1 // -----------------------------------------------------------------------
2 // Copyright (C) 2006 - 2007 FRESCOR consortium partners:
4 // Universidad de Cantabria, SPAIN
5 // University of York, UK
6 // Scuola Superiore Sant'Anna, ITALY
7 // Kaiserslautern University, GERMANY
8 // Univ. Politécnica Valencia, SPAIN
9 // Czech Technical University in Prague, CZECH REPUBLIC
11 // Thales Communication S.A. FRANCE
12 // Visual Tools S.A. SPAIN
13 // Rapita Systems Ltd UK
16 // See http://www.frescor.org for a link to partners' websites
18 // FRESCOR project (FP6/2005/IST/5-034026) is funded
19 // in part by the European Union Sixth Framework Programme
20 // The European Union is not liable of any use that may be
24 // based on previous work (FSF) done in the FIRST project
26 // Copyright (C) 2005 Mälardalen University, SWEDEN
27 // Scuola Superiore S.Anna, ITALY
28 // Universidad de Cantabria, SPAIN
29 // University of York, UK
31 // FSF API web pages: http://marte.unican.es/fsf/docs
32 // http://shark.sssup.it/contrib/first/docs/
34 // This file is part of FRSH API
36 // FRSH API is free software; you can redistribute it and/or modify
37 // it under the terms of the GNU General Public License as published by
38 // the Free Software Foundation; either version 2, or (at your option)
41 // FRSH API is distributed in the hope that it will be useful, but
42 // WITHOUT ANY WARRANTY; without even the implied warranty of
43 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
44 // General Public License for more details.
46 // You should have received a copy of the GNU General Public License
47 // distributed with FRSH API; see file COPYING. If not, write to the
48 // Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
51 // As a special exception, if you include this header file into source
52 // files to be compiled, this header file does not by itself cause
53 // the resulting executable to be covered by the GNU General Public
54 // License. This exception does not however invalidate any other
55 // reasons why the executable file might be covered by the GNU General
57 // -----------------------------------------------------------------------
59 //==============================================
60 // ******** ******* ******** ** **
61 // **///// /**////** **////// /** /**
62 // ** /** /** /** /** /**
63 // ******* /******* /********* /**********
64 // **//// /**///** ////////** /**//////**
65 // ** /** //** /** /** /**
66 // ** /** //** ******** /** /**
67 // // // // //////// // //
69 // FRSH(FRescor ScHeduler), pronounced "fresh"
70 //==============================================
82 #include <sys/types.h>
84 #include "frsh_core_types.h"
85 #include "frsh_spare_capacity.h"
88 * @defgroup core Core module
90 * This module includes the basic functions and services that are
91 * provided by any FRSH implementation. This module includes basic type
92 * definitions, and functions to
94 * - create a contract and initialize it
95 * - set/get the basic parameters of a contract
96 * - negotiate a service contract, obtaining a vres id
97 * - create and bind threads to vres
98 * - create/destroy a synchronization object
99 * - manage bounded workloads
104 //////////////////////////////////////////////////////////////////////
105 // INITIALIZATION SERVICES
106 //////////////////////////////////////////////////////////////////////
109 * @defgroup initialization Initialization services
112 * These functions need to be called before doing any FRSH operation
113 * (including contract initialization).
122 * We cannot call any frsh functions before frsh_init. After calling
123 * frsh_init, the main will be executing in the background. Then, it
124 * can do the negotiations and create new threads if needed. The
125 * second time this function is called it fails.
127 * @return 0 if no error. \n
128 * FRSH_ERR_SYSTEM_ALREADY_INITIALIZED : if the function has already
129 * been called before\n
131 * It may also return any of the errors that may be returned by the
132 * underlying operating system primitives required to perform the
133 * FRSH system start up
141 /////////////////////////////////////////////////////////////
142 // CONTRACT PARAMETERS
143 /////////////////////////////////////////////////////////////
145 * @defgroup contract Contract Creation and Initialization.
148 * These functions are used to create and initialize a contract, and
149 * set its parameters.
156 * frsh_contract_init()
158 * The operation receives a pointer to a contract object
159 * and initializes it, setting it to the default values.
161 * The default values are:
164 * - ressource_type => FRSH_CRT_PROCESSOR
165 * - contract_label => ""
166 * - budget_min => {0,0};
167 * - period_max => {0,0};
168 * - budget_max => {0,0};
169 * - period_min => {0,0};
170 * - workload => FRSH_WT_INDETERMINATE
171 * - d_equals_t => true
172 * - contract_type => FRSH_CT_REGULAR;
173 * - deadline => {0,0};
174 * - budget_overrun_signal => 0; (signal number)
175 * - budget_overrun_siginfo => {0, NULL};
176 * - deadline_miss_signal => 0; (signal number)
177 * - deadline_miss_siginfo => {0, NULL};
179 * - granularity => DEFAULT_GRANULARITY;
180 * - utilization_set; => size = 0
181 * - quality => DEFAULT_QUALITY; (range 0..100)
182 * - importance => DEFAULT_IMPORTANCE; (range 1..5)
183 * - preemption_level => 0; (range 1..2**32-1)
184 * - critical_sections; => size = 0
186 * - sched_policy => DEFAULT_SCHED_POLICY (FRSH_NONE)
188 * @param contract the pointer to the contract variable.
190 * @return 0 if no error \n
191 * FRSH_ERR_BAD_ARGUMENT : contract is NULL
194 int frsh_contract_init(frsh_contract_t *contract);
198 * frsh_contract_set_basic_params()
200 * The operation updates the specified contract parameters object by
201 * setting its budget, period, workload and type to the specified
202 * input parameters. (Note: the workload is a basic parameter because
203 * bounded tasks are triggered by the scheduler (see the
204 * frsh_timed_wait() and frsh_synchobj_wait* operations), while
205 * indeterminate tasks are not; therefore, their programming model is
208 * @param contract the pointer to the contract object
209 * @param[in] budget_min the minimum budget for the contract
210 * @param[in] period_max the maximum period for the contract
211 * @param[in] workload the kind of workload (can be FRSH_WT_BOUNDED,
212 * FRSH_WT_INDETERMINATE or FRSH_OVERHEAD)
213 * @param[in] contract_type can be FRSH_CT_REGULAR,
214 * FRSH_CT_BACKGROUND, FRSH_CT_DUMMY.
216 * @return 0 if no error \n
217 * FRSH_ERR_BAD_ARGUMENT : if any of the pointers is NULL
218 * or if only one of the timespec values is 0, and also if the
219 * workload or the contract type values are unknown in the
222 int frsh_contract_set_basic_params
223 (frsh_contract_t *contract,
224 const struct timespec *budget_min,
225 const struct timespec *period_max,
226 const frsh_workload_t workload,
227 const frsh_contract_type_t contract_type);
230 * frsh_contract_get_basic_params()
232 * This operation obtains from the specified contract object its
233 * budget, period, and workload, and copies them to the places pointed
234 * to by the corresponding output parameters.
236 * @param[in] contract the pointer to the contract object
237 * @param[out] budget_min pointer to preallocated space
238 * @param[out] period_max pointer to preallocated space
239 * @param[out] workload pointer to preallocated space
240 * @param[out] contract_type pointer to preallocated space
242 * @return 0 if no error \n
243 * FRSH_ERR_BAD_ARGUMENT : if one of the contract or
247 int frsh_contract_get_basic_params
248 (const frsh_contract_t *contract,
249 struct timespec *budget_min,
250 struct timespec *period_max,
251 frsh_workload_t *workload,
252 frsh_contract_type_t *contract_type);
255 * frsh_contract_set_resource_and_label()
257 * Specify resource_id and type, and the contract label. Otherwise
258 * default values will apply. If the contract label is too long it is truncated
260 * @return 0 if no error \n
261 * FRSH_ERR_BAD_ARGUMENT : if the contract pointer is NULL.
263 int frsh_contract_set_resource_and_label
264 (frsh_contract_t *contract,
265 const frsh_resource_type_t resource_type,
266 const frsh_resource_id_t resource_id,
267 const char *contract_label);
271 * frsh_contract_get_resource_and_label()
273 * Obtain the resource_id and type, and the contract label.
275 * @return 0 if no error \n
276 * FRSH_ERR_BAD_ARGUMENT : if the contract or the contract_label
279 int frsh_contract_get_resource_and_label
280 (const frsh_contract_t *contract,
281 frsh_resource_type_t *resource_type,
282 frsh_resource_id_t *resource_id,
283 char *contract_label);
287 * frsh_contract_set_timing_reqs()
289 * The operation updates the specified contract object, specifying
290 * additional time-related requirements.
292 * @param contract The pointer to the contract object
294 * @param [in] d_equals_t It is a boolean value, set to true (1) if
295 * we want to specify a deadline different from
296 * the period for the contract.
297 * @param [in] deadline If the previous parameter is set to true,
298 * this parameter is ignored (the contract value
299 * will be NULL_DEADLINE internally). Otherwise, it
300 * contains the desired deadline value.
301 * @param [in] budget_overrun_signal contains the number of the signal
302 * that must be raised if the budget of the vres is overrun.
303 * If the value of this parameter is FRSH_NULL_SIGNAL, no signal will
305 * @param [in] budget_overrun_siginfo contains the value that will be
306 * passed to the signal "catcher" when the signal is raised.
307 * This parameters is not used if the budget_overrun_signal
308 * parameter is set to FRSH_NULL_SIGNAL.
309 * @param [in] deadline_miss_signal contains the number of the
310 * signal that must be raised if the deadline of the
311 * vres is missed. If the value of this parameter is
312 * FRSH_NULL_SIGNAL, no signal is raised.
313 * @param [in] deadline_miss_siginfo contains the value that will be
314 * passed to the signal "catcher" when the signal is
315 * raised. This parameter is not used if the
316 * deadline_signal parameter is set to NULL_SIGNAL
318 * @return 0 if successful\n
319 * FRSH_ERR_BAD_ARGUMENT : if contract is NULL \b or \n
320 * (d_equals_t is true and deadline is not FRSH_NULL_DEADLINE) \b or \n
321 * (budget_overrun_signal is not a valid signal) \b or \n
322 * (deadline_miss_signal is not a valid signal) \b or \n
323 * (d_equals_t is false but (deadline is FRSH_NULL_DEADLINE or its value
324 * is grater than the contract's maximum period))
327 int frsh_contract_set_timing_reqs
328 (frsh_contract_t *contract,
329 const bool d_equals_t,
330 const struct timespec *deadline,
331 const frsh_signal_t budget_overrun_signal,
332 const frsh_signal_info_t budget_overrun_siginfo,
333 const frsh_signal_t deadline_miss_signal,
334 const frsh_signal_info_t deadline_miss_siginfo);
337 * frsh_contract_get_timing_reqs()
339 * The operation obtains the corresponding input parameters from the
340 * specified contract object. If d_equals_t is true, the deadline will
341 * be set to FRSH_NULL_DEADLINE.
343 * @return 0 if no error \n
344 * FRSH_ERR_BAD_ARGUMENT : if contract is NULL
347 int frsh_contract_get_timing_reqs
348 (const frsh_contract_t *contract,
350 struct timespec *deadline,
351 frsh_signal_t *budget_overrun_signal,
352 frsh_signal_info_t *budget_overrun_siginfo,
353 frsh_signal_t *deadline_miss_signal,
354 frsh_signal_info_t *deadline_miss_siginfo);
359 //////////////////////////////////////////////////////////////////
360 // SYNCHRONIZATION OBJECTS
361 //////////////////////////////////////////////////////////////////
363 * @defgroup synch Synchronization objects
366 * Synchronisation objects provide an alternative to timers for
367 * bounded-workload vres to signal the end of their current job and
368 * return their remaining budget to FRSH.
370 * Instead of asking to be reactivated based on an absolute time, they
371 * queue themselves in a synchronisation object and will wait there
372 * until another vres (bounded-workload or indeterminate-workload)
373 * wakes them up with a signal call the earliest at the beginning of
376 * Indeterminate-workload vres cannot queue themselves here because
377 * they don't have any budget to return. However they can signal on
378 * the objects to activate a waiting workload vres.
380 * For classical signal/wait synchronisation paradigms the application
381 * must use whatever mechanism the underlying OS provides.
383 * In the future we may add a broadcast operation that would signal a
384 * group of synchronization objects. We have not included a broadcast
385 * service in this version because it can be easily created by the
386 * user by signalling individual synchronization objects inside a
389 * Notice that for synchronization objects there is no naming service
390 * like in shared objects because tasks that use synchronization are
391 * not developed independently, as they are closely coupled.
398 * frsh_synchobj_create()
400 * This operation creates and initializes a synchronization object
401 * variable managed by the scheduler, and returns a handle to it in
402 * the variable pointed to by synch_handle.
404 * @param[out] synch_handle pointer to the variable that will contain
405 * the handle to the newly created synchronization object
407 * @return 0 if the operation is succesful
408 * FRSH_ERR_TOO_MANY_SYNCH_OBJS if the number of synchronization
409 * objects in the system has already exceeded the maximum
411 * FRSH_ERR_TOO_MANY_SYNCH_OBJS : if the number of synchronization
412 * objects in the system has already exceeded the maximum\n
414 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
415 * scheduled under FRSH\n
417 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not running
420 int frsh_synchobj_create
421 (frsh_synchobj_handle_t *synch_handle);
425 * frsh_synchobj_destroy()
427 * This operation destroys the synchronization object (created by a
428 * previous call to frsh_synchobj_create) that is referenced by the
429 * synch_handle variable. After calling this operation, the
430 * synch_handle variable can not be used until it is initialized again
431 * by a call to frsh_synchobj_create.
433 * @param synch_handle the handle to the synchronization object
436 * @return 0 if no error \n
437 * FRSH_ERR_BAD_ARGUMENT : if synch_handle is 0\n
438 * FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE if the handle is not valid\n
439 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
440 * scheduled under FRSH \n
441 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
444 * @sa frsh_synchobj_create
446 int frsh_synchobj_destroy
447 (const frsh_synchobj_handle_t synchobj_handle);
450 * frsh_synchobj_wait()
452 * This operation is invoked by threads associated with bounded
453 * workload vres to indicate that a job has been completed (and
454 * that the scheduler may reassign the unused capacity of the current
455 * job to other vres).
457 * As a difference with frsh_timed_wait(), here the vres
458 * specifies to be awakened by the arrival of a signal operation
459 * instead of at a precise point of time.
461 * This function can also be called to schedule the first job of a
462 * recently created vres and make it start when a signal operation
463 * has been sent from another thread.
465 * The vres' budget will be made zero for the remainder of the vres'
466 * period, and FRSH will not replenish it until an event has been
467 * notified to the synchronisation object by another vres.
469 * It can happen that the synchronisation object has notification
470 * events queued from the past, in this case one of the events is
471 * dequeued immediately and the vres won't have to wait for another
474 * At the time of reception of a notification event (wether in the
475 * future or in the past), all pending budget replenishments (if any)
476 * are made effective. Once the vres has a positive budget and the
477 * scheduler schedules the calling thread again, the call returns and
478 * the vres continues executing.
480 * If the synchronisation object is destroyed while the vres was
481 * waiting on it, the vres will be awaken and the function will
482 * return with a code FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE
484 * Except for those parameters equal to NULL pointers, the system
485 * reports the current period and budget for the current job, it informs
486 * if the deadline of the previous job was missed or not, and whether the
487 * budget of the previous job was overrun or not.
489 * In a system with hierarchical scheduling, since this call makes the
490 * budget of the current period zero, the other threads in the same
491 * vres are not run. As mentioned above, only when the call finishes
492 * the budget may be replenished.
494 * @param synch_handle Synchronisation object upon which the vres
496 * @param next_budget[out] Upon return of this function, the variable
497 * pointed by this function will be equal to
498 * the current vres budget. If this parameter is
499 * set to NULL, no action is taken
500 * @param next_period[out] The vres period upon return (ignored if NULL).
501 * @param was_deadline_missed Upon return whether the deadline was
502 * missed in the previous period.
503 * @param was_budget_overran
506 * @return 0 if success \n
507 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
509 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
511 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not scheduled
513 * FRSH_ERR_NOT_BOUND : if the calling thread does not have a valid
514 * vres bound to it \n
515 * FRSH_ERR_BAD_ARGUMENT : if synch_handle is 0 \n
516 * FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE if the synch_handle is not
517 * valid or was destroyed while the vres was waiting on it. \n
518 * FRSH_ERR_VRES_WORKLOAD_NOT_COMPATIBLE: if the kind of workload of the vres
519 * is not FRSH_BOUNDED
522 int frsh_synchobj_wait
523 (const frsh_synchobj_handle_t synch_handle,
524 struct timespec *next_budget,
525 struct timespec *next_period,
526 bool *was_deadline_missed,
527 bool *was_budget_overran);
531 * frsh_synchobj_wait_with_timeout()
533 * This call is the same as frsh_synchobj_wait() but with an extra
534 * absolute timeout. The timed_out argument, indicates whether the
535 * function returned because of the expiration of the timeout or not.
537 * @return 0 if no error \n
538 * FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE if the synch_handle is not
540 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
542 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
544 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not scheduled
546 * FRSH_ERR_NOT_BOUND : if the calling thread does not have a valid
547 * vres bound to it \n
548 * FRSH_ERR_BAD_ARGUMENT : if the synch_handle given is not valid or the
549 * abs_timeout argument is NULL or its value is in the past\n
550 * FRSH_ERR_VRES_WORKLOAD_NOT_COMPATIBLE: if the kind of workload of the vres
551 * is not FRSH_BOUNDED
554 int frsh_synchobj_wait_with_timeout
555 (const frsh_synchobj_handle_t synch_handle,
556 const struct timespec *abs_timeout,
558 struct timespec *next_budget,
559 struct timespec *next_period,
560 bool *was_deadline_missed,
561 bool *was_budget_overran);
564 * frsh_synchobj_signal()
566 * This function sends a notification event to the synchronization object
567 * specified as parameter. If there is at least one vres waiting on
568 * the synchronization object, it is awaken. If more than one vres
569 * are waiting, just one of them is awaken. However, which one is
570 * awaken is implementation dependent. If no vres is waiting on the
571 * synchronization object, the notification event is queued.
573 * @param [in] synch_handle the handle of the synchronization object to
576 * @return 0 if no error \n
577 * FRSH_ERR_BAD_ARGUMENT : if synch_handle is 0 \n
578 * FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE if the handle is not valid \n
579 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
580 * scheduled under FRSH \n
581 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
583 * FRSH_ERR_TOO_MANY_EVENTS_IN_SYNCH_OBJ : if the number of events stored
584 * in the synchronization object reaches the maximum defined in the
585 * configuration parameter header file
587 * @sa frsh_synchobj_wait, frsh_synchobj_wait_with_timeout
589 int frsh_synchobj_signal
590 (const frsh_synchobj_handle_t synch_handle);
595 * This operation is invoked by threads associated with bounded
596 * workload vres to indicate that a job has been completed (and
597 * that the scheduler may reassign the unused capacity of the current
598 * job to other vres). It is also invoked when the first job of
599 * such threads has to be scheduled.
601 * As an effect, the system will make the current vres's budget zero
602 * for the remainder of the vres's period, and will not replenish
603 * the budget until the specified absolute time. At that time, all
604 * pending budget replenishments (if any) are made effective. Once the
605 * vres has a positive budget and the scheduler schedules the
606 * calling thread again, the call returns and at that time, except for
607 * those parameters equal to NULL pointers, the system reports the
608 * current period and budget for the current job, whether the deadline
609 * of the previous job was missed or not, and whether the budget of
610 * the previous job was overrun or not.
612 * In a system with hierarchical scheduling, since this call makes the
613 * budget zero, the other threads in the same vres are not run. As
614 * mentioned abobe, only when the call finishes the budget may be
617 * @param [in] abs_time absolute time at which the budget will be
620 * @param [out] next_budget upon return of this function, the variable
621 * pointed by this function will be equal to
622 * the current vres budget. If this parameter is
623 * set to NULL, no action is taken.
625 * @param [out] next_period upon return of this function, the variable
626 * pointed by this function will be equal to
627 * the current vres period. If this parameter is
628 * set to NULL, no action is taken.
630 * @param [out] was_deadline_missed upon return of this function, the
631 * variable pointed by this function will be
632 * equal to true if the previous vres deadline
633 * was missed, to false otherwise. If this
634 * parameter is set to NULL, no action is
637 * @param [out] was_budget_overrun upon return of this function, the
638 * variable pointed by this function will be
639 * equal to true if the previous vres budget was
640 * overrun, to false otherwise. If this
641 * parameter is set to NULL, no action is
644 * @return 0 if the operation is successful \n
645 * FRSH_ERR_TIME_SPEC_IN_THE_PAST if the absolute time specification
647 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong
649 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
651 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling
652 * thread is not scheduled under FRSH \n
653 * FRSH_ERR_NOT_BOUND : if the calling thread does not have a valid
654 * vres bound to it \n
655 * FRSH_ERR_BAD_ARGUMENT : if abs_time is NULL \n
656 * FRSH_ERR_VRES_WORKLOAD_NOT_COMPATIBLE: if the kind of workload of the vres
657 * is not FRSH_BOUNDED
660 * @sa frsh_synchobj_wait, frsh_synchobj_wait_with_timeout
663 (const struct timespec *abs_time,
664 struct timespec *next_budget,
665 struct timespec *next_period,
666 bool *was_deadline_missed,
667 bool *was_budget_overran);
672 * frsh_vresperiod_wait()
674 * Suspend the calling thread until the start of the specified virtual
675 * resource period, for a synchronized workload.
677 * Virtual resource periods are numbered. The number of the current
678 * period can be obtained through the frsh_vres_get_period_number()
681 int frsh_vresperiod_wait
682 (const frsh_vres_id_t vres,
687 * frsh_vres_get_period()
689 * Return the current period number, for a virtual resource of
690 * synchronized workload.
692 int frsh_vres_get_period_number
693 (const frsh_vres_id_t vres,
701 ///////////////////////////////////////////////////////////////////
702 // CONTRACT NEGOCIATION OPERATIONS
703 ///////////////////////////////////////////////////////////////////
706 * @defgroup negotiate Negotiate contract functions
709 * The following functions are used to negotiate contracts and thus
710 * creating vres which are the execution image of a contract.
711 * Besides, these functions allow to assign and unassign threads to
714 * In the case of more than one thread per vres please refer to the
715 * hierarchical module.
723 * frsh_contract_negotiate()
725 * The operation negotiates a contract and if accepted it will return
726 * a vres_id. It will also check that the given contract_label is unique
729 * If the on-line admission test is enabled, it determines whether the
730 * contract can be admitted or not based on the current contracts
731 * established in the system. Then it creates the vres and
732 * recalculates all necessary parameters for the contracts already
733 * present in the system.
735 * This is a potentially blocking operation, it returns when the
736 * system has either rejected the contract, or admitted it and made it
737 * effective. No thread is bound to the newly created vres, which
738 * will be idle until a thread is bound to it via frsh_thread_bind()
739 * or frsh_thread_create_and_bind().
741 * This operation can only be executed by threads that are already
742 * bound to an active vres and therefore are being scheduled by the
745 * @return 0 if successful \n
746 * FRSH_ERR_CONTRACT_REJECTED: The contract is not accepted.\n
747 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
749 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
751 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not scheduled
752 * under FRSH scheduler \n
753 * FRSH_ERR_BAD_ARGUMENT : if the contract or vres arguments are NULL \n
754 * FRSH_ERR_TOO_MANY_VRES : if there is no space for more vres
755 * (the maximum number of them is already reached) \n
756 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS : contract_label is not unique.
759 int frsh_contract_negotiate
760 (const frsh_contract_t *contract,
761 frsh_vres_id_t *vres);
764 * frsh_thread_create_and_bind()
766 * This operation creates a thread and binds it to an existing vres.
768 * This is the preferred way to add threads to the application because
769 * we make sure that the thread won't become unbound.
771 * The vres must not have any thread binded to it. If you want to
772 * bind more than one thread to the vres you must use the
773 * hierarchical module.
775 * The frsh_thread_attr_t parameter is overwritten as necessary to
776 * introduce the adequate scheduling policy and priority, according
777 * to the preemption level given in the contract and the
778 * frsh_priority_map() function defined by the user.
780 * @param[in] vres_id vres with which the thread will be bound.
781 * @param[out] thread frsh_thread_id returned by the system.
782 * @param attr pthread_attr taken and maybe corrected
783 * by the system. Ignored if NULL
784 * @param[in] thread_code Thread function (void func(void *) )
785 * that will constitute the main of the
787 * @param[in] arg Argument for data to be passed at the
788 * thread. Set to NUL if you don't want
789 * to do anything like this.
791 * @return 0 if successful \n
792 * FRSH_ERR_BAD_ARGUMENT : if the contract or vres arguments are
794 * FRSH_ERR_CONTRACT_REJECTED : if the contract is rejected. \n
796 * It may also return all the errors that may be returned by the
797 * fosa_thread_create() function call
800 int frsh_thread_create_and_bind
801 (const frsh_vres_id_t vres,
802 frsh_thread_id_t *thread,
803 frsh_thread_attr_t *attr,
804 frsh_thread_code_t thread_code,
809 * frsh_thread_create_in_background()
811 * This function creates a "background contract" that does not need to
812 * be negotiated, creates a threads and binds to the new vres.
814 * This method is suggested as a way to initate components and
815 * plugins. The event that triggers the component activation should
816 * arrive to an application thread that could use this function to
817 * create a thread used in its initialisation.
819 * The attribute parameter is overwritten as necessary to introduce
820 * the adequate scheduling policy and priority.
822 * @param[in] thread_code Function to be executed by the new
824 * @param[in] thread_arg General pointer that will be passed to
825 * the new thread as initialisation data.
826 * @param attr Pthread attribute with thread params
827 * @param[in] contract_label Contract label for the new vres.
828 * @param[out] thread_id Id of the new thread.
829 * @param[out] vres_id vres_id of the new vres.
831 * @return 0 if successful \n
832 * FRSH_ERR_BAD_ARGUMENT : Any problems with the argument \n
833 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is
834 * not scheduled under FRSH \n
835 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS : contract_label is not unique \n
836 * FRSH_ERR_TOO_MANY_VRES : if there is no space for more vres
837 * (the maximum number of them is already reached)
840 int frsh_thread_create_in_background
841 (frsh_thread_code_t thread_code,
842 const void *thread_arg,
843 const char *contract_label,
844 frsh_thread_attr_t *attr,
845 frsh_thread_id_t *thread_id,
846 frsh_vres_id_t *vres_id);
852 * This operation associates a thread with a vres, which means that
853 * it starts consuming the vres's budget and is executed according
854 * to the contract established for that vres. If the thread is
855 * already bound to another vres, it is effectively unbound from it
856 * and bound to the specified one.
858 * It fails if the vres's policy is different than FRSH_NONE, or if
859 * there is already a thread bound to this vres. In order to bind
860 * more than one vres to the same thread you must use the
861 * hierarchical module.
863 * Implementation dependent issue: In order to allow the usage of
864 * application defined schedulers, the given thread must not have the
865 * scheduling policy SCHED_APP and at the same time be attached to an
866 * application scheduler different than the frsh scheduler.
868 * @return 0 if successful \n
869 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
871 * FRSH_ERR_UNKNOWN_APPSCHEDULED_THREAD : if the thread is attached to
872 * an application defined scheduler different than the frsh
874 * FRSH_ERR_BAD_ARGUMENT : if the vres value does not complain with the
875 * expected format or valid range or the given thread does not
877 * FRSH_ERR_NOT_CONTRACTED_VRES : if the referenced vres is not
879 * FRSH_ERR_VRES_WORKLOAD_NOT_COMPATIBLE: if the kind of workload
880 * of the vres is FRSH_OVERHEAD \n
881 * FRSH_ERR_ALREADY_BOUND : if the given vres has a thread already
886 (const frsh_vres_id_t vres,
887 const frsh_thread_id_t thread);
891 * frsh_thread_unbind()
893 * This operation unbinds a thread from a vres. Since threads with
894 * no vres associated are not allowed to execute, they remain in a
895 * dormant state until they are either eliminated or bound again.
897 * If the thread is inside a critical section the effects of this call
898 * are deferred until the critical section is ended
900 * Implementation dependent issue: in the implementation with an
901 * application scheduler, the thread is still attached to the frsh
902 * scheduler, but suspended.
904 * @return 0 if successful \n
905 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
907 * FRSH_ERR_BAD_ARGUMENT : if the given thread does not exist \n
908 * FRSH_ERR_NOT_SCHEDULED_THREAD : if the given thread is not scheduled
910 * FRSH_ERR_UNKNOWN_APPSCHEDULED_THREAD : if the thread is attached to
911 * an application defined scheduler different than the frsh
913 * FRSH_ERR_NOT_BOUND : if the given thread does not have a valid
916 int frsh_thread_unbind(const frsh_thread_id_t thread);
919 * frsh_thread_get_vres_id()
921 * This operation stores the Id of the vres associated with the
922 * specified thread in the variable pointed to by vres. It returns
923 * an error if the thread does not exist, it is not under the control
924 * of the scheduling framework, or is not bound.
926 * @return 0 if no error \n
927 * FRSH_ERR_NOT_SCHEDULED_THREAD : if the given thread is not scheduled
929 * FRSH_ERR_NOT_BOUND : if the given thread does not have a valid
930 * vres bound to it \n
931 * FRSH_ERR_BAD_ARGUMENT : if the given thread does not exist or the
932 * vres argument is NULL
935 int frsh_thread_get_vres_id(const frsh_thread_id_t thread,
936 frsh_vres_id_t *vres_id);
939 * frsh_vres_get_contract()
941 * This operation stores the contract parameters currently associated
942 * with the specified vres in the variable pointed to by
943 * contract. It returns an error if the vres_id is not recognised.
945 * @return 0 if no error \n
946 * FRSH_ERR_BAD_ARGUMENT : if the contract argument is NULL or the value
947 * of the vres argument is not in range \n
948 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
949 * scheduled under FRSH \n
950 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
952 * FRSH_ERR_NOT_CONTRACTED_VRES: if the vres of the calling thread
953 * has been cancelled or it is not valid
956 int frsh_vres_get_contract
957 (const frsh_vres_id_t vres,
958 frsh_contract_t *contract);
961 * frsh_resource_get_vres_from_label()
963 * This operation retrieves the vres_id whose contract_label
964 * corresponds to the parameter in the resource_id and resource_type
967 * The contract label must refer to a contract negotiated
968 * in the same processing node in which the call is being
969 * made. Otherwise an error is returned.
971 * @return 0 if no error \n
972 * FRSH_ERR_BAD_ARGUMENT : if the contract argument is NULL or the
973 * contract_label is NULL \n
974 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
975 * scheduled under FRSH \n
976 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
978 * FRSH_ERR_CONTRACT_LABEL_UNKNOWN: if the contract_label is not known
980 int frsh_resource_get_vres_from_label
981 (const char *contract_label,
982 const frsh_resource_type_t resource_type,
983 const frsh_resource_id_t resource_id,
984 frsh_vres_id_t *vres);
989 * frsh_contract_cancel()
991 * The operation eliminates the specified vres
992 * and recalculates all necessary parameters for the contracts
993 * remaining in the system. This is a potentially blocking operation;
994 * it returns when the system has made the changes effective.
996 * Note that the thread is not eliminated. We leave the application
997 * the option to either freeze it for a later use or bind it to
1000 * @return 0 if successful \n
1001 * FRSH_ERR_BAD_ARGUMENT : if the value of vres is not in range \n
1002 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1003 * scheduled under FRSH \n
1004 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1006 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1007 * has been cancelled or it is not valid
1010 int frsh_contract_cancel (const frsh_vres_id_t vres);
1014 * frsh_contract_renegotiate_sync()
1016 * The operation renegotiates a contract for an existing vres. If
1017 * the on-line admission test is enabled it determines whether the
1018 * contract can be admitted or not based on the current contracts
1019 * established in the system. If it cannot be admitted, the old
1020 * contract remains in effect and an error is returned. If it can be
1021 * admitted, it recalculates all necessary parameters for the
1022 * contracts already present in the system and returns zero. This is a
1023 * potentially blocking operation; it returns when the system has
1024 * either rejected the new contract, or admitted it and made it
1027 * @return 0 if successful \n
1028 * FRSH_ERR_BAD_ARGUMENT : if the new_contract argument is NULL or the
1029 * value of the vres argument is not in range \n
1030 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1031 * scheduled under FRSH \n
1032 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1034 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1035 * has been cancelled or it is not valid \n
1036 * FRSH_ERR_REJECTED_CONTRACT : if the renegotiation fails
1039 int frsh_contract_renegotiate_sync
1040 (const frsh_contract_t *new_contract,
1041 const frsh_vres_id_t vres);
1045 * frsh_contract_renegotiate_async()
1047 * The operation enqueues a renegotiate operation for an existing
1048 * vres, and returns immediately. The renegotiate operation is
1049 * performed asynchronously, as soon as it is practical; meanwhile the
1050 * system operation will continue normally. When the renegotiation is
1051 * made, if the on-line admission test is enabled it determines
1052 * whether the contract can be admitted or not based on the current
1053 * contracts established in the system. If it cannot be admitted, the
1054 * old contract remains in effect. If it can be admitted, it
1055 * recalculates all necessary parameters for the contracts already
1056 * present in the system.
1058 * When the operation is completed, notification is made to the
1059 * caller, if requested, via a signal. The status of the operation (in
1060 * progress, admitted, rejected) can be checked with the
1061 * frsh_vres_get_renegotiation_status() operation. The argument
1062 * sig_notify can be FRSH_NULL_SIGNAL (no notification), or any FRSH
1063 * signal value and in this case signal_info is to be sent with the signal.
1065 * @param[in] new_contract New contract parameters for the new
1066 * situation if approved.
1067 * @param[in] vres vres_id on which to do the renegotiation.
1068 * @param[in] signal_to_notify Signal number to use to notify vres of
1069 * the negotiation result. If
1070 * FRSH_NULL_SIGNAL, no signal will be raised.
1071 * @param[in] signal_info: Associated info that will come with the
1072 * signal. This parameter will be ignored
1073 * if signal_to_notify == FRSH_NULL_SIGNAL.
1075 * @return 0 if no error \n
1076 * FRSH_ERR_BAD_ARGUMENT : if the new_contract argument is NULL, the
1077 * value of the vres argument is not in range or sig_notify is
1078 * neither NULL nor a valid POSIX signal \n
1079 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1080 * scheduled under FRSH \n
1081 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1083 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1084 * has been cancelled or it is not valid
1087 int frsh_contract_renegotiate_async
1088 (const frsh_contract_t *new_contract,
1089 const frsh_vres_id_t vres,
1090 const frsh_signal_t signal_to_notify,
1091 const frsh_signal_info_t signal_info);
1095 * frsh_vres_get_renegotiation_status()
1097 * The operation reports on the status of the last renegotiation
1098 * operation enqueued for the specified vres. It is callable even
1099 * after notification of the completion of such operation, if
1102 * If the vres is not and has not been involved in any of the
1103 * frsh_contract_renegotiate_async() or frsh_group_change_mode_async()
1104 * operations, the status returned is FRSH_RS_NOT_REQUESTED
1106 * @return 0 if no error \n
1107 * FRSH_ERR_BAD_ARGUMENT : if the renegotiation_status argument is
1108 * NULL or the value of the vres argument is not in range \n
1109 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1110 * scheduled under FRSH \n
1111 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1113 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1114 * has been cancelled or it is not valid
1117 int frsh_vres_get_renegotiation_status
1118 (const frsh_vres_id_t vres,
1119 frsh_renegotiation_status_t *renegotiation_status);
1123 ////////////////////////////////////////////////////////////////////////
1124 // CHANGE OF MODE: GROUPS OF CONTRACTS
1125 ////////////////////////////////////////////////////////////////////////
1127 * @defgroup groupofcontracts Group of contracts
1130 * The following functions are used to negotiate atomically more than
1131 * one contract. This allows to build complex applications by
1132 * splitting them in individual contracts that are negotiated
1133 * simultaneously and atomically.
1139 * frsh_group_negotiate()
1141 * This function negotiates atomically a group of new contracts
1142 * while giving the possibility of cancellling others.
1144 * If the on-line admission test is enabled, FRSH analizes the
1145 * schedulability of the context that results in the new contract
1146 * situation with removed and added contracts.
1148 * If the overall negotiation is successful, all actions will be taken
1149 * inmediatly: the creation of new vres for the contract_up list
1150 * and the cancellation of the designated ones.
1152 * If for any reason one of the contracts is not accepted, a
1153 * corresponding error will be returned and no actions will be taken,
1154 * the previous context will be preserved.
1156 * This call is a synchronous, potentially blocking operation. It
1157 * returns when the system has rejected the contracts or accepted them
1158 * and made them effective.
1160 * @param[in] contracts_up List of new proposed contracts
1162 * @param[in] vres_down List of vres_id to be canceled
1164 * @param[out] vres_up vres_id assigned by the system to the
1165 * corresponding contracts_up.
1167 * @return 0 if no error \n
1169 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1171 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
1173 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not scheduled
1175 * FRSH_ERR_BAD_ARGUMENT : if any of the vres_up or accepted arguments
1176 * is NULL, if the contracts_up and vres_down arguments are both NULL,
1177 * or any of them has erroneous size or its elements are NULL or not in the
1178 * valid range respectively
1180 int frsh_group_negotiate
1181 (const frsh_contracts_group_t *contracts_up,
1182 const frsh_vres_group_t *vres_down,
1183 frsh_vres_group_t *vres_up);
1188 * frsh_group_change_mode_sync()
1190 * An extension of frsh_group_negotiate() by adding the possibility of
1191 * specifying also group contract renegotiation and removal.
1193 * NOTE: This function will be implemented in a second phase after
1194 * having fully implemented frsh_group_negotiate() in order to
1195 * better grasp possible issues that the problems it may raise.
1197 * This is a draft of the specification, it is yet subject to
1200 * This operation performs a global (re)negotiation of a group of
1201 * contracts in an atomic way. Contracts can be added, canceled or
1202 * renegotiated. Note that any of the groups can be empty.
1204 * If the on-line admission test is enabled, FRSH analizes the
1205 * schedulability of the context that would result in the new
1206 * contract situation with removed, changed and added contracts.
1208 * A successful return code will mean that all contracts have been
1209 * accepted and all required operations (creation, cancellation or
1210 * update of vres) have been carried out to reach the new running
1213 * If for any reason one of the contracts is not accepted a
1214 * corresponding error shall be returned and no changes will be made
1215 * to the previously running context.
1217 * This call is a synchronous, potentially blocking operation. It
1218 * returns when the system has rejected the contracts or accepted them
1219 * and made them effective. There is also an asynchronous
1220 * (non-blocking) version of this function below.
1222 * @param[in] contracts_new_vres Contracts to be added.
1223 * @param[out] vres_id_new vres_id's corresponding to the new
1225 * @param[in] contracts_update_vres New contracts for vres to
1227 * @param[in] vres_update vres_id's corresponding to the
1228 * contracts that have to be updated.
1229 * @param[in] vres_removed Vres_id's to be removed.
1231 * @return 0 if no error \n
1232 * FRSH_ERR_BAD_ARGUMENT Invalid pointer or vres_id ranges. \n
1233 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS contract_label not unique. \n
1234 * FRSH_ERR_NOT_CONTRACTED_VRES: One of the provided
1235 * vres_ids is not recognised. \n
1236 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD The calling thread
1237 * is not scheduled under FRSH. \n
1238 * FRSH_ERR_INVALID_SCHEDULER_REPLY: The scheduler is wrong
1239 * or not running. \n
1240 * FRSH_ERR_INTERNAL_ERROR: Erroneous binding or malfunction of
1241 * FRSH main scheduler. \n
1242 * FRSH_ERR_REJECTED_CONTRACT: The negotiation of one of the
1243 * proposed contracts has failed.
1246 int frsh_group_change_mode_sync
1247 (const frsh_contracts_group_t *contracts_new_vres,
1248 frsh_vres_group_t *vres_id_new,
1249 const frsh_contracts_group_t *contracts_update_vres,
1250 const frsh_vres_group_t *vres_update,
1251 const frsh_vres_group_t *vres_removed);
1255 * frsh_group_change_mode_async()
1257 * This operation enqueues a global renegotiation of a group of
1258 * contracts (with a possible addition of new vres) and returns
1259 * immediately. The renegotiation is performed asynchronously as soon
1260 * as it is practical.
1262 * NOTE: This function will be implemented in a second phase after
1263 * having fully implemented frsh_group_negotiate() in order to
1264 * better grasp possible issues that the problem may raise.
1266 * This is a draft of the specification, it is yet subject to
1269 * This is an asynchronous (non-blocking) version of
1270 * frsh_group_change_mode_sync(). Note however that there must
1271 * be at least one existing thread involved in the operation (to be
1272 * canceled or have its contract updated). An operation of puring
1273 * adding a group of new contracts can only be done synchronously.
1275 * The status of the operation (in progress, admitted or rejected) can
1276 * be queried via frsh_vres_get_renegotiation_status() invoked for any of
1277 * the vres involved in the renegotiation (updated or to be
1278 * removed). As an option, a signal can be sent to the caller to
1279 * notify the end-result of the operation.
1281 * @param[in] contracts_new_vres Contracts for new vres to be
1283 * @param[in] contract_labels Contract labels for the corresponding new
1285 * @param[out] vres_id_new vres_id's corresponding to the new
1287 * @param[in] contracts_update_vres New contracts for vres to
1289 * @param[in] vres_update vres_id's corresponding to the
1290 * contracts that have to be updated.
1291 * @param[in] vres_removed vres_id's to be removed.
1293 * @param[in] sig_notify Signal number where the coller expects to
1294 * receive the information.
1295 * @param[in] sig_value Signal data associated with that signal.
1297 * @return 0 if no error \n
1298 * FRSH_ERR_BAD_ARGUMENT Invalid pointer or vres_id ranges. Also
1299 * when the request is for adding only new contracts. \n
1300 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS contract_label not unique. \n
1301 * FRSH_ERR_NOT_CONTRACTED_VRES: One of the provided
1302 * vres_id's is not recognised. \n
1303 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD The calling thread
1304 * is not scheduled under FRSH. \n
1305 * FRSH_ERR_INVALID_SCHEDULER_REPLY: The scheduler is wrong
1306 * or not running. \n
1307 * FRSH_ERR_INTERNAL_ERROR: Erroneous binding or malfunction of
1308 * FRSH main scheduler. \n
1309 * FRSH_ERR_REJECTED_CONTRACT: The negotiation of one of the
1310 * proposed contracts has failed.
1312 int frsh_group_change_mode_async
1313 (const frsh_contracts_group_t *contracts_new_vres,
1314 frsh_vres_group_t *vres_id_new,
1315 const frsh_contracts_group_t *contracts_update_vres,
1316 const frsh_vres_group_t *vres_update,
1317 const frsh_vres_group_t *vres_removed,
1318 const frsh_signal_t signal_notify,
1319 const frsh_signal_info_t signal_info);
1325 ////////////////////////////////////////////////////
1326 // OBTAINING INFORMATION FROM THE SCHEDULER
1327 ////////////////////////////////////////////////////
1330 * @defgroup getschedinfo Obtaining information from the scheduler
1334 * The following functions are used to obtain available budget and
1335 * resource usage in the system. They can be used to adapt the
1336 * execution of threads according to the load of the system.
1343 * frsh_config_is_admission_test_enabled()
1345 * Returns true if the system is
1346 * configured with the on-line admission test enabled, or false
1347 * otherwise. This situation can only be changed at compile time.
1349 bool frsh_config_is_admission_test_enabled();
1352 * frsh_vres_get_usage()
1354 * This function stores the current execution time spent by the
1355 * threads bound to the specified vres in the variable pointed to by
1358 * @return 0 if successful \n
1359 * FRSH_ERR_BAD_ARGUMENT : if the value of the vres argument is not in range or
1360 * cpu_time is NULL \n
1361 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1362 * scheduled under FRSH \n
1363 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1365 * FRSH_ERR_NOT_CONTRACTED_VRESR : if the vres of the calling thread
1366 * has been cancelled or it is not valid
1369 int frsh_vres_get_usage
1370 (const frsh_vres_id_t vres,
1371 struct timespec *spent);
1374 * frsh_vres_get_remaining_budget()
1376 * This function stores in the variable pointed to by budget the
1377 * remaining execution-time budget associated with the specified
1380 * @return 0 if successful \n
1381 * FRSH_ERR_BAD_ARGUMENT : if the value of the vres argument is not in range or
1383 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1384 * scheduled under FRSH \n
1385 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1387 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1388 * has been cancelled or it is not valid
1391 int frsh_vres_get_remaining_budget
1392 (const frsh_vres_id_t vres,
1393 struct timespec *budget);
1397 * frsh_vres_get_budget_and_period()
1399 * This function stores in the variables
1400 * pointed to by budget and period, the execution-time budget and the
1401 * period respectively associated with the specified vres. If any of
1402 * these pointers is NULL, the corresponding information is not stored.
1404 * @return 0 if successful \n
1405 * FRSH_ERR_BAD_ARGUMENT : if the value of the vres argument is not in range,
1406 * or budget and period are both NULL \n
1407 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1408 * scheduled under FRSH \n
1409 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1411 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1412 * has been cancelled or it is not valid
1415 int frsh_vres_get_budget_and_period
1416 (const frsh_vres_id_t vres,
1417 struct timespec *budget,
1418 struct timespec *period);
1422 /////////////////////////////////////////////////////////////////////
1423 // SERVICE THREAD TUNING
1424 /////////////////////////////////////////////////////////////////////
1426 * @defgroup servthtuning Service thread tuning
1430 * The following functions are used to obtain available budget and
1431 * resource usage in the system. They can be used to adapt the
1432 * execution of threads to the load of the system.
1438 * frsh_service_thread_set_data()
1440 * This function allows the application to change the period and
1441 * budget of the service thread that makes the
1442 * negotiations. Increasing the utilization of this thread makes the
1443 * negotiations faster, but introduces additional load in the system
1444 * that may decrease the bandwidth available for the vres. For this
1445 * call, the system will make a schedulability analysis to determine
1446 * if the new situation is acceptable or not. This is reported back in
1447 * the variable pointed to by accepted. If the new service thread data
1448 * is accepted, the system will reassign budgets and periods to the
1449 * vres according to the new bandwidth available, in the same way
1450 * as it does for a regular contract negotiation.
1452 * When its budget is exhausted, the service thread may run in the
1455 * The service thread starts with a default budget and period that are
1458 * Implementation dependency: in the fixed priority implementtaion of
1459 * frsh, the default priority is lower than the priority of any vres,
1460 * but higher than the background. According to the
1461 * implementation-dependent module the priority is adjustable by means
1462 * of a function that changes its preemption level
1464 * @return 0 if successful \n
1465 * FRSH_ERR_BAD_ARGUMENT : if any of the pointer arguments is NULL or
1466 * the budget value is greater than the period value \n
1467 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1468 * scheduled under FRSH \n
1469 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1471 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1472 * has been cancelled or it is not valid
1475 int frsh_service_thread_set_data (const struct timespec *budget,
1476 const struct timespec *period,
1480 * frsh_service_thread_get_data()
1482 * this function returns in the variables pointed by budget and
1483 * period, respectively, the current budget and period of the service
1486 * @return 0 if successful \n
1487 * FRSH_ERR_BAD_ARGUMENT : if any of the pointer arguments is NULL \n
1488 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1489 * scheduled under FRSH \n
1490 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1492 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1493 * has been cancelled or it is not valid
1496 int frsh_service_thread_get_data
1497 (struct timespec *budget,
1498 struct timespec *period);
1504 ////////////////////////////////////////////////////////////////////////
1505 // BACKGROUND MANAGEMENT
1506 ////////////////////////////////////////////////////////////////////////
1508 //A round-robin background scheduling policy is available for those
1509 //threads that do not have real-time requirements. Because some of
1510 //these threads may require sharing information with other threads run
1511 //by regular vres. Special background contracts may be created for
1512 //specifying the synchronization requirements.
1514 //The way of specifying a background contract is by setting
1515 //contract_type to FRSH_CT_BACKGROUND. Negotiation may fail if the contract uses
1516 //shared_objects. If the contract has no shared_objects the returned
1517 //vres id represents the background and may be used to bind more
1518 //than one thread. If the contract has shared objects a vres is
1519 //created to keep track of them, but the associated threads are
1520 //executed in the background, together with the other background
1527 #endif // _FRSH_CORE_H_