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13 General Public License for more details.
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21 * @file util/scheduler.c
22 * @brief schedule computations using continuation passing style
23 * @author Christian Grothoff
26 #include "gnunet_util_lib.h"
31 #define LOG(kind,...) GNUNET_log_from (kind, "util-scheduler", __VA_ARGS__)
33 #define LOG_STRERROR(kind,syscall) GNUNET_log_from_strerror (kind, "util-scheduler", syscall)
40 * Use lsof to generate file descriptor reports on select error?
41 * (turn off for stable releases).
43 #define USE_LSOF GNUNET_NO
46 * Obtain trace information for all scheduler calls that schedule tasks.
48 #define EXECINFO GNUNET_YES
51 * Check each file descriptor before adding
53 #define DEBUG_FDS GNUNET_YES
56 * Depth of the traces collected via EXECINFO.
58 #define MAX_TRACE_DEPTH 50
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
75 * Argument to be passed from the driver to
76 * #GNUNET_SCHEDULER_do_work(). Contains the
77 * scheduler's internal state.
79 struct GNUNET_SCHEDULER_Handle
82 * Passed here to avoid constantly allocating/deallocating
83 * this element, but generally we want to get rid of this.
86 struct GNUNET_NETWORK_FDSet *rs;
89 * Passed here to avoid constantly allocating/deallocating
90 * this element, but generally we want to get rid of this.
93 struct GNUNET_NETWORK_FDSet *ws;
96 * context of the SIGINT handler
98 struct GNUNET_SIGNAL_Context *shc_int;
101 * context of the SIGTERM handler
103 struct GNUNET_SIGNAL_Context *shc_term;
105 #if (SIGTERM != GNUNET_TERM_SIG)
107 * context of the TERM_SIG handler
109 struct GNUNET_SIGNAL_Context *shc_gterm;
114 * context of the SIGQUIT handler
116 struct GNUNET_SIGNAL_Context *shc_quit;
119 * context of the SIGHUP handler
121 struct GNUNET_SIGNAL_Context *shc_hup;
124 * context of hte SIGPIPE handler
126 struct GNUNET_SIGNAL_Context *shc_pipe;
132 * Entry in list of pending tasks.
134 struct GNUNET_SCHEDULER_Task
137 * This is a linked list.
139 struct GNUNET_SCHEDULER_Task *next;
142 * This is a linked list.
144 struct GNUNET_SCHEDULER_Task *prev;
147 * Function to run when ready.
149 GNUNET_SCHEDULER_TaskCallback callback;
152 * Closure for the @e callback.
157 * Information about which FDs are ready for this task (and why).
159 struct GNUNET_SCHEDULER_FdInfo *fds;
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.
166 struct GNUNET_SCHEDULER_FdInfo fdx;
169 * Size of the @e fds array.
171 unsigned int fds_len;
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.
181 * Absolute timeout value for the task, or
182 * #GNUNET_TIME_UNIT_FOREVER_ABS for "no timeout".
184 struct GNUNET_TIME_Absolute timeout;
188 * When was the task scheduled?
190 struct GNUNET_TIME_Absolute start_time;
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 (i.e. read or write ready) will be set over time.
198 enum GNUNET_SCHEDULER_Reason reason;
203 enum GNUNET_SCHEDULER_Priority priority;
206 * Set if we only wait for reading from a single FD, otherwise -1.
211 * Set if we only wait for writing to a single FD, otherwise -1.
216 * Should the existence of this task in the queue be counted as
217 * reason to not shutdown the scheduler?
222 * Is this task run on shutdown?
227 * Is this task in the ready list?
233 * Array of strings which make up a backtrace from the point when this
234 * task was scheduled (essentially, who scheduled the task?)
236 char **backtrace_strings;
239 * Size of the backtrace_strings array
241 int num_backtrace_strings;
248 * A struct representing an event the select driver is waiting for
252 struct Scheduled *prev;
254 struct Scheduled *next;
257 * the task, the event is related to
259 struct GNUNET_SCHEDULER_Task *task;
262 * information about the network socket / file descriptor where
263 * the event is expected to occur
265 struct GNUNET_SCHEDULER_FdInfo *fdi;
268 * the event types (multiple event types can be ORed) the select
269 * driver is expected to wait for
271 enum GNUNET_SCHEDULER_EventType et;
276 * Driver context used by GNUNET_SCHEDULER_run
281 * the head of a DLL containing information about the events the
282 * select driver is waiting for
284 struct Scheduled *scheduled_head;
287 * the tail of a DLL containing information about the events the
288 * select driver is waiting for
290 struct Scheduled *scheduled_tail;
293 * the time when the select driver will wake up again (after
296 struct GNUNET_TIME_Absolute timeout;
301 * The driver used for the event loop. Will be handed over to
302 * the scheduler in #GNUNET_SCHEDULER_do_work(), persisted
303 * there in this variable for later use in functions like
304 * #GNUNET_SCHEDULER_add_select(), #add_without_sets() and
305 * #GNUNET_SCHEDULER_cancel().
307 static const struct GNUNET_SCHEDULER_Driver *scheduler_driver;
310 * Head of list of tasks waiting for an event.
312 static struct GNUNET_SCHEDULER_Task *pending_head;
315 * Tail of list of tasks waiting for an event.
317 static struct GNUNET_SCHEDULER_Task *pending_tail;
320 * Head of list of tasks waiting for shutdown.
322 static struct GNUNET_SCHEDULER_Task *shutdown_head;
325 * Tail of list of tasks waiting for shutdown.
327 static struct GNUNET_SCHEDULER_Task *shutdown_tail;
330 * List of tasks waiting ONLY for a timeout event.
331 * Sorted by timeout (earliest first). Used so that
332 * we do not traverse the list of these tasks when
333 * building select sets (we just look at the head
334 * to determine the respective timeout ONCE).
336 static struct GNUNET_SCHEDULER_Task *pending_timeout_head;
339 * List of tasks waiting ONLY for a timeout event.
340 * Sorted by timeout (earliest first). Used so that
341 * we do not traverse the list of these tasks when
342 * building select sets (we just look at the head
343 * to determine the respective timeout ONCE).
345 static struct GNUNET_SCHEDULER_Task *pending_timeout_tail;
348 * Last inserted task waiting ONLY for a timeout event.
349 * Used to (heuristically) speed up insertion.
351 static struct GNUNET_SCHEDULER_Task *pending_timeout_last;
354 * ID of the task that is running right now.
356 static struct GNUNET_SCHEDULER_Task *active_task;
359 * Head of list of tasks ready to run right now, grouped by importance.
361 static struct GNUNET_SCHEDULER_Task *ready_head[GNUNET_SCHEDULER_PRIORITY_COUNT];
364 * Tail of list of tasks ready to run right now, grouped by importance.
366 static struct GNUNET_SCHEDULER_Task *ready_tail[GNUNET_SCHEDULER_PRIORITY_COUNT];
369 * Task for installing parent control handlers (it might happen that the
370 * scheduler is shutdown before this task is executed, so
371 * GNUNET_SCHEDULER_shutdown must cancel it in that case)
373 static struct GNUNET_SCHEDULER_Task *install_parent_control_task;
376 * Task for reading from a pipe that signal handlers will use to initiate
379 static struct GNUNET_SCHEDULER_Task *shutdown_pipe_task;
382 * Number of tasks on the ready list.
384 static unsigned int ready_count;
387 * Priority of the task running right now. Only
388 * valid while a task is running.
390 static enum GNUNET_SCHEDULER_Priority current_priority;
393 * Priority of the highest task added in the current select
396 static enum GNUNET_SCHEDULER_Priority max_priority_added;
399 * Value of the 'lifeness' flag for the current task.
401 static int current_lifeness;
404 * Function to use as a select() in the scheduler.
405 * If NULL, we use GNUNET_NETWORK_socket_select().
407 static GNUNET_SCHEDULER_select scheduler_select;
410 * Task context of the current task.
412 static struct GNUNET_SCHEDULER_TaskContext tc;
415 * Closure for #scheduler_select.
417 static void *scheduler_select_cls;
421 * Sets the select function to use in the scheduler (scheduler_select).
423 * @param new_select new select function to use
424 * @param new_select_cls closure for @a new_select
425 * @return previously used select function, NULL for default
428 GNUNET_SCHEDULER_set_select (GNUNET_SCHEDULER_select new_select,
429 void *new_select_cls)
431 scheduler_select = new_select;
432 scheduler_select_cls = new_select_cls;
437 * Check that the given priority is legal (and return it).
439 * @param p priority value to check
440 * @return p on success, 0 on error
442 static enum GNUNET_SCHEDULER_Priority
443 check_priority (enum GNUNET_SCHEDULER_Priority p)
445 if ((p >= 0) && (p < GNUNET_SCHEDULER_PRIORITY_COUNT))
448 return 0; /* make compiler happy */
453 * chooses the nearest timeout from all pending tasks, to be used
454 * to tell the driver the next wakeup time (using its set_wakeup
457 struct GNUNET_TIME_Absolute
460 struct GNUNET_SCHEDULER_Task *pos;
461 struct GNUNET_TIME_Absolute now;
462 struct GNUNET_TIME_Absolute timeout;
464 pos = pending_timeout_head;
465 now = GNUNET_TIME_absolute_get ();
466 timeout = GNUNET_TIME_UNIT_FOREVER_ABS;
469 if (0 != pos->reason)
475 timeout = pos->timeout;
478 for (pos = pending_head; NULL != pos; pos = pos->next)
480 if (0 != pos->reason)
484 else if ((pos->timeout.abs_value_us != GNUNET_TIME_UNIT_FOREVER_ABS.abs_value_us) &&
485 (timeout.abs_value_us > pos->timeout.abs_value_us))
487 timeout = pos->timeout;
495 * Put a task that is ready for execution into the ready queue.
497 * @param task task ready for execution
500 queue_ready_task (struct GNUNET_SCHEDULER_Task *task)
502 enum GNUNET_SCHEDULER_Priority p = check_priority (task->priority);
504 GNUNET_CONTAINER_DLL_insert (ready_head[p],
507 task->in_ready_list = GNUNET_YES;
513 * Request the shutdown of a scheduler. Marks all tasks
514 * awaiting shutdown as ready. Note that tasks
515 * scheduled with #GNUNET_SCHEDULER_add_shutdown() AFTER this call
516 * will be delayed until the next shutdown signal.
519 GNUNET_SCHEDULER_shutdown ()
521 struct GNUNET_SCHEDULER_Task *pos;
523 LOG (GNUNET_ERROR_TYPE_DEBUG,
524 "GNUNET_SCHEDULER_shutdown\n");
525 if (NULL != install_parent_control_task)
527 GNUNET_SCHEDULER_cancel (install_parent_control_task);
528 install_parent_control_task = NULL;
530 if (NULL != shutdown_pipe_task)
532 GNUNET_SCHEDULER_cancel (shutdown_pipe_task);
533 shutdown_pipe_task = NULL;
535 while (NULL != (pos = shutdown_head))
537 GNUNET_CONTAINER_DLL_remove (shutdown_head,
540 pos->reason |= GNUNET_SCHEDULER_REASON_SHUTDOWN;
541 queue_ready_task (pos);
547 * Output stack trace of task @a t.
549 * @param t task to dump stack trace of
552 dump_backtrace (struct GNUNET_SCHEDULER_Task *t)
555 for (unsigned int i = 0; i < t->num_backtrace_strings; i++)
556 LOG (GNUNET_ERROR_TYPE_WARNING,
557 "Task %p trace %u: %s\n",
560 t->backtrace_strings[i]);
568 * Destroy a task (release associated resources)
570 * @param t task to destroy
573 destroy_task (struct GNUNET_SCHEDULER_Task *t)
577 LOG (GNUNET_ERROR_TYPE_DEBUG,
578 "destroying task %p\n",
581 if (GNUNET_YES == t->own_handles)
583 for (i = 0; i != t->fds_len; ++i)
585 const struct GNUNET_NETWORK_Handle *fd = t->fds[i].fd;
586 const struct GNUNET_DISK_FileHandle *fh = t->fds[i].fh;
589 GNUNET_NETWORK_socket_free_memory_only_ ((struct GNUNET_NETWORK_Handle *) fd);
593 // FIXME: on WIN32 this is not enough! A function
594 // GNUNET_DISK_file_free_memory_only would be nice
595 GNUNET_free ((void *) fh);
601 GNUNET_array_grow (t->fds, t->fds_len, 0);
604 GNUNET_free (t->backtrace_strings);
611 * Pipe used to communicate shutdown via signal.
613 static struct GNUNET_DISK_PipeHandle *shutdown_pipe_handle;
616 * Process ID of this process at the time we installed the various
622 * Signal handler called for SIGPIPE.
634 // * Wait for a short time.
635 // * Sleeps for @a ms ms (as that should be long enough for virtually all
636 // * modern systems to context switch and allow another process to do
637 // * some 'real' work).
639 // * @param ms how many ms to wait
642 //short_wait (unsigned int ms)
644 // struct GNUNET_TIME_Relative timeout;
646 // timeout = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, ms);
647 // (void) GNUNET_NETWORK_socket_select (NULL, NULL, NULL, timeout);
652 * Signal handler called for signals that should cause us to shutdown.
655 sighandler_shutdown ()
658 int old_errno = errno; /* backup errno */
660 if (getpid () != my_pid)
661 exit (1); /* we have fork'ed since the signal handler was created,
662 * ignore the signal, see https://gnunet.org/vfork discussion */
663 GNUNET_DISK_file_write (GNUNET_DISK_pipe_handle
664 (shutdown_pipe_handle, GNUNET_DISK_PIPE_END_WRITE),
671 shutdown_if_no_lifeness ()
673 struct GNUNET_SCHEDULER_Task *t;
677 for (t = pending_head; NULL != t; t = t->next)
678 if (GNUNET_YES == t->lifeness)
680 for (t = shutdown_head; NULL != t; t = t->next)
681 if (GNUNET_YES == t->lifeness)
683 for (t = pending_timeout_head; NULL != t; t = t->next)
684 if (GNUNET_YES == t->lifeness)
687 GNUNET_SCHEDULER_shutdown ();
692 select_loop (struct GNUNET_SCHEDULER_Handle *sh,
693 struct DriverContext *context);
697 * Initialize and run scheduler. This function will return when all
698 * tasks have completed. On systems with signals, receiving a SIGTERM
699 * (and other similar signals) will cause #GNUNET_SCHEDULER_shutdown()
700 * to be run after the active task is complete. As a result, SIGTERM
701 * causes all active tasks to be scheduled with reason
702 * #GNUNET_SCHEDULER_REASON_SHUTDOWN. (However, tasks added
703 * afterwards will execute normally!). Note that any particular signal
704 * will only shut down one scheduler; applications should always only
705 * create a single scheduler.
707 * @param task task to run immediately
708 * @param task_cls closure of @a task
711 GNUNET_SCHEDULER_run (GNUNET_SCHEDULER_TaskCallback task,
714 struct GNUNET_SCHEDULER_Handle *sh;
715 struct GNUNET_SCHEDULER_Driver *driver;
716 struct DriverContext context = {.scheduled_head = NULL,
717 .scheduled_tail = NULL,
718 .timeout = GNUNET_TIME_absolute_get ()};
720 driver = GNUNET_SCHEDULER_driver_select ();
721 driver->cls = &context;
722 sh = GNUNET_SCHEDULER_driver_init (driver);
723 GNUNET_SCHEDULER_add_with_reason_and_priority (task,
725 GNUNET_SCHEDULER_REASON_STARTUP,
726 GNUNET_SCHEDULER_PRIORITY_DEFAULT);
729 GNUNET_SCHEDULER_driver_done (sh);
730 GNUNET_free (driver);
735 * Obtain the task context, giving the reason why the current task was
738 * @return current tasks' scheduler context
740 const struct GNUNET_SCHEDULER_TaskContext *
741 GNUNET_SCHEDULER_get_task_context ()
743 GNUNET_assert (NULL != active_task);
749 * Get information about the current load of this scheduler. Use this
750 * function to determine if an elective task should be added or simply
751 * dropped (if the decision should be made based on the number of
752 * tasks ready to run).
754 * @param p priority level to look at
755 * @return number of tasks pending right now
758 GNUNET_SCHEDULER_get_load (enum GNUNET_SCHEDULER_Priority p)
760 struct GNUNET_SCHEDULER_Task *pos;
763 GNUNET_assert (NULL != active_task);
764 if (p == GNUNET_SCHEDULER_PRIORITY_COUNT)
766 if (p == GNUNET_SCHEDULER_PRIORITY_KEEP)
767 p = current_priority;
769 for (pos = ready_head[check_priority (p)]; NULL != pos; pos = pos->next)
776 init_fd_info (struct GNUNET_SCHEDULER_Task *t,
777 const struct GNUNET_NETWORK_Handle *const *read_nh,
778 unsigned int read_nh_len,
779 const struct GNUNET_NETWORK_Handle *const *write_nh,
780 unsigned int write_nh_len,
781 const struct GNUNET_DISK_FileHandle *const *read_fh,
782 unsigned int read_fh_len,
783 const struct GNUNET_DISK_FileHandle *const *write_fh,
784 unsigned int write_fh_len)
786 // FIXME: if we have exactly two network handles / exactly two file handles
787 // and they are equal, we can make one FdInfo with both
788 // GNUNET_SCHEDULER_ET_IN and GNUNET_SCHEDULER_ET_OUT set.
789 struct GNUNET_SCHEDULER_FdInfo *fdi;
791 t->fds_len = read_nh_len + write_nh_len + read_fh_len + write_fh_len;
796 if (1 == read_nh_len)
798 GNUNET_assert (NULL != read_nh);
799 GNUNET_assert (NULL != *read_nh);
801 fdi->et = GNUNET_SCHEDULER_ET_IN;
802 fdi->sock = GNUNET_NETWORK_get_fd (*read_nh);
803 t->read_fd = fdi->sock;
806 else if (1 == write_nh_len)
808 GNUNET_assert (NULL != write_nh);
809 GNUNET_assert (NULL != *write_nh);
811 fdi->et = GNUNET_SCHEDULER_ET_OUT;
812 fdi->sock = GNUNET_NETWORK_get_fd (*write_nh);
814 t->write_fd = fdi->sock;
816 else if (1 == read_fh_len)
818 GNUNET_assert (NULL != read_fh);
819 GNUNET_assert (NULL != *read_fh);
821 fdi->et = GNUNET_SCHEDULER_ET_IN;
822 fdi->sock = (*read_fh)->fd; // FIXME: does not work under WIN32
823 t->read_fd = fdi->sock;
828 GNUNET_assert (NULL != write_fh);
829 GNUNET_assert (NULL != *write_fh);
831 fdi->et = GNUNET_SCHEDULER_ET_OUT;
832 fdi->sock = (*write_fh)->fd; // FIXME: does not work under WIN32
834 t->write_fd = fdi->sock;
839 fdi = GNUNET_new_array (t->fds_len, struct GNUNET_SCHEDULER_FdInfo);
844 for (i = 0; i != read_nh_len; ++i)
846 fdi->fd = read_nh[i];
847 GNUNET_assert (NULL != fdi->fd);
848 fdi->et = GNUNET_SCHEDULER_ET_IN;
849 fdi->sock = GNUNET_NETWORK_get_fd (read_nh[i]);
852 for (i = 0; i != write_nh_len; ++i)
854 fdi->fd = write_nh[i];
855 GNUNET_assert (NULL != fdi->fd);
856 fdi->et = GNUNET_SCHEDULER_ET_OUT;
857 fdi->sock = GNUNET_NETWORK_get_fd (write_nh[i]);
860 for (i = 0; i != read_fh_len; ++i)
862 fdi->fh = read_fh[i];
863 GNUNET_assert (NULL != fdi->fh);
864 fdi->et = GNUNET_SCHEDULER_ET_IN;
865 fdi->sock = (read_fh[i])->fd; // FIXME: does not work under WIN32
868 for (i = 0; i != write_fh_len; ++i)
870 fdi->fh = write_fh[i];
871 GNUNET_assert (NULL != fdi->fh);
872 fdi->et = GNUNET_SCHEDULER_ET_OUT;
873 fdi->sock = (write_fh[i])->fd; // FIXME: does not work under WIN32
881 * calls the given function @a func on each FdInfo related to @a t.
882 * Optionally updates the event type field in each FdInfo after calling
886 * @param driver_func the function to call with each FdInfo contained in
888 * @param if_not_ready only call @a driver_func on FdInfos that are not
890 * @param et the event type to be set in each FdInfo after calling
891 * @a driver_func on it, or -1 if no updating not desired.
894 driver_add_multiple (struct GNUNET_SCHEDULER_Task *t)
896 struct GNUNET_SCHEDULER_FdInfo *fdi;
897 int success = GNUNET_YES;
899 for (unsigned int i = 0; i != t->fds_len; ++i)
902 success = scheduler_driver->add (scheduler_driver->cls,
905 fdi->et = GNUNET_SCHEDULER_ET_NONE;
907 if (GNUNET_YES != success)
909 LOG (GNUNET_ERROR_TYPE_ERROR,
910 "driver could not add task\n");
916 install_parent_control_handler (void *cls)
918 install_parent_control_task = NULL;
919 GNUNET_OS_install_parent_control_handler (NULL);
924 shutdown_pipe_cb (void *cls)
927 const struct GNUNET_DISK_FileHandle *pr;
929 shutdown_pipe_task = NULL;
930 pr = GNUNET_DISK_pipe_handle (shutdown_pipe_handle,
931 GNUNET_DISK_PIPE_END_READ);
932 GNUNET_assert (! GNUNET_DISK_handle_invalid (pr));
933 /* consume the signal */
934 GNUNET_DISK_file_read (pr, &c, sizeof (c));
935 /* mark all active tasks as ready due to shutdown */
936 GNUNET_SCHEDULER_shutdown ();
941 * Cancel the task with the specified identifier.
942 * The task must not yet have run. Only allowed to be called as long as the
943 * scheduler is running, that is one of the following conditions is met:
945 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
946 * - #GNUNET_SCHEDULER_driver_init has been run and
947 * #GNUNET_SCHEDULER_driver_done has not been called yet
949 * @param task id of the task to cancel
950 * @return original closure of the task
953 GNUNET_SCHEDULER_cancel (struct GNUNET_SCHEDULER_Task *task)
955 enum GNUNET_SCHEDULER_Priority p;
959 LOG (GNUNET_ERROR_TYPE_DEBUG,
960 "canceling task %p\n",
963 /* scheduler must be running */
964 GNUNET_assert (NULL != scheduler_driver);
965 GNUNET_assert ( (NULL != active_task) ||
966 (GNUNET_NO == task->lifeness) );
967 is_fd_task = (NULL != task->fds);
970 int del_result = scheduler_driver->del (scheduler_driver->cls, task);
971 if (GNUNET_OK != del_result)
973 LOG (GNUNET_ERROR_TYPE_ERROR,
974 "driver could not delete task\n");
978 if (! task->in_ready_list)
982 GNUNET_CONTAINER_DLL_remove (pending_head,
986 else if (GNUNET_YES == task->on_shutdown)
988 GNUNET_CONTAINER_DLL_remove (shutdown_head,
994 GNUNET_CONTAINER_DLL_remove (pending_timeout_head,
995 pending_timeout_tail,
997 if (pending_timeout_last == task)
998 pending_timeout_last = NULL;
1003 p = check_priority (task->priority);
1004 GNUNET_CONTAINER_DLL_remove (ready_head[p],
1009 ret = task->callback_cls;
1010 destroy_task (task);
1016 * Initialize backtrace data for task @a t
1018 * @param t task to initialize
1021 init_backtrace (struct GNUNET_SCHEDULER_Task *t)
1024 void *backtrace_array[MAX_TRACE_DEPTH];
1026 t->num_backtrace_strings
1027 = backtrace (backtrace_array, MAX_TRACE_DEPTH);
1028 t->backtrace_strings =
1029 backtrace_symbols (backtrace_array,
1030 t->num_backtrace_strings);
1039 * Continue the current execution with the given function. This is
1040 * similar to the other "add" functions except that there is no delay
1041 * and the reason code can be specified.
1043 * @param task main function of the task
1044 * @param task_cls closure for @a task
1045 * @param reason reason for task invocation
1046 * @param priority priority to use for the task
1049 GNUNET_SCHEDULER_add_with_reason_and_priority (GNUNET_SCHEDULER_TaskCallback task,
1051 enum GNUNET_SCHEDULER_Reason reason,
1052 enum GNUNET_SCHEDULER_Priority priority)
1054 struct GNUNET_SCHEDULER_Task *t;
1056 GNUNET_assert (NULL != task);
1057 GNUNET_assert ((NULL != active_task) ||
1058 (GNUNET_SCHEDULER_REASON_STARTUP == reason));
1059 t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
1063 t->callback_cls = task_cls;
1065 t->start_time = GNUNET_TIME_absolute_get ();
1068 t->priority = check_priority (priority);
1069 t->lifeness = current_lifeness;
1070 LOG (GNUNET_ERROR_TYPE_DEBUG,
1071 "Adding continuation task %p\n",
1074 queue_ready_task (t);
1079 * Schedule a new task to be run at the specified time. The task
1080 * will be scheduled for execution at time @a at.
1082 * @param at time when the operation should run
1083 * @param priority priority to use for the task
1084 * @param task main function of the task
1085 * @param task_cls closure of @a task
1086 * @return unique task identifier for the job
1087 * only valid until @a task is started!
1089 struct GNUNET_SCHEDULER_Task *
1090 GNUNET_SCHEDULER_add_at_with_priority (struct GNUNET_TIME_Absolute at,
1091 enum GNUNET_SCHEDULER_Priority priority,
1092 GNUNET_SCHEDULER_TaskCallback task,
1095 struct GNUNET_SCHEDULER_Task *t;
1096 struct GNUNET_SCHEDULER_Task *pos;
1097 struct GNUNET_SCHEDULER_Task *prev;
1099 GNUNET_assert (NULL != active_task);
1100 GNUNET_assert (NULL != task);
1101 t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
1103 t->callback_cls = task_cls;
1107 t->start_time = GNUNET_TIME_absolute_get ();
1110 t->priority = check_priority (priority);
1111 t->lifeness = current_lifeness;
1112 /* try tail first (optimization in case we are
1113 * appending to a long list of tasks with timeouts) */
1114 if ( (NULL == pending_timeout_head) ||
1115 (at.abs_value_us < pending_timeout_head->timeout.abs_value_us) )
1117 GNUNET_CONTAINER_DLL_insert (pending_timeout_head,
1118 pending_timeout_tail,
1123 /* first move from heuristic start backwards to before start time */
1124 prev = pending_timeout_last;
1125 while ( (NULL != prev) &&
1126 (prev->timeout.abs_value_us > t->timeout.abs_value_us) )
1128 /* now, move from heuristic start (or head of list) forward to insertion point */
1130 pos = pending_timeout_head;
1133 while ((NULL != pos) && (pos->timeout.abs_value_us <= t->timeout.abs_value_us))
1138 GNUNET_CONTAINER_DLL_insert_after (pending_timeout_head,
1139 pending_timeout_tail,
1143 /* finally, update heuristic insertion point to last insertion... */
1144 pending_timeout_last = t;
1146 LOG (GNUNET_ERROR_TYPE_DEBUG,
1155 * Schedule a new task to be run with a specified delay. The task
1156 * will be scheduled for execution once the delay has expired.
1158 * @param delay when should this operation time out?
1159 * @param priority priority to use for the task
1160 * @param task main function of the task
1161 * @param task_cls closure of @a task
1162 * @return unique task identifier for the job
1163 * only valid until @a task is started!
1165 struct GNUNET_SCHEDULER_Task *
1166 GNUNET_SCHEDULER_add_delayed_with_priority (struct GNUNET_TIME_Relative delay,
1167 enum GNUNET_SCHEDULER_Priority priority,
1168 GNUNET_SCHEDULER_TaskCallback task,
1171 return GNUNET_SCHEDULER_add_at_with_priority (GNUNET_TIME_relative_to_absolute (delay),
1179 * Schedule a new task to be run with a specified priority.
1181 * @param prio how important is the new task?
1182 * @param task main function of the task
1183 * @param task_cls closure of @a task
1184 * @return unique task identifier for the job
1185 * only valid until @a task is started!
1187 struct GNUNET_SCHEDULER_Task *
1188 GNUNET_SCHEDULER_add_with_priority (enum GNUNET_SCHEDULER_Priority prio,
1189 GNUNET_SCHEDULER_TaskCallback task,
1192 return GNUNET_SCHEDULER_add_delayed_with_priority (GNUNET_TIME_UNIT_ZERO,
1200 * Schedule a new task to be run at the specified time. The task
1201 * will be scheduled for execution once specified time has been
1202 * reached. It will be run with the DEFAULT priority.
1204 * @param at time at which this operation should run
1205 * @param task main function of the task
1206 * @param task_cls closure of @a task
1207 * @return unique task identifier for the job
1208 * only valid until @a task is started!
1210 struct GNUNET_SCHEDULER_Task *
1211 GNUNET_SCHEDULER_add_at (struct GNUNET_TIME_Absolute at,
1212 GNUNET_SCHEDULER_TaskCallback task,
1215 return GNUNET_SCHEDULER_add_at_with_priority (at,
1216 GNUNET_SCHEDULER_PRIORITY_DEFAULT,
1223 * Schedule a new task to be run with a specified delay. The task
1224 * will be scheduled for execution once the delay has expired. It
1225 * will be run with the DEFAULT priority.
1227 * @param delay when should this operation time out?
1228 * @param task main function of the task
1229 * @param task_cls closure of @a task
1230 * @return unique task identifier for the job
1231 * only valid until @a task is started!
1233 struct GNUNET_SCHEDULER_Task *
1234 GNUNET_SCHEDULER_add_delayed (struct GNUNET_TIME_Relative delay,
1235 GNUNET_SCHEDULER_TaskCallback task,
1238 return GNUNET_SCHEDULER_add_delayed_with_priority (delay,
1239 GNUNET_SCHEDULER_PRIORITY_DEFAULT,
1246 * Schedule a new task to be run as soon as possible. Note that this
1247 * does not guarantee that this will be the next task that is being
1248 * run, as other tasks with higher priority (or that are already ready
1249 * to run) might get to run first. Just as with delays, clients must
1250 * not rely on any particular order of execution between tasks
1251 * scheduled concurrently.
1253 * The task will be run with the DEFAULT priority.
1255 * @param task main function of the task
1256 * @param task_cls closure of @a task
1257 * @return unique task identifier for the job
1258 * only valid until @a task is started!
1260 struct GNUNET_SCHEDULER_Task *
1261 GNUNET_SCHEDULER_add_now (GNUNET_SCHEDULER_TaskCallback task,
1264 return GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_ZERO,
1271 * Schedule a new task to be run on shutdown, that is when a CTRL-C
1272 * signal is received, or when #GNUNET_SCHEDULER_shutdown() is being
1275 * @param task main function of the task
1276 * @param task_cls closure of @a task
1277 * @return unique task identifier for the job
1278 * only valid until @a task is started!
1280 struct GNUNET_SCHEDULER_Task *
1281 GNUNET_SCHEDULER_add_shutdown (GNUNET_SCHEDULER_TaskCallback task,
1284 struct GNUNET_SCHEDULER_Task *t;
1286 GNUNET_assert (NULL != active_task);
1287 GNUNET_assert (NULL != task);
1288 t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
1290 t->callback_cls = task_cls;
1294 t->start_time = GNUNET_TIME_absolute_get ();
1296 t->timeout = GNUNET_TIME_UNIT_FOREVER_ABS;
1297 t->priority = GNUNET_SCHEDULER_PRIORITY_SHUTDOWN;
1298 t->on_shutdown = GNUNET_YES;
1299 t->lifeness = GNUNET_NO;
1300 GNUNET_CONTAINER_DLL_insert (shutdown_head,
1303 LOG (GNUNET_ERROR_TYPE_DEBUG,
1304 "Adding shutdown task %p\n",
1312 * Schedule a new task to be run as soon as possible with the
1313 * (transitive) ignore-shutdown flag either explicitly set or
1314 * explicitly enabled. This task (and all tasks created from it,
1315 * other than by another call to this function) will either count or
1316 * not count for the "lifeness" of the process. This API is only
1317 * useful in a few special cases.
1319 * @param lifeness #GNUNET_YES if the task counts for lifeness, #GNUNET_NO if not.
1320 * @param task main function of the task
1321 * @param task_cls closure of @a task
1322 * @return unique task identifier for the job
1323 * only valid until @a task is started!
1325 struct GNUNET_SCHEDULER_Task *
1326 GNUNET_SCHEDULER_add_now_with_lifeness (int lifeness,
1327 GNUNET_SCHEDULER_TaskCallback task,
1330 struct GNUNET_SCHEDULER_Task *ret;
1332 ret = GNUNET_SCHEDULER_add_now (task, task_cls);
1333 ret->lifeness = lifeness;
1340 * check a raw file descriptor and abort if it is bad (for debugging purposes)
1342 * @param t the task related to the file descriptor
1343 * @param raw_fd the raw file descriptor to check
1346 check_fd (struct GNUNET_SCHEDULER_Task *t, int raw_fd)
1350 int flags = fcntl (raw_fd, F_GETFD);
1352 if ((flags == -1) && (errno == EBADF))
1354 LOG (GNUNET_ERROR_TYPE_ERROR,
1355 "Got invalid file descriptor %d!\n",
1366 * Schedule a new task to be run with a specified delay or when any of
1367 * the specified file descriptor sets is ready. The delay can be used
1368 * as a timeout on the socket(s) being ready. The task will be
1369 * scheduled for execution once either the delay has expired or any of
1370 * the socket operations is ready. This is the most general
1371 * function of the "add" family. Note that the "prerequisite_task"
1372 * must be satisfied in addition to any of the other conditions. In
1373 * other words, the task will be started when
1375 * (prerequisite-run)
1381 * @param delay how long should we wait?
1382 * @param priority priority to use
1383 * @param rfd file descriptor we want to read (can be -1)
1384 * @param wfd file descriptors we want to write (can be -1)
1385 * @param task main function of the task
1386 * @param task_cls closure of @a task
1387 * @return unique task identifier for the job
1388 * only valid until @a task is started!
1391 static struct GNUNET_SCHEDULER_Task *
1392 add_without_sets (struct GNUNET_TIME_Relative delay,
1393 enum GNUNET_SCHEDULER_Priority priority,
1394 const struct GNUNET_NETWORK_Handle *read_nh,
1395 const struct GNUNET_NETWORK_Handle *write_nh,
1396 const struct GNUNET_DISK_FileHandle *read_fh,
1397 const struct GNUNET_DISK_FileHandle *write_fh,
1398 GNUNET_SCHEDULER_TaskCallback task,
1401 struct GNUNET_SCHEDULER_Task *t;
1403 GNUNET_assert (NULL != active_task);
1404 GNUNET_assert (NULL != task);
1405 t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
1416 t->callback_cls = task_cls;
1418 check_fd (t, NULL != read_nh ? GNUNET_NETWORK_get_fd (read_nh) : -1);
1419 check_fd (t, NULL != write_nh ? GNUNET_NETWORK_get_fd (write_nh) : -1);
1420 check_fd (t, NULL != read_fh ? read_fh->fd : -1);
1421 check_fd (t, NULL != write_fh ? write_fh->fd : -1);
1424 t->start_time = GNUNET_TIME_absolute_get ();
1426 t->timeout = GNUNET_TIME_relative_to_absolute (delay);
1427 t->priority = check_priority ((priority == GNUNET_SCHEDULER_PRIORITY_KEEP) ? current_priority : priority);
1428 t->lifeness = current_lifeness;
1429 GNUNET_CONTAINER_DLL_insert (pending_head,
1432 driver_add_multiple (t);
1433 max_priority_added = GNUNET_MAX (max_priority_added,
1442 * Schedule a new task to be run with a specified delay or when the
1443 * specified file descriptor is ready for reading. The delay can be
1444 * used as a timeout on the socket being ready. The task will be
1445 * scheduled for execution once either the delay has expired or the
1446 * socket operation is ready. It will be run with the DEFAULT priority.
1447 * Only allowed to be called as long as the scheduler is running, that
1448 * is one of the following conditions is met:
1450 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
1451 * - #GNUNET_SCHEDULER_driver_init has been run and
1452 * #GNUNET_SCHEDULER_driver_done has not been called yet
1454 * @param delay when should this operation time out?
1455 * @param rfd read file-descriptor
1456 * @param task main function of the task
1457 * @param task_cls closure of @a task
1458 * @return unique task identifier for the job
1459 * only valid until @a task is started!
1461 struct GNUNET_SCHEDULER_Task *
1462 GNUNET_SCHEDULER_add_read_net (struct GNUNET_TIME_Relative delay,
1463 struct GNUNET_NETWORK_Handle *rfd,
1464 GNUNET_SCHEDULER_TaskCallback task,
1467 return GNUNET_SCHEDULER_add_read_net_with_priority (delay,
1468 GNUNET_SCHEDULER_PRIORITY_DEFAULT,
1469 rfd, task, task_cls);
1474 * Schedule a new task to be run with a specified priority and to be
1475 * run after the specified delay or when the specified file descriptor
1476 * is ready for reading. The delay can be used as a timeout on the
1477 * socket being ready. The task will be scheduled for execution once
1478 * either the delay has expired or the socket operation is ready. It
1479 * will be run with the DEFAULT priority.
1480 * Only allowed to be called as long as the scheduler is running, that
1481 * is one of the following conditions is met:
1483 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
1484 * - #GNUNET_SCHEDULER_driver_init has been run and
1485 * #GNUNET_SCHEDULER_driver_done has not been called yet
1487 * @param delay when should this operation time out?
1488 * @param priority priority to use for the task
1489 * @param rfd read file-descriptor
1490 * @param task main function of the task
1491 * @param task_cls closure of @a task
1492 * @return unique task identifier for the job
1493 * only valid until @a task is started!
1495 struct GNUNET_SCHEDULER_Task *
1496 GNUNET_SCHEDULER_add_read_net_with_priority (struct GNUNET_TIME_Relative delay,
1497 enum GNUNET_SCHEDULER_Priority priority,
1498 struct GNUNET_NETWORK_Handle *rfd,
1499 GNUNET_SCHEDULER_TaskCallback task,
1502 return GNUNET_SCHEDULER_add_net_with_priority (delay, priority,
1511 * Schedule a new task to be run with a specified delay or when the
1512 * specified file descriptor is ready for writing. The delay can be
1513 * used as a timeout on the socket being ready. The task will be
1514 * scheduled for execution once either the delay has expired or the
1515 * socket operation is ready. It will be run with the priority of
1517 * Only allowed to be called as long as the scheduler is running, that
1518 * is one of the following conditions is met:
1520 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
1521 * - #GNUNET_SCHEDULER_driver_init has been run and
1522 * #GNUNET_SCHEDULER_driver_done has not been called yet
1524 * @param delay when should this operation time out?
1525 * @param wfd write file-descriptor
1526 * @param task main function of the task
1527 * @param task_cls closure of @a task
1528 * @return unique task identifier for the job
1529 * only valid until @a task is started!
1531 struct GNUNET_SCHEDULER_Task *
1532 GNUNET_SCHEDULER_add_write_net (struct GNUNET_TIME_Relative delay,
1533 struct GNUNET_NETWORK_Handle *wfd,
1534 GNUNET_SCHEDULER_TaskCallback task,
1537 return GNUNET_SCHEDULER_add_net_with_priority (delay,
1538 GNUNET_SCHEDULER_PRIORITY_DEFAULT,
1540 GNUNET_NO, GNUNET_YES,
1545 * Schedule a new task to be run with a specified delay or when the
1546 * specified file descriptor is ready. 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.
1550 * Only allowed to be called as long as the scheduler is running, that
1551 * is one of the following conditions is met:
1553 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
1554 * - #GNUNET_SCHEDULER_driver_init has been run and
1555 * #GNUNET_SCHEDULER_driver_done has not been called yet
1557 * @param delay when should this operation time out?
1558 * @param priority priority of the task
1559 * @param fd file-descriptor
1560 * @param on_read whether to poll the file-descriptor for readability
1561 * @param on_write whether to poll the file-descriptor for writability
1562 * @param task main function of the task
1563 * @param task_cls closure of task
1564 * @return unique task identifier for the job
1565 * only valid until "task" is started!
1567 struct GNUNET_SCHEDULER_Task *
1568 GNUNET_SCHEDULER_add_net_with_priority (struct GNUNET_TIME_Relative delay,
1569 enum GNUNET_SCHEDULER_Priority priority,
1570 struct GNUNET_NETWORK_Handle *fd,
1573 GNUNET_SCHEDULER_TaskCallback task,
1576 /* scheduler must be running */
1577 GNUNET_assert (NULL != scheduler_driver);
1580 struct GNUNET_NETWORK_FDSet *s;
1581 struct GNUNET_SCHEDULER_Task * ret;
1583 GNUNET_assert (NULL != fd);
1584 s = GNUNET_NETWORK_fdset_create ();
1585 GNUNET_NETWORK_fdset_set (s, fd);
1586 ret = GNUNET_SCHEDULER_add_select (
1589 on_write ? s : NULL,
1591 GNUNET_NETWORK_fdset_destroy (s);
1594 GNUNET_assert (on_read || on_write);
1595 GNUNET_assert (GNUNET_NETWORK_get_fd (fd) >= 0);
1596 return add_without_sets (delay, priority,
1597 on_read ? fd : NULL,
1598 on_write ? fd : NULL,
1607 * Schedule a new task to be run with a specified delay or when the
1608 * specified file descriptor is ready for reading. The delay can be
1609 * used as a timeout on the socket being ready. The task will be
1610 * scheduled for execution once either the delay has expired or the
1611 * socket operation is ready. It will be run with the DEFAULT priority.
1612 * Only allowed to be called as long as the scheduler is running, that
1613 * is one of the following conditions is met:
1615 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
1616 * - #GNUNET_SCHEDULER_driver_init has been run and
1617 * #GNUNET_SCHEDULER_driver_done has not been called yet
1619 * @param delay when should this operation time out?
1620 * @param rfd read file-descriptor
1621 * @param task main function of the task
1622 * @param task_cls closure of @a task
1623 * @return unique task identifier for the job
1624 * only valid until @a task is started!
1626 struct GNUNET_SCHEDULER_Task *
1627 GNUNET_SCHEDULER_add_read_file (struct GNUNET_TIME_Relative delay,
1628 const struct GNUNET_DISK_FileHandle *rfd,
1629 GNUNET_SCHEDULER_TaskCallback task, void *task_cls)
1631 return GNUNET_SCHEDULER_add_file_with_priority (
1632 delay, GNUNET_SCHEDULER_PRIORITY_DEFAULT,
1633 rfd, GNUNET_YES, GNUNET_NO,
1639 * Schedule a new task to be run with a specified delay or when the
1640 * specified file descriptor is ready for writing. The delay can be
1641 * used as a timeout on the socket being ready. The task will be
1642 * scheduled for execution once either the delay has expired or the
1643 * socket operation is ready. It will be run with the DEFAULT priority.
1644 * Only allowed to be called as long as the scheduler is running, that
1645 * is one of the following conditions is met:
1647 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
1648 * - #GNUNET_SCHEDULER_driver_init has been run and
1649 * #GNUNET_SCHEDULER_driver_done has not been called yet
1651 * @param delay when should this operation time out?
1652 * @param wfd write file-descriptor
1653 * @param task main function of the task
1654 * @param task_cls closure of @a task
1655 * @return unique task identifier for the job
1656 * only valid until @a task is started!
1658 struct GNUNET_SCHEDULER_Task *
1659 GNUNET_SCHEDULER_add_write_file (struct GNUNET_TIME_Relative delay,
1660 const struct GNUNET_DISK_FileHandle *wfd,
1661 GNUNET_SCHEDULER_TaskCallback task, void *task_cls)
1663 return GNUNET_SCHEDULER_add_file_with_priority (
1664 delay, GNUNET_SCHEDULER_PRIORITY_DEFAULT,
1665 wfd, GNUNET_NO, GNUNET_YES,
1671 * Schedule a new task to be run with a specified delay or when the
1672 * specified file descriptor is ready. The delay can be
1673 * used as a timeout on the socket being ready. The task will be
1674 * scheduled for execution once either the delay has expired or the
1675 * socket operation is ready.
1676 * Only allowed to be called as long as the scheduler is running, that
1677 * is one of the following conditions is met:
1679 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
1680 * - #GNUNET_SCHEDULER_driver_init has been run and
1681 * #GNUNET_SCHEDULER_driver_done has not been called yet
1683 * @param delay when should this operation time out?
1684 * @param priority priority of the task
1685 * @param fd file-descriptor
1686 * @param on_read whether to poll the file-descriptor for readability
1687 * @param on_write whether to poll the file-descriptor for writability
1688 * @param task main function of the task
1689 * @param task_cls closure of @a task
1690 * @return unique task identifier for the job
1691 * only valid until @a task is started!
1693 struct GNUNET_SCHEDULER_Task *
1694 GNUNET_SCHEDULER_add_file_with_priority (struct GNUNET_TIME_Relative delay,
1695 enum GNUNET_SCHEDULER_Priority priority,
1696 const struct GNUNET_DISK_FileHandle *fd,
1697 int on_read, int on_write,
1698 GNUNET_SCHEDULER_TaskCallback task, void *task_cls)
1700 /* scheduler must be running */
1701 GNUNET_assert (NULL != scheduler_driver);
1704 struct GNUNET_NETWORK_FDSet *s;
1705 struct GNUNET_SCHEDULER_Task * ret;
1707 GNUNET_assert (NULL != fd);
1708 s = GNUNET_NETWORK_fdset_create ();
1709 GNUNET_NETWORK_fdset_handle_set (s, fd);
1710 ret = GNUNET_SCHEDULER_add_select (
1713 on_write ? s : NULL,
1715 GNUNET_NETWORK_fdset_destroy (s);
1718 GNUNET_assert (on_read || on_write);
1719 GNUNET_assert (fd->fd >= 0);
1720 return add_without_sets (delay, priority,
1723 on_read ? fd : NULL,
1724 on_write ? fd : NULL,
1731 extract_handles (const struct GNUNET_NETWORK_FDSet *fdset,
1732 const struct GNUNET_NETWORK_Handle ***ntarget,
1733 unsigned int *extracted_nhandles,
1734 const struct GNUNET_DISK_FileHandle ***ftarget,
1735 unsigned int *extracted_fhandles)
1737 // FIXME: this implementation only works for unix, for WIN32 the file handles
1738 // in fdset must be handled separately
1739 const struct GNUNET_NETWORK_Handle **nhandles;
1740 const struct GNUNET_DISK_FileHandle **fhandles;
1741 unsigned int nhandles_len;
1742 unsigned int fhandles_len;
1748 for (int sock = 0; sock != fdset->nsds; ++sock)
1750 if (GNUNET_YES == GNUNET_NETWORK_fdset_test_native (fdset, sock))
1752 struct GNUNET_NETWORK_Handle *nhandle;
1753 struct GNUNET_DISK_FileHandle *fhandle;
1755 nhandle = GNUNET_NETWORK_socket_box_native (sock);
1756 if (NULL != nhandle)
1758 GNUNET_array_append (nhandles, nhandles_len, nhandle);
1762 fhandle = GNUNET_DISK_get_handle_from_int_fd (sock);
1763 if (NULL != fhandle)
1765 GNUNET_array_append (fhandles, fhandles_len, fhandle);
1774 *ntarget = nhandles_len > 0 ? nhandles : NULL;
1775 *ftarget = fhandles_len > 0 ? fhandles : NULL;
1776 *extracted_nhandles = nhandles_len;
1777 *extracted_fhandles = fhandles_len;
1782 * Schedule a new task to be run with a specified delay or when any of
1783 * the specified file descriptor sets is ready. The delay can be used
1784 * as a timeout on the socket(s) being ready. The task will be
1785 * scheduled for execution once either the delay has expired or any of
1786 * the socket operations is ready. This is the most general
1787 * function of the "add" family. Note that the "prerequisite_task"
1788 * must be satisfied in addition to any of the other conditions. In
1789 * other words, the task will be started when
1791 * (prerequisite-run)
1794 * || any-ws-ready) )
1796 * Only allowed to be called as long as the scheduler is running, that
1797 * is one of the following conditions is met:
1799 * - #GNUNET_SCHEDULER_run has been called and has not returned yet
1800 * - #GNUNET_SCHEDULER_driver_init has been run and
1801 * #GNUNET_SCHEDULER_driver_done has not been called yet
1803 * @param prio how important is this task?
1804 * @param delay how long should we wait?
1805 * @param rs set of file descriptors we want to read (can be NULL)
1806 * @param ws set of file descriptors we want to write (can be NULL)
1807 * @param task main function of the task
1808 * @param task_cls closure of @a task
1809 * @return unique task identifier for the job
1810 * only valid until @a task is started!
1812 struct GNUNET_SCHEDULER_Task *
1813 GNUNET_SCHEDULER_add_select (enum GNUNET_SCHEDULER_Priority prio,
1814 struct GNUNET_TIME_Relative delay,
1815 const struct GNUNET_NETWORK_FDSet *rs,
1816 const struct GNUNET_NETWORK_FDSet *ws,
1817 GNUNET_SCHEDULER_TaskCallback task,
1820 struct GNUNET_SCHEDULER_Task *t;
1821 const struct GNUNET_NETWORK_Handle **read_nhandles = NULL;
1822 const struct GNUNET_NETWORK_Handle **write_nhandles = NULL;
1823 const struct GNUNET_DISK_FileHandle **read_fhandles = NULL;
1824 const struct GNUNET_DISK_FileHandle **write_fhandles = NULL;
1825 unsigned int read_nhandles_len = 0;
1826 unsigned int write_nhandles_len = 0;
1827 unsigned int read_fhandles_len = 0;
1828 unsigned int write_fhandles_len = 0;
1830 /* scheduler must be running */
1831 GNUNET_assert (NULL != scheduler_driver);
1832 GNUNET_assert (NULL != active_task);
1833 GNUNET_assert (NULL != task);
1834 int no_rs = (NULL == rs);
1835 int no_ws = (NULL == ws);
1836 int empty_rs = (NULL != rs) && (0 == rs->nsds);
1837 int empty_ws = (NULL != ws) && (0 == ws->nsds);
1838 int no_fds = (no_rs && no_ws) ||
1839 (empty_rs && empty_ws) ||
1840 (no_rs && empty_ws) ||
1841 (no_ws && empty_rs);
1846 extract_handles (rs,
1850 &read_fhandles_len);
1854 extract_handles (ws,
1856 &write_nhandles_len,
1858 &write_fhandles_len);
1862 * here we consider the case that a GNUNET_NETWORK_FDSet might be empty
1863 * although its maximum FD number (nsds) is greater than 0. We handle
1864 * this case gracefully because some libraries such as libmicrohttpd
1865 * only provide a hint what the maximum FD number in an FD set might be
1866 * and not the exact FD number (see e.g. gnunet-rest-service.c)
1868 int no_fds_extracted = (0 == read_nhandles_len) &&
1869 (0 == read_fhandles_len) &&
1870 (0 == write_nhandles_len) &&
1871 (0 == write_fhandles_len);
1872 if (no_fds || no_fds_extracted)
1873 return GNUNET_SCHEDULER_add_delayed_with_priority (delay,
1877 t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
1886 write_fhandles_len);
1888 t->callback_cls = task_cls;
1889 t->own_handles = GNUNET_YES;
1890 /* free the arrays of pointers to network / file handles, the actual
1891 * handles will be freed in destroy_task */
1892 GNUNET_array_grow (read_nhandles, read_nhandles_len, 0);
1893 GNUNET_array_grow (write_nhandles, write_nhandles_len, 0);
1894 GNUNET_array_grow (read_fhandles, read_fhandles_len, 0);
1895 GNUNET_array_grow (write_fhandles, write_fhandles_len, 0);
1897 t->start_time = GNUNET_TIME_absolute_get ();
1899 t->timeout = GNUNET_TIME_relative_to_absolute (delay);
1901 check_priority ((prio ==
1902 GNUNET_SCHEDULER_PRIORITY_KEEP) ? current_priority :
1904 t->lifeness = current_lifeness;
1905 GNUNET_CONTAINER_DLL_insert (pending_head,
1908 driver_add_multiple (t);
1909 max_priority_added = GNUNET_MAX (max_priority_added,
1911 LOG (GNUNET_ERROR_TYPE_DEBUG,
1920 * Function used by event-loop implementations to signal the scheduler
1921 * that a particular @a task is ready due to an event specified in the
1922 * et field of @a fdi.
1924 * This function will then queue the task to notify the application
1925 * that the task is ready (with the respective priority).
1927 * @param task the task that is ready
1928 * @param fdi information about the related FD
1931 GNUNET_SCHEDULER_task_ready (struct GNUNET_SCHEDULER_Task *task,
1932 struct GNUNET_SCHEDULER_FdInfo *fdi)
1934 enum GNUNET_SCHEDULER_Reason reason;
1936 reason = task->reason;
1937 if ( (0 == (reason & GNUNET_SCHEDULER_REASON_READ_READY)) &&
1938 (0 != (GNUNET_SCHEDULER_ET_IN & fdi->et)) )
1939 reason |= GNUNET_SCHEDULER_REASON_READ_READY;
1940 if ( (0 == (reason & GNUNET_SCHEDULER_REASON_WRITE_READY)) &&
1941 (0 != (GNUNET_SCHEDULER_ET_OUT & fdi->et)) )
1942 reason |= GNUNET_SCHEDULER_REASON_WRITE_READY;
1943 reason |= GNUNET_SCHEDULER_REASON_PREREQ_DONE;
1944 task->reason = reason;
1945 if (GNUNET_NO == task->in_ready_list)
1947 GNUNET_CONTAINER_DLL_remove (pending_head,
1950 queue_ready_task (task);
1956 * Function called by external event loop implementations to tell the
1957 * scheduler to run some of the tasks that are ready. Must be called
1958 * only after #GNUNET_SCHEDULER_driver_init has been called and before
1959 * #GNUNET_SCHEDULER_driver_done is called.
1960 * This function may return even though there are tasks left to run
1961 * just to give other tasks a chance as well. If we return #GNUNET_YES,
1962 * the event loop implementation should call this function again as
1963 * soon as possible, while if we return #GNUNET_NO it must block until
1964 * either the operating system has more work (the scheduler has no more
1965 * work to do right now) or the timeout set by the scheduler (using the
1966 * set_wakeup callback) is reached.
1968 * @param sh scheduler handle that was returned by
1969 * #GNUNET_SCHEDULER_driver_init
1970 * @return #GNUNET_YES if there are more tasks that are ready,
1971 * and thus we would like to run more (yield to avoid
1972 * blocking other activities for too long) #GNUNET_NO
1973 * if we are done running tasks (yield to block)
1976 GNUNET_SCHEDULER_do_work (struct GNUNET_SCHEDULER_Handle *sh)
1978 enum GNUNET_SCHEDULER_Priority p;
1979 struct GNUNET_SCHEDULER_Task *pos;
1980 struct GNUNET_TIME_Absolute now;
1982 /* check for tasks that reached the timeout! */
1983 now = GNUNET_TIME_absolute_get ();
1984 pos = pending_timeout_head;
1987 struct GNUNET_SCHEDULER_Task *next = pos->next;
1988 if (now.abs_value_us >= pos->timeout.abs_value_us)
1989 pos->reason |= GNUNET_SCHEDULER_REASON_TIMEOUT;
1990 if (0 == pos->reason)
1992 GNUNET_CONTAINER_DLL_remove (pending_timeout_head,
1993 pending_timeout_tail,
1995 if (pending_timeout_last == pos)
1996 pending_timeout_last = NULL;
1997 queue_ready_task (pos);
2003 struct GNUNET_SCHEDULER_Task *next = pos->next;
2004 if (now.abs_value_us >= pos->timeout.abs_value_us)
2006 pos->reason |= GNUNET_SCHEDULER_REASON_TIMEOUT;
2007 GNUNET_CONTAINER_DLL_remove (pending_head,
2010 queue_ready_task (pos);
2015 if (0 == ready_count)
2017 struct GNUNET_TIME_Absolute timeout = get_timeout ();
2019 if (timeout.abs_value_us > now.abs_value_us)
2022 * The driver called this function before the current timeout was
2023 * reached (and no FD tasks are ready). This can happen in the
2024 * rare case when the system time is changed while the driver is
2025 * waiting for the timeout, so we handle this gracefully. It might
2026 * also be a programming error in the driver though.
2028 LOG (GNUNET_ERROR_TYPE_DEBUG,
2029 "GNUNET_SCHEDULER_do_work did not find any ready "
2030 "tasks and timeout has not been reached yet.\n");
2034 * the current timeout was reached but no ready tasks were found,
2035 * internal scheduler error!
2040 /* find out which task priority level we are going to
2041 process this time */
2042 max_priority_added = GNUNET_SCHEDULER_PRIORITY_KEEP;
2043 GNUNET_assert (NULL == ready_head[GNUNET_SCHEDULER_PRIORITY_KEEP]);
2044 /* yes, p>0 is correct, 0 is "KEEP" which should
2045 * always be an empty queue (see assertion)! */
2046 for (p = GNUNET_SCHEDULER_PRIORITY_COUNT - 1; p > 0; p--)
2048 pos = ready_head[p];
2052 GNUNET_assert (NULL != pos); /* ready_count wrong? */
2054 /* process all tasks at this priority level, then yield */
2055 while (NULL != (pos = ready_head[p]))
2057 GNUNET_CONTAINER_DLL_remove (ready_head[p],
2061 current_priority = pos->priority;
2062 current_lifeness = pos->lifeness;
2065 if (GNUNET_TIME_absolute_get_duration (pos->start_time).rel_value_us >
2066 DELAY_THRESHOLD.rel_value_us)
2068 LOG (GNUNET_ERROR_TYPE_DEBUG,
2069 "Task %p took %s to be scheduled\n",
2071 GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_duration (pos->start_time),
2075 tc.reason = pos->reason;
2076 GNUNET_NETWORK_fdset_zero (sh->rs);
2077 GNUNET_NETWORK_fdset_zero (sh->ws);
2078 // FIXME: do we have to remove FdInfos from fds if they are not ready?
2079 tc.fds_len = pos->fds_len;
2081 for (unsigned int i = 0; i != pos->fds_len; ++i)
2083 struct GNUNET_SCHEDULER_FdInfo *fdi = &pos->fds[i];
2084 if (0 != (GNUNET_SCHEDULER_ET_IN & fdi->et))
2086 GNUNET_NETWORK_fdset_set_native (sh->rs,
2089 if (0 != (GNUNET_SCHEDULER_ET_OUT & fdi->et))
2091 GNUNET_NETWORK_fdset_set_native (sh->ws,
2095 tc.read_ready = sh->rs;
2096 tc.write_ready = sh->ws;
2097 LOG (GNUNET_ERROR_TYPE_DEBUG,
2098 "Running task %p\n",
2100 GNUNET_assert (NULL != pos->callback);
2101 pos->callback (pos->callback_cls);
2102 if (NULL != pos->fds)
2104 int del_result = scheduler_driver->del (scheduler_driver->cls, pos);
2105 if (GNUNET_OK != del_result)
2107 LOG (GNUNET_ERROR_TYPE_ERROR,
2108 "driver could not delete task %p\n", pos);
2113 dump_backtrace (pos);
2116 shutdown_if_no_lifeness ();
2117 if (0 == ready_count)
2119 scheduler_driver->set_wakeup (scheduler_driver->cls,
2123 scheduler_driver->set_wakeup (scheduler_driver->cls,
2124 GNUNET_TIME_absolute_get ());
2130 * Function called by external event loop implementations to initialize
2131 * the scheduler. An external implementation has to provide @a driver
2132 * which contains callbacks for the scheduler (see definition of struct
2133 * #GNUNET_SCHEDULER_Driver). The callbacks are used to instruct the
2134 * external implementation to watch for events. If it detects any of
2135 * those events it is expected to call #GNUNET_SCHEDULER_do_work to let
2136 * the scheduler handle it. If an event is related to a specific task
2137 * (e.g. the scheduler gave instructions to watch a file descriptor),
2138 * the external implementation is expected to mark that task ready
2139 * before by calling #GNUNET_SCHEDULER_task_ready.
2141 * This function has to be called before any tasks are scheduled and
2142 * before GNUNET_SCHEDULER_do_work is called for the first time. It
2143 * allocates resources that have to be freed again by calling
2144 * #GNUNET_SCHEDULER_driver_done.
2146 * This function installs the same signal handlers as
2147 * #GNUNET_SCHEDULER_run. This means SIGTERM (and other similar signals)
2148 * will induce a call to #GNUNET_SCHEDULER_shutdown during the next
2149 * call to #GNUNET_SCHEDULER_do_work. As a result, SIGTERM causes all
2150 * active tasks to be scheduled with reason
2151 * #GNUNET_SCHEDULER_REASON_SHUTDOWN. (However, tasks added afterwards
2152 * will execute normally!). Note that any particular signal will only
2153 * shut down one scheduler; applications should always only create a
2156 * @param driver to use for the event loop
2157 * @return handle to be passed to #GNUNET_SCHEDULER_do_work and
2158 * #GNUNET_SCHEDULER_driver_done
2160 struct GNUNET_SCHEDULER_Handle *
2161 GNUNET_SCHEDULER_driver_init (const struct GNUNET_SCHEDULER_Driver *driver)
2163 struct GNUNET_SCHEDULER_Handle *sh;
2164 struct GNUNET_SCHEDULER_Task tsk;
2165 const struct GNUNET_DISK_FileHandle *pr;
2167 /* general set-up */
2168 GNUNET_assert (NULL == active_task);
2169 GNUNET_assert (NULL == shutdown_pipe_handle);
2170 sh = GNUNET_new (struct GNUNET_SCHEDULER_Handle);
2171 shutdown_pipe_handle = GNUNET_DISK_pipe (GNUNET_NO,
2175 GNUNET_assert (NULL != shutdown_pipe_handle);
2176 pr = GNUNET_DISK_pipe_handle (shutdown_pipe_handle,
2177 GNUNET_DISK_PIPE_END_READ);
2179 scheduler_driver = driver;
2181 /* install signal handlers */
2182 LOG (GNUNET_ERROR_TYPE_DEBUG,
2183 "Registering signal handlers\n");
2184 sh->shc_int = GNUNET_SIGNAL_handler_install (SIGINT,
2185 &sighandler_shutdown);
2186 sh->shc_term = GNUNET_SIGNAL_handler_install (SIGTERM,
2187 &sighandler_shutdown);
2188 #if (SIGTERM != GNUNET_TERM_SIG)
2189 sh->shc_gterm = GNUNET_SIGNAL_handler_install (GNUNET_TERM_SIG,
2190 &sighandler_shutdown);
2193 sh->shc_pipe = GNUNET_SIGNAL_handler_install (SIGPIPE,
2195 sh->shc_quit = GNUNET_SIGNAL_handler_install (SIGQUIT,
2196 &sighandler_shutdown);
2197 sh->shc_hup = GNUNET_SIGNAL_handler_install (SIGHUP,
2198 &sighandler_shutdown);
2201 /* Setup initial tasks */
2202 current_priority = GNUNET_SCHEDULER_PRIORITY_DEFAULT;
2203 current_lifeness = GNUNET_NO;
2208 install_parent_control_task =
2209 GNUNET_SCHEDULER_add_now (&install_parent_control_handler,
2211 shutdown_pipe_task =
2212 GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
2216 current_lifeness = GNUNET_YES;
2218 scheduler_driver->set_wakeup (scheduler_driver->cls,
2220 /* begin main event loop */
2221 sh->rs = GNUNET_NETWORK_fdset_create ();
2222 sh->ws = GNUNET_NETWORK_fdset_create ();
2223 GNUNET_NETWORK_fdset_handle_set (sh->rs, pr);
2229 * Counter-part of #GNUNET_SCHEDULER_driver_init. Has to be called
2230 * by external event loop implementations after the scheduler has
2231 * shut down. This is the case if both of the following conditions
2234 * - all tasks the scheduler has added through the driver's add
2235 * callback have been removed again through the driver's del
2237 * - the timeout the scheduler has set through the driver's
2238 * add_wakeup callback is FOREVER
2240 * @param sh the handle returned by #GNUNET_SCHEDULER_driver_init
2242 void GNUNET_SCHEDULER_driver_done (struct GNUNET_SCHEDULER_Handle *sh)
2244 GNUNET_assert (NULL == pending_head);
2245 GNUNET_assert (NULL == pending_timeout_head);
2246 GNUNET_assert (NULL == shutdown_head);
2247 for (int i = 0; i != GNUNET_SCHEDULER_PRIORITY_COUNT; ++i)
2249 GNUNET_assert (NULL == ready_head[i]);
2251 GNUNET_NETWORK_fdset_destroy (sh->rs);
2252 GNUNET_NETWORK_fdset_destroy (sh->ws);
2254 /* uninstall signal handlers */
2255 GNUNET_SIGNAL_handler_uninstall (sh->shc_int);
2256 GNUNET_SIGNAL_handler_uninstall (sh->shc_term);
2257 #if (SIGTERM != GNUNET_TERM_SIG)
2258 GNUNET_SIGNAL_handler_uninstall (sh->shc_gterm);
2261 GNUNET_SIGNAL_handler_uninstall (sh->shc_pipe);
2262 GNUNET_SIGNAL_handler_uninstall (sh->shc_quit);
2263 GNUNET_SIGNAL_handler_uninstall (sh->shc_hup);
2265 GNUNET_DISK_pipe_close (shutdown_pipe_handle);
2266 shutdown_pipe_handle = NULL;
2267 scheduler_driver = NULL;
2273 select_loop (struct GNUNET_SCHEDULER_Handle *sh,
2274 struct DriverContext *context)
2276 struct GNUNET_NETWORK_FDSet *rs;
2277 struct GNUNET_NETWORK_FDSet *ws;
2280 GNUNET_assert (NULL != context);
2281 rs = GNUNET_NETWORK_fdset_create ();
2282 ws = GNUNET_NETWORK_fdset_create ();
2283 while ( (NULL != context->scheduled_head) ||
2284 (GNUNET_TIME_UNIT_FOREVER_ABS.abs_value_us != context->timeout.abs_value_us) )
2286 LOG (GNUNET_ERROR_TYPE_DEBUG,
2287 "select timeout = %s\n",
2288 GNUNET_STRINGS_absolute_time_to_string (context->timeout));
2290 GNUNET_NETWORK_fdset_zero (rs);
2291 GNUNET_NETWORK_fdset_zero (ws);
2293 for (struct Scheduled *pos = context->scheduled_head;
2297 if (0 != (GNUNET_SCHEDULER_ET_IN & pos->et))
2299 GNUNET_NETWORK_fdset_set_native (rs, pos->fdi->sock);
2301 if (0 != (GNUNET_SCHEDULER_ET_OUT & pos->et))
2303 GNUNET_NETWORK_fdset_set_native (ws, pos->fdi->sock);
2306 struct GNUNET_TIME_Relative time_remaining =
2307 GNUNET_TIME_absolute_get_remaining (context->timeout);
2308 if (NULL == scheduler_select)
2310 select_result = GNUNET_NETWORK_socket_select (rs,
2317 select_result = scheduler_select (scheduler_select_cls,
2323 if (select_result == GNUNET_SYSERR)
2328 LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR,
2340 if (0 != system (lsof))
2341 LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING,
2346 for (struct Scheduled *s = context->scheduled_head;
2350 int flags = fcntl (s->fdi->sock,
2353 if ( (flags == -1) &&
2356 LOG (GNUNET_ERROR_TYPE_ERROR,
2357 "Got invalid file descriptor %d!\n",
2360 dump_backtrace (s->task);
2366 GNUNET_NETWORK_fdset_destroy (rs);
2367 GNUNET_NETWORK_fdset_destroy (ws);
2368 return GNUNET_SYSERR;
2370 if (select_result > 0)
2372 for (struct Scheduled *pos = context->scheduled_head;
2376 int is_ready = GNUNET_NO;
2378 if (0 != (GNUNET_SCHEDULER_ET_IN & pos->et) &&
2380 GNUNET_NETWORK_fdset_test_native (rs,
2383 pos->fdi->et |= GNUNET_SCHEDULER_ET_IN;
2384 is_ready = GNUNET_YES;
2386 if (0 != (GNUNET_SCHEDULER_ET_OUT & pos->et) &&
2388 GNUNET_NETWORK_fdset_test_native (ws,
2391 pos->fdi->et |= GNUNET_SCHEDULER_ET_OUT;
2392 is_ready = GNUNET_YES;
2394 if (GNUNET_YES == is_ready)
2396 GNUNET_SCHEDULER_task_ready (pos->task,
2401 if (GNUNET_YES == GNUNET_SCHEDULER_do_work (sh))
2403 LOG (GNUNET_ERROR_TYPE_DEBUG,
2404 "scheduler has more tasks ready!\n");
2407 GNUNET_NETWORK_fdset_destroy (rs);
2408 GNUNET_NETWORK_fdset_destroy (ws);
2414 select_add (void *cls,
2415 struct GNUNET_SCHEDULER_Task *task,
2416 struct GNUNET_SCHEDULER_FdInfo *fdi)
2418 struct DriverContext *context = cls;
2419 GNUNET_assert (NULL != context);
2420 GNUNET_assert (NULL != task);
2421 GNUNET_assert (NULL != fdi);
2422 GNUNET_assert (0 != (GNUNET_SCHEDULER_ET_IN & fdi->et) ||
2423 0 != (GNUNET_SCHEDULER_ET_OUT & fdi->et));
2425 if (!((NULL != fdi->fd) ^ (NULL != fdi->fh)) || (fdi->sock < 0))
2427 /* exactly one out of {fd, hf} must be != NULL and the OS handle must be valid */
2428 return GNUNET_SYSERR;
2431 struct Scheduled *scheduled = GNUNET_new (struct Scheduled);
2432 scheduled->task = task;
2433 scheduled->fdi = fdi;
2434 scheduled->et = fdi->et;
2436 GNUNET_CONTAINER_DLL_insert (context->scheduled_head,
2437 context->scheduled_tail,
2444 select_del (void *cls,
2445 struct GNUNET_SCHEDULER_Task *task)
2447 struct DriverContext *context;
2448 struct Scheduled *pos;
2451 GNUNET_assert (NULL != cls);
2454 ret = GNUNET_SYSERR;
2455 pos = context->scheduled_head;
2458 struct Scheduled *next = pos->next;
2459 if (pos->task == task)
2461 GNUNET_CONTAINER_DLL_remove (context->scheduled_head,
2462 context->scheduled_tail,
2474 select_set_wakeup (void *cls,
2475 struct GNUNET_TIME_Absolute dt)
2477 struct DriverContext *context = cls;
2479 GNUNET_assert (NULL != context);
2480 context->timeout = dt;
2485 * Obtain the driver for using select() as the event loop.
2487 * @return NULL on error
2489 struct GNUNET_SCHEDULER_Driver *
2490 GNUNET_SCHEDULER_driver_select ()
2492 struct GNUNET_SCHEDULER_Driver *select_driver;
2493 select_driver = GNUNET_new (struct GNUNET_SCHEDULER_Driver);
2495 select_driver->add = &select_add;
2496 select_driver->del = &select_del;
2497 select_driver->set_wakeup = &select_set_wakeup;
2499 return select_driver;
2503 /* end of scheduler.c */