1 // -----------------------------------------------------------------------
2 // Copyright (C) 2006 - 2009 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 (FRescor ScHeduler)
36 // FRSH is free software; you can redistribute it and/or modify it
37 // under terms of the GNU General Public License as published by the
38 // Free Software Foundation; either version 2, or (at your option) any
39 // later version. FRSH is distributed in the hope that it will be
40 // useful, but WITHOUT ANY WARRANTY; without even the implied warranty
41 // of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
42 // General Public License for more details. You should have received a
43 // copy of the GNU General Public License along with FRSH; see file
44 // COPYING. If not, write to the Free Software Foundation, 675 Mass Ave,
45 // Cambridge, MA 02139, USA.
47 // As a special exception, including FRSH header files in a file,
48 // instantiating FRSH generics or templates, or linking other files
49 // with FRSH objects to produce an executable application, does not
50 // by itself cause the resulting executable application to be covered
51 // by the GNU General Public License. This exception does not
52 // however invalidate any other reasons why the executable file might be
53 // covered by the GNU Public License.
54 // -----------------------------------------------------------------------
56 //==============================================
57 // ******** ******* ******** ** **
58 // **///// /**////** **////// /** /**
59 // ** /** /** /** /** /**
60 // ******* /******* /********* /**********
61 // **//// /**///** ////////** /**//////**
62 // ** /** //** /** /** /**
63 // ** /** //** ******** /** /**
64 // // // // //////// // //
66 // FRSH(FRescor ScHeduler), pronounced "fresh"
67 //==============================================
79 #include <sys/types.h>
81 #include "frsh_core_types.h"
82 #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_destroy()
200 * The operation deallocates all memory which might be allocated for
203 * @param contract the pointer to the contract variable.
205 void frsh_contract_destroy(frsh_contract_t *contract);
209 * frsh_contract_set_basic_params()
211 * The operation updates the specified contract parameters object by
212 * setting its budget, period, workload and type to the specified
213 * input parameters. (Note: the workload is a basic parameter because
214 * bounded tasks are triggered by the scheduler (see the
215 * frsh_timed_wait() and frsh_synchobj_wait* operations), while
216 * indeterminate tasks are not; therefore, their programming model is
219 * @param contract the pointer to the contract object
220 * @param[in] budget_min the minimum budget for the contract
221 * @param[in] period_max the maximum period for the contract
222 * @param[in] workload the kind of workload (can be FRSH_WT_BOUNDED,
223 * FRSH_WT_INDETERMINATE or FRSH_OVERHEAD)
224 * @param[in] contract_type can be FRSH_CT_REGULAR,
225 * FRSH_CT_BACKGROUND, FRSH_CT_DUMMY.
227 * @return 0 if no error \n
228 * FRSH_ERR_BAD_ARGUMENT : if any of the pointers is NULL
229 * or if only one of the time values is 0, and also if the
230 * workload or the contract type values are unknown in the
233 int frsh_contract_set_basic_params
234 (frsh_contract_t *contract,
235 const frsh_rel_time_t *budget_min,
236 const frsh_rel_time_t *period_max,
237 const frsh_workload_t workload,
238 const frsh_contract_type_t contract_type);
241 * frsh_contract_get_basic_params()
243 * This operation obtains from the specified contract object its
244 * budget, period, and workload, and copies them to the places pointed
245 * to by the corresponding output parameters.
247 * @param[in] contract the pointer to the contract object
248 * @param[out] budget_min pointer to preallocated space
249 * @param[out] period_max pointer to preallocated space
250 * @param[out] workload pointer to preallocated space
251 * @param[out] contract_type pointer to preallocated space
253 * @return 0 if no error \n
254 * FRSH_ERR_BAD_ARGUMENT : if one of the contract or
258 int frsh_contract_get_basic_params
259 (const frsh_contract_t *contract,
260 frsh_rel_time_t *budget_min,
261 frsh_rel_time_t *period_max,
262 frsh_workload_t *workload,
263 frsh_contract_type_t *contract_type);
266 * frsh_contract_set_resource_and_label()
268 * Specify resource_id and type, and the contract label. Otherwise
269 * default values will apply. If the contract label is too long it is truncated
271 * @return 0 if no error \n
272 * FRSH_ERR_BAD_ARGUMENT : if the contract pointer is NULL.
274 int frsh_contract_set_resource_and_label
275 (frsh_contract_t *contract,
276 const frsh_resource_type_t resource_type,
277 const frsh_resource_id_t resource_id,
278 const char *contract_label);
282 * frsh_contract_get_resource_and_label()
284 * Obtain the resource_id and type, and the contract label.
286 * @return 0 if no error \n
287 * FRSH_ERR_BAD_ARGUMENT : if the contract or the contract_label
290 int frsh_contract_get_resource_and_label
291 (const frsh_contract_t *contract,
292 frsh_resource_type_t *resource_type,
293 frsh_resource_id_t *resource_id,
294 char *contract_label);
298 * frsh_contract_set_timing_reqs()
300 * The operation updates the specified contract object, specifying
301 * additional time-related requirements.
303 * @param contract The pointer to the contract object
305 * @param [in] d_equals_t It is a boolean value, set to true (1) if
306 * we want to specify a deadline different from
307 * the period for the contract.
308 * @param [in] deadline If the previous parameter is set to true,
309 * this parameter is ignored (the contract value
310 * will be NULL_DEADLINE internally). Otherwise, it
311 * contains the desired deadline value.
312 * @param [in] budget_overrun_signal contains the number of the signal
313 * that must be raised if the budget of the vres is overrun.
314 * If the value of this parameter is FRSH_NULL_SIGNAL, no signal will
316 * @param [in] budget_overrun_siginfo contains the value that will be
317 * passed to the signal "catcher" when the signal is raised.
318 * This parameters is not used if the budget_overrun_signal
319 * parameter is set to FRSH_NULL_SIGNAL.
320 * @param [in] deadline_miss_signal contains the number of the
321 * signal that must be raised if the deadline of the
322 * vres is missed. If the value of this parameter is
323 * FRSH_NULL_SIGNAL, no signal is raised.
324 * @param [in] deadline_miss_siginfo contains the value that will be
325 * passed to the signal "catcher" when the signal is
326 * raised. This parameter is not used if the
327 * deadline_signal parameter is set to NULL_SIGNAL
329 * @return 0 if successful\n
330 * FRSH_ERR_BAD_ARGUMENT : if contract is NULL \b or \n
331 * (d_equals_t is true and deadline is not FRSH_NULL_DEADLINE) \b or \n
332 * (budget_overrun_signal is not a valid signal) \b or \n
333 * (deadline_miss_signal is not a valid signal) \b or \n
334 * (d_equals_t is false but (deadline is FRSH_NULL_DEADLINE or its value
335 * is grater than the contract's maximum period))
338 int frsh_contract_set_timing_reqs
339 (frsh_contract_t *contract,
340 const bool d_equals_t,
341 const frsh_rel_time_t *deadline,
342 const frsh_signal_t budget_overrun_signal,
343 const frsh_signal_info_t budget_overrun_siginfo,
344 const frsh_signal_t deadline_miss_signal,
345 const frsh_signal_info_t deadline_miss_siginfo);
348 * frsh_contract_get_timing_reqs()
350 * The operation obtains the corresponding input parameters from the
351 * specified contract object. If d_equals_t is true, the deadline will
352 * be set to FRSH_NULL_DEADLINE.
354 * @return 0 if no error \n
355 * FRSH_ERR_BAD_ARGUMENT : if contract is NULL
358 int frsh_contract_get_timing_reqs
359 (const frsh_contract_t *contract,
361 frsh_rel_time_t *deadline,
362 frsh_signal_t *budget_overrun_signal,
363 frsh_signal_info_t *budget_overrun_siginfo,
364 frsh_signal_t *deadline_miss_signal,
365 frsh_signal_info_t *deadline_miss_siginfo);
370 //////////////////////////////////////////////////////////////////
371 // SYNCHRONIZATION OBJECTS
372 //////////////////////////////////////////////////////////////////
374 * @defgroup synch Synchronization objects
377 * Synchronisation objects provide an alternative to timers for
378 * bounded-workload vres to signal the end of their current job and
379 * return their remaining budget to FRSH.
381 * Instead of asking to be reactivated based on an absolute time, they
382 * queue themselves in a synchronisation object and will wait there
383 * until another vres (bounded-workload or indeterminate-workload)
384 * wakes them up with a signal call the earliest at the beginning of
387 * Indeterminate-workload vres cannot queue themselves here because
388 * they don't have any budget to return. However they can signal on
389 * the objects to activate a waiting workload vres.
391 * For classical signal/wait synchronisation paradigms the application
392 * must use whatever mechanism the underlying OS provides.
394 * In the future we may add a broadcast operation that would signal a
395 * group of synchronization objects. We have not included a broadcast
396 * service in this version because it can be easily created by the
397 * user by signalling individual synchronization objects inside a
400 * Notice that for synchronization objects there is no naming service
401 * like in shared objects because tasks that use synchronization are
402 * not developed independently, as they are closely coupled.
409 * frsh_synchobj_create()
411 * This operation creates and initializes a synchronization object
412 * variable managed by the scheduler, and returns a handle to it in
413 * the variable pointed to by synch_handle.
415 * @param[out] synch_handle pointer to the variable that will contain
416 * the handle to the newly created synchronization object
418 * @return 0 if the operation is succesful
419 * FRSH_ERR_TOO_MANY_SYNCH_OBJS if the number of synchronization
420 * objects in the system has already exceeded the maximum
422 * FRSH_ERR_TOO_MANY_SYNCH_OBJS : if the number of synchronization
423 * objects in the system has already exceeded the maximum\n
425 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
426 * scheduled under FRSH\n
428 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not running
431 int frsh_synchobj_create
432 (frsh_synchobj_handle_t *synch_handle);
436 * frsh_synchobj_destroy()
438 * This operation destroys the synchronization object (created by a
439 * previous call to frsh_synchobj_create) that is referenced by the
440 * synch_handle variable. After calling this operation, the
441 * synch_handle variable can not be used until it is initialized again
442 * by a call to frsh_synchobj_create.
444 * @param synch_handle the handle to the synchronization object
447 * @return 0 if no error \n
448 * FRSH_ERR_BAD_ARGUMENT : if synch_handle is 0\n
449 * FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE if the handle is not valid\n
450 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
451 * scheduled under FRSH \n
452 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
455 * @sa frsh_synchobj_create
457 int frsh_synchobj_destroy
458 (const frsh_synchobj_handle_t synchobj_handle);
461 * frsh_synchobj_wait()
463 * This operation is invoked by threads associated with bounded
464 * workload vres to indicate that a job has been completed (and
465 * that the scheduler may reassign the unused capacity of the current
466 * job to other vres).
468 * As a difference with frsh_timed_wait(), here the vres
469 * specifies to be awakened by the arrival of a signal operation
470 * instead of at a precise point of time.
472 * This function can also be called to schedule the first job of a
473 * recently created vres and make it start when a signal operation
474 * has been sent from another thread.
476 * The vres' budget will be made zero for the remainder of the vres'
477 * period, and FRSH will not replenish it until an event has been
478 * notified to the synchronisation object by another vres.
480 * It can happen that the synchronisation object has notification
481 * events queued from the past, in this case one of the events is
482 * dequeued immediately and the vres won't have to wait for another
485 * At the time of reception of a notification event (wether in the
486 * future or in the past), all pending budget replenishments (if any)
487 * are made effective. Once the vres has a positive budget and the
488 * scheduler schedules the calling thread again, the call returns and
489 * the vres continues executing.
491 * If the synchronisation object is destroyed while the vres was
492 * waiting on it, the vres will be awaken and the function will
493 * return with a code FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE
495 * Except for those parameters equal to NULL pointers, the system
496 * reports the current period and budget for the current job, it informs
497 * if the deadline of the previous job was missed or not, and whether the
498 * budget of the previous job was overrun or not.
500 * In a system with hierarchical scheduling, since this call makes the
501 * budget of the current period zero, the other threads in the same
502 * vres are not run. As mentioned above, only when the call finishes
503 * the budget may be replenished.
505 * @param synch_handle Synchronisation object upon which the vres
507 * @param next_budget[out] Upon return of this function, the variable
508 * pointed by this function will be equal to
509 * the current vres budget. If this parameter is
510 * set to NULL, no action is taken
511 * @param next_period[out] The vres period upon return (ignored if NULL).
512 * @param was_deadline_missed Upon return whether the deadline was
513 * missed in the previous period.
514 * @param was_budget_overran
517 * @return 0 if success \n
518 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
520 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
522 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not scheduled
524 * FRSH_ERR_NOT_BOUND : if the calling thread does not have a valid
525 * vres bound to it \n
526 * FRSH_ERR_BAD_ARGUMENT : if synch_handle is 0 \n
527 * FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE if the synch_handle is not
528 * valid or was destroyed while the vres was waiting on it. \n
529 * FRSH_ERR_VRES_WORKLOAD_NOT_COMPATIBLE: if the kind of workload of the vres
530 * is not FRSH_BOUNDED
533 int frsh_synchobj_wait
534 (const frsh_synchobj_handle_t synch_handle,
535 frsh_rel_time_t *next_budget,
536 frsh_rel_time_t *next_period,
537 bool *was_deadline_missed,
538 bool *was_budget_overran);
542 * frsh_synchobj_wait_with_timeout()
544 * This call is the same as frsh_synchobj_wait() but with an extra
545 * absolute timeout. The timed_out argument, indicates whether the
546 * function returned because of the expiration of the timeout or not.
548 * @return 0 if no error \n
549 * FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE if the synch_handle is not
551 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
553 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
555 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not scheduled
557 * FRSH_ERR_NOT_BOUND : if the calling thread does not have a valid
558 * vres bound to it \n
559 * FRSH_ERR_BAD_ARGUMENT : if the synch_handle given is not valid or the
560 * abs_timeout argument is NULL or its value is in the past\n
561 * FRSH_ERR_VRES_WORKLOAD_NOT_COMPATIBLE: if the kind of workload of the vres
562 * is not FRSH_BOUNDED
565 int frsh_synchobj_wait_with_timeout
566 (const frsh_synchobj_handle_t synch_handle,
567 const frsh_abs_time_t *abs_timeout,
569 frsh_rel_time_t *next_budget,
570 frsh_rel_time_t *next_period,
571 bool *was_deadline_missed,
572 bool *was_budget_overran);
575 * frsh_synchobj_signal()
577 * This function sends a notification event to the synchronization object
578 * specified as parameter. If there is at least one vres waiting on
579 * the synchronization object, it is awaken. If more than one vres
580 * are waiting, just one of them is awaken. However, which one is
581 * awaken is implementation dependent. If no vres is waiting on the
582 * synchronization object, the notification event is queued.
584 * @param [in] synch_handle the handle of the synchronization object to
587 * @return 0 if no error \n
588 * FRSH_ERR_BAD_ARGUMENT : if synch_handle is 0 \n
589 * FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE if the handle is not valid \n
590 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
591 * scheduled under FRSH \n
592 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
594 * FRSH_ERR_TOO_MANY_EVENTS_IN_SYNCH_OBJ : if the number of events stored
595 * in the synchronization object reaches the maximum defined in the
596 * configuration parameter header file
598 * @sa frsh_synchobj_wait, frsh_synchobj_wait_with_timeout
600 int frsh_synchobj_signal
601 (const frsh_synchobj_handle_t synch_handle);
606 * This operation is invoked by threads associated with bounded
607 * workload vres to indicate that a job has been completed (and
608 * that the scheduler may reassign the unused capacity of the current
609 * job to other vres). It is also invoked when the first job of
610 * such threads has to be scheduled.
612 * As an effect, the system will make the current vres's budget zero
613 * for the remainder of the vres's period, and will not replenish
614 * the budget until the specified absolute time. At that time, all
615 * pending budget replenishments (if any) are made effective. Once the
616 * vres has a positive budget and the scheduler schedules the
617 * calling thread again, the call returns and at that time, except for
618 * those parameters equal to NULL pointers, the system reports the
619 * current period and budget for the current job, whether the deadline
620 * of the previous job was missed or not, and whether the budget of
621 * the previous job was overrun or not.
623 * In a system with hierarchical scheduling, since this call makes the
624 * budget zero, the other threads in the same vres are not run. As
625 * mentioned abobe, only when the call finishes the budget may be
628 * @param [in] abs_time absolute time at which the budget will be
631 * @param [out] next_budget upon return of this function, the variable
632 * pointed by this function will be equal to
633 * the current vres budget. If this parameter is
634 * set to NULL, no action is taken.
636 * @param [out] next_period upon return of this function, the variable
637 * pointed by this function will be equal to
638 * the current vres period. If this parameter is
639 * set to NULL, no action is taken.
641 * @param [out] was_deadline_missed upon return of this function, the
642 * variable pointed by this function will be
643 * equal to true if the previous vres deadline
644 * was missed, to false otherwise. If this
645 * parameter is set to NULL, no action is
648 * @param [out] was_budget_overrun upon return of this function, the
649 * variable pointed by this function will be
650 * equal to true if the previous vres budget was
651 * overrun, to false otherwise. If this
652 * parameter is set to NULL, no action is
655 * @return 0 if the operation is successful \n
656 * FRSH_ERR_TIME_SPEC_IN_THE_PAST if the absolute time specification
658 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong
660 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
662 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling
663 * thread is not scheduled under FRSH \n
664 * FRSH_ERR_NOT_BOUND : if the calling thread does not have a valid
665 * vres bound to it \n
666 * FRSH_ERR_BAD_ARGUMENT : if abs_time is NULL \n
667 * FRSH_ERR_VRES_WORKLOAD_NOT_COMPATIBLE: if the kind of workload of the vres
668 * is not FRSH_BOUNDED
671 * @sa frsh_synchobj_wait, frsh_synchobj_wait_with_timeout
674 (const frsh_abs_time_t *abs_time,
675 frsh_rel_time_t *next_budget,
676 frsh_rel_time_t *next_period,
677 bool *was_deadline_missed,
678 bool *was_budget_overran);
683 * frsh_vresperiod_wait()
685 * Suspend the calling thread until the start of the specified virtual
686 * resource period of a vres_id, for a synchronized workload.
688 * Virtual resource periods are numbered. The number of the current
689 * period can be obtained through the frsh_vres_get_period_number()
692 int frsh_vresperiod_wait(unsigned long period_num,
693 frsh_rel_time_t *next_budget,
694 frsh_rel_time_t *next_period,
695 bool *was_deadline_missed,
696 bool *was_budget_overran);
700 * frsh_vres_get_period()
702 * Return the current period number, for a virtual resource of
703 * synchronized workload.
705 int frsh_vres_get_period_number
706 (const frsh_vres_id_t vres,
714 ///////////////////////////////////////////////////////////////////
715 // CONTRACT NEGOCIATION OPERATIONS
716 ///////////////////////////////////////////////////////////////////
719 * @defgroup negotiate Negotiate contract functions
722 * The following functions are used to negotiate contracts and thus
723 * creating vres which are the execution image of a contract.
724 * Besides, these functions allow to assign and unassign threads to
727 * In the case of more than one thread per vres please refer to the
728 * hierarchical module.
736 * frsh_contract_negotiate()
738 * The operation negotiates a contract and if accepted it will return
739 * a vres_id. It will also check that the given contract_label is unique
742 * If the on-line admission test is enabled, it determines whether the
743 * contract can be admitted or not based on the current contracts
744 * established in the system. Then it creates the vres and
745 * recalculates all necessary parameters for the contracts already
746 * present in the system.
748 * This is a potentially blocking operation, it returns when the
749 * system has either rejected the contract, or admitted it and made it
750 * effective. No thread is bound to the newly created vres, which
751 * will be idle until a thread is bound to it via frsh_thread_bind()
752 * or frsh_thread_create_and_bind().
754 * This operation can only be executed by threads that are already
755 * bound to an active vres and therefore are being scheduled by the
758 * @return 0 if successful \n
759 * FRSH_ERR_CONTRACT_REJECTED: The contract is not accepted.\n
760 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
762 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
764 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not scheduled
765 * under FRSH scheduler \n
766 * FRSH_ERR_BAD_ARGUMENT : if the contract or vres arguments are NULL \n
767 * FRSH_ERR_TOO_MANY_VRES : if there is no space for more vres
768 * (the maximum number of them is already reached) \n
769 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS : contract_label is not unique.
772 int frsh_contract_negotiate
773 (const frsh_contract_t *contract,
774 frsh_vres_id_t *vres);
777 * frsh_thread_create_and_bind()
779 * This operation creates a thread and binds it to an existing vres.
781 * This is the preferred way to add threads to the application because
782 * we make sure that the thread won't become unbound.
784 * The vres must not have any thread binded to it. If you want to
785 * bind more than one thread to the vres you must use the
786 * hierarchical module.
788 * The frsh_thread_attr_t parameter is overwritten as necessary to
789 * introduce the adequate scheduling policy and priority, according
790 * to the preemption level given in the contract and the
791 * frsh_priority_map() function defined by the user.
793 * @param[in] vres_id vres with which the thread will be bound.
794 * @param[out] thread frsh_thread_id returned by the system.
795 * @param attr pthread_attr taken and maybe corrected
796 * by the system. Ignored if NULL
797 * @param[in] thread_code Thread function (void func(void *) )
798 * that will constitute the main of the
800 * @param[in] arg Argument for data to be passed at the
801 * thread. Set to NUL if you don't want
802 * to do anything like this.
804 * @return 0 if successful \n
805 * FRSH_ERR_BAD_ARGUMENT : if the contract or vres arguments are
807 * FRSH_ERR_CONTRACT_REJECTED : if the contract is rejected. \n
809 * It may also return all the errors that may be returned by the
810 * fosa_thread_create() function call
813 int frsh_thread_create_and_bind
814 (const frsh_vres_id_t vres,
815 frsh_thread_id_t *thread,
816 frsh_thread_attr_t *attr,
817 frsh_thread_code_t thread_code,
822 * frsh_thread_create_in_background()
824 * This function creates a "background contract" that does not need to
825 * be negotiated, creates a threads and binds to the new vres.
827 * This method is suggested as a way to initate components and
828 * plugins. The event that triggers the component activation should
829 * arrive to an application thread that could use this function to
830 * create a thread used in its initialisation.
832 * The attribute parameter is overwritten as necessary to introduce
833 * the adequate scheduling policy and priority.
835 * @param[in] thread_code Function to be executed by the new
837 * @param[in] thread_arg General pointer that will be passed to
838 * the new thread as initialisation data.
839 * @param attr Pthread attribute with thread params
840 * @param[in] contract_label Contract label for the new vres.
841 * @param[out] thread_id Id of the new thread.
842 * @param[out] vres_id vres_id of the new vres.
844 * @return 0 if successful \n
845 * FRSH_ERR_BAD_ARGUMENT : Any problems with the argument \n
846 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is
847 * not scheduled under FRSH \n
848 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS : contract_label is not unique \n
849 * FRSH_ERR_TOO_MANY_VRES : if there is no space for more vres
850 * (the maximum number of them is already reached)
853 int frsh_thread_create_in_background
854 (frsh_thread_code_t thread_code,
855 const void *thread_arg,
856 const char *contract_label,
857 frsh_thread_attr_t *attr,
858 frsh_thread_id_t *thread_id,
859 frsh_vres_id_t *vres_id);
864 * frsh_thread_join_in_background()
866 * This function is aimed for external threads to join FRSH in the
867 * least disturbing possible mode.
869 * Upon calling this function by a thread which has been created
870 * natively in the OS, it joins the framework and gets inmediately
871 * bound to an on-the-fly generated background contract.
873 * In order to gain a higher priority then it can renegotiate a
874 * contract for its vres with the needed parameters.
876 * @param[in] resource_id: Resource (CPU) in which the vres will
879 * @param[in] resource_type: Resource type (should be CPU) for the
882 * @param[in] label: Label to be added to the contract.
884 * @param[out] vres_id: Resulting vres_id from the on-the-fly
885 * generated background contract.
887 * @return 0 if successful\n
888 * FRSH_ERR_NOT_CONTRACTED_VRES if the thread is already
891 int frsh_thread_join_in_background(frsh_resource_id_t resource_id,
892 frsh_resource_type_t resource_type,
894 frsh_vres_id_t *vres_id);
901 * This operation associates a thread with a vres, which means that
902 * it starts consuming the vres's budget and is executed according
903 * to the contract established for that vres. If the thread is
904 * already bound to another vres, it is effectively unbound from it
905 * and bound to the specified one.
907 * It fails if the vres's policy is different than FRSH_NONE, or if
908 * there is already a thread bound to this vres. In order to bind
909 * more than one vres to the same thread you must use the
910 * hierarchical module.
912 * Implementation dependent issue: In order to allow the usage of
913 * application defined schedulers, the given thread must not have the
914 * scheduling policy SCHED_APP and at the same time be attached to an
915 * application scheduler different than the frsh scheduler.
917 * @return 0 if successful \n
918 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
920 * FRSH_ERR_UNKNOWN_APPSCHEDULED_THREAD : if the thread is attached to
921 * an application defined scheduler different than the frsh
923 * FRSH_ERR_BAD_ARGUMENT : if the vres value does not complain with the
924 * expected format or valid range or the given thread does not
926 * FRSH_ERR_NOT_CONTRACTED_VRES : if the referenced vres is not
928 * FRSH_ERR_VRES_WORKLOAD_NOT_COMPATIBLE: if the kind of workload
929 * of the vres is FRSH_OVERHEAD \n
930 * FRSH_ERR_ALREADY_BOUND : if the given vres has a thread already
935 (const frsh_vres_id_t vres,
936 const frsh_thread_id_t thread);
940 * frsh_thread_unbind()
942 * This operation unbinds a thread from a vres. Since threads with
943 * no vres associated are not allowed to execute, they remain in a
944 * dormant state until they are either eliminated or bound again.
946 * If the thread is inside a critical section the effects of this call
947 * are deferred until the critical section is ended
949 * Implementation dependent issue: in the implementation with an
950 * application scheduler, the thread is still attached to the frsh
951 * scheduler, but suspended.
953 * @return 0 if successful \n
954 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
956 * FRSH_ERR_BAD_ARGUMENT : if the given thread does not exist \n
957 * FRSH_ERR_NOT_SCHEDULED_THREAD : if the given thread is not scheduled
959 * FRSH_ERR_UNKNOWN_APPSCHEDULED_THREAD : if the thread is attached to
960 * an application defined scheduler different than the frsh
962 * FRSH_ERR_NOT_BOUND : if the given thread does not have a valid
965 int frsh_thread_unbind(const frsh_thread_id_t thread);
968 * frsh_thread_get_vres_id()
970 * This operation stores the Id of the vres associated with the
971 * specified thread in the variable pointed to by vres. It returns
972 * an error if the thread does not exist, it is not under the control
973 * of the scheduling framework, or is not bound.
975 * @return 0 if no error \n
976 * FRSH_ERR_NOT_SCHEDULED_THREAD : if the given thread is not scheduled
978 * FRSH_ERR_NOT_BOUND : if the given thread does not have a valid
979 * vres bound to it \n
980 * FRSH_ERR_BAD_ARGUMENT : if the given thread does not exist or the
981 * vres argument is NULL
984 int frsh_thread_get_vres_id(const frsh_thread_id_t thread,
985 frsh_vres_id_t *vres_id);
988 * frsh_vres_get_priority()
990 * This operation stores the priority currently associated
991 * with the specified vres in the variable pointed to by
992 * priority. It returns an error if the vres_id is not recognised.
994 * @return 0 if no error \n
995 * FRSH_ERR_BAD_ARGUMENT : if the contract argument is NULL or the value
996 * of the vres argument is not in range \n
997 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
998 * scheduled under FRSH \n
999 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1001 * FRSH_ERR_NOT_CONTRACTED_VRES: if the vres of the calling thread
1002 * has been cancelled or it is not valid
1005 int frsh_vres_get_priority
1006 (frsh_vres_id_t vres_id,
1010 * frsh_vres_get_contract()
1012 * This operation stores the contract parameters currently associated
1013 * with the specified vres in the variable pointed to by
1014 * contract. It returns an error if the vres_id is not recognised.
1016 * @return 0 if no error \n
1017 * FRSH_ERR_BAD_ARGUMENT : if the contract argument is NULL or the value
1018 * of the vres argument is not in range \n
1019 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1020 * scheduled under FRSH \n
1021 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1023 * FRSH_ERR_NOT_CONTRACTED_VRES: if the vres of the calling thread
1024 * has been cancelled or it is not valid
1027 int frsh_vres_get_contract
1028 (const frsh_vres_id_t vres,
1029 frsh_contract_t *contract);
1032 * frsh_resource_get_vres_from_label()
1034 * This operation retrieves the vres_id whose contract_label
1035 * corresponds to the parameter in the resource_id and resource_type
1038 * The contract label must refer to a contract negotiated
1039 * in the same processing node in which the call is being
1040 * made. Otherwise an error is returned.
1042 * @return 0 if no error \n
1043 * FRSH_ERR_BAD_ARGUMENT : if the contract argument is NULL or the
1044 * contract_label is NULL \n
1045 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1046 * scheduled under FRSH \n
1047 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1049 * FRSH_ERR_CONTRACT_LABEL_UNKNOWN: if the contract_label is not known
1051 int frsh_resource_get_vres_from_label
1052 (const char *contract_label,
1053 const frsh_resource_type_t resource_type,
1054 const frsh_resource_id_t resource_id,
1055 frsh_vres_id_t *vres);
1060 * frsh_contract_cancel()
1062 * The operation eliminates the specified vres
1063 * and recalculates all necessary parameters for the contracts
1064 * remaining in the system. This is a potentially blocking operation;
1065 * it returns when the system has made the changes effective.
1067 * Note that the thread is not eliminated. We leave the application
1068 * the option to either freeze it for a later use or bind it to
1071 * @return 0 if successful \n
1072 * FRSH_ERR_BAD_ARGUMENT : if the value of vres is not in range \n
1073 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1074 * scheduled under FRSH \n
1075 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1077 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1078 * has been cancelled or it is not valid
1081 int frsh_contract_cancel (const frsh_vres_id_t vres);
1085 * frsh_contract_renegotiate_sync()
1087 * The operation renegotiates a contract for an existing vres. If
1088 * the on-line admission test is enabled it determines whether the
1089 * contract can be admitted or not based on the current contracts
1090 * established in the system. If it cannot be admitted, the old
1091 * contract remains in effect and an error is returned. If it can be
1092 * admitted, it recalculates all necessary parameters for the
1093 * contracts already present in the system and returns zero. This is a
1094 * potentially blocking operation; it returns when the system has
1095 * either rejected the new contract, or admitted it and made it
1098 * @return 0 if successful \n
1099 * FRSH_ERR_BAD_ARGUMENT : if the new_contract argument is NULL or the
1100 * value of the vres argument is not in range \n
1101 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1102 * scheduled under FRSH \n
1103 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1105 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1106 * has been cancelled or it is not valid \n
1107 * FRSH_ERR_CONTRACT_REJECTED : if the renegotiation fails
1110 int frsh_contract_renegotiate_sync
1111 (const frsh_contract_t *new_contract,
1112 const frsh_vres_id_t vres);
1116 * frsh_contract_renegotiate_async()
1118 * The operation enqueues a renegotiate operation for an existing
1119 * vres, and returns immediately. The renegotiate operation is
1120 * performed asynchronously, as soon as it is practical; meanwhile the
1121 * system operation will continue normally. When the renegotiation is
1122 * made, if the on-line admission test is enabled it determines
1123 * whether the contract can be admitted or not based on the current
1124 * contracts established in the system. If it cannot be admitted, the
1125 * old contract remains in effect. If it can be admitted, it
1126 * recalculates all necessary parameters for the contracts already
1127 * present in the system.
1129 * When the operation is completed, notification is made to the
1130 * caller, if requested, via a signal. The status of the operation (in
1131 * progress, admitted, rejected) can be checked with the
1132 * frsh_vres_get_renegotiation_status() operation. The argument
1133 * sig_notify can be FRSH_NULL_SIGNAL (no notification), or any FRSH
1134 * signal value and in this case signal_info is to be sent with the signal.
1136 * @param[in] new_contract New contract parameters for the new
1137 * situation if approved.
1138 * @param[in] vres vres_id on which to do the renegotiation.
1139 * @param[in] signal_to_notify Signal number to use to notify vres of
1140 * the negotiation result. If
1141 * FRSH_NULL_SIGNAL, no signal will be raised.
1142 * @param[in] signal_info: Associated info that will come with the
1143 * signal. This parameter will be ignored
1144 * if signal_to_notify == FRSH_NULL_SIGNAL.
1146 * @return 0 if no error \n
1147 * FRSH_ERR_BAD_ARGUMENT : if the new_contract argument is NULL, the
1148 * value of the vres argument is not in range or sig_notify is
1149 * neither NULL nor a valid POSIX signal \n
1150 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1151 * scheduled under FRSH \n
1152 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1154 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1155 * has been cancelled or it is not valid
1158 int frsh_contract_renegotiate_async
1159 (const frsh_contract_t *new_contract,
1160 const frsh_vres_id_t vres,
1161 const frsh_signal_t signal_to_notify,
1162 const frsh_signal_info_t signal_info);
1166 * frsh_vres_get_renegotiation_status()
1168 * The operation reports on the status of the last renegotiation
1169 * operation enqueued for the specified vres. It is callable even
1170 * after notification of the completion of such operation, if
1173 * If the vres is not and has not been involved in any of the
1174 * frsh_contract_renegotiate_async() or frsh_group_change_mode_async()
1175 * operations, the status returned is FRSH_RS_NOT_REQUESTED
1177 * @return 0 if no error \n
1178 * FRSH_ERR_BAD_ARGUMENT : if the renegotiation_status argument is
1179 * NULL or the value of the vres argument is not in range \n
1180 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1181 * scheduled under FRSH \n
1182 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1184 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1185 * has been cancelled or it is not valid
1188 int frsh_vres_get_renegotiation_status
1189 (const frsh_vres_id_t vres,
1190 frsh_renegotiation_status_t *renegotiation_status);
1194 ////////////////////////////////////////////////////////////////////////
1195 // CHANGE OF MODE: GROUPS OF CONTRACTS
1196 ////////////////////////////////////////////////////////////////////////
1198 * @defgroup groupofcontracts Group of contracts
1201 * The following functions are used to negotiate atomically more than
1202 * one contract. This allows to build complex applications by
1203 * splitting them in individual contracts that are negotiated
1204 * simultaneously and atomically.
1210 * frsh_group_change_mode_sync()
1212 * This function performs a set of negotiation operations which can
1213 * include: adding new contracts (neg), modifying existing vres (reneg)
1214 * or cancelling existing vres (cancel).
1216 * If one of the group operations has a NULL value, unless it causes an
1217 * inconsistency the system will suppose that no operation of that
1218 * type (neg, reneg or cancel) should be done.
1220 * The virtual resources resulting from negotiations of new contracts are
1221 * returned in the parameter 'new_vres' which must be provided by the user.
1223 * If the on-line admission test is enabled, FRSH analizes the
1224 * schedulability of the context that would result in the new
1225 * contract situation with removed, changed and added contracts.
1227 * A successful return code will mean that all contracts have been
1228 * accepted and all required operations (creation, cancellation or
1229 * update of vres) have been carried out to reach the new running
1232 * If any of the contracts is not accepted a corresponding error shall be
1233 * returned and no changes will be made to the previously running context.
1235 * This call is a synchronous, potentially blocking operation. It
1236 * returns when the system has rejected the contracts or accepted
1237 * and made them effective.
1239 * @param[in] contracts_to_neg List of new contracts to negotiate
1240 * @param[in] contracts_to_reneg List of contracts to renegotiate
1241 * @param[in] vres_to_reneg List of vres to renegotiate
1242 * @param[in] vres_to_cancel List of vres to cancel
1243 * @param[out] new_vres List of vres of new contracts.
1245 * @return 0 if no error \n
1246 * FRSH_ERR_BAD_ARGUMENT Invalid pointer or group identifier. \n
1247 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS contract_label not unique. \n
1248 * FRSH_ERR_NOT_CONTRACTED_VRES: One of the provided vres_ids
1249 * is not recognised. \n
1250 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD The calling thread
1251 * is not scheduled under FRSH. \n
1252 * FRSH_ERR_INVALID_SCHEDULER_REPLY: The scheduler is wrong or
1254 * FRSH_ERR_INTERNAL_ERROR: Erroneous binding or malfunction of
1255 * FRSH main scheduler. \n
1256 * FRSH_ERR_REJECTED_CONTRACT: The negotiation of one of the
1257 * proposed contracts has failed.
1259 int frsh_group_change_mode_sync
1260 (const frsh_contracts_group_t *contracts_to_neg,
1261 const frsh_contracts_group_t *contracts_to_reneg,
1262 const frsh_vres_group_t *vres_to_reneg,
1263 const frsh_vres_group_t *vres_to_cancel,
1264 frsh_vres_group_t *new_vres);
1267 * frsh_group_change_mode_async()
1269 * This is an asynchronous (non-blocking) version of the previous function,
1270 * frsh_group_change_mode_sync() and thus, it returns inmediately.
1272 * The status of the change of mode and the identifiers for new virtual
1273 * resources must be requested with the function 'frsh_group_get_status'
1274 * by using the return parameter 'group'.
1276 * As in the asynchronous renegotiations, when the operation is completed,
1277 * the user is notified with a signal so he can check the final result with
1278 * 'frsh_group_get_status'. In case that FRSH_NULL_SIGNAL is used, no
1279 * signal will be sent to the user.
1281 * @param[in] contracts_to_neg List of new contracts to negotiate
1282 * @param[in] contracts_to_reneg List of contracts to renegotiate
1283 * @param[in] vres_to_reneg List of vres to renegotiate
1284 * @param[in] vres_to_cancel List of vres to cancel
1285 * @param[in] signal Signal number to notify completion of
1286 * the change of mode. If FRSH_NULL_SIGNAL,
1287 * no signal will be raised.
1288 * @param[in] signal_info Data associated to the signal
1289 * @param[out] group The group identifier to get the status
1291 * @return 0 if no error \n
1292 * FRSH_ERR_BAD_ARGUMENT Invalid pointer, signal or group identifier. \n
1293 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS contract_label not unique. \n
1294 * FRSH_ERR_NOT_CONTRACTED_VRES: One of the provided vres_ids
1295 * is not recognised. \n
1296 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD The calling thread
1297 * is not scheduled under FRSH. \n
1298 * FRSH_ERR_INVALID_SCHEDULER_REPLY: The scheduler is wrong or
1300 * FRSH_ERR_INTERNAL_ERROR: Erroneous binding or malfunction of
1301 * FRSH main scheduler.
1303 int frsh_group_change_mode_async
1304 (const frsh_contracts_group_t *contracts_to_neg,
1305 const frsh_contracts_group_t *contracts_to_reneg,
1306 const frsh_vres_group_t *vres_to_reneg,
1307 const frsh_vres_group_t *vres_to_cancel,
1308 const frsh_signal_t signal,
1309 const frsh_signal_info_t signal_info,
1310 frsh_group_id_t *group);
1313 * frsh_group_get_status()
1315 * This function is similar to 'frsh_vres_get_renegotiation_status' but it
1316 * is intented for group negotiations (changes of mode).
1318 * The operation reports on the status of the last negotiation
1319 * operation enqueued for the specified group identifier.
1321 * The status value can be one of the following values:
1323 * - FRSH_RS_IN_PROGRESS: the change of mode is in progress
1324 * - FRSH_RS_REJECTED: the change of mode was not accepted
1325 * - FRSH_RS_ADMITTED: the change of mode was accepted
1326 * - FRSH_RS_NOT_REQUESTED: no change of mode has been requested yet
1328 * When status returns 'FRSH_RS_ADMITTED', the array 'new_vres' contains
1329 * the values for the new virtual resources (if there was any).
1331 * This function frees the group identifier when status returns something
1332 * different than FRSH_RS_IN_PROGRESS so further calls to this function may
1333 * return inconsistent values.
1335 * @param[in] group The group identifier
1336 * @param[out] status The status of the change of mode
1337 * @param[out] new_vres List of vres for the negotiation of new contracts.
1339 * @return 0 if no error \n
1340 * FRSH_ERR_BAD_ARGUMENT Invalid pointer, signal or group identifier. \n
1341 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS contract_label not unique. \n
1342 * FRSH_ERR_NOT_CONTRACTED_VRES: One of the provided vres_ids
1343 * is not recognised. \n
1344 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD The calling thread
1345 * is not scheduled under FRSH. \n
1346 * FRSH_ERR_INVALID_SCHEDULER_REPLY: The scheduler is wrong or
1348 * FRSH_ERR_INTERNAL_ERROR: Erroneous binding or malfunction of
1349 * FRSH main scheduler.
1351 int frsh_group_get_status(const frsh_group_id_t group,
1352 frsh_renegotiation_status_t *status,
1353 frsh_vres_group_t *new_vres);
1359 ////////////////////////////////////////////////////
1360 // OBTAINING INFORMATION FROM THE SCHEDULER
1361 ////////////////////////////////////////////////////
1364 * @defgroup getschedinfo Obtaining information from the scheduler
1368 * The following functions are used to obtain available budget and
1369 * resource usage in the system. They can be used to adapt the
1370 * execution of threads according to the load of the system.
1377 * frsh_config_is_admission_test_enabled()
1379 * Returns true if the system is
1380 * configured with the on-line admission test enabled, or false
1381 * otherwise. This situation can only be changed at compile time.
1383 bool frsh_config_is_admission_test_enabled();
1386 * frsh_vres_get_usage()
1388 * This function stores the current execution time spent by the
1389 * threads bound to the specified vres in the variable pointed to by
1392 * @return 0 if successful \n
1393 * FRSH_ERR_BAD_ARGUMENT : if the value of the vres argument is not in range or
1394 * cpu_time is NULL \n
1395 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1396 * scheduled under FRSH \n
1397 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1399 * FRSH_ERR_NOT_CONTRACTED_VRESR : if the vres of the calling thread
1400 * has been cancelled or it is not valid
1403 int frsh_vres_get_usage
1404 (const frsh_vres_id_t vres,
1405 frsh_rel_time_t *spent);
1409 * frsh_vres_get_job_usage()
1411 * Get the execution time of the current job of the specified virtual
1412 * resource for a bounded or synchronized workload.
1414 int frsh_vres_get_job_usage
1415 (const frsh_vres_id_t vres,
1416 frsh_rel_time_t *spent);
1420 * frsh_vres_get_remaining_budget()
1422 * This function stores in the variable pointed to by budget the
1423 * remaining execution-time budget associated with the specified
1426 * @return 0 if successful \n
1427 * FRSH_ERR_BAD_ARGUMENT : if the value of the vres argument is not in range or
1429 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1430 * scheduled under FRSH \n
1431 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1433 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1434 * has been cancelled or it is not valid
1437 int frsh_vres_get_remaining_budget
1438 (const frsh_vres_id_t vres,
1439 frsh_rel_time_t *budget);
1443 * frsh_vres_get_budget_and_period()
1445 * This function stores in the variables
1446 * pointed to by budget and period, the execution-time budget and the
1447 * period respectively associated with the specified vres. If any of
1448 * these pointers is NULL, the corresponding information is not stored.
1450 * @return 0 if successful \n
1451 * FRSH_ERR_BAD_ARGUMENT : if the value of the vres argument is not in range,
1452 * or budget and period are both NULL \n
1453 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1454 * scheduled under FRSH \n
1455 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1457 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1458 * has been cancelled or it is not valid
1461 int frsh_vres_get_budget_and_period
1462 (const frsh_vres_id_t vres,
1463 frsh_rel_time_t *budget,
1464 frsh_rel_time_t *period);
1468 /////////////////////////////////////////////////////////////////////
1469 // SERVICE THREAD TUNING
1470 /////////////////////////////////////////////////////////////////////
1472 * @defgroup servthtuning Service thread tuning
1476 * The following functions are used to obtain available budget and
1477 * resource usage in the system. They can be used to adapt the
1478 * execution of threads to the load of the system.
1484 * frsh_service_thread_set_data()
1486 * This function allows the application to change the period and
1487 * budget of the service thread that makes the
1488 * negotiations. Increasing the utilization of this thread makes the
1489 * negotiations faster, but introduces additional load in the system
1490 * that may decrease the bandwidth available for the vres. For this
1491 * call, the system will make a schedulability analysis to determine
1492 * if the new situation is acceptable or not. This is reported back in
1493 * the variable pointed to by accepted. If the new service thread data
1494 * is accepted, the system will reassign budgets and periods to the
1495 * vres according to the new bandwidth available, in the same way
1496 * as it does for a regular contract negotiation.
1498 * When its budget is exhausted, the service thread may run in the
1501 * The service thread starts with a default budget and period that are
1504 * Implementation dependency: in the fixed priority implementtaion of
1505 * frsh, the default priority is lower than the priority of any vres,
1506 * but higher than the background. According to the
1507 * implementation-dependent module the priority is adjustable by means
1508 * of a function that changes its preemption level
1510 * @return 0 if successful \n
1511 * FRSH_ERR_BAD_ARGUMENT : if any of the pointer arguments is NULL or
1512 * the budget value is greater than the period value \n
1513 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1514 * scheduled under FRSH \n
1515 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1517 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1518 * has been cancelled or it is not valid
1521 int frsh_service_thread_set_data (const frsh_rel_time_t *budget,
1522 const frsh_rel_time_t *period,
1526 * frsh_service_thread_get_data()
1528 * this function returns in the variables pointed by budget and
1529 * period, respectively, the current budget and period of the service
1532 * @return 0 if successful \n
1533 * FRSH_ERR_BAD_ARGUMENT : if any of the pointer arguments is NULL \n
1534 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1535 * scheduled under FRSH \n
1536 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1538 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1539 * has been cancelled or it is not valid
1542 int frsh_service_thread_get_data
1543 (frsh_rel_time_t *budget,
1544 frsh_rel_time_t *period);
1550 ////////////////////////////////////////////////////////////////////////
1551 // BACKGROUND MANAGEMENT
1552 ////////////////////////////////////////////////////////////////////////
1554 //A round-robin background scheduling policy is available for those
1555 //threads that do not have real-time requirements. Because some of
1556 //these threads may require sharing information with other threads run
1557 //by regular vres. Special background contracts may be created for
1558 //specifying the synchronization requirements.
1560 //The way of specifying a background contract is by setting
1561 //contract_type to FRSH_CT_BACKGROUND. Negotiation may fail if the contract uses
1562 //shared_objects. If the contract has no shared_objects the returned
1563 //vres id represents the background and may be used to bind more
1564 //than one thread. If the contract has shared objects a vres is
1565 //created to keep track of them, but the associated threads are
1566 //executed in the background, together with the other background
1572 #endif // _FRSH_CORE_H_