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3 (C) 2009 Christian Grothoff (and other contributing authors)
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22 * @file include/gnunet_scheduler_lib.h
23 * @brief API to schedule computations using continuation passing style
24 * @author Christian Grothoff
27 #ifndef GNUNET_SCHEDULER_LIB_H
28 #define GNUNET_SCHEDULER_LIB_H
33 #if 0 /* keep Emacsens' auto-indent happy */
40 * Opaque handle for the scheduling service.
42 struct GNUNET_SCHEDULER_Handle;
45 * Opaque reference to a task.
47 typedef unsigned long long GNUNET_SCHEDULER_TaskIdentifier;
51 * Constant used to indicate that the scheduled
52 * task has no others as prerequisites.
54 #define GNUNET_SCHEDULER_NO_TASK ((GNUNET_SCHEDULER_TaskIdentifier) 0)
57 * Reasons why the schedule may have triggered
60 enum GNUNET_SCHEDULER_Reason
63 * This is the very first task run during startup.
65 GNUNET_SCHEDULER_REASON_STARTUP = 0,
68 * We are shutting down and are running all shutdown-related tasks
69 * (regardless of timeout, etc.).
71 GNUNET_SCHEDULER_REASON_SHUTDOWN = 1,
74 * The specified timeout has expired.
75 * (also set if the delay given was 0).
77 GNUNET_SCHEDULER_REASON_TIMEOUT = 2,
80 * The reading socket is ready.
82 GNUNET_SCHEDULER_REASON_READ_READY = 4,
85 * The writing socket is ready.
87 GNUNET_SCHEDULER_REASON_WRITE_READY = 8,
90 * The prerequisite task is done.
92 GNUNET_SCHEDULER_REASON_PREREQ_DONE = 16
97 * Valid task priorities. Use these, do not
98 * pass random integers!
100 enum GNUNET_SCHEDULER_Priority
103 * Run with the same priority as the current job.
105 GNUNET_SCHEDULER_PRIORITY_KEEP = 0,
108 * Run when otherwise idle.
110 GNUNET_SCHEDULER_PRIORITY_IDLE = 1,
113 * Run as background job (higher than idle,
114 * lower than default).
116 GNUNET_SCHEDULER_PRIORITY_BACKGROUND = 2,
119 * Run with the default priority (normal
120 * P2P operations). Higher than BACKGROUND.
122 GNUNET_SCHEDULER_PRIORITY_DEFAULT = 3,
125 * Run with high priority (important requests).
126 * Higher than DEFAULT.
128 GNUNET_SCHEDULER_PRIORITY_HIGH = 4,
131 * Run with priority for interactive tasks.
132 * Higher than "HIGH".
134 GNUNET_SCHEDULER_PRIORITY_UI = 5,
137 * Run with priority for urgent tasks. Use
138 * for things like aborts and shutdowns that
139 * need to preempt "UI"-level tasks.
142 GNUNET_SCHEDULER_PRIORITY_URGENT = 6,
145 * Number of priorities (must be the last priority).
146 * This priority must not be used by clients.
148 GNUNET_SCHEDULER_PRIORITY_COUNT = 7
151 #include "gnunet_time_lib.h"
152 #include "gnunet_network_lib.h"
156 * Context information passed to each scheduler task.
158 struct GNUNET_SCHEDULER_TaskContext
162 * Scheduler running the task
164 struct GNUNET_SCHEDULER_Handle *sched;
167 * Reason why the task is run now
169 enum GNUNET_SCHEDULER_Reason reason;
172 * Set of file descriptors ready for reading;
173 * note that additional bits may be set
174 * that were not in the original request
176 const struct GNUNET_NETWORK_FDSet *read_ready;
179 * Set of file descriptors ready for writing;
180 * note that additional bits may be set
181 * that were not in the original request.
183 const struct GNUNET_NETWORK_FDSet *write_ready;
189 * Signature of the main function of a task.
192 * @param tc context information (why was this task triggered now)
194 typedef void (*GNUNET_SCHEDULER_Task) (void *cls,
196 GNUNET_SCHEDULER_TaskContext * tc);
200 * Initialize and run scheduler. This function will return when
201 * either a shutdown was initiated (via signal) and all tasks marked
202 * to "run_on_shutdown" have been completed or when all tasks in
203 * general have been completed.
205 * @param task task to run immediately
206 * @param cls closure of task
208 void GNUNET_SCHEDULER_run (GNUNET_SCHEDULER_Task task, void *cls);
212 * Request the shutdown of a scheduler. This function can be used to
213 * stop a scheduler, for example from within the signal
214 * handler for signals causing shutdowns.
216 void GNUNET_SCHEDULER_shutdown (struct GNUNET_SCHEDULER_Handle *sched);
220 * Get information about the current load of this scheduler. Use this
221 * function to determine if an elective task should be added or simply
222 * dropped (if the decision should be made based on the number of
223 * tasks ready to run).
225 * @param sched scheduler to query
226 * @param p priority-level to query, use KEEP to query the level
227 * of the current task, use COUNT to get the sum over
228 * all priority levels
229 * @return number of tasks pending right now
231 unsigned int GNUNET_SCHEDULER_get_load (struct GNUNET_SCHEDULER_Handle *sched,
232 enum GNUNET_SCHEDULER_Priority p);
236 * Cancel the task with the specified identifier.
237 * The task must not yet have run.
239 * @param sched scheduler to use
240 * @param task id of the task to cancel
241 * @return the closure of the callback of the cancelled task
243 void *GNUNET_SCHEDULER_cancel (struct GNUNET_SCHEDULER_Handle *sched,
244 GNUNET_SCHEDULER_TaskIdentifier task);
248 * Continue the current execution with the given function. This is
249 * similar to the other "add" functions except that there is no delay
250 * and the reason code can be specified.
252 * @param sched scheduler to use
253 * @param main main function of the task
254 * @param cls closure of task
255 * @param reason reason for task invocation
258 GNUNET_SCHEDULER_add_continuation (struct GNUNET_SCHEDULER_Handle *sched,
260 GNUNET_SCHEDULER_Task main,
262 enum GNUNET_SCHEDULER_Reason reason);
266 * Schedule a new task to be run after the specified
267 * prerequisite task has completed.
269 * @param sched scheduler to use
270 * @param run_on_shutdown run on shutdown?
271 * @param prio how important is this task?
272 * @param prerequisite_task run this task after the task with the given
273 * task identifier completes (and any of our other
274 * conditions, such as delay, read or write-readyness
275 * are satisfied). Use GNUNET_SCHEDULER_NO_TASK to not have any dependency
276 * on completion of other tasks.
277 * @param main main function of the task
278 * @param cls closure of task
279 * @return unique task identifier for the job
280 * only valid until "main" is started!
282 GNUNET_SCHEDULER_TaskIdentifier
283 GNUNET_SCHEDULER_add_after (struct GNUNET_SCHEDULER_Handle *sched,
285 enum GNUNET_SCHEDULER_Priority prio,
286 GNUNET_SCHEDULER_TaskIdentifier prerequisite_task,
287 GNUNET_SCHEDULER_Task main, void *cls);
291 * Schedule a new task to be run with a specified delay. The task
292 * will be scheduled for execution once the delay has expired and the
293 * prerequisite task has completed.
295 * @param sched scheduler to use
296 * @param run_on_shutdown run on shutdown? You can use this
297 * argument to run a function only during shutdown
298 * by setting delay to -1. Set this
299 * argument to GNUNET_NO to skip this task if
300 * the user requested process termination.
301 * @param prio how important is this task?
302 * @param prerequisite_task run this task after the task with the given
303 * task identifier completes (and any of our other
304 * conditions, such as delay, read or write-readyness
305 * are satisfied). Use GNUNET_SCHEDULER_NO_TASK to not have any dependency
306 * on completion of other tasks.
307 * @param delay how long should we wait? Use GNUNET_TIME_UNIT_FOREVER_REL for "forever"
308 * @param main main function of the task
309 * @param cls closure of task
310 * @return unique task identifier for the job
311 * only valid until "main" is started!
313 GNUNET_SCHEDULER_TaskIdentifier
314 GNUNET_SCHEDULER_add_delayed (struct GNUNET_SCHEDULER_Handle *sched,
316 enum GNUNET_SCHEDULER_Priority prio,
317 GNUNET_SCHEDULER_TaskIdentifier
319 struct GNUNET_TIME_Relative delay,
320 GNUNET_SCHEDULER_Task main, void *cls);
324 * Schedule a new task to be run with a specified delay or when the
325 * specified file descriptor is ready for reading. The delay can be
326 * used as a timeout on the socket being ready. The task will be
327 * scheduled for execution once either the delay has expired or the
328 * socket operation is ready.
330 * @param sched scheduler to use
331 * @param run_on_shutdown run on shutdown? Set this
332 * argument to GNUNET_NO to skip this task if
333 * the user requested process termination.
334 * @param prio how important is this task?
335 * @param prerequisite_task run this task after the task with the given
336 * task identifier completes (and any of our other
337 * conditions, such as delay, read or write-readyness
338 * are satisfied). Use GNUNET_SCHEDULER_NO_TASK to not have any dependency
339 * on completion of other tasks.
340 * @param delay how long should we wait? Use GNUNET_TIME_UNIT_FOREVER_REL for "forever"
341 * @param rfd read file-descriptor
342 * @param main main function of the task
343 * @param cls closure of task
344 * @return unique task identifier for the job
345 * only valid until "main" is started!
347 GNUNET_SCHEDULER_TaskIdentifier
348 GNUNET_SCHEDULER_add_read_net (struct GNUNET_SCHEDULER_Handle *sched,
350 enum GNUNET_SCHEDULER_Priority prio,
351 GNUNET_SCHEDULER_TaskIdentifier prerequisite_task,
352 struct GNUNET_TIME_Relative delay,
353 struct GNUNET_NETWORK_Handle *rfd, GNUNET_SCHEDULER_Task main, void *cls);
357 * Schedule a new task to be run with a specified delay or when the
358 * specified file descriptor is ready for writing. The delay can be
359 * used as a timeout on the socket being ready. The task will be
360 * scheduled for execution once either the delay has expired or the
361 * socket operation is ready.
363 * @param sched scheduler to use
364 * @param run_on_shutdown run on shutdown? Set this
365 * argument to GNUNET_NO to skip this task if
366 * the user requested process termination.
367 * @param prio how important is this task?
368 * @param prerequisite_task run this task after the task with the given
369 * task identifier completes (and any of our other
370 * conditions, such as delay, read or write-readyness
371 * are satisfied). Use GNUNET_SCHEDULER_NO_TASK to not have any dependency
372 * on completion of other tasks.
373 * @param delay how long should we wait? Use GNUNET_TIME_UNIT_FOREVER_REL for "forever"
374 * @param wfd write file-descriptor
375 * @param main main function of the task
376 * @param cls closure of task
377 * @return unique task identifier for the job
378 * only valid until "main" is started!
380 GNUNET_SCHEDULER_TaskIdentifier
381 GNUNET_SCHEDULER_add_write_net (struct GNUNET_SCHEDULER_Handle *sched,
383 enum GNUNET_SCHEDULER_Priority prio,
384 GNUNET_SCHEDULER_TaskIdentifier prerequisite_task,
385 struct GNUNET_TIME_Relative delay,
386 struct GNUNET_NETWORK_Handle *wfd, GNUNET_SCHEDULER_Task main, void *cls);
390 * Schedule a new task to be run with a specified delay or when the
391 * specified file descriptor is ready for reading. The delay can be
392 * used as a timeout on the socket being ready. The task will be
393 * scheduled for execution once either the delay has expired or the
394 * socket operation is ready.
396 * @param sched scheduler to use
397 * @param run_on_shutdown run on shutdown? Set this
398 * argument to GNUNET_NO to skip this task if
399 * the user requested process termination.
400 * @param prio how important is this task?
401 * @param prerequisite_task run this task after the task with the given
402 * task identifier completes (and any of our other
403 * conditions, such as delay, read or write-readyness
404 * are satisfied). Use GNUNET_SCHEDULER_NO_TASK to not have any dependency
405 * on completion of other tasks.
406 * @param delay how long should we wait? Use GNUNET_TIME_UNIT_FOREVER_REL for "forever"
407 * @param rfd read file-descriptor
408 * @param main main function of the task
409 * @param cls closure of task
410 * @return unique task identifier for the job
411 * only valid until "main" is started!
413 GNUNET_SCHEDULER_TaskIdentifier
414 GNUNET_SCHEDULER_add_read_file (struct GNUNET_SCHEDULER_Handle *sched,
416 enum GNUNET_SCHEDULER_Priority prio,
417 GNUNET_SCHEDULER_TaskIdentifier prerequisite_task,
418 struct GNUNET_TIME_Relative delay,
419 const struct GNUNET_DISK_FileHandle *rfd,
420 GNUNET_SCHEDULER_Task main, void *cls);
424 * Schedule a new task to be run with a specified delay or when the
425 * specified file descriptor is ready for writing. The delay can be
426 * used as a timeout on the socket being ready. The task will be
427 * scheduled for execution once either the delay has expired or the
428 * socket operation is ready.
430 * @param sched scheduler to use
431 * @param run_on_shutdown run on shutdown? Set this
432 * argument to GNUNET_NO to skip this task if
433 * the user requested process termination.
434 * @param prio how important is this task?
435 * @param prerequisite_task run this task after the task with the given
436 * task identifier completes (and any of our other
437 * conditions, such as delay, read or write-readyness
438 * are satisfied). Use GNUNET_SCHEDULER_NO_TASK to not have any dependency
439 * on completion of other tasks.
440 * @param delay how long should we wait? Use GNUNET_TIME_UNIT_FOREVER_REL for "forever"
441 * @param wfd write file-descriptor
442 * @param main main function of the task
443 * @param cls closure of task
444 * @return unique task identifier for the job
445 * only valid until "main" is started!
447 GNUNET_SCHEDULER_TaskIdentifier
448 GNUNET_SCHEDULER_add_write_file (struct GNUNET_SCHEDULER_Handle *sched,
450 enum GNUNET_SCHEDULER_Priority prio,
451 GNUNET_SCHEDULER_TaskIdentifier prerequisite_task,
452 struct GNUNET_TIME_Relative delay,
453 const struct GNUNET_DISK_FileHandle *wfd,
454 GNUNET_SCHEDULER_Task main, void *cls);
458 * Schedule a new task to be run with a specified delay or when any of
459 * the specified file descriptor sets is ready. The delay can be used
460 * as a timeout on the socket(s) being ready. The task will be
461 * scheduled for execution once either the delay has expired or any of
462 * the socket operations is ready. This is the most general
463 * function of the "add" family. Note that the "prerequisite_task"
464 * must be satisfied in addition to any of the other conditions. In
465 * other words, the task will be started when
471 * || (shutdown-active && run-on-shutdown) )
474 * @param sched scheduler to use
475 * @param run_on_shutdown run on shutdown? Set this
476 * argument to GNUNET_NO to skip this task if
477 * the user requested process termination.
478 * @param prio how important is this task?
479 * @param prerequisite_task run this task after the task with the given
480 * task identifier completes (and any of our other
481 * conditions, such as delay, read or write-readyness
482 * are satisfied). Use GNUNET_SCHEDULER_NO_TASK to not have any dependency
483 * on completion of other tasks.
484 * @param delay how long should we wait? Use GNUNET_TIME_UNIT_FOREVER_REL for "forever"
485 * @param rs set of file descriptors we want to read (can be NULL)
486 * @param ws set of file descriptors we want to write (can be NULL)
487 * @param main main function of the task
488 * @param cls closure of task
489 * @return unique task identifier for the job
490 * only valid until "main" is started!
492 GNUNET_SCHEDULER_TaskIdentifier
493 GNUNET_SCHEDULER_add_select (struct GNUNET_SCHEDULER_Handle *sched,
495 enum GNUNET_SCHEDULER_Priority prio,
496 GNUNET_SCHEDULER_TaskIdentifier
498 struct GNUNET_TIME_Relative delay,
499 const struct GNUNET_NETWORK_FDSet * rs,
500 const struct GNUNET_NETWORK_FDSet * ws,
501 GNUNET_SCHEDULER_Task main, void *cls);
503 #if 0 /* keep Emacsens' auto-indent happy */