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-rw-r--r--src/util/scheduler.c2569
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diff --git a/src/util/scheduler.c b/src/util/scheduler.c
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1/*
2 This file is part of GNUnet
3 Copyright (C) 2009-2017 GNUnet e.V.
4
5 GNUnet is free software: you can redistribute it and/or modify it
6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
8 or (at your option) any later version.
9
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 Affero General Public License for more details.
14
15 You should have received a copy of the GNU Affero General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
17
18 SPDX-License-Identifier: AGPL3.0-or-later
19 */
20/**
21 * @file util/scheduler.c
22 * @brief schedule computations using continuation passing style
23 * @author Christian Grothoff
24 */
25#include "platform.h"
26#include "gnunet_util_lib.h"
27#include "disk.h"
28// DEBUG
29#include <inttypes.h>
30
31#define LOG(kind, ...) GNUNET_log_from (kind, "util-scheduler", __VA_ARGS__)
32
33#define LOG_STRERROR(kind, syscall) GNUNET_log_from_strerror (kind, \
34 "util-scheduler", \
35 syscall)
36
37
38#if HAVE_EXECINFO_H
39#include "execinfo.h"
40
41/**
42 * Use lsof to generate file descriptor reports on select error?
43 * (turn off for stable releases).
44 */
45#define USE_LSOF GNUNET_NO
46
47/**
48 * Obtain trace information for all scheduler calls that schedule tasks.
49 */
50#define EXECINFO GNUNET_NO
51
52/**
53 * Check each file descriptor before adding
54 */
55#define DEBUG_FDS GNUNET_NO
56
57/**
58 * Depth of the traces collected via EXECINFO.
59 */
60#define MAX_TRACE_DEPTH 50
61#endif
62
63/**
64 * Should we figure out which tasks are delayed for a while
65 * before they are run? (Consider using in combination with EXECINFO).
66 */
67#define PROFILE_DELAYS GNUNET_NO
68
69/**
70 * Task that were in the queue for longer than this are reported if
71 * PROFILE_DELAYS is active.
72 */
73#define DELAY_THRESHOLD GNUNET_TIME_UNIT_SECONDS
74
75
76/**
77 * Argument to be passed from the driver to
78 * #GNUNET_SCHEDULER_do_work(). Contains the
79 * scheduler's internal state.
80 */
81struct GNUNET_SCHEDULER_Handle
82{
83 /**
84 * Passed here to avoid constantly allocating/deallocating
85 * this element, but generally we want to get rid of this.
86 * @deprecated
87 */
88 struct GNUNET_NETWORK_FDSet *rs;
89
90 /**
91 * Passed here to avoid constantly allocating/deallocating
92 * this element, but generally we want to get rid of this.
93 * @deprecated
94 */
95 struct GNUNET_NETWORK_FDSet *ws;
96
97 /**
98 * context of the SIGINT handler
99 */
100 struct GNUNET_SIGNAL_Context *shc_int;
101
102 /**
103 * context of the SIGTERM handler
104 */
105 struct GNUNET_SIGNAL_Context *shc_term;
106
107#if (SIGTERM != GNUNET_TERM_SIG)
108 /**
109 * context of the TERM_SIG handler
110 */
111 struct GNUNET_SIGNAL_Context *shc_gterm;
112#endif
113
114 /**
115 * context of the SIGQUIT handler
116 */
117 struct GNUNET_SIGNAL_Context *shc_quit;
118
119 /**
120 * context of the SIGHUP handler
121 */
122 struct GNUNET_SIGNAL_Context *shc_hup;
123
124 /**
125 * context of the SIGPIPE handler
126 */
127 struct GNUNET_SIGNAL_Context *shc_pipe;
128};
129
130
131/**
132 * Entry in list of pending tasks.
133 */
134struct GNUNET_SCHEDULER_Task
135{
136 /**
137 * This is a linked list.
138 */
139 struct GNUNET_SCHEDULER_Task *next;
140
141 /**
142 * This is a linked list.
143 */
144 struct GNUNET_SCHEDULER_Task *prev;
145
146 /**
147 * Function to run when ready.
148 */
149 GNUNET_SCHEDULER_TaskCallback callback;
150
151 /**
152 * Closure for the @e callback.
153 */
154 void *callback_cls;
155
156 /**
157 * Information about which FDs are ready for this task (and why).
158 */
159 struct GNUNET_SCHEDULER_FdInfo *fds;
160
161 /**
162 * Storage location used for @e fds if we want to avoid
163 * a separate malloc() call in the common case that this
164 * task is only about a single FD.
165 */
166 struct GNUNET_SCHEDULER_FdInfo fdx;
167
168 /**
169 * Size of the @e fds array.
170 */
171 unsigned int fds_len;
172
173 /**
174 * Do we own the network and file handles referenced by the FdInfo
175 * structs in the fds array. This will only be GNUNET_YES if the
176 * task was created by the #GNUNET_SCHEDULER_add_select function.
177 */
178 int own_handles;
179
180 /**
181 * Absolute timeout value for the task, or
182 * #GNUNET_TIME_UNIT_FOREVER_ABS for "no timeout".
183 */
184 struct GNUNET_TIME_Absolute timeout;
185
186#if PROFILE_DELAYS
187 /**
188 * When was the task scheduled?
189 */
190 struct GNUNET_TIME_Absolute start_time;
191#endif
192
193 /**
194 * Why is the task ready? Set after task is added to ready queue.
195 * Initially set to zero. All reasons that have already been
196 * satisfied (e.g. read or write ready) will be set over time.
197 */
198 enum GNUNET_SCHEDULER_Reason reason;
199
200 /**
201 * Task priority.
202 */
203 enum GNUNET_SCHEDULER_Priority priority;
204
205 /**
206 * Set if we only wait for reading from a single FD, otherwise -1.
207 */
208 int read_fd;
209
210 /**
211 * Set if we only wait for writing to a single FD, otherwise -1.
212 */
213 int write_fd;
214
215 /**
216 * Should the existence of this task in the queue be counted as
217 * reason to not shutdown the scheduler?
218 */
219 int lifeness;
220
221 /**
222 * Is this task run on shutdown?
223 */
224 int on_shutdown;
225
226 /**
227 * Is this task in the ready list?
228 */
229 int in_ready_list;
230
231#if EXECINFO
232 /**
233 * Array of strings which make up a backtrace from the point when this
234 * task was scheduled (essentially, who scheduled the task?)
235 */
236 char **backtrace_strings;
237
238 /**
239 * Size of the backtrace_strings array
240 */
241 int num_backtrace_strings;
242#endif
243
244 /**
245 * Asynchronous scope of the task that scheduled this scope,
246 */
247 struct GNUNET_AsyncScopeSave scope;
248};
249
250
251/**
252 * A struct representing an event the select driver is waiting for
253 */
254struct Scheduled
255{
256 struct Scheduled *prev;
257
258 struct Scheduled *next;
259
260 /**
261 * the task, the event is related to
262 */
263 struct GNUNET_SCHEDULER_Task *task;
264
265 /**
266 * information about the network socket / file descriptor where
267 * the event is expected to occur
268 */
269 struct GNUNET_SCHEDULER_FdInfo *fdi;
270
271 /**
272 * the event types (multiple event types can be ORed) the select
273 * driver is expected to wait for
274 */
275 enum GNUNET_SCHEDULER_EventType et;
276};
277
278
279/**
280 * Driver context used by GNUNET_SCHEDULER_run
281 */
282struct DriverContext
283{
284 /**
285 * the head of a DLL containing information about the events the
286 * select driver is waiting for
287 */
288 struct Scheduled *scheduled_head;
289
290 /**
291 * the tail of a DLL containing information about the events the
292 * select driver is waiting for
293 */
294 struct Scheduled *scheduled_tail;
295
296 /**
297 * the time when the select driver will wake up again (after
298 * calling select)
299 */
300 struct GNUNET_TIME_Absolute timeout;
301};
302
303
304/**
305 * The driver used for the event loop. Will be handed over to
306 * the scheduler in #GNUNET_SCHEDULER_do_work(), persisted
307 * there in this variable for later use in functions like
308 * #GNUNET_SCHEDULER_add_select(), #add_without_sets() and
309 * #GNUNET_SCHEDULER_cancel().
310 */
311static const struct GNUNET_SCHEDULER_Driver *scheduler_driver;
312
313/**
314 * Head of list of tasks waiting for an event.
315 */
316static struct GNUNET_SCHEDULER_Task *pending_head;
317
318/**
319 * Tail of list of tasks waiting for an event.
320 */
321static struct GNUNET_SCHEDULER_Task *pending_tail;
322
323/**
324 * Head of list of tasks waiting for shutdown.
325 */
326static struct GNUNET_SCHEDULER_Task *shutdown_head;
327
328/**
329 * Tail of list of tasks waiting for shutdown.
330 */
331static struct GNUNET_SCHEDULER_Task *shutdown_tail;
332
333/**
334 * List of tasks waiting ONLY for a timeout event.
335 * Sorted by timeout (earliest first). Used so that
336 * we do not traverse the list of these tasks when
337 * building select sets (we just look at the head
338 * to determine the respective timeout ONCE).
339 */
340static struct GNUNET_SCHEDULER_Task *pending_timeout_head;
341
342/**
343 * List of tasks waiting ONLY for a timeout event.
344 * Sorted by timeout (earliest first). Used so that
345 * we do not traverse the list of these tasks when
346 * building select sets (we just look at the head
347 * to determine the respective timeout ONCE).
348 */
349static struct GNUNET_SCHEDULER_Task *pending_timeout_tail;
350
351/**
352 * Last inserted task waiting ONLY for a timeout event.
353 * Used to (heuristically) speed up insertion.
354 */
355static struct GNUNET_SCHEDULER_Task *pending_timeout_last;
356
357/**
358 * ID of the task that is running right now.
359 */
360static struct GNUNET_SCHEDULER_Task *active_task;
361
362/**
363 * Head of list of tasks ready to run right now, grouped by importance.
364 */
365static struct
366GNUNET_SCHEDULER_Task *ready_head[GNUNET_SCHEDULER_PRIORITY_COUNT];
367
368/**
369 * Tail of list of tasks ready to run right now, grouped by importance.
370 */
371static struct
372GNUNET_SCHEDULER_Task *ready_tail[GNUNET_SCHEDULER_PRIORITY_COUNT];
373
374/**
375 * Task for installing parent control handlers (it might happen that the
376 * scheduler is shutdown before this task is executed, so
377 * GNUNET_SCHEDULER_shutdown must cancel it in that case)
378 */
379static struct GNUNET_SCHEDULER_Task *install_parent_control_task;
380
381/**
382 * Task for reading from a pipe that signal handlers will use to initiate
383 * shutdown
384 */
385static struct GNUNET_SCHEDULER_Task *shutdown_pipe_task;
386
387/**
388 * Number of tasks on the ready list.
389 */
390static unsigned int ready_count;
391
392/**
393 * Priority of the task running right now. Only
394 * valid while a task is running.
395 */
396static enum GNUNET_SCHEDULER_Priority current_priority;
397
398/**
399 * Priority of the highest task added in the current select
400 * iteration.
401 */
402static enum GNUNET_SCHEDULER_Priority max_priority_added;
403
404/**
405 * Value of the 'lifeness' flag for the current task.
406 */
407static int current_lifeness;
408
409/**
410 * Priority used currently in #GNUNET_SCHEDULER_do_work().
411 */
412static enum GNUNET_SCHEDULER_Priority work_priority;
413
414/**
415 * Function to use as a select() in the scheduler.
416 * If NULL, we use GNUNET_NETWORK_socket_select().
417 */
418static GNUNET_SCHEDULER_select scheduler_select;
419
420/**
421 * Task context of the current task.
422 */
423static struct GNUNET_SCHEDULER_TaskContext tc;
424
425/**
426 * Closure for #scheduler_select.
427 */
428static void *scheduler_select_cls;
429
430
431/**
432 * Sets the select function to use in the scheduler (scheduler_select).
433 *
434 * @param new_select new select function to use
435 * @param new_select_cls closure for @a new_select
436 * @return previously used select function, NULL for default
437 */
438void
439GNUNET_SCHEDULER_set_select (GNUNET_SCHEDULER_select new_select,
440 void *new_select_cls)
441{
442 scheduler_select = new_select;
443 scheduler_select_cls = new_select_cls;
444}
445
446
447/**
448 * Check that the given priority is legal (and return it).
449 *
450 * @param p priority value to check
451 * @return p on success, 0 on error
452 */
453static enum GNUNET_SCHEDULER_Priority
454check_priority (enum GNUNET_SCHEDULER_Priority p)
455{
456 if ((p >= 0) && (p < GNUNET_SCHEDULER_PRIORITY_COUNT))
457 return p;
458 GNUNET_assert (0);
459 return 0; /* make compiler happy */
460}
461
462
463/**
464 * chooses the nearest timeout from all pending tasks, to be used
465 * to tell the driver the next wakeup time (using its set_wakeup
466 * callback)
467 */
468struct GNUNET_TIME_Absolute
469get_timeout ()
470{
471 struct GNUNET_SCHEDULER_Task *pos;
472 struct GNUNET_TIME_Absolute now;
473 struct GNUNET_TIME_Absolute timeout;
474
475 pos = pending_timeout_head;
476 now = GNUNET_TIME_absolute_get ();
477 timeout = GNUNET_TIME_UNIT_FOREVER_ABS;
478 if (NULL != pos)
479 {
480 if (0 != pos->reason)
481 {
482 return now;
483 }
484 else
485 {
486 timeout = pos->timeout;
487 }
488 }
489 for (pos = pending_head; NULL != pos; pos = pos->next)
490 {
491 if (0 != pos->reason)
492 {
493 return now;
494 }
495 else if ((pos->timeout.abs_value_us !=
496 GNUNET_TIME_UNIT_FOREVER_ABS.abs_value_us) &&
497 (timeout.abs_value_us > pos->timeout.abs_value_us))
498 {
499 timeout = pos->timeout;
500 }
501 }
502 return timeout;
503}
504
505
506/**
507 * Put a task that is ready for execution into the ready queue.
508 *
509 * @param task task ready for execution
510 */
511static void
512queue_ready_task (struct GNUNET_SCHEDULER_Task *task)
513{
514 enum GNUNET_SCHEDULER_Priority p = check_priority (task->priority);
515
516 GNUNET_CONTAINER_DLL_insert_tail (ready_head[p],
517 ready_tail[p],
518 task);
519 task->in_ready_list = GNUNET_YES;
520 ready_count++;
521}
522
523
524/**
525 * Request the shutdown of a scheduler. Marks all tasks
526 * awaiting shutdown as ready. Note that tasks
527 * scheduled with #GNUNET_SCHEDULER_add_shutdown() AFTER this call
528 * will be delayed until the next shutdown signal.
529 */
530void
531GNUNET_SCHEDULER_shutdown ()
532{
533 struct GNUNET_SCHEDULER_Task *pos;
534
535 LOG (GNUNET_ERROR_TYPE_DEBUG,
536 "GNUNET_SCHEDULER_shutdown\n");
537 if (NULL != install_parent_control_task)
538 {
539 GNUNET_SCHEDULER_cancel (install_parent_control_task);
540 install_parent_control_task = NULL;
541 }
542 if (NULL != shutdown_pipe_task)
543 {
544 GNUNET_SCHEDULER_cancel (shutdown_pipe_task);
545 shutdown_pipe_task = NULL;
546 }
547 while (NULL != (pos = shutdown_head))
548 {
549 GNUNET_CONTAINER_DLL_remove (shutdown_head,
550 shutdown_tail,
551 pos);
552 pos->reason |= GNUNET_SCHEDULER_REASON_SHUTDOWN;
553 queue_ready_task (pos);
554 }
555}
556
557
558/**
559 * Output stack trace of task @a t.
560 *
561 * @param t task to dump stack trace of
562 */
563static void
564dump_backtrace (struct GNUNET_SCHEDULER_Task *t)
565{
566#if EXECINFO
567 for (unsigned int i = 0; i < t->num_backtrace_strings; i++)
568 LOG (GNUNET_ERROR_TYPE_WARNING,
569 "Task %p trace %u: %s\n",
570 t,
571 i,
572 t->backtrace_strings[i]);
573#else
574 (void) t;
575#endif
576}
577
578
579/**
580 * Destroy a task (release associated resources)
581 *
582 * @param t task to destroy
583 */
584static void
585destroy_task (struct GNUNET_SCHEDULER_Task *t)
586{
587 LOG (GNUNET_ERROR_TYPE_DEBUG,
588 "destroying task %p\n",
589 t);
590
591 if (GNUNET_YES == t->own_handles)
592 {
593 for (unsigned int i = 0; i != t->fds_len; ++i)
594 {
595 const struct GNUNET_NETWORK_Handle *fd = t->fds[i].fd;
596 const struct GNUNET_DISK_FileHandle *fh = t->fds[i].fh;
597 if (fd)
598 {
599 GNUNET_NETWORK_socket_free_memory_only_ (
600 (struct GNUNET_NETWORK_Handle *) fd);
601 }
602 if (fh)
603 {
604 // FIXME: on WIN32 this is not enough! A function
605 // GNUNET_DISK_file_free_memory_only would be nice
606 GNUNET_free_nz ((void *) fh);
607 }
608 }
609 }
610 if (t->fds_len > 1)
611 {
612 GNUNET_array_grow (t->fds, t->fds_len, 0);
613 }
614#if EXECINFO
615 GNUNET_free (t->backtrace_strings);
616#endif
617 GNUNET_free (t);
618}
619
620
621/**
622 * Pipe used to communicate shutdown via signal.
623 */
624static struct GNUNET_DISK_PipeHandle *shutdown_pipe_handle;
625
626/**
627 * Process ID of this process at the time we installed the various
628 * signal handlers.
629 */
630static pid_t my_pid;
631
632/**
633 * Signal handler called for SIGPIPE.
634 */
635static void
636sighandler_pipe ()
637{
638 return;
639}
640
641
642///**
643// * Wait for a short time.
644// * Sleeps for @a ms ms (as that should be long enough for virtually all
645// * modern systems to context switch and allow another process to do
646// * some 'real' work).
647// *
648// * @param ms how many ms to wait
649// */
650// static void
651// short_wait (unsigned int ms)
652// {
653// struct GNUNET_TIME_Relative timeout;
654//
655// timeout = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, ms);
656// (void) GNUNET_NETWORK_socket_select (NULL, NULL, NULL, timeout);
657// }
658
659
660/**
661 * Signal handler called for signals that should cause us to shutdown.
662 */
663static void
664sighandler_shutdown ()
665{
666 static char c;
667 int old_errno = errno; /* backup errno */
668
669 if (getpid () != my_pid)
670 _exit (1); /* we have fork'ed since the signal handler was created,
671 * ignore the signal, see https://gnunet.org/vfork discussion */
672 GNUNET_DISK_file_write (GNUNET_DISK_pipe_handle
673 (shutdown_pipe_handle, GNUNET_DISK_PIPE_END_WRITE),
674 &c, sizeof(c));
675 errno = old_errno;
676}
677
678
679static void
680shutdown_if_no_lifeness ()
681{
682 struct GNUNET_SCHEDULER_Task *t;
683
684 if (ready_count > 0)
685 return;
686 for (t = pending_head; NULL != t; t = t->next)
687 if (GNUNET_YES == t->lifeness)
688 return;
689 for (t = shutdown_head; NULL != t; t = t->next)
690 if (GNUNET_YES == t->lifeness)
691 return;
692 for (t = pending_timeout_head; NULL != t; t = t->next)
693 if (GNUNET_YES == t->lifeness)
694 return;
695 /* No lifeness! */
696 GNUNET_SCHEDULER_shutdown ();
697}
698
699
700static int
701select_loop (struct GNUNET_SCHEDULER_Handle *sh,
702 struct DriverContext *context);
703
704
705/**
706 * Initialize and run scheduler. This function will return when all
707 * tasks have completed. On systems with signals, receiving a SIGTERM
708 * (and other similar signals) will cause #GNUNET_SCHEDULER_shutdown()
709 * to be run after the active task is complete. As a result, SIGTERM
710 * causes all active tasks to be scheduled with reason
711 * #GNUNET_SCHEDULER_REASON_SHUTDOWN. (However, tasks added
712 * afterwards will execute normally!). Note that any particular signal
713 * will only shut down one scheduler; applications should always only
714 * create a single scheduler.
715 *
716 * @param task task to run immediately
717 * @param task_cls closure of @a task
718 */
719void
720GNUNET_SCHEDULER_run (GNUNET_SCHEDULER_TaskCallback task,
721 void *task_cls)
722{
723 struct GNUNET_SCHEDULER_Handle *sh;
724 struct GNUNET_SCHEDULER_Driver *driver;
725 struct DriverContext context = {
726 .scheduled_head = NULL,
727 .scheduled_tail = NULL,
728 .timeout = GNUNET_TIME_absolute_get ()
729 };
730
731 driver = GNUNET_SCHEDULER_driver_select ();
732 driver->cls = &context;
733 sh = GNUNET_SCHEDULER_driver_init (driver);
734 GNUNET_SCHEDULER_add_with_reason_and_priority (task,
735 task_cls,
736 GNUNET_SCHEDULER_REASON_STARTUP,
737 GNUNET_SCHEDULER_PRIORITY_DEFAULT);
738 select_loop (sh,
739 &context);
740 GNUNET_SCHEDULER_driver_done (sh);
741 GNUNET_free (driver);
742}
743
744
745/**
746 * Obtain the task context, giving the reason why the current task was
747 * started.
748 *
749 * @return current tasks' scheduler context
750 */
751const struct GNUNET_SCHEDULER_TaskContext *
752GNUNET_SCHEDULER_get_task_context ()
753{
754 GNUNET_assert (NULL != active_task);
755 return &tc;
756}
757
758
759/**
760 * Get information about the current load of this scheduler. Use this
761 * function to determine if an elective task should be added or simply
762 * dropped (if the decision should be made based on the number of
763 * tasks ready to run).
764 *
765 * @param p priority level to look at
766 * @return number of tasks pending right now
767 */
768unsigned int
769GNUNET_SCHEDULER_get_load (enum GNUNET_SCHEDULER_Priority p)
770{
771 unsigned int ret;
772
773 GNUNET_assert (NULL != active_task);
774 if (p == GNUNET_SCHEDULER_PRIORITY_COUNT)
775 return ready_count;
776 if (p == GNUNET_SCHEDULER_PRIORITY_KEEP)
777 p = current_priority;
778 ret = 0;
779 for (struct GNUNET_SCHEDULER_Task *pos = ready_head[check_priority (p)];
780 NULL != pos;
781 pos = pos->next)
782 ret++;
783 return ret;
784}
785
786
787void
788init_fd_info (struct GNUNET_SCHEDULER_Task *t,
789 const struct GNUNET_NETWORK_Handle *const *read_nh,
790 unsigned int read_nh_len,
791 const struct GNUNET_NETWORK_Handle *const *write_nh,
792 unsigned int write_nh_len,
793 const struct GNUNET_DISK_FileHandle *const *read_fh,
794 unsigned int read_fh_len,
795 const struct GNUNET_DISK_FileHandle *const *write_fh,
796 unsigned int write_fh_len)
797{
798 // FIXME: if we have exactly two network handles / exactly two file handles
799 // and they are equal, we can make one FdInfo with both
800 // GNUNET_SCHEDULER_ET_IN and GNUNET_SCHEDULER_ET_OUT set.
801 struct GNUNET_SCHEDULER_FdInfo *fdi;
802
803 t->fds_len = read_nh_len + write_nh_len + read_fh_len + write_fh_len;
804 if (1 == t->fds_len)
805 {
806 fdi = &t->fdx;
807 t->fds = fdi;
808 if (1 == read_nh_len)
809 {
810 GNUNET_assert (NULL != read_nh);
811 GNUNET_assert (NULL != *read_nh);
812 fdi->fd = *read_nh;
813 fdi->et = GNUNET_SCHEDULER_ET_IN;
814 fdi->sock = GNUNET_NETWORK_get_fd (*read_nh);
815 t->read_fd = fdi->sock;
816 t->write_fd = -1;
817 }
818 else if (1 == write_nh_len)
819 {
820 GNUNET_assert (NULL != write_nh);
821 GNUNET_assert (NULL != *write_nh);
822 fdi->fd = *write_nh;
823 fdi->et = GNUNET_SCHEDULER_ET_OUT;
824 fdi->sock = GNUNET_NETWORK_get_fd (*write_nh);
825 t->read_fd = -1;
826 t->write_fd = fdi->sock;
827 }
828 else if (1 == read_fh_len)
829 {
830 GNUNET_assert (NULL != read_fh);
831 GNUNET_assert (NULL != *read_fh);
832 fdi->fh = *read_fh;
833 fdi->et = GNUNET_SCHEDULER_ET_IN;
834 fdi->sock = (*read_fh)->fd; // FIXME: does not work under WIN32
835 t->read_fd = fdi->sock;
836 t->write_fd = -1;
837 }
838 else
839 {
840 GNUNET_assert (NULL != write_fh);
841 GNUNET_assert (NULL != *write_fh);
842 fdi->fh = *write_fh;
843 fdi->et = GNUNET_SCHEDULER_ET_OUT;
844 fdi->sock = (*write_fh)->fd; // FIXME: does not work under WIN32
845 t->read_fd = -1;
846 t->write_fd = fdi->sock;
847 }
848 }
849 else
850 {
851 fdi = GNUNET_new_array (t->fds_len, struct GNUNET_SCHEDULER_FdInfo);
852 t->fds = fdi;
853 t->read_fd = -1;
854 t->write_fd = -1;
855 unsigned int i;
856 for (i = 0; i != read_nh_len; ++i)
857 {
858 fdi->fd = read_nh[i];
859 GNUNET_assert (NULL != fdi->fd);
860 fdi->et = GNUNET_SCHEDULER_ET_IN;
861 fdi->sock = GNUNET_NETWORK_get_fd (read_nh[i]);
862 ++fdi;
863 }
864 for (i = 0; i != write_nh_len; ++i)
865 {
866 fdi->fd = write_nh[i];
867 GNUNET_assert (NULL != fdi->fd);
868 fdi->et = GNUNET_SCHEDULER_ET_OUT;
869 fdi->sock = GNUNET_NETWORK_get_fd (write_nh[i]);
870 ++fdi;
871 }
872 for (i = 0; i != read_fh_len; ++i)
873 {
874 fdi->fh = read_fh[i];
875 GNUNET_assert (NULL != fdi->fh);
876 fdi->et = GNUNET_SCHEDULER_ET_IN;
877 fdi->sock = (read_fh[i])->fd; // FIXME: does not work under WIN32
878 ++fdi;
879 }
880 for (i = 0; i != write_fh_len; ++i)
881 {
882 fdi->fh = write_fh[i];
883 GNUNET_assert (NULL != fdi->fh);
884 fdi->et = GNUNET_SCHEDULER_ET_OUT;
885 fdi->sock = (write_fh[i])->fd; // FIXME: does not work under WIN32
886 ++fdi;
887 }
888 }
889}
890
891
892/**
893 * calls the given function @a func on each FdInfo related to @a t.
894 * Optionally updates the event type field in each FdInfo after calling
895 * @a func.
896 *
897 * @param t the task
898 * @param driver_func the function to call with each FdInfo contained in
899 * in @a t
900 * @param if_not_ready only call @a driver_func on FdInfos that are not
901 * ready
902 * @param et the event type to be set in each FdInfo after calling
903 * @a driver_func on it, or -1 if no updating not desired.
904 */
905static void
906driver_add_multiple (struct GNUNET_SCHEDULER_Task *t)
907{
908 struct GNUNET_SCHEDULER_FdInfo *fdi;
909 int success = GNUNET_YES;
910
911 for (unsigned int i = 0; i != t->fds_len; ++i)
912 {
913 fdi = &t->fds[i];
914 success = scheduler_driver->add (scheduler_driver->cls,
915 t,
916 fdi) && success;
917 fdi->et = GNUNET_SCHEDULER_ET_NONE;
918 }
919 if (GNUNET_YES != success)
920 {
921 LOG (GNUNET_ERROR_TYPE_ERROR,
922 "driver could not add task\n");
923 }
924}
925
926
927static void
928install_parent_control_handler (void *cls)
929{
930 (void) cls;
931 install_parent_control_task = NULL;
932 GNUNET_OS_install_parent_control_handler (NULL);
933}
934
935
936static void
937shutdown_pipe_cb (void *cls)
938{
939 char c;
940 const struct GNUNET_DISK_FileHandle *pr;
941
942 (void) cls;
943 shutdown_pipe_task = NULL;
944 pr = GNUNET_DISK_pipe_handle (shutdown_pipe_handle,
945 GNUNET_DISK_PIPE_END_READ);
946 GNUNET_assert (! GNUNET_DISK_handle_invalid (pr));
947 /* consume the signal */
948 GNUNET_DISK_file_read (pr, &c, sizeof(c));
949 /* mark all active tasks as ready due to shutdown */
950 GNUNET_SCHEDULER_shutdown ();
951 shutdown_pipe_task =
952 GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
953 pr,
954 &shutdown_pipe_cb,
955 NULL);
956}
957
958
959/**
960 * Cancel the task with the specified identifier.
961 * The task must not yet have run. Only allowed to be called as long as the
962 * scheduler is running, that is one of the following conditions is met:
963 *
964 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
965 * - #GNUNET_SCHEDULER_driver_init has been run and
966 * #GNUNET_SCHEDULER_driver_done has not been called yet
967 *
968 * @param task id of the task to cancel
969 * @return original closure of the task
970 */
971void *
972GNUNET_SCHEDULER_cancel (struct GNUNET_SCHEDULER_Task *task)
973{
974 enum GNUNET_SCHEDULER_Priority p;
975 int is_fd_task;
976 void *ret;
977
978 LOG (GNUNET_ERROR_TYPE_DEBUG,
979 "canceling task %p\n",
980 task);
981
982 /* scheduler must be running */
983 GNUNET_assert (NULL != scheduler_driver);
984 is_fd_task = (NULL != task->fds);
985 if (is_fd_task)
986 {
987 int del_result = scheduler_driver->del (scheduler_driver->cls, task);
988 if (GNUNET_OK != del_result)
989 {
990 LOG (GNUNET_ERROR_TYPE_ERROR,
991 "driver could not delete task\n");
992 GNUNET_assert (0);
993 }
994 }
995 if (! task->in_ready_list)
996 {
997 if (is_fd_task)
998 {
999 GNUNET_CONTAINER_DLL_remove (pending_head,
1000 pending_tail,
1001 task);
1002 }
1003 else if (GNUNET_YES == task->on_shutdown)
1004 {
1005 GNUNET_CONTAINER_DLL_remove (shutdown_head,
1006 shutdown_tail,
1007 task);
1008 }
1009 else
1010 {
1011 GNUNET_CONTAINER_DLL_remove (pending_timeout_head,
1012 pending_timeout_tail,
1013 task);
1014 if (pending_timeout_last == task)
1015 pending_timeout_last = NULL;
1016 }
1017 }
1018 else
1019 {
1020 p = check_priority (task->priority);
1021 GNUNET_CONTAINER_DLL_remove (ready_head[p],
1022 ready_tail[p],
1023 task);
1024 ready_count--;
1025 }
1026 ret = task->callback_cls;
1027 destroy_task (task);
1028 return ret;
1029}
1030
1031
1032/**
1033 * Initialize backtrace data for task @a t
1034 *
1035 * @param t task to initialize
1036 */
1037static void
1038init_backtrace (struct GNUNET_SCHEDULER_Task *t)
1039{
1040#if EXECINFO
1041 void *backtrace_array[MAX_TRACE_DEPTH];
1042
1043 t->num_backtrace_strings
1044 = backtrace (backtrace_array, MAX_TRACE_DEPTH);
1045 t->backtrace_strings =
1046 backtrace_symbols (backtrace_array,
1047 t->num_backtrace_strings);
1048 dump_backtrace (t);
1049#else
1050 (void) t;
1051#endif
1052}
1053
1054
1055/**
1056 * Continue the current execution with the given function. This is
1057 * similar to the other "add" functions except that there is no delay
1058 * and the reason code can be specified.
1059 *
1060 * @param task main function of the task
1061 * @param task_cls closure for @a task
1062 * @param reason reason for task invocation
1063 * @param priority priority to use for the task
1064 */
1065void
1066GNUNET_SCHEDULER_add_with_reason_and_priority (GNUNET_SCHEDULER_TaskCallback
1067 task,
1068 void *task_cls,
1069 enum GNUNET_SCHEDULER_Reason
1070 reason,
1071 enum GNUNET_SCHEDULER_Priority
1072 priority)
1073{
1074 struct GNUNET_SCHEDULER_Task *t;
1075
1076 /* scheduler must be running */
1077 GNUNET_assert (NULL != scheduler_driver);
1078 GNUNET_assert (NULL != task);
1079 t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
1080 t->read_fd = -1;
1081 t->write_fd = -1;
1082 t->callback = task;
1083 t->callback_cls = task_cls;
1084#if PROFILE_DELAYS
1085 t->start_time = GNUNET_TIME_absolute_get ();
1086#endif
1087 t->reason = reason;
1088 t->priority = check_priority (priority);
1089 t->lifeness = current_lifeness;
1090 LOG (GNUNET_ERROR_TYPE_DEBUG,
1091 "Adding continuation task %p\n",
1092 t);
1093 init_backtrace (t);
1094 queue_ready_task (t);
1095}
1096
1097
1098/**
1099 * Schedule a new task to be run at the specified time. The task
1100 * will be scheduled for execution at time @a at.
1101 *
1102 * @param at time when the operation should run
1103 * @param priority priority to use for the task
1104 * @param task main function of the task
1105 * @param task_cls closure of @a task
1106 * @return unique task identifier for the job
1107 * only valid until @a task is started!
1108 */
1109struct GNUNET_SCHEDULER_Task *
1110GNUNET_SCHEDULER_add_at_with_priority (struct GNUNET_TIME_Absolute at,
1111 enum GNUNET_SCHEDULER_Priority priority,
1112 GNUNET_SCHEDULER_TaskCallback task,
1113 void *task_cls)
1114{
1115 struct GNUNET_SCHEDULER_Task *t;
1116 struct GNUNET_SCHEDULER_Task *pos;
1117 struct GNUNET_SCHEDULER_Task *prev;
1118 struct GNUNET_TIME_Relative left;
1119
1120 /* scheduler must be running */
1121 GNUNET_assert (NULL != scheduler_driver);
1122 GNUNET_assert (NULL != task);
1123 t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
1124 GNUNET_async_scope_get (&t->scope);
1125 t->callback = task;
1126 t->callback_cls = task_cls;
1127 t->read_fd = -1;
1128 t->write_fd = -1;
1129#if PROFILE_DELAYS
1130 t->start_time = GNUNET_TIME_absolute_get ();
1131#endif
1132 t->timeout = at;
1133 t->priority = check_priority (priority);
1134 t->lifeness = current_lifeness;
1135 init_backtrace (t);
1136
1137 left = GNUNET_TIME_absolute_get_remaining (at);
1138 if (0 == left.rel_value_us)
1139 {
1140 queue_ready_task (t);
1141 if (priority > work_priority)
1142 work_priority = priority;
1143 return t;
1144 }
1145
1146 /* try tail first (optimization in case we are
1147 * appending to a long list of tasks with timeouts) */
1148 if ((NULL == pending_timeout_head) ||
1149 (at.abs_value_us < pending_timeout_head->timeout.abs_value_us))
1150 {
1151 GNUNET_CONTAINER_DLL_insert (pending_timeout_head,
1152 pending_timeout_tail,
1153 t);
1154 }
1155 else
1156 {
1157 /* first move from heuristic start backwards to before start time */
1158 prev = pending_timeout_last;
1159 while ((NULL != prev) &&
1160 (prev->timeout.abs_value_us > t->timeout.abs_value_us))
1161 prev = prev->prev;
1162 /* now, move from heuristic start (or head of list) forward to insertion point */
1163 if (NULL == prev)
1164 pos = pending_timeout_head;
1165 else
1166 pos = prev->next;
1167 while ((NULL != pos) && (pos->timeout.abs_value_us <=
1168 t->timeout.abs_value_us))
1169 {
1170 prev = pos;
1171 pos = pos->next;
1172 }
1173 GNUNET_CONTAINER_DLL_insert_after (pending_timeout_head,
1174 pending_timeout_tail,
1175 prev,
1176 t);
1177 }
1178 /* finally, update heuristic insertion point to last insertion... */
1179 pending_timeout_last = t;
1180 LOG (GNUNET_ERROR_TYPE_DEBUG,
1181 "Adding task %p\n",
1182 t);
1183 return t;
1184}
1185
1186
1187/**
1188 * Schedule a new task to be run with a specified delay. The task
1189 * will be scheduled for execution once the delay has expired.
1190 *
1191 * @param delay when should this operation time out?
1192 * @param priority priority to use for the task
1193 * @param task main function of the task
1194 * @param task_cls closure of @a task
1195 * @return unique task identifier for the job
1196 * only valid until @a task is started!
1197 */
1198struct GNUNET_SCHEDULER_Task *
1199GNUNET_SCHEDULER_add_delayed_with_priority (struct GNUNET_TIME_Relative delay,
1200 enum GNUNET_SCHEDULER_Priority
1201 priority,
1202 GNUNET_SCHEDULER_TaskCallback task,
1203 void *task_cls)
1204{
1205 return GNUNET_SCHEDULER_add_at_with_priority (
1206 GNUNET_TIME_relative_to_absolute (delay),
1207 priority,
1208 task,
1209 task_cls);
1210}
1211
1212
1213/**
1214 * Schedule a new task to be run with a specified priority.
1215 *
1216 * @param prio how important is the new task?
1217 * @param task main function of the task
1218 * @param task_cls closure of @a task
1219 * @return unique task identifier for the job
1220 * only valid until @a task is started!
1221 */
1222struct GNUNET_SCHEDULER_Task *
1223GNUNET_SCHEDULER_add_with_priority (enum GNUNET_SCHEDULER_Priority prio,
1224 GNUNET_SCHEDULER_TaskCallback task,
1225 void *task_cls)
1226{
1227 return GNUNET_SCHEDULER_add_delayed_with_priority (GNUNET_TIME_UNIT_ZERO,
1228 prio,
1229 task,
1230 task_cls);
1231}
1232
1233
1234/**
1235 * Schedule a new task to be run at the specified time. The task
1236 * will be scheduled for execution once specified time has been
1237 * reached. It will be run with the DEFAULT priority.
1238 *
1239 * @param at time at which this operation should run
1240 * @param task main function of the task
1241 * @param task_cls closure of @a task
1242 * @return unique task identifier for the job
1243 * only valid until @a task is started!
1244 */
1245struct GNUNET_SCHEDULER_Task *
1246GNUNET_SCHEDULER_add_at (struct GNUNET_TIME_Absolute at,
1247 GNUNET_SCHEDULER_TaskCallback task,
1248 void *task_cls)
1249{
1250 return GNUNET_SCHEDULER_add_at_with_priority (at,
1251 GNUNET_SCHEDULER_PRIORITY_DEFAULT,
1252 task,
1253 task_cls);
1254}
1255
1256
1257/**
1258 * Schedule a new task to be run with a specified delay. The task
1259 * will be scheduled for execution once the delay has expired. It
1260 * will be run with the DEFAULT priority.
1261 *
1262 * @param delay when should this operation time out?
1263 * @param task main function of the task
1264 * @param task_cls closure of @a task
1265 * @return unique task identifier for the job
1266 * only valid until @a task is started!
1267 */
1268struct GNUNET_SCHEDULER_Task *
1269GNUNET_SCHEDULER_add_delayed (struct GNUNET_TIME_Relative delay,
1270 GNUNET_SCHEDULER_TaskCallback task,
1271 void *task_cls)
1272{
1273 return GNUNET_SCHEDULER_add_delayed_with_priority (delay,
1274 GNUNET_SCHEDULER_PRIORITY_DEFAULT,
1275 task,
1276 task_cls);
1277}
1278
1279
1280/**
1281 * Schedule a new task to be run as soon as possible. Note that this
1282 * does not guarantee that this will be the next task that is being
1283 * run, as other tasks with higher priority (or that are already ready
1284 * to run) might get to run first. Just as with delays, clients must
1285 * not rely on any particular order of execution between tasks
1286 * scheduled concurrently.
1287 *
1288 * The task will be run with the DEFAULT priority.
1289 *
1290 * @param task main function of the task
1291 * @param task_cls closure of @a task
1292 * @return unique task identifier for the job
1293 * only valid until @a task is started!
1294 */
1295struct GNUNET_SCHEDULER_Task *
1296GNUNET_SCHEDULER_add_now (GNUNET_SCHEDULER_TaskCallback task,
1297 void *task_cls)
1298{
1299 struct GNUNET_SCHEDULER_Task *t;
1300
1301 t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
1302 GNUNET_async_scope_get (&t->scope);
1303 t->callback = task;
1304 t->callback_cls = task_cls;
1305 t->read_fd = -1;
1306 t->write_fd = -1;
1307#if PROFILE_DELAYS
1308 t->start_time = GNUNET_TIME_absolute_get ();
1309#endif
1310 t->timeout = GNUNET_TIME_UNIT_ZERO_ABS;
1311 t->priority = current_priority;
1312 t->on_shutdown = GNUNET_YES;
1313 t->lifeness = current_lifeness;
1314 queue_ready_task (t);
1315 init_backtrace (t);
1316 return t;
1317}
1318
1319
1320/**
1321 * Schedule a new task to be run on shutdown, that is when a CTRL-C
1322 * signal is received, or when #GNUNET_SCHEDULER_shutdown() is being
1323 * invoked.
1324 *
1325 * @param task main function of the task
1326 * @param task_cls closure of @a task
1327 * @return unique task identifier for the job
1328 * only valid until @a task is started!
1329 */
1330struct GNUNET_SCHEDULER_Task *
1331GNUNET_SCHEDULER_add_shutdown (GNUNET_SCHEDULER_TaskCallback task,
1332 void *task_cls)
1333{
1334 struct GNUNET_SCHEDULER_Task *t;
1335
1336 /* scheduler must be running */
1337 GNUNET_assert (NULL != scheduler_driver);
1338 GNUNET_assert (NULL != task);
1339 t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
1340 GNUNET_async_scope_get (&t->scope);
1341 t->callback = task;
1342 t->callback_cls = task_cls;
1343 t->read_fd = -1;
1344 t->write_fd = -1;
1345#if PROFILE_DELAYS
1346 t->start_time = GNUNET_TIME_absolute_get ();
1347#endif
1348 t->timeout = GNUNET_TIME_UNIT_FOREVER_ABS;
1349 t->priority = GNUNET_SCHEDULER_PRIORITY_SHUTDOWN;
1350 t->on_shutdown = GNUNET_YES;
1351 t->lifeness = GNUNET_NO;
1352 GNUNET_CONTAINER_DLL_insert (shutdown_head,
1353 shutdown_tail,
1354 t);
1355 LOG (GNUNET_ERROR_TYPE_DEBUG,
1356 "Adding shutdown task %p\n",
1357 t);
1358 init_backtrace (t);
1359 return t;
1360}
1361
1362
1363/**
1364 * Schedule a new task to be run as soon as possible with the
1365 * (transitive) ignore-shutdown flag either explicitly set or
1366 * explicitly enabled. This task (and all tasks created from it,
1367 * other than by another call to this function) will either count or
1368 * not count for the "lifeness" of the process. This API is only
1369 * useful in a few special cases.
1370 *
1371 * @param lifeness #GNUNET_YES if the task counts for lifeness, #GNUNET_NO if not.
1372 * @param task main function of the task
1373 * @param task_cls closure of @a task
1374 * @return unique task identifier for the job
1375 * only valid until @a task is started!
1376 */
1377struct GNUNET_SCHEDULER_Task *
1378GNUNET_SCHEDULER_add_now_with_lifeness (int lifeness,
1379 GNUNET_SCHEDULER_TaskCallback task,
1380 void *task_cls)
1381{
1382 struct GNUNET_SCHEDULER_Task *ret;
1383
1384 ret = GNUNET_SCHEDULER_add_now (task, task_cls);
1385 ret->lifeness = lifeness;
1386 return ret;
1387}
1388
1389
1390#if DEBUG_FDS
1391/**
1392 * check a raw file descriptor and abort if it is bad (for debugging purposes)
1393 *
1394 * @param t the task related to the file descriptor
1395 * @param raw_fd the raw file descriptor to check
1396 */
1397void
1398check_fd (struct GNUNET_SCHEDULER_Task *t, int raw_fd)
1399{
1400 if (-1 != raw_fd)
1401 {
1402 int flags = fcntl (raw_fd, F_GETFD);
1403
1404 if ((flags == -1) && (errno == EBADF))
1405 {
1406 LOG (GNUNET_ERROR_TYPE_ERROR,
1407 "Got invalid file descriptor %d!\n",
1408 raw_fd);
1409 init_backtrace (t);
1410 GNUNET_assert (0);
1411 }
1412 }
1413}
1414
1415
1416#endif
1417
1418
1419/**
1420 * Schedule a new task to be run with a specified delay or when any of
1421 * the specified file descriptor sets is ready. The delay can be used
1422 * as a timeout on the socket(s) being ready. The task will be
1423 * scheduled for execution once either the delay has expired or any of
1424 * the socket operations is ready. This is the most general
1425 * function of the "add" family. Note that the "prerequisite_task"
1426 * must be satisfied in addition to any of the other conditions. In
1427 * other words, the task will be started when
1428 * <code>
1429 * (prerequisite-run)
1430 * && (delay-ready
1431 * || any-rs-ready
1432 * || any-ws-ready)
1433 * </code>
1434 *
1435 * @param delay how long should we wait?
1436 * @param priority priority to use
1437 * @param rfd file descriptor we want to read (can be -1)
1438 * @param wfd file descriptors we want to write (can be -1)
1439 * @param task main function of the task
1440 * @param task_cls closure of @a task
1441 * @return unique task identifier for the job
1442 * only valid until @a task is started!
1443 */
1444static struct GNUNET_SCHEDULER_Task *
1445add_without_sets (struct GNUNET_TIME_Relative delay,
1446 enum GNUNET_SCHEDULER_Priority priority,
1447 const struct GNUNET_NETWORK_Handle *read_nh,
1448 const struct GNUNET_NETWORK_Handle *write_nh,
1449 const struct GNUNET_DISK_FileHandle *read_fh,
1450 const struct GNUNET_DISK_FileHandle *write_fh,
1451 GNUNET_SCHEDULER_TaskCallback task,
1452 void *task_cls)
1453{
1454 struct GNUNET_SCHEDULER_Task *t;
1455
1456 /* scheduler must be running */
1457 GNUNET_assert (NULL != scheduler_driver);
1458 GNUNET_assert (NULL != task);
1459 t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
1460 GNUNET_async_scope_get (&t->scope);
1461 init_fd_info (t,
1462 &read_nh,
1463 read_nh ? 1 : 0,
1464 &write_nh,
1465 write_nh ? 1 : 0,
1466 &read_fh,
1467 read_fh ? 1 : 0,
1468 &write_fh,
1469 write_fh ? 1 : 0);
1470 t->callback = task;
1471 t->callback_cls = task_cls;
1472#if DEBUG_FDS
1473 check_fd (t, NULL != read_nh ? GNUNET_NETWORK_get_fd (read_nh) : -1);
1474 check_fd (t, NULL != write_nh ? GNUNET_NETWORK_get_fd (write_nh) : -1);
1475 check_fd (t, NULL != read_fh ? read_fh->fd : -1);
1476 check_fd (t, NULL != write_fh ? write_fh->fd : -1);
1477#endif
1478#if PROFILE_DELAYS
1479 t->start_time = GNUNET_TIME_absolute_get ();
1480#endif
1481 t->timeout = GNUNET_TIME_relative_to_absolute (delay);
1482 t->priority = check_priority ((priority == GNUNET_SCHEDULER_PRIORITY_KEEP) ?
1483 current_priority : priority);
1484 t->lifeness = current_lifeness;
1485 GNUNET_CONTAINER_DLL_insert (pending_head,
1486 pending_tail,
1487 t);
1488 driver_add_multiple (t);
1489 max_priority_added = GNUNET_MAX (max_priority_added,
1490 t->priority);
1491 init_backtrace (t);
1492 return t;
1493}
1494
1495
1496/**
1497 * Schedule a new task to be run with a specified delay or when the
1498 * specified file descriptor is ready for reading. The delay can be
1499 * used as a timeout on the socket being ready. The task will be
1500 * scheduled for execution once either the delay has expired or the
1501 * socket operation is ready. It will be run with the DEFAULT priority.
1502 * Only allowed to be called as long as the scheduler is running, that
1503 * is one of the following conditions is met:
1504 *
1505 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
1506 * - #GNUNET_SCHEDULER_driver_init has been run and
1507 * #GNUNET_SCHEDULER_driver_done has not been called yet
1508 *
1509 * @param delay when should this operation time out?
1510 * @param rfd read file-descriptor
1511 * @param task main function of the task
1512 * @param task_cls closure of @a task
1513 * @return unique task identifier for the job
1514 * only valid until @a task is started!
1515 */
1516struct GNUNET_SCHEDULER_Task *
1517GNUNET_SCHEDULER_add_read_net (struct GNUNET_TIME_Relative delay,
1518 struct GNUNET_NETWORK_Handle *rfd,
1519 GNUNET_SCHEDULER_TaskCallback task,
1520 void *task_cls)
1521{
1522 return GNUNET_SCHEDULER_add_read_net_with_priority (delay,
1523 GNUNET_SCHEDULER_PRIORITY_DEFAULT,
1524 rfd, task, task_cls);
1525}
1526
1527
1528/**
1529 * Schedule a new task to be run with a specified priority and to be
1530 * run after the specified delay or when the specified file descriptor
1531 * is ready for reading. The delay can be used as a timeout on the
1532 * socket being ready. The task will be scheduled for execution once
1533 * either the delay has expired or the socket operation is ready. It
1534 * will be run with the DEFAULT priority.
1535 * Only allowed to be called as long as the scheduler is running, that
1536 * is one of the following conditions is met:
1537 *
1538 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
1539 * - #GNUNET_SCHEDULER_driver_init has been run and
1540 * #GNUNET_SCHEDULER_driver_done has not been called yet
1541 *
1542 * @param delay when should this operation time out?
1543 * @param priority priority to use for the task
1544 * @param rfd read file-descriptor
1545 * @param task main function of the task
1546 * @param task_cls closure of @a task
1547 * @return unique task identifier for the job
1548 * only valid until @a task is started!
1549 */
1550struct GNUNET_SCHEDULER_Task *
1551GNUNET_SCHEDULER_add_read_net_with_priority (struct GNUNET_TIME_Relative delay,
1552 enum GNUNET_SCHEDULER_Priority
1553 priority,
1554 struct GNUNET_NETWORK_Handle *rfd,
1555 GNUNET_SCHEDULER_TaskCallback task,
1556 void *task_cls)
1557{
1558 return GNUNET_SCHEDULER_add_net_with_priority (delay, priority,
1559 rfd,
1560 GNUNET_YES,
1561 GNUNET_NO,
1562 task, task_cls);
1563}
1564
1565
1566/**
1567 * Schedule a new task to be run with a specified delay or when the
1568 * specified file descriptor is ready for writing. The delay can be
1569 * used as a timeout on the socket being ready. The task will be
1570 * scheduled for execution once either the delay has expired or the
1571 * socket operation is ready. It will be run with the priority of
1572 * the calling task.
1573 * Only allowed to be called as long as the scheduler is running, that
1574 * is one of the following conditions is met:
1575 *
1576 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
1577 * - #GNUNET_SCHEDULER_driver_init has been run and
1578 * #GNUNET_SCHEDULER_driver_done has not been called yet
1579 *
1580 * @param delay when should this operation time out?
1581 * @param wfd write file-descriptor
1582 * @param task main function of the task
1583 * @param task_cls closure of @a task
1584 * @return unique task identifier for the job
1585 * only valid until @a task is started!
1586 */
1587struct GNUNET_SCHEDULER_Task *
1588GNUNET_SCHEDULER_add_write_net (struct GNUNET_TIME_Relative delay,
1589 struct GNUNET_NETWORK_Handle *wfd,
1590 GNUNET_SCHEDULER_TaskCallback task,
1591 void *task_cls)
1592{
1593 return GNUNET_SCHEDULER_add_net_with_priority (delay,
1594 GNUNET_SCHEDULER_PRIORITY_DEFAULT,
1595 wfd,
1596 GNUNET_NO, GNUNET_YES,
1597 task, task_cls);
1598}
1599
1600
1601/**
1602 * Schedule a new task to be run with a specified delay or when the
1603 * specified file descriptor is ready. The delay can be
1604 * used as a timeout on the socket being ready. The task will be
1605 * scheduled for execution once either the delay has expired or the
1606 * socket operation is ready.
1607 * Only allowed to be called as long as the scheduler is running, that
1608 * is one of the following conditions is met:
1609 *
1610 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
1611 * - #GNUNET_SCHEDULER_driver_init has been run and
1612 * #GNUNET_SCHEDULER_driver_done has not been called yet
1613 *
1614 * @param delay when should this operation time out?
1615 * @param priority priority of the task
1616 * @param fd file-descriptor
1617 * @param on_read whether to poll the file-descriptor for readability
1618 * @param on_write whether to poll the file-descriptor for writability
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!
1623 */
1624struct GNUNET_SCHEDULER_Task *
1625GNUNET_SCHEDULER_add_net_with_priority (struct GNUNET_TIME_Relative delay,
1626 enum GNUNET_SCHEDULER_Priority priority,
1627 struct GNUNET_NETWORK_Handle *fd,
1628 int on_read,
1629 int on_write,
1630 GNUNET_SCHEDULER_TaskCallback task,
1631 void *task_cls)
1632{
1633 /* scheduler must be running */
1634 GNUNET_assert (NULL != scheduler_driver);
1635 GNUNET_assert (on_read || on_write);
1636 GNUNET_assert (GNUNET_NETWORK_get_fd (fd) >= 0);
1637 return add_without_sets (delay, priority,
1638 on_read ? fd : NULL,
1639 on_write ? fd : NULL,
1640 NULL,
1641 NULL,
1642 task, task_cls);
1643}
1644
1645
1646/**
1647 * Schedule a new task to be run with a specified delay or when the
1648 * specified file descriptor is ready for reading. The delay can be
1649 * used as a timeout on the socket being ready. The task will be
1650 * scheduled for execution once either the delay has expired or the
1651 * socket operation is ready. It will be run with the DEFAULT priority.
1652 * Only allowed to be called as long as the scheduler is running, that
1653 * is one of the following conditions is met:
1654 *
1655 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
1656 * - #GNUNET_SCHEDULER_driver_init has been run and
1657 * #GNUNET_SCHEDULER_driver_done has not been called yet
1658 *
1659 * @param delay when should this operation time out?
1660 * @param rfd read file-descriptor
1661 * @param task main function of the task
1662 * @param task_cls closure of @a task
1663 * @return unique task identifier for the job
1664 * only valid until @a task is started!
1665 */
1666struct GNUNET_SCHEDULER_Task *
1667GNUNET_SCHEDULER_add_read_file (struct GNUNET_TIME_Relative delay,
1668 const struct GNUNET_DISK_FileHandle *rfd,
1669 GNUNET_SCHEDULER_TaskCallback task,
1670 void *task_cls)
1671{
1672 return GNUNET_SCHEDULER_add_file_with_priority (
1673 delay, GNUNET_SCHEDULER_PRIORITY_DEFAULT,
1674 rfd, GNUNET_YES, GNUNET_NO,
1675 task, task_cls);
1676}
1677
1678
1679/**
1680 * Schedule a new task to be run with a specified delay or when the
1681 * specified file descriptor is ready for writing. The delay can be
1682 * used as a timeout on the socket being ready. The task will be
1683 * scheduled for execution once either the delay has expired or the
1684 * socket operation is ready. It will be run with the DEFAULT priority.
1685 * Only allowed to be called as long as the scheduler is running, that
1686 * is one of the following conditions is met:
1687 *
1688 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
1689 * - #GNUNET_SCHEDULER_driver_init has been run and
1690 * #GNUNET_SCHEDULER_driver_done has not been called yet
1691 *
1692 * @param delay when should this operation time out?
1693 * @param wfd write file-descriptor
1694 * @param task main function of the task
1695 * @param task_cls closure of @a task
1696 * @return unique task identifier for the job
1697 * only valid until @a task is started!
1698 */
1699struct GNUNET_SCHEDULER_Task *
1700GNUNET_SCHEDULER_add_write_file (struct GNUNET_TIME_Relative delay,
1701 const struct GNUNET_DISK_FileHandle *wfd,
1702 GNUNET_SCHEDULER_TaskCallback task,
1703 void *task_cls)
1704{
1705 return GNUNET_SCHEDULER_add_file_with_priority (
1706 delay, GNUNET_SCHEDULER_PRIORITY_DEFAULT,
1707 wfd, GNUNET_NO, GNUNET_YES,
1708 task, task_cls);
1709}
1710
1711
1712/**
1713 * Schedule a new task to be run with a specified delay or when the
1714 * specified file descriptor is ready. The delay can be
1715 * used as a timeout on the socket being ready. The task will be
1716 * scheduled for execution once either the delay has expired or the
1717 * socket operation is ready.
1718 * Only allowed to be called as long as the scheduler is running, that
1719 * is one of the following conditions is met:
1720 *
1721 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
1722 * - #GNUNET_SCHEDULER_driver_init has been run and
1723 * #GNUNET_SCHEDULER_driver_done has not been called yet
1724 *
1725 * @param delay when should this operation time out?
1726 * @param priority priority of the task
1727 * @param fd file-descriptor
1728 * @param on_read whether to poll the file-descriptor for readability
1729 * @param on_write whether to poll the file-descriptor for writability
1730 * @param task main function of the task
1731 * @param task_cls closure of @a task
1732 * @return unique task identifier for the job
1733 * only valid until @a task is started!
1734 */
1735struct GNUNET_SCHEDULER_Task *
1736GNUNET_SCHEDULER_add_file_with_priority (struct GNUNET_TIME_Relative delay,
1737 enum GNUNET_SCHEDULER_Priority
1738 priority,
1739 const struct
1740 GNUNET_DISK_FileHandle *fd,
1741 int on_read, int on_write,
1742 GNUNET_SCHEDULER_TaskCallback task,
1743 void *task_cls)
1744{
1745 /* scheduler must be running */
1746 GNUNET_assert (NULL != scheduler_driver);
1747 GNUNET_assert (on_read || on_write);
1748 GNUNET_assert (fd->fd >= 0);
1749 return add_without_sets (delay, priority,
1750 NULL,
1751 NULL,
1752 on_read ? fd : NULL,
1753 on_write ? fd : NULL,
1754 task, task_cls);
1755}
1756
1757
1758void
1759extract_handles (const struct GNUNET_NETWORK_FDSet *fdset,
1760 const struct GNUNET_NETWORK_Handle ***ntarget,
1761 unsigned int *extracted_nhandles,
1762 const struct GNUNET_DISK_FileHandle ***ftarget,
1763 unsigned int *extracted_fhandles)
1764{
1765 // FIXME: this implementation only works for unix, for WIN32 the file handles
1766 // in fdset must be handled separately
1767 const struct GNUNET_NETWORK_Handle **nhandles;
1768 const struct GNUNET_DISK_FileHandle **fhandles;
1769 unsigned int nhandles_len;
1770 unsigned int fhandles_len;
1771
1772 nhandles = NULL;
1773 fhandles = NULL;
1774 nhandles_len = 0;
1775 fhandles_len = 0;
1776 for (int sock = 0; sock != fdset->nsds; ++sock)
1777 {
1778 if (GNUNET_YES == GNUNET_NETWORK_fdset_test_native (fdset, sock))
1779 {
1780 struct GNUNET_NETWORK_Handle *nhandle;
1781 struct GNUNET_DISK_FileHandle *fhandle;
1782
1783 nhandle = GNUNET_NETWORK_socket_box_native (sock);
1784 if (NULL != nhandle)
1785 {
1786 GNUNET_array_append (nhandles, nhandles_len, nhandle);
1787 }
1788 else
1789 {
1790 fhandle = GNUNET_DISK_get_handle_from_int_fd (sock);
1791 if (NULL != fhandle)
1792 {
1793 GNUNET_array_append (fhandles, fhandles_len, fhandle);
1794 }
1795 else
1796 {
1797 GNUNET_assert (0);
1798 }
1799 }
1800 }
1801 }
1802 *ntarget = nhandles_len > 0 ? nhandles : NULL;
1803 *ftarget = fhandles_len > 0 ? fhandles : NULL;
1804 *extracted_nhandles = nhandles_len;
1805 *extracted_fhandles = fhandles_len;
1806}
1807
1808
1809/**
1810 * Schedule a new task to be run with a specified delay or when any of
1811 * the specified file descriptor sets is ready. The delay can be used
1812 * as a timeout on the socket(s) being ready. The task will be
1813 * scheduled for execution once either the delay has expired or any of
1814 * the socket operations is ready. This is the most general
1815 * function of the "add" family. Note that the "prerequisite_task"
1816 * must be satisfied in addition to any of the other conditions. In
1817 * other words, the task will be started when
1818 * <code>
1819 * (prerequisite-run)
1820 * && (delay-ready
1821 * || any-rs-ready
1822 * || any-ws-ready) )
1823 * </code>
1824 * Only allowed to be called as long as the scheduler is running, that
1825 * is one of the following conditions is met:
1826 *
1827 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
1828 * - #GNUNET_SCHEDULER_driver_init has been run and
1829 * #GNUNET_SCHEDULER_driver_done has not been called yet
1830 *
1831 * @param prio how important is this task?
1832 * @param delay how long should we wait?
1833 * @param rs set of file descriptors we want to read (can be NULL)
1834 * @param ws set of file descriptors we want to write (can be NULL)
1835 * @param task main function of the task
1836 * @param task_cls closure of @a task
1837 * @return unique task identifier for the job
1838 * only valid until @a task is started!
1839 */
1840struct GNUNET_SCHEDULER_Task *
1841GNUNET_SCHEDULER_add_select (enum GNUNET_SCHEDULER_Priority prio,
1842 struct GNUNET_TIME_Relative delay,
1843 const struct GNUNET_NETWORK_FDSet *rs,
1844 const struct GNUNET_NETWORK_FDSet *ws,
1845 GNUNET_SCHEDULER_TaskCallback task,
1846 void *task_cls)
1847{
1848 struct GNUNET_SCHEDULER_Task *t;
1849 const struct GNUNET_NETWORK_Handle **read_nhandles = NULL;
1850 const struct GNUNET_NETWORK_Handle **write_nhandles = NULL;
1851 const struct GNUNET_DISK_FileHandle **read_fhandles = NULL;
1852 const struct GNUNET_DISK_FileHandle **write_fhandles = NULL;
1853 unsigned int read_nhandles_len = 0;
1854 unsigned int write_nhandles_len = 0;
1855 unsigned int read_fhandles_len = 0;
1856 unsigned int write_fhandles_len = 0;
1857
1858 /* scheduler must be running */
1859 GNUNET_assert (NULL != scheduler_driver);
1860 GNUNET_assert (NULL != task);
1861 int no_rs = (NULL == rs);
1862 int no_ws = (NULL == ws);
1863 int empty_rs = (NULL != rs) && (0 == rs->nsds);
1864 int empty_ws = (NULL != ws) && (0 == ws->nsds);
1865 int no_fds = (no_rs && no_ws) ||
1866 (empty_rs && empty_ws) ||
1867 (no_rs && empty_ws) ||
1868 (no_ws && empty_rs);
1869 if (! no_fds)
1870 {
1871 if (NULL != rs)
1872 {
1873 extract_handles (rs,
1874 &read_nhandles,
1875 &read_nhandles_len,
1876 &read_fhandles,
1877 &read_fhandles_len);
1878 }
1879 if (NULL != ws)
1880 {
1881 extract_handles (ws,
1882 &write_nhandles,
1883 &write_nhandles_len,
1884 &write_fhandles,
1885 &write_fhandles_len);
1886 }
1887 }
1888 /**
1889 * here we consider the case that a GNUNET_NETWORK_FDSet might be empty
1890 * although its maximum FD number (nsds) is greater than 0. We handle
1891 * this case gracefully because some libraries such as libmicrohttpd
1892 * only provide a hint what the maximum FD number in an FD set might be
1893 * and not the exact FD number (see e.g. gnunet-rest-service.c)
1894 */int no_fds_extracted = (0 == read_nhandles_len) &&
1895 (0 == read_fhandles_len) &&
1896 (0 == write_nhandles_len) &&
1897 (0 == write_fhandles_len);
1898 if (no_fds || no_fds_extracted)
1899 return GNUNET_SCHEDULER_add_delayed_with_priority (delay,
1900 prio,
1901 task,
1902 task_cls);
1903 t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
1904 GNUNET_async_scope_get (&t->scope);
1905 init_fd_info (t,
1906 read_nhandles,
1907 read_nhandles_len,
1908 write_nhandles,
1909 write_nhandles_len,
1910 read_fhandles,
1911 read_fhandles_len,
1912 write_fhandles,
1913 write_fhandles_len);
1914 t->callback = task;
1915 t->callback_cls = task_cls;
1916 t->own_handles = GNUNET_YES;
1917 /* free the arrays of pointers to network / file handles, the actual
1918 * handles will be freed in destroy_task */
1919 GNUNET_array_grow (read_nhandles, read_nhandles_len, 0);
1920 GNUNET_array_grow (write_nhandles, write_nhandles_len, 0);
1921 GNUNET_array_grow (read_fhandles, read_fhandles_len, 0);
1922 GNUNET_array_grow (write_fhandles, write_fhandles_len, 0);
1923#if PROFILE_DELAYS
1924 t->start_time = GNUNET_TIME_absolute_get ();
1925#endif
1926 t->timeout = GNUNET_TIME_relative_to_absolute (delay);
1927 t->priority =
1928 check_priority ((prio ==
1929 GNUNET_SCHEDULER_PRIORITY_KEEP) ? current_priority :
1930 prio);
1931 t->lifeness = current_lifeness;
1932 GNUNET_CONTAINER_DLL_insert (pending_head,
1933 pending_tail,
1934 t);
1935 driver_add_multiple (t);
1936 max_priority_added = GNUNET_MAX (max_priority_added,
1937 t->priority);
1938 LOG (GNUNET_ERROR_TYPE_DEBUG,
1939 "Adding task %p\n",
1940 t);
1941 init_backtrace (t);
1942 return t;
1943}
1944
1945
1946/**
1947 * Function used by event-loop implementations to signal the scheduler
1948 * that a particular @a task is ready due to an event specified in the
1949 * et field of @a fdi.
1950 *
1951 * This function will then queue the task to notify the application
1952 * that the task is ready (with the respective priority).
1953 *
1954 * @param task the task that is ready
1955 * @param fdi information about the related FD
1956 */
1957void
1958GNUNET_SCHEDULER_task_ready (struct GNUNET_SCHEDULER_Task *task,
1959 struct GNUNET_SCHEDULER_FdInfo *fdi)
1960{
1961 enum GNUNET_SCHEDULER_Reason reason;
1962
1963 reason = task->reason;
1964 if ((0 == (reason & GNUNET_SCHEDULER_REASON_READ_READY)) &&
1965 (0 != (GNUNET_SCHEDULER_ET_IN & fdi->et)))
1966 reason |= GNUNET_SCHEDULER_REASON_READ_READY;
1967 if ((0 == (reason & GNUNET_SCHEDULER_REASON_WRITE_READY)) &&
1968 (0 != (GNUNET_SCHEDULER_ET_OUT & fdi->et)))
1969 reason |= GNUNET_SCHEDULER_REASON_WRITE_READY;
1970 reason |= GNUNET_SCHEDULER_REASON_PREREQ_DONE;
1971 task->reason = reason;
1972 if (GNUNET_NO == task->in_ready_list)
1973 {
1974 GNUNET_CONTAINER_DLL_remove (pending_head,
1975 pending_tail,
1976 task);
1977 queue_ready_task (task);
1978 }
1979}
1980
1981
1982/**
1983 * Function called by external event loop implementations to tell the
1984 * scheduler to run some of the tasks that are ready. Must be called
1985 * only after #GNUNET_SCHEDULER_driver_init has been called and before
1986 * #GNUNET_SCHEDULER_driver_done is called.
1987 * This function may return even though there are tasks left to run
1988 * just to give other tasks a chance as well. If we return #GNUNET_YES,
1989 * the event loop implementation should call this function again as
1990 * soon as possible, while if we return #GNUNET_NO it must block until
1991 * either the operating system has more work (the scheduler has no more
1992 * work to do right now) or the timeout set by the scheduler (using the
1993 * set_wakeup callback) is reached.
1994 *
1995 * @param sh scheduler handle that was returned by
1996 * #GNUNET_SCHEDULER_driver_init
1997 * @return #GNUNET_YES if there are more tasks that are ready,
1998 * and thus we would like to run more (yield to avoid
1999 * blocking other activities for too long) #GNUNET_NO
2000 * if we are done running tasks (yield to block)
2001 */
2002int
2003GNUNET_SCHEDULER_do_work (struct GNUNET_SCHEDULER_Handle *sh)
2004{
2005 struct GNUNET_SCHEDULER_Task *pos;
2006 struct GNUNET_TIME_Absolute now;
2007
2008 /* check for tasks that reached the timeout! */
2009 now = GNUNET_TIME_absolute_get ();
2010 pos = pending_timeout_head;
2011 while (NULL != pos)
2012 {
2013 struct GNUNET_SCHEDULER_Task *next = pos->next;
2014 if (now.abs_value_us >= pos->timeout.abs_value_us)
2015 pos->reason |= GNUNET_SCHEDULER_REASON_TIMEOUT;
2016 if (0 == pos->reason)
2017 break;
2018 GNUNET_CONTAINER_DLL_remove (pending_timeout_head,
2019 pending_timeout_tail,
2020 pos);
2021 if (pending_timeout_last == pos)
2022 pending_timeout_last = NULL;
2023 queue_ready_task (pos);
2024 pos = next;
2025 }
2026 pos = pending_head;
2027 while (NULL != pos)
2028 {
2029 struct GNUNET_SCHEDULER_Task *next = pos->next;
2030 if (now.abs_value_us >= pos->timeout.abs_value_us)
2031 {
2032 pos->reason |= GNUNET_SCHEDULER_REASON_TIMEOUT;
2033 GNUNET_CONTAINER_DLL_remove (pending_head,
2034 pending_tail,
2035 pos);
2036 queue_ready_task (pos);
2037 }
2038 pos = next;
2039 }
2040
2041 if (0 == ready_count)
2042 {
2043 struct GNUNET_TIME_Absolute timeout = get_timeout ();
2044
2045 if (timeout.abs_value_us > now.abs_value_us)
2046 {
2047 /**
2048 * The event loop called this function before the current timeout was
2049 * reached (and no FD tasks are ready). This is acceptable if
2050 *
2051 * - the system time was changed while the driver was waiting for
2052 * the timeout
2053 * - an external event loop called GNUnet API functions outside of
2054 * the callbacks called in GNUNET_SCHEDULER_do_work and thus
2055 * wasn't notified about the new timeout
2056 *
2057 * It might also mean we are busy-waiting because of a programming
2058 * error in the external event loop.
2059 */LOG (GNUNET_ERROR_TYPE_DEBUG,
2060 "GNUNET_SCHEDULER_do_work did not find any ready "
2061 "tasks and timeout has not been reached yet.\n");
2062 }
2063 else
2064 {
2065 /**
2066 * the current timeout was reached but no ready tasks were found,
2067 * internal scheduler error!
2068 */
2069 GNUNET_assert (0);
2070 }
2071 }
2072 else
2073 {
2074 /* find out which task priority level we are going to
2075 process this time */
2076 max_priority_added = GNUNET_SCHEDULER_PRIORITY_KEEP;
2077 GNUNET_assert (NULL == ready_head[GNUNET_SCHEDULER_PRIORITY_KEEP]);
2078 /* yes, p>0 is correct, 0 is "KEEP" which should
2079 * always be an empty queue (see assertion)! */
2080 for (work_priority = GNUNET_SCHEDULER_PRIORITY_COUNT - 1;
2081 work_priority > 0;
2082 work_priority--)
2083 {
2084 pos = ready_head[work_priority];
2085 if (NULL != pos)
2086 break;
2087 }
2088 GNUNET_assert (NULL != pos); /* ready_count wrong? */
2089
2090 /* process all tasks at this priority level, then yield */
2091 while (NULL != (pos = ready_head[work_priority]))
2092 {
2093 GNUNET_CONTAINER_DLL_remove (ready_head[work_priority],
2094 ready_tail[work_priority],
2095 pos);
2096 ready_count--;
2097 current_priority = pos->priority;
2098 current_lifeness = pos->lifeness;
2099 active_task = pos;
2100#if PROFILE_DELAYS
2101 if (GNUNET_TIME_absolute_get_duration (pos->start_time).rel_value_us >
2102 DELAY_THRESHOLD.rel_value_us)
2103 {
2104 LOG (GNUNET_ERROR_TYPE_DEBUG,
2105 "Task %p took %s to be scheduled\n",
2106 pos,
2107 GNUNET_STRINGS_relative_time_to_string (
2108 GNUNET_TIME_absolute_get_duration (pos->start_time),
2109 GNUNET_YES));
2110 }
2111#endif
2112 tc.reason = pos->reason;
2113 GNUNET_NETWORK_fdset_zero (sh->rs);
2114 GNUNET_NETWORK_fdset_zero (sh->ws);
2115 // FIXME: do we have to remove FdInfos from fds if they are not ready?
2116 tc.fds_len = pos->fds_len;
2117 tc.fds = pos->fds;
2118 for (unsigned int i = 0; i != pos->fds_len; ++i)
2119 {
2120 struct GNUNET_SCHEDULER_FdInfo *fdi = &pos->fds[i];
2121 if (0 != (GNUNET_SCHEDULER_ET_IN & fdi->et))
2122 {
2123 GNUNET_NETWORK_fdset_set_native (sh->rs,
2124 fdi->sock);
2125 }
2126 if (0 != (GNUNET_SCHEDULER_ET_OUT & fdi->et))
2127 {
2128 GNUNET_NETWORK_fdset_set_native (sh->ws,
2129 fdi->sock);
2130 }
2131 }
2132 tc.read_ready = sh->rs;
2133 tc.write_ready = sh->ws;
2134 LOG (GNUNET_ERROR_TYPE_DEBUG,
2135 "Running task %p\n",
2136 pos);
2137 GNUNET_assert (NULL != pos->callback);
2138 {
2139 struct GNUNET_AsyncScopeSave old_scope;
2140 if (pos->scope.have_scope)
2141 GNUNET_async_scope_enter (&pos->scope.scope_id, &old_scope);
2142 else
2143 GNUNET_async_scope_get (&old_scope);
2144 pos->callback (pos->callback_cls);
2145 GNUNET_async_scope_restore (&old_scope);
2146 }
2147 if (NULL != pos->fds)
2148 {
2149 int del_result = scheduler_driver->del (scheduler_driver->cls, pos);
2150 if (GNUNET_OK != del_result)
2151 {
2152 LOG (GNUNET_ERROR_TYPE_ERROR,
2153 "driver could not delete task %p\n", pos);
2154 GNUNET_assert (0);
2155 }
2156 }
2157 active_task = NULL;
2158 dump_backtrace (pos);
2159 destroy_task (pos);
2160 }
2161 }
2162 shutdown_if_no_lifeness ();
2163 if (0 == ready_count)
2164 {
2165 scheduler_driver->set_wakeup (scheduler_driver->cls,
2166 get_timeout ());
2167 return GNUNET_NO;
2168 }
2169 scheduler_driver->set_wakeup (scheduler_driver->cls,
2170 GNUNET_TIME_absolute_get ());
2171 return GNUNET_YES;
2172}
2173
2174
2175/**
2176 * Function called by external event loop implementations to initialize
2177 * the scheduler. An external implementation has to provide @a driver
2178 * which contains callbacks for the scheduler (see definition of struct
2179 * #GNUNET_SCHEDULER_Driver). The callbacks are used to instruct the
2180 * external implementation to watch for events. If it detects any of
2181 * those events it is expected to call #GNUNET_SCHEDULER_do_work to let
2182 * the scheduler handle it. If an event is related to a specific task
2183 * (e.g. the scheduler gave instructions to watch a file descriptor),
2184 * the external implementation is expected to mark that task ready
2185 * before by calling #GNUNET_SCHEDULER_task_ready.
2186
2187 * This function has to be called before any tasks are scheduled and
2188 * before GNUNET_SCHEDULER_do_work is called for the first time. It
2189 * allocates resources that have to be freed again by calling
2190 * #GNUNET_SCHEDULER_driver_done.
2191 *
2192 * This function installs the same signal handlers as
2193 * #GNUNET_SCHEDULER_run. This means SIGTERM (and other similar signals)
2194 * will induce a call to #GNUNET_SCHEDULER_shutdown during the next
2195 * call to #GNUNET_SCHEDULER_do_work. As a result, SIGTERM causes all
2196 * active tasks to be scheduled with reason
2197 * #GNUNET_SCHEDULER_REASON_SHUTDOWN. (However, tasks added afterwards
2198 * will execute normally!). Note that any particular signal will only
2199 * shut down one scheduler; applications should always only create a
2200 * single scheduler.
2201 *
2202 * @param driver to use for the event loop
2203 * @return handle to be passed to #GNUNET_SCHEDULER_do_work and
2204 * #GNUNET_SCHEDULER_driver_done
2205 */
2206struct GNUNET_SCHEDULER_Handle *
2207GNUNET_SCHEDULER_driver_init (const struct GNUNET_SCHEDULER_Driver *driver)
2208{
2209 struct GNUNET_SCHEDULER_Handle *sh;
2210 const struct GNUNET_DISK_FileHandle *pr;
2211
2212 /* scheduler must not be running */
2213 GNUNET_assert (NULL == scheduler_driver);
2214 GNUNET_assert (NULL == shutdown_pipe_handle);
2215 /* general set-up */
2216 sh = GNUNET_new (struct GNUNET_SCHEDULER_Handle);
2217 shutdown_pipe_handle = GNUNET_DISK_pipe (GNUNET_DISK_PF_NONE);
2218 GNUNET_assert (NULL != shutdown_pipe_handle);
2219 pr = GNUNET_DISK_pipe_handle (shutdown_pipe_handle,
2220 GNUNET_DISK_PIPE_END_READ);
2221 my_pid = getpid ();
2222 scheduler_driver = driver;
2223
2224 /* install signal handlers */
2225 LOG (GNUNET_ERROR_TYPE_DEBUG,
2226 "Registering signal handlers\n");
2227 sh->shc_int = GNUNET_SIGNAL_handler_install (SIGINT,
2228 &sighandler_shutdown);
2229 sh->shc_term = GNUNET_SIGNAL_handler_install (SIGTERM,
2230 &sighandler_shutdown);
2231#if (SIGTERM != GNUNET_TERM_SIG)
2232 sh->shc_gterm = GNUNET_SIGNAL_handler_install (GNUNET_TERM_SIG,
2233 &sighandler_shutdown);
2234#endif
2235 sh->shc_pipe = GNUNET_SIGNAL_handler_install (SIGPIPE,
2236 &sighandler_pipe);
2237 sh->shc_quit = GNUNET_SIGNAL_handler_install (SIGQUIT,
2238 &sighandler_shutdown);
2239 sh->shc_hup = GNUNET_SIGNAL_handler_install (SIGHUP,
2240 &sighandler_shutdown);
2241
2242 /* Setup initial tasks */
2243 current_priority = GNUNET_SCHEDULER_PRIORITY_DEFAULT;
2244 current_lifeness = GNUNET_NO;
2245 /* ensure this task runs first, by using a priority level reserved for
2246 the scheduler (not really shutdown, but start-up ;-) */
2247 install_parent_control_task =
2248 GNUNET_SCHEDULER_add_with_priority (GNUNET_SCHEDULER_PRIORITY_SHUTDOWN,
2249 &install_parent_control_handler,
2250 NULL);
2251 shutdown_pipe_task =
2252 GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
2253 pr,
2254 &shutdown_pipe_cb,
2255 NULL);
2256 current_lifeness = GNUNET_YES;
2257 scheduler_driver->set_wakeup (scheduler_driver->cls,
2258 get_timeout ());
2259 /* begin main event loop */
2260 sh->rs = GNUNET_NETWORK_fdset_create ();
2261 sh->ws = GNUNET_NETWORK_fdset_create ();
2262 GNUNET_NETWORK_fdset_handle_set (sh->rs, pr);
2263 return sh;
2264}
2265
2266
2267/**
2268 * Counter-part of #GNUNET_SCHEDULER_driver_init. Has to be called
2269 * by external event loop implementations after the scheduler has
2270 * shut down. This is the case if both of the following conditions
2271 * are met:
2272 *
2273 * - all tasks the scheduler has added through the driver's add
2274 * callback have been removed again through the driver's del
2275 * callback
2276 * - the timeout the scheduler has set through the driver's
2277 * add_wakeup callback is FOREVER
2278 *
2279 * @param sh the handle returned by #GNUNET_SCHEDULER_driver_init
2280 */
2281void
2282GNUNET_SCHEDULER_driver_done (struct GNUNET_SCHEDULER_Handle *sh)
2283{
2284 GNUNET_assert (NULL == pending_head);
2285 GNUNET_assert (NULL == pending_timeout_head);
2286 GNUNET_assert (NULL == shutdown_head);
2287 for (int i = 0; i != GNUNET_SCHEDULER_PRIORITY_COUNT; ++i)
2288 {
2289 GNUNET_assert (NULL == ready_head[i]);
2290 }
2291 GNUNET_NETWORK_fdset_destroy (sh->rs);
2292 GNUNET_NETWORK_fdset_destroy (sh->ws);
2293
2294 /* uninstall signal handlers */
2295 GNUNET_SIGNAL_handler_uninstall (sh->shc_int);
2296 GNUNET_SIGNAL_handler_uninstall (sh->shc_term);
2297#if (SIGTERM != GNUNET_TERM_SIG)
2298 GNUNET_SIGNAL_handler_uninstall (sh->shc_gterm);
2299#endif
2300 GNUNET_SIGNAL_handler_uninstall (sh->shc_pipe);
2301 GNUNET_SIGNAL_handler_uninstall (sh->shc_quit);
2302 GNUNET_SIGNAL_handler_uninstall (sh->shc_hup);
2303 GNUNET_DISK_pipe_close (shutdown_pipe_handle);
2304 shutdown_pipe_handle = NULL;
2305 scheduler_driver = NULL;
2306 GNUNET_free (sh);
2307}
2308
2309
2310static int
2311select_loop (struct GNUNET_SCHEDULER_Handle *sh,
2312 struct DriverContext *context)
2313{
2314 struct GNUNET_NETWORK_FDSet *rs;
2315 struct GNUNET_NETWORK_FDSet *ws;
2316 int select_result;
2317
2318 GNUNET_assert (NULL != context);
2319 rs = GNUNET_NETWORK_fdset_create ();
2320 ws = GNUNET_NETWORK_fdset_create ();
2321 while ((NULL != context->scheduled_head) ||
2322 (GNUNET_TIME_UNIT_FOREVER_ABS.abs_value_us !=
2323 context->timeout.abs_value_us))
2324 {
2325 struct GNUNET_TIME_Relative time_remaining;
2326
2327 LOG (GNUNET_ERROR_TYPE_DEBUG,
2328 "select timeout = %s\n",
2329 GNUNET_STRINGS_absolute_time_to_string (context->timeout));
2330
2331 GNUNET_NETWORK_fdset_zero (rs);
2332 GNUNET_NETWORK_fdset_zero (ws);
2333
2334 for (struct Scheduled *pos = context->scheduled_head;
2335 NULL != pos;
2336 pos = pos->next)
2337 {
2338 if (0 != (GNUNET_SCHEDULER_ET_IN & pos->et))
2339 {
2340 GNUNET_NETWORK_fdset_set_native (rs, pos->fdi->sock);
2341 }
2342 if (0 != (GNUNET_SCHEDULER_ET_OUT & pos->et))
2343 {
2344 GNUNET_NETWORK_fdset_set_native (ws, pos->fdi->sock);
2345 }
2346 }
2347 time_remaining = GNUNET_TIME_absolute_get_remaining (context->timeout);
2348 if (0 < ready_count)
2349 time_remaining = GNUNET_TIME_UNIT_ZERO;
2350 if (NULL == scheduler_select)
2351 {
2352 select_result = GNUNET_NETWORK_socket_select (rs,
2353 ws,
2354 NULL,
2355 time_remaining);
2356 }
2357 else
2358 {
2359 select_result = scheduler_select (scheduler_select_cls,
2360 rs,
2361 ws,
2362 NULL,
2363 time_remaining);
2364 }
2365 if (select_result == GNUNET_SYSERR)
2366 {
2367 if (errno == EINTR)
2368 continue;
2369
2370 LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR,
2371 "select");
2372#if USE_LSOF
2373 char lsof[512];
2374
2375 snprintf (lsof,
2376 sizeof(lsof),
2377 "lsof -p %d",
2378 getpid ());
2379 (void) close (1);
2380 (void) dup2 (2, 1);
2381 if (0 != system (lsof))
2382 LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING,
2383 "system");
2384#endif
2385#if DEBUG_FDS
2386 for (struct Scheduled *s = context->scheduled_head;
2387 NULL != s;
2388 s = s->next)
2389 {
2390 int flags = fcntl (s->fdi->sock,
2391 F_GETFD);
2392
2393 if ((flags == -1) &&
2394 (EBADF == errno))
2395 {
2396 LOG (GNUNET_ERROR_TYPE_ERROR,
2397 "Got invalid file descriptor %d!\n",
2398 s->fdi->sock);
2399#if EXECINFO
2400 dump_backtrace (s->task);
2401#endif
2402 }
2403 }
2404#endif
2405 GNUNET_assert (0);
2406 GNUNET_NETWORK_fdset_destroy (rs);
2407 GNUNET_NETWORK_fdset_destroy (ws);
2408 return GNUNET_SYSERR;
2409 }
2410 if (select_result > 0)
2411 {
2412 for (struct Scheduled *pos = context->scheduled_head;
2413 NULL != pos;
2414 pos = pos->next)
2415 {
2416 int is_ready = GNUNET_NO;
2417
2418 if ((0 != (GNUNET_SCHEDULER_ET_IN & pos->et)) &&
2419 (GNUNET_YES ==
2420 GNUNET_NETWORK_fdset_test_native (rs,
2421 pos->fdi->sock)) )
2422 {
2423 pos->fdi->et |= GNUNET_SCHEDULER_ET_IN;
2424 is_ready = GNUNET_YES;
2425 }
2426 if ((0 != (GNUNET_SCHEDULER_ET_OUT & pos->et)) &&
2427 (GNUNET_YES ==
2428 GNUNET_NETWORK_fdset_test_native (ws,
2429 pos->fdi->sock)) )
2430 {
2431 pos->fdi->et |= GNUNET_SCHEDULER_ET_OUT;
2432 is_ready = GNUNET_YES;
2433 }
2434 if (GNUNET_YES == is_ready)
2435 {
2436 GNUNET_SCHEDULER_task_ready (pos->task,
2437 pos->fdi);
2438 }
2439 }
2440 }
2441 if (GNUNET_YES == GNUNET_SCHEDULER_do_work (sh))
2442 {
2443 LOG (GNUNET_ERROR_TYPE_DEBUG,
2444 "scheduler has more tasks ready!\n");
2445 }
2446 }
2447 GNUNET_NETWORK_fdset_destroy (rs);
2448 GNUNET_NETWORK_fdset_destroy (ws);
2449 return GNUNET_OK;
2450}
2451
2452
2453static int
2454select_add (void *cls,
2455 struct GNUNET_SCHEDULER_Task *task,
2456 struct GNUNET_SCHEDULER_FdInfo *fdi)
2457{
2458 struct DriverContext *context = cls;
2459
2460 GNUNET_assert (NULL != context);
2461 GNUNET_assert (NULL != task);
2462 GNUNET_assert (NULL != fdi);
2463 GNUNET_assert (0 != (GNUNET_SCHEDULER_ET_IN & fdi->et) ||
2464 0 != (GNUNET_SCHEDULER_ET_OUT & fdi->et));
2465
2466 if (! ((NULL != fdi->fd) ^ (NULL != fdi->fh)) || (fdi->sock < 0))
2467 {
2468 /* exactly one out of {fd, hf} must be != NULL and the OS handle must be valid */
2469 return GNUNET_SYSERR;
2470 }
2471
2472 struct Scheduled *scheduled = GNUNET_new (struct Scheduled);
2473 scheduled->task = task;
2474 scheduled->fdi = fdi;
2475 scheduled->et = fdi->et;
2476
2477 GNUNET_CONTAINER_DLL_insert (context->scheduled_head,
2478 context->scheduled_tail,
2479 scheduled);
2480 return GNUNET_OK;
2481}
2482
2483
2484static int
2485select_del (void *cls,
2486 struct GNUNET_SCHEDULER_Task *task)
2487{
2488 struct DriverContext *context;
2489 struct Scheduled *pos;
2490 int ret;
2491
2492 GNUNET_assert (NULL != cls);
2493
2494 context = cls;
2495 ret = GNUNET_SYSERR;
2496 pos = context->scheduled_head;
2497 while (NULL != pos)
2498 {
2499 struct Scheduled *next = pos->next;
2500 if (pos->task == task)
2501 {
2502 GNUNET_CONTAINER_DLL_remove (context->scheduled_head,
2503 context->scheduled_tail,
2504 pos);
2505 GNUNET_free (pos);
2506 ret = GNUNET_OK;
2507 }
2508 pos = next;
2509 }
2510 return ret;
2511}
2512
2513
2514static void
2515select_set_wakeup (void *cls,
2516 struct GNUNET_TIME_Absolute dt)
2517{
2518 struct DriverContext *context = cls;
2519
2520 GNUNET_assert (NULL != context);
2521 context->timeout = dt;
2522}
2523
2524
2525/**
2526 * Obtain the driver for using select() as the event loop.
2527 *
2528 * @return NULL on error
2529 */
2530struct GNUNET_SCHEDULER_Driver *
2531GNUNET_SCHEDULER_driver_select ()
2532{
2533 struct GNUNET_SCHEDULER_Driver *select_driver;
2534
2535 select_driver = GNUNET_new (struct GNUNET_SCHEDULER_Driver);
2536
2537 select_driver->add = &select_add;
2538 select_driver->del = &select_del;
2539 select_driver->set_wakeup = &select_set_wakeup;
2540
2541 return select_driver;
2542}
2543
2544
2545/**
2546 * Change the async scope for the currently executing task and (transitively)
2547 * for all tasks scheduled by the current task after calling this function.
2548 * Nested tasks can begin their own nested async scope.
2549 *
2550 * Once the current task is finished, the async scope ID is reset to
2551 * its previous value.
2552 *
2553 * Must only be called from a running task.
2554 *
2555 * @param aid the asynchronous scope id to enter
2556 */
2557void
2558GNUNET_SCHEDULER_begin_async_scope (struct GNUNET_AsyncScopeId *aid)
2559{
2560 struct GNUNET_AsyncScopeSave dummy_old_scope;
2561
2562 GNUNET_assert (NULL != active_task);
2563 /* Since we're in a task, the context will be automatically
2564 restored by the scheduler. */
2565 GNUNET_async_scope_enter (aid, &dummy_old_scope);
2566}
2567
2568
2569/* end of scheduler.c */
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-19 11:30:56 +0000