
501 if (NULL != n_ops_) *n_ops_ = n_ops;
507 * Merges an array of operations into another, eliminating duplicates. No
508 * ordering is guaranteed.
510 * @param old the array into which the merging is done.
511 * @param n_old the number of operations in old array
512 * @param new the array from which operations are to be merged
513 * @param n_new the number of operations in new array
516 merge_ops (struct GNUNET_TESTBED_Operation ***old,
518 struct GNUNET_TESTBED_Operation **new,
521 struct GNUNET_TESTBED_Operation **cur;
526 GNUNET_assert (NULL != old);
529 for (i = 0; i < n_new; i++)
531 for (j = 0; j < *n_old; j++)
533 if (new[i] == cur[j])
538 GNUNET_array_append (cur, n_cur, new[j]);
547 * Checks for the readiness of an operation and schedules a operation start task
549 * @param op the operation
550 * @param GNUNET_NO if the given operation cannot be made active; GNUNET_YES if
551 * it can be activated (has enough resources) and is kept in ready
555 check_readiness (struct GNUNET_TESTBED_Operation *op)
557 struct GNUNET_TESTBED_Operation **evict_ops;
558 struct GNUNET_TESTBED_Operation **ops;
560 unsigned int n_evict_ops;
563 GNUNET_assert (NULL == op->rq_entry);
564 GNUNET_assert (OP_STATE_WAITING == op->state);
567 for (i = 0; i < op->nqueues; i++)
571 if (GNUNET_NO == decide_capacity (op->queues[i], op->qentries[i],
574 GNUNET_free_non_null (evict_ops);
579 merge_ops (&evict_ops, &n_evict_ops, ops, n_ops);
582 if (NULL != evict_ops)
584 for (i = 0; i < n_evict_ops; i++)
585 GNUNET_TESTBED_operation_release_ (evict_ops[i]);
586 GNUNET_free (evict_ops);
588 /* Evicting the operations should schedule this operation */
589 GNUNET_assert (OP_STATE_READY == op->state);
592 for (i = 0; i < op->nqueues; i++)
593 op->queues[i]->active += op->nres[i];
594 change_state (op, OP_STATE_READY);
601 * Defers a ready to be executed operation back to waiting
603 * @param op the operation to defer
606 defer (struct GNUNET_TESTBED_Operation *op)
610 GNUNET_assert (OP_STATE_READY == op->state);
612 for (i = 0; i < op->nqueues; i++)
613 op->queues[i]->active--;
614 change_state (op, OP_STATE_WAITING);
619 * Create an 'operation' to be performed.
621 * @param cls closure for the callbacks
622 * @param start function to call to start the operation
623 * @param release function to call to close down the operation
624 * @return handle to the operation
626 struct GNUNET_TESTBED_Operation *
627 GNUNET_TESTBED_operation_create_ (void *cls, OperationStart start,
628 OperationRelease release)
630 struct GNUNET_TESTBED_Operation *op;
632 op = GNUNET_malloc (sizeof (struct GNUNET_TESTBED_Operation));
634 op->state = OP_STATE_INIT;
635 op->release = release;
642 * Create an operation queue.
644 * @param max_active maximum number of operations in this
645 * queue that can be active in parallel at the same time
646 * @return handle to the queue
648 struct OperationQueue *
649 GNUNET_TESTBED_operation_queue_create_ (unsigned int max_active)
651 struct OperationQueue *queue;
653 queue = GNUNET_malloc (sizeof (struct OperationQueue));
654 queue->max_active = max_active;
660 * Destroy an operation queue. The queue MUST be empty
663 * @param queue queue to destroy
666 GNUNET_TESTBED_operation_queue_destroy_ (struct OperationQueue *queue)
668 GNUNET_break (GNUNET_YES == is_queue_empty (queue));
674 * Destroys the operation queue if it is empty. If not empty return GNUNET_NO.
676 * @param queue the queue to destroy if empty
677 * @return GNUNET_YES if the queue is destroyed. GNUNET_NO if not (because it
681 GNUNET_TESTBED_operation_queue_destroy_empty_ (struct OperationQueue *queue)
683 if (GNUNET_NO == is_queue_empty (queue))
685 GNUNET_TESTBED_operation_queue_destroy_ (queue);
691 * Rechecks if any of the operations in the given operation queue's waiting list
694 * @param opq the operation queue
697 recheck_waiting (struct OperationQueue *opq)
699 struct QueueEntry *entry;
700 struct QueueEntry *entry2;
702 entry = opq->wq_head;
703 while (NULL != entry)
705 entry2 = entry->next;
706 if (GNUNET_NO == check_readiness (entry->op))
714 * Function to reset the maximum number of operations in the given queue. If
715 * max_active is lesser than the number of currently active operations, the
716 * active operations are not stopped immediately.
718 * @param queue the operation queue which has to be modified
719 * @param max_active the new maximum number of active operations
722 GNUNET_TESTBED_operation_queue_reset_max_active_ (struct OperationQueue *queue,
723 unsigned int max_active)
725 struct QueueEntry *entry;
727 queue->max_active = max_active;
728 while ( (queue->active > queue->max_active)
729 && (NULL != (entry = queue->rq_head)) )
731 recheck_waiting (queue);
736 * Add an operation to a queue. An operation can be in multiple queues at
737 * once. Once the operation is inserted into all the queues
738 * GNUNET_TESTBED_operation_begin_wait_() has to be called to actually start
739 * waiting for the operation to become active.
741 * @param queue queue to add the operation to
742 * @param op operation to add to the queue
743 * @param nres the number of units of the resources of queue needed by the
744 * operation. Should be greater than 0.
747 GNUNET_TESTBED_operation_queue_insert2_ (struct OperationQueue *queue,
748 struct GNUNET_TESTBED_Operation *op,
753 GNUNET_assert (0 < nres);
755 GNUNET_array_append (op->queues, op->nqueues, queue);
756 GNUNET_array_append (op->nres, qsize, nres);
757 GNUNET_assert (qsize == op->nqueues);
762 * Add an operation to a queue. An operation can be in multiple queues at
763 * once. Once the operation is inserted into all the queues
764 * GNUNET_TESTBED_operation_begin_wait_() has to be called to actually start
765 * waiting for the operation to become active. The operation is assumed to take
766 * 1 queue resource. Use GNUNET_TESTBED_operation_queue_insert2_() if it
767 * requires more than 1
769 * @param queue queue to add the operation to
770 * @param op operation to add to the queue
773 GNUNET_TESTBED_operation_queue_insert_ (struct OperationQueue *queue,
774 struct GNUNET_TESTBED_Operation *op)
776 return GNUNET_TESTBED_operation_queue_insert2_ (queue, op, 1);
781 * Marks the given operation as waiting on the queues. Once all queues permit
782 * the operation to become active, the operation will be activated. The actual
783 * activation will occur in a separate task (thus allowing multiple queue
784 * insertions to be made without having the first one instantly trigger the
785 * operation if the first queue has sufficient resources).
787 * @param op the operation to marks as waiting
790 GNUNET_TESTBED_operation_begin_wait_ (struct GNUNET_TESTBED_Operation *op)
792 GNUNET_assert (NULL == op->rq_entry);
793 change_state (op, OP_STATE_WAITING);
794 (void) check_readiness (op);
799 * Marks an active operation as inactive - the operation will be kept in a
800 * ready-to-be-released state and continues to hold resources until another
801 * operation contents for them.
803 * @param op the operation to be marked as inactive. The operation start
804 * callback should have been called before for this operation to mark
808 GNUNET_TESTBED_operation_inactivate_ (struct GNUNET_TESTBED_Operation *op)
810 struct OperationQueue **queues;
812 unsigned int nqueues;
815 GNUNET_assert (OP_STATE_ACTIVE == op->state);
816 change_state (op, OP_STATE_INACTIVE);
817 nqueues = op->nqueues;
818 ms = sizeof (struct OperationQueue *) * nqueues;
819 queues = GNUNET_malloc (ms);
820 /* Cloning is needed as the operation be released by waiting operations and
821 hence its nqueues memory ptr will be freed */
822 GNUNET_assert (NULL != (queues = memcpy (queues, op->queues, ms)));
823 for (i = 0; i < nqueues; i++)
824 recheck_waiting (queues[i]);
825 GNUNET_free (queues);
830 * Marks and inactive operation as active. This fuction should be called to
831 * ensure that the oprelease callback will not be called until it is either
832 * marked as inactive or released.
834 * @param op the operation to be marked as active
837 GNUNET_TESTBED_operation_activate_ (struct GNUNET_TESTBED_Operation *op)
840 GNUNET_assert (OP_STATE_INACTIVE == op->state);
841 change_state (op, OP_STATE_ACTIVE);
846 * An operation is 'done' (was cancelled or finished); remove
847 * it from the queues and release associated resources.
849 * @param op operation that finished
852 GNUNET_TESTBED_operation_release_ (struct GNUNET_TESTBED_Operation *op)
854 struct QueueEntry *entry;
855 struct OperationQueue *opq;
858 if (OP_STATE_INIT == op->state)
863 if (OP_STATE_READY == op->state)
865 if (OP_STATE_INACTIVE == op->state) /* Activate the operation if inactive */
866 GNUNET_TESTBED_operation_activate_ (op);
867 GNUNET_assert (NULL != op->queues);
868 GNUNET_assert (NULL != op->qentries);
869 for (i = 0; i < op->nqueues; i++)
871 entry = op->qentries[i];
872 remove_queue_entry (op, i);
877 case OP_STATE_INACTIVE:
880 case OP_STATE_WAITING:
883 case OP_STATE_ACTIVE:
884 GNUNET_assert (0 != opq->active);
885 GNUNET_assert (opq->active >= entry->nres);
886 opq->active -= entry->nres;
887 recheck_waiting (opq);
892 GNUNET_free_non_null (op->qentries);
893 GNUNET_free (op->queues);
894 GNUNET_free (op->nres);
895 if (NULL != op->release)
896 op->release (op->cb_cls);
901 /* end of testbed_api_operations.c */