2 This file is part of GNUnet
3 (C) 2009, 2011 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 2, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file util/scheduler.c
23 * @brief schedule computations using continuation passing style
24 * @author Christian Grothoff
27 #include "gnunet_common.h"
28 #include "gnunet_os_lib.h"
29 #include "gnunet_scheduler_lib.h"
30 #include "gnunet_signal_lib.h"
31 #include "gnunet_time_lib.h"
38 * Use lsof to generate file descriptor reports on select error?
39 * (turn off for stable releases).
41 #define USE_LSOF GNUNET_NO
44 * Obtain trace information for all scheduler calls that schedule tasks.
46 #define EXECINFO GNUNET_NO
49 * Check each file descriptor before adding
51 #define DEBUG_FDS GNUNET_EXTRA_LOGGING
54 * Depth of the traces collected via EXECINFO.
56 #define MAX_TRACE_DEPTH 50
59 #define DEBUG_TASKS GNUNET_EXTRA_LOGGING
62 * Should we figure out which tasks are delayed for a while
63 * before they are run? (Consider using in combination with EXECINFO).
65 #define PROFILE_DELAYS GNUNET_NO
68 * Task that were in the queue for longer than this are reported if
69 * PROFILE_DELAYS is active.
71 #define DELAY_THRESHOLD GNUNET_TIME_UNIT_SECONDS
74 * Linked list of pending tasks.
79 * This is a linked list.
84 * Function to run when ready.
86 GNUNET_SCHEDULER_Task callback;
89 * Closure for the callback.
94 * Set of file descriptors this task is waiting
95 * for for reading. Once ready, this is updated
96 * to reflect the set of file descriptors ready
99 struct GNUNET_NETWORK_FDSet *read_set;
102 * Set of file descriptors this task is waiting for for writing.
103 * Once ready, this is updated to reflect the set of file
104 * descriptors ready for operation.
106 struct GNUNET_NETWORK_FDSet *write_set;
109 * Unique task identifier.
111 GNUNET_SCHEDULER_TaskIdentifier id;
114 * Identifier of a prerequisite task.
116 GNUNET_SCHEDULER_TaskIdentifier prereq_id;
119 * Absolute timeout value for the task, or
120 * GNUNET_TIME_UNIT_FOREVER_ABS for "no timeout".
122 struct GNUNET_TIME_Absolute timeout;
126 * When was the task scheduled?
128 struct GNUNET_TIME_Absolute start_time;
132 * Why is the task ready? Set after task is added to ready queue.
133 * Initially set to zero. All reasons that have already been
134 * satisfied (i.e. read or write ready) will be set over time.
136 enum GNUNET_SCHEDULER_Reason reason;
141 enum GNUNET_SCHEDULER_Priority priority;
144 * Set if we only wait for reading from a single FD, otherwise -1.
149 * Set if we only wait for writing to a single FD, otherwise -1.
154 * Should the existence of this task in the queue be counted as
155 * reason to not shutdown the scheduler?
161 * Array of strings which make up a backtrace from the point when this
162 * task was scheduled (essentially, who scheduled the task?)
164 char **backtrace_strings;
167 * Size of the backtrace_strings array
169 int num_backtrace_strings;
177 * List of tasks waiting for an event.
179 static struct Task *pending;
182 * List of tasks waiting ONLY for a timeout event.
183 * Sorted by timeout (earliest first). Used so that
184 * we do not traverse the list of these tasks when
185 * building select sets (we just look at the head
186 * to determine the respective timeout ONCE).
188 static struct Task *pending_timeout;
191 * Last inserted task waiting ONLY for a timeout event.
192 * Used to (heuristically) speed up insertion.
194 static struct Task *pending_timeout_last;
197 * ID of the task that is running right now.
199 static struct Task *active_task;
202 * List of tasks ready to run right now,
203 * grouped by importance.
205 static struct Task *ready[GNUNET_SCHEDULER_PRIORITY_COUNT];
208 * Identity of the last task queued. Incremented for each task to
209 * generate a unique task ID (it is virtually impossible to start
210 * more than 2^64 tasks during the lifetime of a process).
212 static GNUNET_SCHEDULER_TaskIdentifier last_id;
215 * Highest number so that all tasks with smaller identifiers
216 * have already completed. Also the lowest number of a task
217 * still waiting to be executed.
219 static GNUNET_SCHEDULER_TaskIdentifier lowest_pending_id;
222 * Number of tasks on the ready list.
224 static unsigned int ready_count;
227 * How many tasks have we run so far?
229 static unsigned long long tasks_run;
232 * Priority of the task running right now. Only
233 * valid while a task is running.
235 static enum GNUNET_SCHEDULER_Priority current_priority;
238 * Priority of the highest task added in the current select
241 static enum GNUNET_SCHEDULER_Priority max_priority_added;
244 * Value of the 'lifeness' flag for the current task.
246 static int current_lifeness;
249 * Function to use as a select() in the scheduler.
250 * If NULL, we use GNUNET_NETWORK_socket_select ().
252 static GNUNET_SCHEDULER_select scheduler_select;
255 * Closure for 'scheduler_select'.
257 static void *scheduler_select_cls;
260 * Sets the select function to use in the scheduler (scheduler_select).
262 * @param new_select new select function to use
263 * @param new_select_cls closure for 'new_select'
264 * @return previously used select function, NULL for default
267 GNUNET_SCHEDULER_set_select (GNUNET_SCHEDULER_select new_select,
268 void *new_select_cls)
270 scheduler_select = new_select;
271 scheduler_select_cls = new_select_cls;
276 * Check that the given priority is legal (and return it).
278 * @param p priority value to check
279 * @return p on success, 0 on error
281 static enum GNUNET_SCHEDULER_Priority
282 check_priority (enum GNUNET_SCHEDULER_Priority p)
284 if ((p >= 0) && (p < GNUNET_SCHEDULER_PRIORITY_COUNT))
287 return 0; /* make compiler happy */
292 * Is a task with this identifier still pending? Also updates
293 * "lowest_pending_id" as a side-effect (for faster checks in the
294 * future), but only if the return value is "GNUNET_NO" (and
295 * the "lowest_pending_id" check failed).
297 * @param id which task are we checking for
298 * @return GNUNET_YES if so, GNUNET_NO if not
301 is_pending (GNUNET_SCHEDULER_TaskIdentifier id)
304 enum GNUNET_SCHEDULER_Priority p;
305 GNUNET_SCHEDULER_TaskIdentifier min;
307 if (id < lowest_pending_id)
309 min = -1; /* maximum value */
319 pos = pending_timeout;
328 for (p = 0; p < GNUNET_SCHEDULER_PRIORITY_COUNT; p++)
340 lowest_pending_id = min;
346 * Update all sets and timeout for select.
348 * @param rs read-set, set to all FDs we would like to read (updated)
349 * @param ws write-set, set to all FDs we would like to write (updated)
350 * @param timeout next timeout (updated)
353 update_sets (struct GNUNET_NETWORK_FDSet *rs, struct GNUNET_NETWORK_FDSet *ws,
354 struct GNUNET_TIME_Relative *timeout)
357 struct GNUNET_TIME_Absolute now;
358 struct GNUNET_TIME_Relative to;
360 now = GNUNET_TIME_absolute_get ();
361 pos = pending_timeout;
364 to = GNUNET_TIME_absolute_get_difference (now, pos->timeout);
365 if (timeout->rel_value > to.rel_value)
367 if (pos->reason != 0)
368 *timeout = GNUNET_TIME_UNIT_ZERO;
373 if ((pos->prereq_id != GNUNET_SCHEDULER_NO_TASK) &&
374 (GNUNET_YES == is_pending (pos->prereq_id)))
379 if (pos->timeout.abs_value != GNUNET_TIME_UNIT_FOREVER_ABS.abs_value)
381 to = GNUNET_TIME_absolute_get_difference (now, pos->timeout);
382 if (timeout->rel_value > to.rel_value)
385 if (pos->read_fd != -1)
386 GNUNET_NETWORK_fdset_set_native (rs, pos->read_fd);
387 if (pos->write_fd != -1)
388 GNUNET_NETWORK_fdset_set_native (ws, pos->write_fd);
389 if (pos->read_set != NULL)
390 GNUNET_NETWORK_fdset_add (rs, pos->read_set);
391 if (pos->write_set != NULL)
392 GNUNET_NETWORK_fdset_add (ws, pos->write_set);
393 if (pos->reason != 0)
394 *timeout = GNUNET_TIME_UNIT_ZERO;
401 * Check if the ready set overlaps with the set we want to have ready.
402 * If so, update the want set (set all FDs that are ready). If not,
405 * @param ready set that is ready
406 * @param want set that we want to be ready
407 * @return GNUNET_YES if there was some overlap
410 set_overlaps (const struct GNUNET_NETWORK_FDSet *ready,
411 struct GNUNET_NETWORK_FDSet *want)
413 if ((NULL == want) || (NULL == ready))
415 if (GNUNET_NETWORK_fdset_overlap (ready, want))
417 /* copy all over (yes, there maybe unrelated bits,
418 * but this should not hurt well-written clients) */
419 GNUNET_NETWORK_fdset_copy (want, ready);
427 * Check if the given task is eligible to run now.
428 * Also set the reason why it is eligible.
430 * @param task task to check if it is ready
431 * @param now the current time
432 * @param rs set of FDs ready for reading
433 * @param ws set of FDs ready for writing
434 * @return GNUNET_YES if we can run it, GNUNET_NO if not.
437 is_ready (struct Task *task, struct GNUNET_TIME_Absolute now,
438 const struct GNUNET_NETWORK_FDSet *rs,
439 const struct GNUNET_NETWORK_FDSet *ws)
441 enum GNUNET_SCHEDULER_Reason reason;
443 reason = task->reason;
444 if (now.abs_value >= task->timeout.abs_value)
445 reason |= GNUNET_SCHEDULER_REASON_TIMEOUT;
446 if ((0 == (reason & GNUNET_SCHEDULER_REASON_READ_READY)) &&
447 (((task->read_fd != -1) &&
448 (GNUNET_YES == GNUNET_NETWORK_fdset_test_native (rs, task->read_fd)))
449 || (set_overlaps (rs, task->read_set))))
450 reason |= GNUNET_SCHEDULER_REASON_READ_READY;
451 if ((0 == (reason & GNUNET_SCHEDULER_REASON_WRITE_READY)) &&
452 (((task->write_fd != -1) &&
453 (GNUNET_YES == GNUNET_NETWORK_fdset_test_native (ws, task->write_fd)))
454 || (set_overlaps (ws, task->write_set))))
455 reason |= GNUNET_SCHEDULER_REASON_WRITE_READY;
457 return GNUNET_NO; /* not ready */
458 if (task->prereq_id != GNUNET_SCHEDULER_NO_TASK)
460 if (GNUNET_YES == is_pending (task->prereq_id))
462 task->reason = reason;
463 return GNUNET_NO; /* prereq waiting */
465 reason |= GNUNET_SCHEDULER_REASON_PREREQ_DONE;
467 task->reason = reason;
473 * Put a task that is ready for execution into the ready queue.
475 * @param task task ready for execution
478 queue_ready_task (struct Task *task)
480 enum GNUNET_SCHEDULER_Priority p = task->priority;
482 if (0 != (task->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
483 p = GNUNET_SCHEDULER_PRIORITY_SHUTDOWN;
484 task->next = ready[check_priority (p)];
485 ready[check_priority (p)] = task;
491 * Check which tasks are ready and move them
492 * to the respective ready queue.
494 * @param rs FDs ready for reading
495 * @param ws FDs ready for writing
498 check_ready (const struct GNUNET_NETWORK_FDSet *rs,
499 const struct GNUNET_NETWORK_FDSet *ws)
504 struct GNUNET_TIME_Absolute now;
506 now = GNUNET_TIME_absolute_get ();
508 pos = pending_timeout;
512 if (now.abs_value >= pos->timeout.abs_value)
513 pos->reason |= GNUNET_SCHEDULER_REASON_TIMEOUT;
514 if (0 == pos->reason)
516 pending_timeout = next;
517 if (pending_timeout_last == pos)
518 pending_timeout_last = NULL;
519 queue_ready_task (pos);
526 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
528 "Checking readiness of task: %llu / %p\n", pos->id,
532 if (GNUNET_YES == is_ready (pos, now, rs, ws))
538 queue_ready_task (pos);
549 * Request the shutdown of a scheduler. Marks all currently
550 * pending tasks as ready because of shutdown. This will
551 * cause all tasks to run (as soon as possible, respecting
552 * priorities and prerequisite tasks). Note that tasks
553 * scheduled AFTER this call may still be delayed arbitrarily.
556 GNUNET_SCHEDULER_shutdown ()
561 pos = pending_timeout;
564 pos->reason |= GNUNET_SCHEDULER_REASON_SHUTDOWN;
565 /* we don't move the task into the ready queue yet; check_ready
566 * will do that later, possibly adding additional
567 * readiness-factors */
573 pos->reason |= GNUNET_SCHEDULER_REASON_SHUTDOWN;
574 /* we don't move the task into the ready queue yet; check_ready
575 * will do that later, possibly adding additional
576 * readiness-factors */
579 for (i = 0; i < GNUNET_SCHEDULER_PRIORITY_COUNT; i++)
584 pos->reason |= GNUNET_SCHEDULER_REASON_SHUTDOWN;
585 /* we don't move the task into the ready queue yet; check_ready
586 * will do that later, possibly adding additional
587 * readiness-factors */
595 * Destroy a task (release associated resources)
597 * @param t task to destroy
600 destroy_task (struct Task *t)
602 if (NULL != t->read_set)
603 GNUNET_NETWORK_fdset_destroy (t->read_set);
604 if (NULL != t->write_set)
605 GNUNET_NETWORK_fdset_destroy (t->write_set);
607 GNUNET_free (t->backtrace_strings);
614 * Run at least one task in the highest-priority queue that is not
615 * empty. Keep running tasks until we are either no longer running
616 * "URGENT" tasks or until we have at least one "pending" task (which
617 * may become ready, hence we should select on it). Naturally, if
618 * there are no more ready tasks, we also return.
620 * @param rs FDs ready for reading
621 * @param ws FDs ready for writing
624 run_ready (struct GNUNET_NETWORK_FDSet *rs, struct GNUNET_NETWORK_FDSet *ws)
626 enum GNUNET_SCHEDULER_Priority p;
628 struct GNUNET_SCHEDULER_TaskContext tc;
630 max_priority_added = GNUNET_SCHEDULER_PRIORITY_KEEP;
633 if (ready_count == 0)
635 GNUNET_assert (ready[GNUNET_SCHEDULER_PRIORITY_KEEP] == NULL);
636 /* yes, p>0 is correct, 0 is "KEEP" which should
637 * always be an empty queue (see assertion)! */
638 for (p = GNUNET_SCHEDULER_PRIORITY_COUNT - 1; p > 0; p--)
644 GNUNET_assert (pos != NULL); /* ready_count wrong? */
645 ready[p] = pos->next;
647 if (current_priority != pos->priority)
649 current_priority = pos->priority;
650 (void) GNUNET_OS_set_process_priority (GNUNET_OS_process_current (),
653 current_lifeness = pos->lifeness;
656 if (GNUNET_TIME_absolute_get_duration (pos->start_time).rel_value >
657 DELAY_THRESHOLD.rel_value)
659 GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
661 "Task %llu took %llums to be scheduled\n", pos->id,
663 GNUNET_TIME_absolute_get_duration
664 (pos->start_time).rel_value);
667 tc.reason = pos->reason;
668 tc.read_ready = (pos->read_set == NULL) ? rs : pos->read_set;
669 if ((pos->read_fd != -1) &&
670 (0 != (pos->reason & GNUNET_SCHEDULER_REASON_READ_READY)))
671 GNUNET_NETWORK_fdset_set_native (rs, pos->read_fd);
672 tc.write_ready = (pos->write_set == NULL) ? ws : pos->write_set;
673 if ((pos->write_fd != -1) &&
674 (0 != (pos->reason & GNUNET_SCHEDULER_REASON_WRITE_READY)))
675 GNUNET_NETWORK_fdset_set_native (ws, pos->write_fd);
676 if (((tc.reason & GNUNET_SCHEDULER_REASON_WRITE_READY) != 0) &&
677 (pos->write_fd != -1) &&
678 (!GNUNET_NETWORK_fdset_test_native (ws, pos->write_fd)))
679 abort (); // added to ready in previous select loop!
681 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
683 "Running task: %llu / %p\n", pos->id,
686 pos->callback (pos->callback_cls, &tc);
690 for (i = 0; i < pos->num_backtrace_strings; i++)
691 GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
693 "Task %llu trace %d: %s\n", pos->id,
694 i, pos->backtrace_strings[i]);
700 while ((pending == NULL) || (p >= max_priority_added));
704 * Pipe used to communicate shutdown via signal.
706 static struct GNUNET_DISK_PipeHandle *shutdown_pipe_handle;
709 * Signal handler called for SIGPIPE.
719 * Signal handler called for signals that should cause us to shutdown.
722 sighandler_shutdown ()
725 int old_errno = errno; /* backup errno */
727 GNUNET_DISK_file_write (GNUNET_DISK_pipe_handle
728 (shutdown_pipe_handle, GNUNET_DISK_PIPE_END_WRITE),
735 * Check if the system is still life. Trigger shutdown if we
736 * have tasks, but none of them give us lifeness.
738 * @return GNUNET_OK to continue the main loop,
748 for (t = pending; NULL != t; t = t->next)
749 if (t->lifeness == GNUNET_YES)
751 for (t = pending_timeout; NULL != t; t = t->next)
752 if (t->lifeness == GNUNET_YES)
754 if ((NULL != pending) || (NULL != pending_timeout))
756 GNUNET_SCHEDULER_shutdown ();
764 * Initialize and run scheduler. This function will return when all
765 * tasks have completed. On systems with signals, receiving a SIGTERM
766 * (and other similar signals) will cause "GNUNET_SCHEDULER_shutdown"
767 * to be run after the active task is complete. As a result, SIGTERM
768 * causes all active tasks to be scheduled with reason
769 * "GNUNET_SCHEDULER_REASON_SHUTDOWN". (However, tasks added
770 * afterwards will execute normally!). Note that any particular signal
771 * will only shut down one scheduler; applications should always only
772 * create a single scheduler.
774 * @param task task to run immediately
775 * @param task_cls closure of task
778 GNUNET_SCHEDULER_run (GNUNET_SCHEDULER_Task task, void *task_cls)
780 struct GNUNET_NETWORK_FDSet *rs;
781 struct GNUNET_NETWORK_FDSet *ws;
782 struct GNUNET_TIME_Relative timeout;
784 struct GNUNET_SIGNAL_Context *shc_int;
785 struct GNUNET_SIGNAL_Context *shc_term;
788 struct GNUNET_SIGNAL_Context *shc_quit;
789 struct GNUNET_SIGNAL_Context *shc_hup;
790 struct GNUNET_SIGNAL_Context *shc_pipe;
792 unsigned long long last_tr;
793 unsigned int busy_wait_warning;
794 const struct GNUNET_DISK_FileHandle *pr;
797 GNUNET_assert (active_task == NULL);
798 rs = GNUNET_NETWORK_fdset_create ();
799 ws = GNUNET_NETWORK_fdset_create ();
800 GNUNET_assert (shutdown_pipe_handle == NULL);
801 shutdown_pipe_handle = GNUNET_DISK_pipe (GNUNET_NO, GNUNET_NO, GNUNET_NO);
802 GNUNET_assert (shutdown_pipe_handle != NULL);
803 pr = GNUNET_DISK_pipe_handle (shutdown_pipe_handle,
804 GNUNET_DISK_PIPE_END_READ);
805 GNUNET_assert (pr != NULL);
806 shc_int = GNUNET_SIGNAL_handler_install (SIGINT, &sighandler_shutdown);
807 shc_term = GNUNET_SIGNAL_handler_install (SIGTERM, &sighandler_shutdown);
809 shc_pipe = GNUNET_SIGNAL_handler_install (SIGPIPE, &sighandler_pipe);
810 shc_quit = GNUNET_SIGNAL_handler_install (SIGQUIT, &sighandler_shutdown);
811 shc_hup = GNUNET_SIGNAL_handler_install (SIGHUP, &sighandler_shutdown);
813 current_priority = GNUNET_SCHEDULER_PRIORITY_DEFAULT;
814 current_lifeness = GNUNET_YES;
815 GNUNET_SCHEDULER_add_continuation (task, task_cls,
816 GNUNET_SCHEDULER_REASON_STARTUP);
817 #if ENABLE_WINDOWS_WORKAROUNDS
818 active_task = (void *) (long) -1; /* force passing of sanity check */
819 GNUNET_SCHEDULER_add_now_with_lifeness (GNUNET_NO,
820 &GNUNET_OS_install_parent_control_handler,
825 busy_wait_warning = 0;
826 while (GNUNET_OK == check_lifeness ())
828 GNUNET_NETWORK_fdset_zero (rs);
829 GNUNET_NETWORK_fdset_zero (ws);
830 timeout = GNUNET_TIME_UNIT_FOREVER_REL;
831 update_sets (rs, ws, &timeout);
832 GNUNET_NETWORK_fdset_handle_set (rs, pr);
835 /* no blocking, more work already ready! */
836 timeout = GNUNET_TIME_UNIT_ZERO;
838 if (NULL == scheduler_select)
839 ret = GNUNET_NETWORK_socket_select (rs, ws, NULL, timeout);
841 ret = scheduler_select (scheduler_select_cls, rs, ws, NULL, timeout);
842 if (ret == GNUNET_SYSERR)
847 GNUNET_log_from_strerror (GNUNET_ERROR_TYPE_ERROR, "util",
853 snprintf (lsof, sizeof (lsof), "lsof -p %d", getpid ());
856 if (0 != system (lsof))
857 GNUNET_log_from_strerror (GNUNET_ERROR_TYPE_WARNING, "util",
864 if ((ret == 0) && (timeout.rel_value == 0) && (busy_wait_warning > 16))
866 GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING,
867 "util", _("Looks like we're busy waiting...\n"));
868 sleep (1); /* mitigate */
870 check_ready (rs, ws);
872 if (GNUNET_NETWORK_fdset_handle_isset (rs, pr))
874 /* consume the signal */
875 GNUNET_DISK_file_read (pr, &c, sizeof (c));
876 /* mark all active tasks as ready due to shutdown */
877 GNUNET_SCHEDULER_shutdown ();
879 if (last_tr == tasks_run)
886 busy_wait_warning = 0;
889 GNUNET_SIGNAL_handler_uninstall (shc_int);
890 GNUNET_SIGNAL_handler_uninstall (shc_term);
892 GNUNET_SIGNAL_handler_uninstall (shc_pipe);
893 GNUNET_SIGNAL_handler_uninstall (shc_quit);
894 GNUNET_SIGNAL_handler_uninstall (shc_hup);
896 GNUNET_DISK_pipe_close (shutdown_pipe_handle);
897 shutdown_pipe_handle = NULL;
898 GNUNET_NETWORK_fdset_destroy (rs);
899 GNUNET_NETWORK_fdset_destroy (ws);
904 * Obtain the reason code for why the current task was
905 * started. Will return the same value as
906 * the GNUNET_SCHEDULER_TaskContext's reason field.
908 * @return reason(s) why the current task is run
910 enum GNUNET_SCHEDULER_Reason
911 GNUNET_SCHEDULER_get_reason ()
913 GNUNET_assert (active_task != NULL);
914 return active_task->reason;
919 * Get information about the current load of this scheduler. Use this
920 * function to determine if an elective task should be added or simply
921 * dropped (if the decision should be made based on the number of
922 * tasks ready to run).
924 * @param p priority level to look at
925 * @return number of tasks pending right now
928 GNUNET_SCHEDULER_get_load (enum GNUNET_SCHEDULER_Priority p)
933 GNUNET_assert (active_task != NULL);
934 if (p == GNUNET_SCHEDULER_PRIORITY_COUNT)
936 if (p == GNUNET_SCHEDULER_PRIORITY_KEEP)
937 p = current_priority;
939 pos = ready[check_priority (p)];
950 * Cancel the task with the specified identifier.
951 * The task must not yet have run.
953 * @param task id of the task to cancel
954 * @return original closure of the task
957 GNUNET_SCHEDULER_cancel (GNUNET_SCHEDULER_TaskIdentifier task)
961 enum GNUNET_SCHEDULER_Priority p;
965 GNUNET_assert (active_task != NULL);
988 if (pending_timeout_last == t)
989 pending_timeout_last = NULL;
995 if (p >= GNUNET_SCHEDULER_PRIORITY_COUNT)
997 GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
999 _("Attempt to cancel dead task %llu!\n"),
1000 (unsigned long long) task);
1026 pending_timeout = t->next;
1036 prev->next = t->next;
1038 ret = t->callback_cls;
1040 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1042 "Canceling task: %llu / %p\n", task, t->callback_cls);
1050 * Continue the current execution with the given function. This is
1051 * similar to the other "add" functions except that there is no delay
1052 * and the reason code can be specified.
1054 * @param task main function of the task
1055 * @param task_cls closure for 'main'
1056 * @param reason reason for task invocation
1059 GNUNET_SCHEDULER_add_continuation (GNUNET_SCHEDULER_Task task, void *task_cls,
1060 enum GNUNET_SCHEDULER_Reason reason)
1065 void *backtrace_array[50];
1068 GNUNET_assert (NULL != task);
1069 GNUNET_assert ((active_task != NULL) ||
1070 (reason == GNUNET_SCHEDULER_REASON_STARTUP));
1071 t = GNUNET_malloc (sizeof (struct Task));
1073 t->num_backtrace_strings = backtrace (backtrace_array, 50);
1074 t->backtrace_strings =
1075 backtrace_symbols (backtrace_array, t->num_backtrace_strings);
1080 t->callback_cls = task_cls;
1083 t->start_time = GNUNET_TIME_absolute_get ();
1086 t->priority = current_priority;
1087 t->lifeness = current_lifeness;
1089 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1091 "Adding continuation task: %llu / %p\n",
1092 t->id, t->callback_cls);
1094 queue_ready_task (t);
1100 * Schedule a new task to be run after the specified prerequisite task
1101 * has completed. It will be run with the priority of the calling
1104 * @param prerequisite_task run this task after the task with the given
1105 * task identifier completes (and any of our other
1106 * conditions, such as delay, read or write-readiness
1107 * are satisfied). Use GNUNET_SCHEDULER_NO_TASK to not have any dependency
1108 * on completion of other tasks (this will cause the task to run as
1109 * soon as possible).
1110 * @param task main function of the task
1111 * @param task_cls closure of task
1112 * @return unique task identifier for the job
1113 * only valid until "task" is started!
1115 GNUNET_SCHEDULER_TaskIdentifier
1116 GNUNET_SCHEDULER_add_after (GNUNET_SCHEDULER_TaskIdentifier prerequisite_task,
1117 GNUNET_SCHEDULER_Task task, void *task_cls)
1119 return GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_KEEP,
1121 GNUNET_TIME_UNIT_ZERO, NULL, NULL, task,
1127 * Schedule a new task to be run with a specified priority.
1129 * @param prio how important is the new task?
1130 * @param task main function of the task
1131 * @param task_cls closure of task
1132 * @return unique task identifier for the job
1133 * only valid until "task" is started!
1135 GNUNET_SCHEDULER_TaskIdentifier
1136 GNUNET_SCHEDULER_add_with_priority (enum GNUNET_SCHEDULER_Priority prio,
1137 GNUNET_SCHEDULER_Task task,
1140 return GNUNET_SCHEDULER_add_select (prio, GNUNET_SCHEDULER_NO_TASK,
1141 GNUNET_TIME_UNIT_ZERO, NULL, NULL, task,
1148 * Schedule a new task to be run with a specified delay. The task
1149 * will be scheduled for execution once the delay has expired. It
1150 * will be run with the priority of the calling task.
1152 * @param delay when should this operation time out? Use
1153 * GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
1154 * @param task main function of the task
1155 * @param task_cls closure of task
1156 * @return unique task identifier for the job
1157 * only valid until "task" is started!
1159 GNUNET_SCHEDULER_TaskIdentifier
1160 GNUNET_SCHEDULER_add_delayed (struct GNUNET_TIME_Relative delay,
1161 GNUNET_SCHEDULER_Task task, void *task_cls)
1164 /* new, optimized version */
1170 void *backtrace_array[MAX_TRACE_DEPTH];
1173 GNUNET_assert (active_task != NULL);
1174 GNUNET_assert (NULL != task);
1175 t = GNUNET_malloc (sizeof (struct Task));
1177 t->callback_cls = task_cls;
1179 t->num_backtrace_strings = backtrace (backtrace_array, MAX_TRACE_DEPTH);
1180 t->backtrace_strings =
1181 backtrace_symbols (backtrace_array, t->num_backtrace_strings);
1187 t->start_time = GNUNET_TIME_absolute_get ();
1189 t->timeout = GNUNET_TIME_relative_to_absolute (delay);
1190 t->priority = current_priority;
1191 t->lifeness = current_lifeness;
1192 /* try tail first (optimization in case we are
1193 * appending to a long list of tasks with timeouts) */
1194 prev = pending_timeout_last;
1197 if (prev->timeout.abs_value > t->timeout.abs_value)
1200 pos = prev->next; /* heuristic success! */
1204 /* heuristic failed, do traversal of timeout list */
1205 pos = pending_timeout;
1207 while ((pos != NULL) &&
1208 ((pos->timeout.abs_value <= t->timeout.abs_value) ||
1209 (pos->reason != 0)))
1215 pending_timeout = t;
1219 /* hyper-optimization... */
1220 pending_timeout_last = t;
1223 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1225 "Adding task: %llu / %p\n", t->id, t->callback_cls);
1230 for (i = 0; i < t->num_backtrace_strings; i++)
1231 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1233 "Task %llu trace %d: %s\n", t->id, i,
1234 t->backtrace_strings[i]);
1239 /* unoptimized version */
1240 return GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_KEEP,
1241 GNUNET_SCHEDULER_NO_TASK, delay, NULL,
1242 NULL, task, task_cls);
1249 * Schedule a new task to be run as soon as possible. The task
1250 * will be run with the priority of the calling task.
1252 * @param task main function of the task
1253 * @param task_cls closure of task
1254 * @return unique task identifier for the job
1255 * only valid until "task" is started!
1257 GNUNET_SCHEDULER_TaskIdentifier
1258 GNUNET_SCHEDULER_add_now (GNUNET_SCHEDULER_Task task, void *task_cls)
1260 return GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_KEEP,
1261 GNUNET_SCHEDULER_NO_TASK,
1262 GNUNET_TIME_UNIT_ZERO, NULL, NULL, task,
1268 * Schedule a new task to be run as soon as possible with the
1269 * (transitive) ignore-shutdown flag either explicitly set or
1270 * explicitly enabled. This task (and all tasks created from it,
1271 * other than by another call to this function) will either count or
1272 * not count for the 'lifeness' of the process. This API is only
1273 * useful in a few special cases.
1275 * @param lifeness GNUNET_YES if the task counts for lifeness, GNUNET_NO if not.
1276 * @param task main function of the task
1277 * @param task_cls closure of task
1278 * @return unique task identifier for the job
1279 * only valid until "task" is started!
1281 GNUNET_SCHEDULER_TaskIdentifier
1282 GNUNET_SCHEDULER_add_now_with_lifeness (int lifeness,
1283 GNUNET_SCHEDULER_Task task,
1286 GNUNET_SCHEDULER_TaskIdentifier ret;
1289 GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_KEEP,
1290 GNUNET_SCHEDULER_NO_TASK,
1291 GNUNET_TIME_UNIT_ZERO, NULL, NULL, task,
1293 GNUNET_assert (pending->id == ret);
1294 pending->lifeness = lifeness;
1302 * Schedule a new task to be run with a specified delay or when any of
1303 * the specified file descriptor sets is ready. The delay can be used
1304 * as a timeout on the socket(s) being ready. The task will be
1305 * scheduled for execution once either the delay has expired or any of
1306 * the socket operations is ready. This is the most general
1307 * function of the "add" family. Note that the "prerequisite_task"
1308 * must be satisfied in addition to any of the other conditions. In
1309 * other words, the task will be started when
1311 * (prerequisite-run)
1315 * || shutdown-active )
1318 * @param delay how long should we wait? Use GNUNET_TIME_UNIT_FOREVER_REL for "forever",
1319 * which means that the task will only be run after we receive SIGTERM
1320 * @param rfd file descriptor we want to read (can be -1)
1321 * @param wfd file descriptors we want to write (can be -1)
1322 * @param task main function of the task
1323 * @param task_cls closure of task
1324 * @return unique task identifier for the job
1325 * only valid until "task" is started!
1328 GNUNET_SCHEDULER_TaskIdentifier
1329 add_without_sets (struct GNUNET_TIME_Relative delay, int rfd, int wfd,
1330 GNUNET_SCHEDULER_Task task, void *task_cls)
1335 void *backtrace_array[MAX_TRACE_DEPTH];
1338 GNUNET_assert (active_task != NULL);
1339 GNUNET_assert (NULL != task);
1340 t = GNUNET_malloc (sizeof (struct Task));
1342 t->callback_cls = task_cls;
1344 t->num_backtrace_strings = backtrace (backtrace_array, MAX_TRACE_DEPTH);
1345 t->backtrace_strings =
1346 backtrace_symbols (backtrace_array, t->num_backtrace_strings);
1351 int flags = fcntl (rfd, F_GETFD);
1353 if ((flags == -1) && (errno == EBADF))
1355 GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
1356 "util", "Got invalid file descriptor %d!\n", rfd);
1360 for (i = 0; i < t->num_backtrace_strings; i++)
1361 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1362 "util", "Trace: %s\n", t->backtrace_strings[i]);
1369 int flags = fcntl (wfd, F_GETFD);
1371 if (flags == -1 && errno == EBADF)
1373 GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
1374 "util", "Got invalid file descriptor %d!\n", wfd);
1378 for (i = 0; i < t->num_backtrace_strings; i++)
1379 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1380 "util", "Trace: %s\n", t->backtrace_strings[i]);
1387 GNUNET_assert (wfd >= -1);
1391 t->start_time = GNUNET_TIME_absolute_get ();
1393 t->prereq_id = GNUNET_SCHEDULER_NO_TASK;
1394 t->timeout = GNUNET_TIME_relative_to_absolute (delay);
1395 t->priority = check_priority (current_priority);
1396 t->lifeness = current_lifeness;
1399 max_priority_added = GNUNET_MAX (max_priority_added, t->priority);
1401 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1403 "Adding task: %llu / %p\n", t->id, t->callback_cls);
1408 for (i = 0; i < t->num_backtrace_strings; i++)
1409 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "util",
1410 "Task %llu trace %d: %s\n", t->id, i,
1411 t->backtrace_strings[i]);
1420 * Schedule a new task to be run with a specified delay or when the
1421 * specified file descriptor is ready for reading. The delay can be
1422 * used as a timeout on the socket being ready. The task will be
1423 * scheduled for execution once either the delay has expired or the
1424 * socket operation is ready. It will be run with the priority of
1427 * @param delay when should this operation time out? Use
1428 * GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
1429 * @param rfd read file-descriptor
1430 * @param task main function of the task
1431 * @param task_cls closure of task
1432 * @return unique task identifier for the job
1433 * only valid until "task" is started!
1435 GNUNET_SCHEDULER_TaskIdentifier
1436 GNUNET_SCHEDULER_add_read_net (struct GNUNET_TIME_Relative delay,
1437 struct GNUNET_NETWORK_Handle * rfd,
1438 GNUNET_SCHEDULER_Task task, void *task_cls)
1441 struct GNUNET_NETWORK_FDSet *rs;
1442 GNUNET_SCHEDULER_TaskIdentifier ret;
1444 GNUNET_assert (rfd != NULL);
1445 rs = GNUNET_NETWORK_fdset_create ();
1446 GNUNET_NETWORK_fdset_set (rs, rfd);
1448 GNUNET_SCHEDULER_add_select (check_priority (current_priority),
1449 GNUNET_SCHEDULER_NO_TASK, delay, rs, NULL,
1451 GNUNET_NETWORK_fdset_destroy (rs);
1454 return add_without_sets (delay, GNUNET_NETWORK_get_fd (rfd), -1, task,
1461 * Schedule a new task to be run with a specified delay or when the
1462 * specified file descriptor is ready for writing. The delay can be
1463 * used as a timeout on the socket being ready. The task will be
1464 * scheduled for execution once either the delay has expired or the
1465 * socket operation is ready. It will be run with the priority of
1468 * @param delay when should this operation time out? Use
1469 * GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
1470 * @param wfd write file-descriptor
1471 * @param task main function of the task
1472 * @param task_cls closure of task
1473 * @return unique task identifier for the job
1474 * only valid until "task" is started!
1476 GNUNET_SCHEDULER_TaskIdentifier
1477 GNUNET_SCHEDULER_add_write_net (struct GNUNET_TIME_Relative delay,
1478 struct GNUNET_NETWORK_Handle * wfd,
1479 GNUNET_SCHEDULER_Task task, void *task_cls)
1482 struct GNUNET_NETWORK_FDSet *ws;
1483 GNUNET_SCHEDULER_TaskIdentifier ret;
1485 GNUNET_assert (wfd != NULL);
1486 ws = GNUNET_NETWORK_fdset_create ();
1487 GNUNET_NETWORK_fdset_set (ws, wfd);
1489 GNUNET_SCHEDULER_add_select (check_priority (current_priority),
1490 GNUNET_SCHEDULER_NO_TASK, delay, NULL, ws,
1492 GNUNET_NETWORK_fdset_destroy (ws);
1495 GNUNET_assert (GNUNET_NETWORK_get_fd (wfd) >= 0);
1496 return add_without_sets (delay, -1, GNUNET_NETWORK_get_fd (wfd), task,
1503 * Schedule a new task to be run with a specified delay or when the
1504 * specified file descriptor is ready for reading. The delay can be
1505 * used as a timeout on the socket being ready. The task will be
1506 * scheduled for execution once either the delay has expired or the
1507 * socket operation is ready. It will be run with the priority of
1510 * @param delay when should this operation time out? Use
1511 * GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
1512 * @param rfd read file-descriptor
1513 * @param task main function of the task
1514 * @param task_cls closure of task
1515 * @return unique task identifier for the job
1516 * only valid until "task" is started!
1518 GNUNET_SCHEDULER_TaskIdentifier
1519 GNUNET_SCHEDULER_add_read_file (struct GNUNET_TIME_Relative delay,
1520 const struct GNUNET_DISK_FileHandle * rfd,
1521 GNUNET_SCHEDULER_Task task, void *task_cls)
1524 struct GNUNET_NETWORK_FDSet *rs;
1525 GNUNET_SCHEDULER_TaskIdentifier ret;
1527 GNUNET_assert (rfd != NULL);
1528 rs = GNUNET_NETWORK_fdset_create ();
1529 GNUNET_NETWORK_fdset_handle_set (rs, rfd);
1531 GNUNET_SCHEDULER_add_select (check_priority (current_priority),
1532 GNUNET_SCHEDULER_NO_TASK, delay, rs, NULL,
1534 GNUNET_NETWORK_fdset_destroy (rs);
1539 GNUNET_DISK_internal_file_handle_ (rfd, &fd, sizeof (int));
1540 return add_without_sets (delay, fd, -1, task, task_cls);
1547 * Schedule a new task to be run with a specified delay or when the
1548 * specified file descriptor is ready for writing. The delay can be
1549 * used as a timeout on the socket being ready. The task will be
1550 * scheduled for execution once either the delay has expired or the
1551 * socket operation is ready. It will be run with the priority of
1554 * @param delay when should this operation time out? Use
1555 * GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
1556 * @param wfd write file-descriptor
1557 * @param task main function of the task
1558 * @param task_cls closure of task
1559 * @return unique task identifier for the job
1560 * only valid until "task" is started!
1562 GNUNET_SCHEDULER_TaskIdentifier
1563 GNUNET_SCHEDULER_add_write_file (struct GNUNET_TIME_Relative delay,
1564 const struct GNUNET_DISK_FileHandle * wfd,
1565 GNUNET_SCHEDULER_Task task, void *task_cls)
1568 struct GNUNET_NETWORK_FDSet *ws;
1569 GNUNET_SCHEDULER_TaskIdentifier ret;
1571 GNUNET_assert (wfd != NULL);
1572 ws = GNUNET_NETWORK_fdset_create ();
1573 GNUNET_NETWORK_fdset_handle_set (ws, wfd);
1575 GNUNET_SCHEDULER_add_select (check_priority (current_priority),
1576 GNUNET_SCHEDULER_NO_TASK, delay, NULL, ws,
1578 GNUNET_NETWORK_fdset_destroy (ws);
1583 GNUNET_DISK_internal_file_handle_ (wfd, &fd, sizeof (int));
1584 GNUNET_assert (fd >= 0);
1585 return add_without_sets (delay, -1, fd, task, task_cls);
1593 * Schedule a new task to be run with a specified delay or when any of
1594 * the specified file descriptor sets is ready. The delay can be used
1595 * as a timeout on the socket(s) being ready. The task will be
1596 * scheduled for execution once either the delay has expired or any of
1597 * the socket operations is ready. This is the most general
1598 * function of the "add" family. Note that the "prerequisite_task"
1599 * must be satisfied in addition to any of the other conditions. In
1600 * other words, the task will be started when
1602 * (prerequisite-run)
1606 * || (shutdown-active && run-on-shutdown) )
1609 * @param prio how important is this task?
1610 * @param prerequisite_task run this task after the task with the given
1611 * task identifier completes (and any of our other
1612 * conditions, such as delay, read or write-readiness
1613 * are satisfied). Use GNUNET_SCHEDULER_NO_TASK to not have any dependency
1614 * on completion of other tasks.
1615 * @param delay how long should we wait? Use GNUNET_TIME_UNIT_FOREVER_REL for "forever",
1616 * which means that the task will only be run after we receive SIGTERM
1617 * @param rs set of file descriptors we want to read (can be NULL)
1618 * @param ws set of file descriptors we want to write (can be NULL)
1619 * @param task main function of the task
1620 * @param task_cls closure of task
1621 * @return unique task identifier for the job
1622 * only valid until "task" is started!
1624 GNUNET_SCHEDULER_TaskIdentifier
1625 GNUNET_SCHEDULER_add_select (enum GNUNET_SCHEDULER_Priority prio,
1626 GNUNET_SCHEDULER_TaskIdentifier
1628 struct GNUNET_TIME_Relative delay,
1629 const struct GNUNET_NETWORK_FDSet * rs,
1630 const struct GNUNET_NETWORK_FDSet * ws,
1631 GNUNET_SCHEDULER_Task task, void *task_cls)
1636 void *backtrace_array[MAX_TRACE_DEPTH];
1639 GNUNET_assert (active_task != NULL);
1640 GNUNET_assert (NULL != task);
1641 t = GNUNET_malloc (sizeof (struct Task));
1643 t->callback_cls = task_cls;
1645 t->num_backtrace_strings = backtrace (backtrace_array, MAX_TRACE_DEPTH);
1646 t->backtrace_strings =
1647 backtrace_symbols (backtrace_array, t->num_backtrace_strings);
1653 t->read_set = GNUNET_NETWORK_fdset_create ();
1654 GNUNET_NETWORK_fdset_copy (t->read_set, rs);
1658 t->write_set = GNUNET_NETWORK_fdset_create ();
1659 GNUNET_NETWORK_fdset_copy (t->write_set, ws);
1663 t->start_time = GNUNET_TIME_absolute_get ();
1665 t->prereq_id = prerequisite_task;
1666 t->timeout = GNUNET_TIME_relative_to_absolute (delay);
1668 check_priority ((prio ==
1669 GNUNET_SCHEDULER_PRIORITY_KEEP) ? current_priority :
1671 t->lifeness = current_lifeness;
1674 max_priority_added = GNUNET_MAX (max_priority_added, t->priority);
1676 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1678 "Adding task: %llu / %p\n", t->id, t->callback_cls);
1683 for (i = 0; i < t->num_backtrace_strings; i++)
1684 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1686 "Task %llu trace %d: %s\n", t->id, i,
1687 t->backtrace_strings[i]);
1692 /* end of scheduler.c */