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_NO
54 * Depth of the traces collected via EXECINFO.
56 #define MAX_TRACE_DEPTH 50
59 #define DEBUG_TASKS GNUNET_NO
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 * @return previously used select function, NULL for default
266 GNUNET_SCHEDULER_set_select (GNUNET_SCHEDULER_select new_select,
267 void *new_select_cls)
269 scheduler_select = new_select;
270 scheduler_select_cls = new_select_cls;
275 * Check that the given priority is legal (and return it).
277 * @param p priority value to check
278 * @return p on success, 0 on error
280 static enum GNUNET_SCHEDULER_Priority
281 check_priority (enum GNUNET_SCHEDULER_Priority p)
283 if ((p >= 0) && (p < GNUNET_SCHEDULER_PRIORITY_COUNT))
286 return 0; /* make compiler happy */
291 * Is a task with this identifier still pending? Also updates
292 * "lowest_pending_id" as a side-effect (for faster checks in the
293 * future), but only if the return value is "GNUNET_NO" (and
294 * the "lowest_pending_id" check failed).
296 * @param id which task are we checking for
297 * @return GNUNET_YES if so, GNUNET_NO if not
300 is_pending (GNUNET_SCHEDULER_TaskIdentifier id)
303 enum GNUNET_SCHEDULER_Priority p;
304 GNUNET_SCHEDULER_TaskIdentifier min;
306 if (id < lowest_pending_id)
308 min = -1; /* maximum value */
318 pos = pending_timeout;
327 for (p = 0; p < GNUNET_SCHEDULER_PRIORITY_COUNT; p++)
339 lowest_pending_id = min;
345 * Update all sets and timeout for select.
347 * @param rs read-set, set to all FDs we would like to read (updated)
348 * @param ws write-set, set to all FDs we would like to write (updated)
349 * @param timeout next timeout (updated)
352 update_sets (struct GNUNET_NETWORK_FDSet *rs,
353 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,
438 struct GNUNET_TIME_Absolute now,
439 const struct GNUNET_NETWORK_FDSet *rs,
440 const struct GNUNET_NETWORK_FDSet *ws)
442 enum GNUNET_SCHEDULER_Reason reason;
444 reason = task->reason;
445 if (now.abs_value >= task->timeout.abs_value)
446 reason |= GNUNET_SCHEDULER_REASON_TIMEOUT;
447 if ( (0 == (reason & GNUNET_SCHEDULER_REASON_READ_READY)) &&
448 ( ( (task->read_fd != -1) &&
449 (GNUNET_YES == GNUNET_NETWORK_fdset_test_native (rs, task->read_fd)) ) ||
450 (set_overlaps (rs, task->read_set) ) ) )
451 reason |= GNUNET_SCHEDULER_REASON_READ_READY;
452 if ((0 == (reason & GNUNET_SCHEDULER_REASON_WRITE_READY)) &&
453 ( ( (task->write_fd != -1) &&
454 (GNUNET_YES == GNUNET_NETWORK_fdset_test_native (ws, task->write_fd)) ) ||
455 (set_overlaps (ws, task->write_set) ) ) )
456 reason |= GNUNET_SCHEDULER_REASON_WRITE_READY;
458 return GNUNET_NO; /* not ready */
459 if (task->prereq_id != GNUNET_SCHEDULER_NO_TASK)
461 if (GNUNET_YES == is_pending (task->prereq_id))
463 task->reason = reason;
464 return GNUNET_NO; /* prereq waiting */
466 reason |= GNUNET_SCHEDULER_REASON_PREREQ_DONE;
468 task->reason = reason;
474 * Put a task that is ready for execution into the ready queue.
476 * @param task task ready for execution
479 queue_ready_task (struct Task *task)
481 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 (GNUNET_ERROR_TYPE_DEBUG,
527 "Checking readiness of task: %llu / %p\n",
528 pos->id, pos->callback_cls);
531 if (GNUNET_YES == is_ready (pos, now, rs, ws))
537 queue_ready_task (pos);
548 * Request the shutdown of a scheduler. Marks all currently
549 * pending tasks as ready because of shutdown. This will
550 * cause all tasks to run (as soon as possible, respecting
551 * priorities and prerequisite tasks). Note that tasks
552 * scheduled AFTER this call may still be delayed arbitrarily.
555 GNUNET_SCHEDULER_shutdown ()
560 pos = pending_timeout;
563 pos->reason |= GNUNET_SCHEDULER_REASON_SHUTDOWN;
564 /* we don't move the task into the ready queue yet; check_ready
565 will do that later, possibly adding additional
572 pos->reason |= GNUNET_SCHEDULER_REASON_SHUTDOWN;
573 /* we don't move the task into the ready queue yet; check_ready
574 will do that later, possibly adding additional
578 for (i=0;i<GNUNET_SCHEDULER_PRIORITY_COUNT;i++)
583 pos->reason |= GNUNET_SCHEDULER_REASON_SHUTDOWN;
584 /* we don't move the task into the ready queue yet; check_ready
585 will do that later, possibly adding additional
594 * Destroy a task (release associated resources)
596 * @param t task to destroy
599 destroy_task (struct Task *t)
601 if (NULL != t->read_set)
602 GNUNET_NETWORK_fdset_destroy (t->read_set);
603 if (NULL != t->write_set)
604 GNUNET_NETWORK_fdset_destroy (t->write_set);
606 GNUNET_free (t->backtrace_strings);
613 * Run at least one task in the highest-priority queue that is not
614 * empty. Keep running tasks until we are either no longer running
615 * "URGENT" tasks or until we have at least one "pending" task (which
616 * may become ready, hence we should select on it). Naturally, if
617 * there are no more ready tasks, we also return.
619 * @param rs FDs ready for reading
620 * @param ws FDs ready for writing
623 run_ready (struct GNUNET_NETWORK_FDSet *rs,
624 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 (GNUNET_ERROR_TYPE_ERROR,
660 "Task %llu took %llums to be scheduled\n",
662 (unsigned long long) GNUNET_TIME_absolute_get_duration (pos->start_time).rel_value);
665 tc.reason = pos->reason;
666 tc.read_ready = (pos->read_set == NULL) ? rs : pos->read_set;
667 if ( (pos->read_fd != -1) &&
668 (0 != (pos->reason & GNUNET_SCHEDULER_REASON_READ_READY)) )
669 GNUNET_NETWORK_fdset_set_native (rs,
671 tc.write_ready = (pos->write_set == NULL) ? ws : pos->write_set;
672 if ( (pos->write_fd != -1) &&
673 (0 != (pos->reason & GNUNET_SCHEDULER_REASON_WRITE_READY)) )
674 GNUNET_NETWORK_fdset_set_native (ws,
676 if ( ( (tc.reason & GNUNET_SCHEDULER_REASON_WRITE_READY) != 0) &&
677 (pos->write_fd != -1) &&
678 (! GNUNET_NETWORK_fdset_test_native (ws,
680 abort (); // added to ready in previous select loop!
682 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
683 "Running task: %llu / %p\n", pos->id, pos->callback_cls);
685 pos->callback (pos->callback_cls, &tc);
688 for (i=0;i<pos->num_backtrace_strings;i++)
689 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
690 "Task %llu trace %d: %s\n",
693 pos->backtrace_strings[i]);
699 while ( (pending == NULL) || (p >= max_priority_added) );
703 * Pipe used to communicate shutdown via signal.
705 static struct GNUNET_DISK_PipeHandle *shutdown_pipe_handle;
708 * Signal handler called for SIGPIPE.
718 * Signal handler called for signals that should cause us to shutdown.
721 sighandler_shutdown ()
724 int old_errno = errno; /* backup errno */
726 GNUNET_DISK_file_write (GNUNET_DISK_pipe_handle
727 (shutdown_pipe_handle, GNUNET_DISK_PIPE_END_WRITE), &c,
734 * Check if the system is still life. Trigger shutdown if we
735 * have tasks, but none of them give us lifeness.
737 * @return GNUNET_OK to continue the main loop,
746 for (t = pending; NULL != t; t = t->next)
747 if (t->lifeness == GNUNET_YES)
749 for (t = pending_timeout; NULL != t; t = t->next)
750 if (t->lifeness == GNUNET_YES)
752 if ( (NULL != pending) || (NULL != pending_timeout) )
754 GNUNET_SCHEDULER_shutdown ();
762 * Initialize and run scheduler. This function will return when all
763 * tasks have completed. On systems with signals, receiving a SIGTERM
764 * (and other similar signals) will cause "GNUNET_SCHEDULER_shutdown"
765 * to be run after the active task is complete. As a result, SIGTERM
766 * causes all active tasks to be scheduled with reason
767 * "GNUNET_SCHEDULER_REASON_SHUTDOWN". (However, tasks added
768 * afterwards will execute normally!). Note that any particular signal
769 * will only shut down one scheduler; applications should always only
770 * create a single scheduler.
772 * @param task task to run immediately
773 * @param task_cls closure of task
776 GNUNET_SCHEDULER_run (GNUNET_SCHEDULER_Task task, void *task_cls)
778 struct GNUNET_NETWORK_FDSet *rs;
779 struct GNUNET_NETWORK_FDSet *ws;
780 struct GNUNET_TIME_Relative timeout;
782 struct GNUNET_SIGNAL_Context *shc_int;
783 struct GNUNET_SIGNAL_Context *shc_term;
785 struct GNUNET_SIGNAL_Context *shc_quit;
786 struct GNUNET_SIGNAL_Context *shc_hup;
787 struct GNUNET_SIGNAL_Context *shc_pipe;
789 unsigned long long last_tr;
790 unsigned int busy_wait_warning;
791 const struct GNUNET_DISK_FileHandle *pr;
794 GNUNET_assert (active_task == NULL);
795 rs = GNUNET_NETWORK_fdset_create ();
796 ws = GNUNET_NETWORK_fdset_create ();
797 GNUNET_assert (shutdown_pipe_handle == NULL);
798 shutdown_pipe_handle = GNUNET_DISK_pipe (GNUNET_NO, GNUNET_NO, GNUNET_NO);
799 GNUNET_assert (shutdown_pipe_handle != NULL);
800 pr = GNUNET_DISK_pipe_handle (shutdown_pipe_handle, GNUNET_DISK_PIPE_END_READ);
801 GNUNET_assert (pr != NULL);
802 shc_int = GNUNET_SIGNAL_handler_install (SIGINT, &sighandler_shutdown);
803 shc_term = GNUNET_SIGNAL_handler_install (SIGTERM, &sighandler_shutdown);
805 shc_pipe = GNUNET_SIGNAL_handler_install (SIGPIPE, &sighandler_pipe);
806 shc_quit = GNUNET_SIGNAL_handler_install (SIGQUIT, &sighandler_shutdown);
807 shc_hup = GNUNET_SIGNAL_handler_install (SIGHUP, &sighandler_shutdown);
809 current_priority = GNUNET_SCHEDULER_PRIORITY_DEFAULT;
810 current_lifeness = GNUNET_YES;
811 GNUNET_SCHEDULER_add_continuation (task,
813 GNUNET_SCHEDULER_REASON_STARTUP);
814 #if ENABLE_WINDOWS_WORKAROUNDS
815 active_task = (void*) (long) -1; /* force passing of sanity check */
816 GNUNET_SCHEDULER_add_now_with_lifeness (GNUNET_NO,
817 &GNUNET_OS_install_parent_control_handler,
822 busy_wait_warning = 0;
823 while (GNUNET_OK == check_lifeness ())
825 GNUNET_NETWORK_fdset_zero (rs);
826 GNUNET_NETWORK_fdset_zero (ws);
827 timeout = GNUNET_TIME_UNIT_FOREVER_REL;
828 update_sets (rs, ws, &timeout);
829 GNUNET_NETWORK_fdset_handle_set (rs, pr);
832 /* no blocking, more work already ready! */
833 timeout = GNUNET_TIME_UNIT_ZERO;
835 if (NULL == scheduler_select)
836 ret = GNUNET_NETWORK_socket_select (rs, ws, NULL, timeout);
838 ret = scheduler_select (scheduler_select_cls,
841 if (ret == GNUNET_SYSERR)
846 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "select");
850 snprintf (lsof, sizeof (lsof), "lsof -p %d", getpid());
853 if (0 != system (lsof))
854 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "system");
860 if ((ret == 0) && (timeout.rel_value == 0) && (busy_wait_warning > 16))
862 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
863 _("Looks like we're busy waiting...\n"));
864 sleep (1); /* mitigate */
866 check_ready (rs, ws);
868 if (GNUNET_NETWORK_fdset_handle_isset (rs, pr))
870 /* consume the signal */
871 GNUNET_DISK_file_read (pr, &c, sizeof (c));
872 /* mark all active tasks as ready due to shutdown */
873 GNUNET_SCHEDULER_shutdown ();
875 if (last_tr == tasks_run)
882 busy_wait_warning = 0;
885 GNUNET_SIGNAL_handler_uninstall (shc_int);
886 GNUNET_SIGNAL_handler_uninstall (shc_term);
888 GNUNET_SIGNAL_handler_uninstall (shc_pipe);
889 GNUNET_SIGNAL_handler_uninstall (shc_quit);
890 GNUNET_SIGNAL_handler_uninstall (shc_hup);
892 GNUNET_DISK_pipe_close (shutdown_pipe_handle);
893 shutdown_pipe_handle = NULL;
894 GNUNET_NETWORK_fdset_destroy (rs);
895 GNUNET_NETWORK_fdset_destroy (ws);
900 * Obtain the reason code for why the current task was
901 * started. Will return the same value as
902 * the GNUNET_SCHEDULER_TaskContext's reason field.
904 * @return reason(s) why the current task is run
906 enum GNUNET_SCHEDULER_Reason
907 GNUNET_SCHEDULER_get_reason ()
909 GNUNET_assert (active_task != NULL);
910 return active_task->reason;
915 * Get information about the current load of this scheduler. Use this
916 * function to determine if an elective task should be added or simply
917 * dropped (if the decision should be made based on the number of
918 * tasks ready to run).
920 * @param p priority level to look at
921 * @return number of tasks pending right now
924 GNUNET_SCHEDULER_get_load (enum GNUNET_SCHEDULER_Priority p)
929 GNUNET_assert (active_task != NULL);
930 if (p == GNUNET_SCHEDULER_PRIORITY_COUNT)
932 if (p == GNUNET_SCHEDULER_PRIORITY_KEEP)
933 p = current_priority;
935 pos = ready[check_priority (p)];
946 * Cancel the task with the specified identifier.
947 * The task must not yet have run.
949 * @param task id of the task to cancel
950 * @return original closure of the task
953 GNUNET_SCHEDULER_cancel (GNUNET_SCHEDULER_TaskIdentifier task)
957 enum GNUNET_SCHEDULER_Priority p;
961 GNUNET_assert (active_task != NULL);
984 if (pending_timeout_last == t)
985 pending_timeout_last = NULL;
991 if (p >= GNUNET_SCHEDULER_PRIORITY_COUNT)
993 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
994 _("Attempt to cancel dead task %llu!\n"),
995 (unsigned long long) task);
1021 pending_timeout = t->next;
1031 prev->next = t->next;
1033 ret = t->callback_cls;
1035 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1036 "Canceling task: %llu / %p\n", task, t->callback_cls);
1044 * Continue the current execution with the given function. This is
1045 * similar to the other "add" functions except that there is no delay
1046 * and the reason code can be specified.
1048 * @param task main function of the task
1049 * @param task_cls closure for 'main'
1050 * @param reason reason for task invocation
1053 GNUNET_SCHEDULER_add_continuation (GNUNET_SCHEDULER_Task task,
1055 enum GNUNET_SCHEDULER_Reason reason)
1059 void *backtrace_array[50];
1062 GNUNET_assert (NULL != task);
1063 GNUNET_assert ( (active_task != NULL) ||
1064 (reason == GNUNET_SCHEDULER_REASON_STARTUP) );
1065 t = GNUNET_malloc (sizeof (struct Task));
1067 t->num_backtrace_strings = backtrace(backtrace_array, 50);
1068 t->backtrace_strings = backtrace_symbols(backtrace_array, t->num_backtrace_strings);
1073 t->callback_cls = task_cls;
1076 t->start_time = GNUNET_TIME_absolute_get ();
1079 t->priority = current_priority;
1080 t->lifeness = current_lifeness;
1082 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1083 "Adding continuation task: %llu / %p\n",
1084 t->id, t->callback_cls);
1086 queue_ready_task (t);
1092 * Schedule a new task to be run after the specified prerequisite task
1093 * has completed. It will be run with the priority of the calling
1096 * @param prerequisite_task run this task after the task with the given
1097 * task identifier completes (and any of our other
1098 * conditions, such as delay, read or write-readiness
1099 * are satisfied). Use GNUNET_SCHEDULER_NO_TASK to not have any dependency
1100 * on completion of other tasks (this will cause the task to run as
1101 * soon as possible).
1102 * @param task main function of the task
1103 * @param task_cls closure of task
1104 * @return unique task identifier for the job
1105 * only valid until "task" is started!
1107 GNUNET_SCHEDULER_TaskIdentifier
1108 GNUNET_SCHEDULER_add_after (GNUNET_SCHEDULER_TaskIdentifier prerequisite_task,
1109 GNUNET_SCHEDULER_Task task, void *task_cls)
1111 return GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_KEEP,
1113 GNUNET_TIME_UNIT_ZERO,
1114 NULL, NULL, task, task_cls);
1119 * Schedule a new task to be run with a specified priority.
1121 * @param prio how important is the new task?
1122 * @param task main function of the task
1123 * @param task_cls closure of task
1124 * @return unique task identifier for the job
1125 * only valid until "task" is started!
1127 GNUNET_SCHEDULER_TaskIdentifier
1128 GNUNET_SCHEDULER_add_with_priority (enum GNUNET_SCHEDULER_Priority prio,
1129 GNUNET_SCHEDULER_Task task,
1132 return GNUNET_SCHEDULER_add_select (prio,
1133 GNUNET_SCHEDULER_NO_TASK,
1134 GNUNET_TIME_UNIT_ZERO,
1135 NULL, NULL, task, task_cls);
1141 * Schedule a new task to be run with a specified delay. The task
1142 * will be scheduled for execution once the delay has expired. It
1143 * will be run with the priority of the calling task.
1145 * @param delay when should this operation time out? Use
1146 * GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
1147 * @param task main function of the task
1148 * @param task_cls closure of task
1149 * @return unique task identifier for the job
1150 * only valid until "task" is started!
1152 GNUNET_SCHEDULER_TaskIdentifier
1153 GNUNET_SCHEDULER_add_delayed (struct GNUNET_TIME_Relative delay,
1154 GNUNET_SCHEDULER_Task task, void *task_cls)
1157 /* new, optimized version */
1162 void *backtrace_array[MAX_TRACE_DEPTH];
1165 GNUNET_assert (active_task != NULL);
1166 GNUNET_assert (NULL != task);
1167 t = GNUNET_malloc (sizeof (struct Task));
1169 t->callback_cls = task_cls;
1171 t->num_backtrace_strings = backtrace(backtrace_array, MAX_TRACE_DEPTH);
1172 t->backtrace_strings = backtrace_symbols(backtrace_array, t->num_backtrace_strings);
1178 t->start_time = GNUNET_TIME_absolute_get ();
1180 t->timeout = GNUNET_TIME_relative_to_absolute (delay);
1181 t->priority = current_priority;
1182 t->lifeness = current_lifeness;
1183 /* try tail first (optimization in case we are
1184 appending to a long list of tasks with timeouts) */
1185 prev = pending_timeout_last;
1188 if (prev->timeout.abs_value > t->timeout.abs_value)
1191 pos = prev->next; /* heuristic success! */
1195 /* heuristic failed, do traversal of timeout list */
1196 pos = pending_timeout;
1198 while ( (pos != NULL) &&
1199 ( (pos->timeout.abs_value <= t->timeout.abs_value) ||
1200 (pos->reason != 0) ) )
1206 pending_timeout = t;
1210 /* hyper-optimization... */
1211 pending_timeout_last = t;
1214 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1215 "Adding task: %llu / %p\n", t->id, t->callback_cls);
1220 for (i=0;i<t->num_backtrace_strings;i++)
1221 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1222 "Task %llu trace %d: %s\n",
1225 t->backtrace_strings[i]);
1230 /* unoptimized version */
1231 return GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_KEEP,
1232 GNUNET_SCHEDULER_NO_TASK, delay,
1233 NULL, NULL, task, task_cls);
1240 * Schedule a new task to be run as soon as possible. The task
1241 * will be run with the priority of the calling task.
1243 * @param task main function of the task
1244 * @param task_cls closure of task
1245 * @return unique task identifier for the job
1246 * only valid until "task" is started!
1248 GNUNET_SCHEDULER_TaskIdentifier
1249 GNUNET_SCHEDULER_add_now (GNUNET_SCHEDULER_Task task,
1252 return GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_KEEP,
1253 GNUNET_SCHEDULER_NO_TASK,
1254 GNUNET_TIME_UNIT_ZERO,
1255 NULL, NULL, task, task_cls);
1260 * Schedule a new task to be run as soon as possible with the
1261 * (transitive) ignore-shutdown flag either explicitly set or
1262 * explicitly enabled. This task (and all tasks created from it,
1263 * other than by another call to this function) will either count or
1264 * not count for the 'lifeness' of the process. This API is only
1265 * useful in a few special cases.
1267 * @param lifeness GNUNET_YES if the task counts for lifeness, GNUNET_NO if not.
1268 * @param task main function of the task
1269 * @param task_cls closure of task
1270 * @return unique task identifier for the job
1271 * only valid until "task" is started!
1273 GNUNET_SCHEDULER_TaskIdentifier
1274 GNUNET_SCHEDULER_add_now_with_lifeness (int lifeness,
1275 GNUNET_SCHEDULER_Task task,
1278 GNUNET_SCHEDULER_TaskIdentifier ret;
1280 ret = GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_KEEP,
1281 GNUNET_SCHEDULER_NO_TASK,
1282 GNUNET_TIME_UNIT_ZERO,
1283 NULL, NULL, task, task_cls);
1284 GNUNET_assert (pending->id == ret);
1285 pending->lifeness = lifeness;
1293 * Schedule a new task to be run with a specified delay or when any of
1294 * the specified file descriptor sets is ready. The delay can be used
1295 * as a timeout on the socket(s) being ready. The task will be
1296 * scheduled for execution once either the delay has expired or any of
1297 * the socket operations is ready. This is the most general
1298 * function of the "add" family. Note that the "prerequisite_task"
1299 * must be satisfied in addition to any of the other conditions. In
1300 * other words, the task will be started when
1302 * (prerequisite-run)
1306 * || shutdown-active )
1309 * @param delay how long should we wait? Use GNUNET_TIME_UNIT_FOREVER_REL for "forever",
1310 * which means that the task will only be run after we receive SIGTERM
1311 * @param rfd file descriptor we want to read (can be -1)
1312 * @param wfd file descriptors we want to write (can be -1)
1313 * @param task main function of the task
1314 * @param task_cls closure of task
1315 * @return unique task identifier for the job
1316 * only valid until "task" is started!
1319 GNUNET_SCHEDULER_TaskIdentifier
1320 add_without_sets (struct GNUNET_TIME_Relative delay,
1323 GNUNET_SCHEDULER_Task task, void *task_cls)
1327 void *backtrace_array[MAX_TRACE_DEPTH];
1330 GNUNET_assert (active_task != NULL);
1331 GNUNET_assert (NULL != task);
1332 t = GNUNET_malloc (sizeof (struct Task));
1334 t->callback_cls = task_cls;
1336 t->num_backtrace_strings = backtrace(backtrace_array, MAX_TRACE_DEPTH);
1337 t->backtrace_strings = backtrace_symbols(backtrace_array, t->num_backtrace_strings);
1342 int flags = fcntl(rfd, F_GETFD);
1343 if (flags == -1 && errno == EBADF)
1345 GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Got invalid file descriptor %d!\n", rfd);
1349 for (i=0;i<t->num_backtrace_strings;i++)
1350 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1352 t->backtrace_strings[i]);
1359 int flags = fcntl(wfd, F_GETFD);
1360 if (flags == -1 && errno == EBADF)
1362 GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Got invalid file descriptor %d!\n", wfd);
1366 for (i=0;i<t->num_backtrace_strings;i++)
1367 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1369 t->backtrace_strings[i]);
1376 GNUNET_assert(wfd >= -1);
1380 t->start_time = GNUNET_TIME_absolute_get ();
1382 t->prereq_id = GNUNET_SCHEDULER_NO_TASK;
1383 t->timeout = GNUNET_TIME_relative_to_absolute (delay);
1384 t->priority = check_priority (current_priority);
1385 t->lifeness = current_lifeness;
1388 max_priority_added = GNUNET_MAX (max_priority_added,
1391 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1392 "Adding task: %llu / %p\n", t->id, t->callback_cls);
1397 for (i=0;i<t->num_backtrace_strings;i++)
1398 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1399 "Task %llu trace %d: %s\n",
1402 t->backtrace_strings[i]);
1411 * Schedule a new task to be run with a specified delay or when the
1412 * specified file descriptor is ready for reading. The delay can be
1413 * used as a timeout on the socket being ready. The task will be
1414 * scheduled for execution once either the delay has expired or the
1415 * socket operation is ready. It will be run with the priority of
1418 * @param delay when should this operation time out? Use
1419 * GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
1420 * @param rfd read file-descriptor
1421 * @param task main function of the task
1422 * @param task_cls closure of task
1423 * @return unique task identifier for the job
1424 * only valid until "task" is started!
1426 GNUNET_SCHEDULER_TaskIdentifier
1427 GNUNET_SCHEDULER_add_read_net (struct GNUNET_TIME_Relative delay,
1428 struct GNUNET_NETWORK_Handle * rfd,
1429 GNUNET_SCHEDULER_Task task, void *task_cls)
1432 struct GNUNET_NETWORK_FDSet *rs;
1433 GNUNET_SCHEDULER_TaskIdentifier ret;
1435 GNUNET_assert (rfd != NULL);
1436 rs = GNUNET_NETWORK_fdset_create ();
1437 GNUNET_NETWORK_fdset_set (rs, rfd);
1438 ret = GNUNET_SCHEDULER_add_select (check_priority (current_priority),
1439 GNUNET_SCHEDULER_NO_TASK, delay,
1440 rs, NULL, task, task_cls);
1441 GNUNET_NETWORK_fdset_destroy (rs);
1444 return add_without_sets (delay,
1445 GNUNET_NETWORK_get_fd (rfd),
1454 * Schedule a new task to be run with a specified delay or when the
1455 * specified file descriptor is ready for writing. The delay can be
1456 * used as a timeout on the socket being ready. The task will be
1457 * scheduled for execution once either the delay has expired or the
1458 * socket operation is ready. It will be run with the priority of
1461 * @param delay when should this operation time out? Use
1462 * GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
1463 * @param wfd write file-descriptor
1464 * @param task main function of the task
1465 * @param task_cls closure of task
1466 * @return unique task identifier for the job
1467 * only valid until "task" is started!
1469 GNUNET_SCHEDULER_TaskIdentifier
1470 GNUNET_SCHEDULER_add_write_net (struct GNUNET_TIME_Relative delay,
1471 struct GNUNET_NETWORK_Handle * wfd,
1472 GNUNET_SCHEDULER_Task task, void *task_cls)
1475 struct GNUNET_NETWORK_FDSet *ws;
1476 GNUNET_SCHEDULER_TaskIdentifier ret;
1478 GNUNET_assert (wfd != NULL);
1479 ws = GNUNET_NETWORK_fdset_create ();
1480 GNUNET_NETWORK_fdset_set (ws, wfd);
1481 ret = GNUNET_SCHEDULER_add_select (check_priority (current_priority),
1482 GNUNET_SCHEDULER_NO_TASK, delay,
1483 NULL, ws, task, task_cls);
1484 GNUNET_NETWORK_fdset_destroy (ws);
1487 GNUNET_assert(GNUNET_NETWORK_get_fd(wfd) >= 0);
1488 return add_without_sets (delay,
1490 GNUNET_NETWORK_get_fd (wfd),
1498 * Schedule a new task to be run with a specified delay or when the
1499 * specified file descriptor is ready for reading. The delay can be
1500 * used as a timeout on the socket being ready. The task will be
1501 * scheduled for execution once either the delay has expired or the
1502 * socket operation is ready. It will be run with the priority of
1505 * @param delay when should this operation time out? Use
1506 * GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
1507 * @param rfd read file-descriptor
1508 * @param task main function of the task
1509 * @param task_cls closure of task
1510 * @return unique task identifier for the job
1511 * only valid until "task" is started!
1513 GNUNET_SCHEDULER_TaskIdentifier
1514 GNUNET_SCHEDULER_add_read_file (struct GNUNET_TIME_Relative delay,
1515 const struct GNUNET_DISK_FileHandle * rfd,
1516 GNUNET_SCHEDULER_Task task, void *task_cls)
1519 struct GNUNET_NETWORK_FDSet *rs;
1520 GNUNET_SCHEDULER_TaskIdentifier ret;
1522 GNUNET_assert (rfd != NULL);
1523 rs = GNUNET_NETWORK_fdset_create ();
1524 GNUNET_NETWORK_fdset_handle_set (rs, rfd);
1525 ret = GNUNET_SCHEDULER_add_select (check_priority (current_priority),
1526 GNUNET_SCHEDULER_NO_TASK, delay,
1527 rs, NULL, task, task_cls);
1528 GNUNET_NETWORK_fdset_destroy (rs);
1533 GNUNET_DISK_internal_file_handle_ (rfd, &fd, sizeof (int));
1534 return add_without_sets (delay,
1545 * Schedule a new task to be run with a specified delay or when the
1546 * specified file descriptor is ready for writing. The delay can be
1547 * used as a timeout on the socket being ready. The task will be
1548 * scheduled for execution once either the delay has expired or the
1549 * socket operation is ready. It will be run with the priority of
1552 * @param delay when should this operation time out? Use
1553 * GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
1554 * @param wfd write file-descriptor
1555 * @param task main function of the task
1556 * @param task_cls closure of task
1557 * @return unique task identifier for the job
1558 * only valid until "task" is started!
1560 GNUNET_SCHEDULER_TaskIdentifier
1561 GNUNET_SCHEDULER_add_write_file (struct GNUNET_TIME_Relative delay,
1562 const struct GNUNET_DISK_FileHandle * wfd,
1563 GNUNET_SCHEDULER_Task task, void *task_cls)
1566 struct GNUNET_NETWORK_FDSet *ws;
1567 GNUNET_SCHEDULER_TaskIdentifier ret;
1569 GNUNET_assert (wfd != NULL);
1570 ws = GNUNET_NETWORK_fdset_create ();
1571 GNUNET_NETWORK_fdset_handle_set (ws, wfd);
1572 ret = GNUNET_SCHEDULER_add_select (check_priority (current_priority),
1573 GNUNET_SCHEDULER_NO_TASK,
1574 delay, NULL, ws, task, task_cls);
1575 GNUNET_NETWORK_fdset_destroy (ws);
1580 GNUNET_DISK_internal_file_handle_ (wfd, &fd, sizeof (int));
1581 GNUNET_assert(fd >= 0);
1582 return add_without_sets (delay,
1594 * Schedule a new task to be run with a specified delay or when any of
1595 * the specified file descriptor sets is ready. The delay can be used
1596 * as a timeout on the socket(s) being ready. The task will be
1597 * scheduled for execution once either the delay has expired or any of
1598 * the socket operations is ready. This is the most general
1599 * function of the "add" family. Note that the "prerequisite_task"
1600 * must be satisfied in addition to any of the other conditions. In
1601 * other words, the task will be started when
1603 * (prerequisite-run)
1607 * || (shutdown-active && run-on-shutdown) )
1610 * @param prio how important is this task?
1611 * @param prerequisite_task run this task after the task with the given
1612 * task identifier completes (and any of our other
1613 * conditions, such as delay, read or write-readiness
1614 * are satisfied). Use GNUNET_SCHEDULER_NO_TASK to not have any dependency
1615 * on completion of other tasks.
1616 * @param delay how long should we wait? Use GNUNET_TIME_UNIT_FOREVER_REL for "forever",
1617 * which means that the task will only be run after we receive SIGTERM
1618 * @param rs set of file descriptors we want to read (can be NULL)
1619 * @param ws set of file descriptors we want to write (can be NULL)
1620 * @param task main function of the task
1621 * @param task_cls closure of task
1622 * @return unique task identifier for the job
1623 * only valid until "task" is started!
1625 GNUNET_SCHEDULER_TaskIdentifier
1626 GNUNET_SCHEDULER_add_select (enum GNUNET_SCHEDULER_Priority prio,
1627 GNUNET_SCHEDULER_TaskIdentifier
1629 struct GNUNET_TIME_Relative delay,
1630 const struct GNUNET_NETWORK_FDSet * rs,
1631 const struct GNUNET_NETWORK_FDSet * ws,
1632 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 = backtrace_symbols(backtrace_array, t->num_backtrace_strings);
1652 t->read_set = GNUNET_NETWORK_fdset_create ();
1653 GNUNET_NETWORK_fdset_copy (t->read_set, rs);
1657 t->write_set = GNUNET_NETWORK_fdset_create ();
1658 GNUNET_NETWORK_fdset_copy (t->write_set, ws);
1662 t->start_time = GNUNET_TIME_absolute_get ();
1664 t->prereq_id = prerequisite_task;
1665 t->timeout = GNUNET_TIME_relative_to_absolute (delay);
1667 check_priority ((prio ==
1668 GNUNET_SCHEDULER_PRIORITY_KEEP) ? current_priority
1670 t->lifeness = current_lifeness;
1673 max_priority_added = GNUNET_MAX (max_priority_added,
1676 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1677 "Adding task: %llu / %p\n", t->id, t->callback_cls);
1682 for (i=0;i<t->num_backtrace_strings;i++)
1683 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1684 "Task %llu trace %d: %s\n",
1687 t->backtrace_strings[i]);
1692 /* end of scheduler.c */