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.
313 * @return 0 if successful\n
314 * FRSH_ERR_BAD_ARGUMENT : if contract is NULL \b or \n
315 * (d_equals_t is true and deadline is not FRSH_NULL_DEADLINE) \b or \n
316 * (budget_overrun_signal is not a valid signal) \b or \n
317 * (deadline_miss_signal is not a valid signal) \b or \n
318 * (d_equals_t is false but (deadline is FRSH_NULL_DEADLINE or its value
319 * is grater than the contract's maximum period))
322 int frsh_contract_set_timing_reqs
323 (frsh_contract_t *contract,
324 const bool d_equals_t,
325 const frsh_rel_time_t *deadline);
328 * frsh_contract_get_timing_reqs()
330 * The operation obtains the corresponding input parameters from the
331 * specified contract object. If d_equals_t is true, the deadline will
332 * be set to FRSH_NULL_DEADLINE.
334 * @return 0 if no error \n
335 * FRSH_ERR_BAD_ARGUMENT : if contract is NULL
338 int frsh_contract_get_timing_reqs
339 (const frsh_contract_t *contract,
341 frsh_rel_time_t *deadline);
346 //////////////////////////////////////////////////////////////////
347 // SYNCHRONIZATION OBJECTS
348 //////////////////////////////////////////////////////////////////
350 * @defgroup synch Synchronization objects
353 * Synchronisation objects provide an alternative to timers for
354 * bounded-workload vres to signal the end of their current job and
355 * return their remaining budget to FRSH.
357 * Instead of asking to be reactivated based on an absolute time, they
358 * queue themselves in a synchronisation object and will wait there
359 * until another vres (bounded-workload or indeterminate-workload)
360 * wakes them up with a signal call the earliest at the beginning of
363 * Indeterminate-workload vres cannot queue themselves here because
364 * they don't have any budget to return. However they can signal on
365 * the objects to activate a waiting workload vres.
367 * For classical signal/wait synchronisation paradigms the application
368 * must use whatever mechanism the underlying OS provides.
370 * In the future we may add a broadcast operation that would signal a
371 * group of synchronization objects. We have not included a broadcast
372 * service in this version because it can be easily created by the
373 * user by signalling individual synchronization objects inside a
376 * Notice that for synchronization objects there is no naming service
377 * like in shared objects because tasks that use synchronization are
378 * not developed independently, as they are closely coupled.
385 * frsh_synchobj_create()
387 * This operation creates and initializes a synchronization object
388 * variable managed by the scheduler, and returns a handle to it in
389 * the variable pointed to by synch_handle.
391 * @param[out] synch_handle pointer to the variable that will contain
392 * the handle to the newly created synchronization object
394 * @return 0 if the operation is succesful
395 * FRSH_ERR_TOO_MANY_SYNCH_OBJS if the number of synchronization
396 * objects in the system has already exceeded the maximum
398 * FRSH_ERR_TOO_MANY_SYNCH_OBJS : if the number of synchronization
399 * objects in the system has already exceeded the maximum\n
401 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
402 * scheduled under FRSH\n
404 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not running
407 int frsh_synchobj_create
408 (frsh_synchobj_handle_t *synch_handle);
412 * frsh_synchobj_destroy()
414 * This operation destroys the synchronization object (created by a
415 * previous call to frsh_synchobj_create) that is referenced by the
416 * synch_handle variable. After calling this operation, the
417 * synch_handle variable can not be used until it is initialized again
418 * by a call to frsh_synchobj_create.
420 * @param synch_handle the handle to the synchronization object
423 * @return 0 if no error \n
424 * FRSH_ERR_BAD_ARGUMENT : if synch_handle is 0\n
425 * FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE if the handle is not valid\n
426 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
427 * scheduled under FRSH \n
428 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
431 * @sa frsh_synchobj_create
433 int frsh_synchobj_destroy
434 (const frsh_synchobj_handle_t synchobj_handle);
437 * frsh_synchobj_wait()
439 * This operation is invoked by threads associated with bounded
440 * workload vres to indicate that a job has been completed (and
441 * that the scheduler may reassign the unused capacity of the current
442 * job to other vres).
444 * As a difference with frsh_timed_wait(), here the vres
445 * specifies to be awakened by the arrival of a signal operation
446 * instead of at a precise point of time.
448 * This function can also be called to schedule the first job of a
449 * recently created vres and make it start when a signal operation
450 * has been sent from another thread.
452 * The vres' budget will be made zero for the remainder of the vres'
453 * period, and FRSH will not replenish it until an event has been
454 * notified to the synchronisation object by another vres.
456 * It can happen that the synchronisation object has notification
457 * events queued from the past, in this case one of the events is
458 * dequeued immediately and the vres won't have to wait for another
461 * At the time of reception of a notification event (wether in the
462 * future or in the past), all pending budget replenishments (if any)
463 * are made effective. Once the vres has a positive budget and the
464 * scheduler schedules the calling thread again, the call returns and
465 * the vres continues executing.
467 * If the synchronisation object is destroyed while the vres was
468 * waiting on it, the vres will be awaken and the function will
469 * return with a code FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE
471 * Except for those parameters equal to NULL pointers, the system
472 * reports the current period and budget for the current job, it informs
473 * if the deadline of the previous job was missed or not, and whether the
474 * budget of the previous job was overrun or not.
476 * In a system with hierarchical scheduling, since this call makes the
477 * budget of the current period zero, the other threads in the same
478 * vres are not run. As mentioned above, only when the call finishes
479 * the budget may be replenished.
481 * @param synch_handle Synchronisation object upon which the vres
483 * @param next_budget[out] Upon return of this function, the variable
484 * pointed by this function will be equal to
485 * the current vres budget. If this parameter is
486 * set to NULL, no action is taken
487 * @param next_period[out] The vres period upon return (ignored if NULL).
488 * @param was_deadline_missed Upon return whether the deadline was
489 * missed in the previous period.
490 * @param was_budget_overran
493 * @return 0 if success \n
494 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
496 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
498 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not scheduled
500 * FRSH_ERR_NOT_BOUND : if the calling thread does not have a valid
501 * vres bound to it \n
502 * FRSH_ERR_BAD_ARGUMENT : if synch_handle is 0 \n
503 * FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE if the synch_handle is not
504 * valid or was destroyed while the vres was waiting on it. \n
505 * FRSH_ERR_VRES_WORKLOAD_NOT_COMPATIBLE: if the kind of workload of the vres
506 * is not FRSH_BOUNDED
509 int frsh_synchobj_wait
510 (const frsh_synchobj_handle_t synch_handle,
511 frsh_rel_time_t *next_budget,
512 frsh_rel_time_t *next_period,
513 bool *was_deadline_missed,
514 bool *was_budget_overran);
518 * frsh_synchobj_wait_with_timeout()
520 * This call is the same as frsh_synchobj_wait() but with an extra
521 * absolute timeout. The timed_out argument, indicates whether the
522 * function returned because of the expiration of the timeout or not.
524 * @return 0 if no error \n
525 * FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE if the synch_handle is not
527 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
529 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
531 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not scheduled
533 * FRSH_ERR_NOT_BOUND : if the calling thread does not have a valid
534 * vres bound to it \n
535 * FRSH_ERR_BAD_ARGUMENT : if the synch_handle given is not valid or the
536 * abs_timeout argument is NULL or its value is in the past\n
537 * FRSH_ERR_VRES_WORKLOAD_NOT_COMPATIBLE: if the kind of workload of the vres
538 * is not FRSH_BOUNDED
541 int frsh_synchobj_wait_with_timeout
542 (const frsh_synchobj_handle_t synch_handle,
543 const frsh_abs_time_t *abs_timeout,
545 frsh_rel_time_t *next_budget,
546 frsh_rel_time_t *next_period,
547 bool *was_deadline_missed,
548 bool *was_budget_overran);
551 * frsh_synchobj_signal()
553 * This function sends a notification event to the synchronization object
554 * specified as parameter. If there is at least one vres waiting on
555 * the synchronization object, it is awaken. If more than one vres
556 * are waiting, just one of them is awaken. However, which one is
557 * awaken is implementation dependent. If no vres is waiting on the
558 * synchronization object, the notification event is queued.
560 * @param [in] synch_handle the handle of the synchronization object to
563 * @return 0 if no error \n
564 * FRSH_ERR_BAD_ARGUMENT : if synch_handle is 0 \n
565 * FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE if the handle is not valid \n
566 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
567 * scheduled under FRSH \n
568 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
570 * FRSH_ERR_TOO_MANY_EVENTS_IN_SYNCH_OBJ : if the number of events stored
571 * in the synchronization object reaches the maximum defined in the
572 * configuration parameter header file
574 * @sa frsh_synchobj_wait, frsh_synchobj_wait_with_timeout
576 int frsh_synchobj_signal
577 (const frsh_synchobj_handle_t synch_handle);
582 * This operation is invoked by threads associated with bounded
583 * workload vres to indicate that a job has been completed (and
584 * that the scheduler may reassign the unused capacity of the current
585 * job to other vres). It is also invoked when the first job of
586 * such threads has to be scheduled.
588 * As an effect, the system will make the current vres's budget zero
589 * for the remainder of the vres's period, and will not replenish
590 * the budget until the specified absolute time. At that time, all
591 * pending budget replenishments (if any) are made effective. Once the
592 * vres has a positive budget and the scheduler schedules the
593 * calling thread again, the call returns and at that time, except for
594 * those parameters equal to NULL pointers, the system reports the
595 * current period and budget for the current job, whether the deadline
596 * of the previous job was missed or not, and whether the budget of
597 * the previous job was overrun or not.
599 * In a system with hierarchical scheduling, since this call makes the
600 * budget zero, the other threads in the same vres are not run. As
601 * mentioned abobe, only when the call finishes the budget may be
604 * @param [in] abs_time absolute time at which the budget will be
607 * @param [out] next_budget upon return of this function, the variable
608 * pointed by this function will be equal to
609 * the current vres budget. If this parameter is
610 * set to NULL, no action is taken.
612 * @param [out] next_period upon return of this function, the variable
613 * pointed by this function will be equal to
614 * the current vres period. If this parameter is
615 * set to NULL, no action is taken.
617 * @param [out] was_deadline_missed upon return of this function, the
618 * variable pointed by this function will be
619 * equal to true if the previous vres deadline
620 * was missed, to false otherwise. If this
621 * parameter is set to NULL, no action is
624 * @param [out] was_budget_overrun upon return of this function, the
625 * variable pointed by this function will be
626 * equal to true if the previous vres budget was
627 * overrun, to false otherwise. If this
628 * parameter is set to NULL, no action is
631 * @return 0 if the operation is successful \n
632 * FRSH_ERR_TIME_SPEC_IN_THE_PAST if the absolute time specification
634 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong
636 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
638 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling
639 * thread is not scheduled under FRSH \n
640 * FRSH_ERR_NOT_BOUND : if the calling thread does not have a valid
641 * vres bound to it \n
642 * FRSH_ERR_BAD_ARGUMENT : if abs_time is NULL \n
643 * FRSH_ERR_VRES_WORKLOAD_NOT_COMPATIBLE: if the kind of workload of the vres
644 * is not FRSH_BOUNDED
647 * @sa frsh_synchobj_wait, frsh_synchobj_wait_with_timeout
650 (const frsh_abs_time_t *abs_time,
651 frsh_rel_time_t *next_budget,
652 frsh_rel_time_t *next_period,
653 bool *was_deadline_missed,
654 bool *was_budget_overran);
659 * frsh_vresperiod_wait()
661 * Suspend the calling thread until the start of the specified virtual
662 * resource period of a vres_id, for a synchronized workload.
664 * Virtual resource periods are numbered. The number of the current
665 * period can be obtained through the frsh_vres_get_period_number()
668 int frsh_vresperiod_wait(unsigned long period_num,
669 frsh_rel_time_t *next_budget,
670 frsh_rel_time_t *next_period,
671 bool *was_deadline_missed,
672 bool *was_budget_overran);
676 * frsh_vres_get_period()
678 * Return the current period number, for a virtual resource of
679 * synchronized workload.
681 int frsh_vres_get_period_number
682 (const frsh_vres_id_t vres,
690 ///////////////////////////////////////////////////////////////////
691 // CONTRACT NEGOCIATION OPERATIONS
692 ///////////////////////////////////////////////////////////////////
695 * @defgroup negotiate Negotiate contract functions
698 * The following functions are used to negotiate contracts and thus
699 * creating vres which are the execution image of a contract.
700 * Besides, these functions allow to assign and unassign threads to
703 * In the case of more than one thread per vres please refer to the
704 * hierarchical module.
712 * frsh_contract_negotiate()
714 * The operation negotiates a contract and if accepted it will return
715 * a vres_id. It will also check that the given contract_label is unique
718 * If the on-line admission test is enabled, it determines whether the
719 * contract can be admitted or not based on the current contracts
720 * established in the system. Then it creates the vres and
721 * recalculates all necessary parameters for the contracts already
722 * present in the system.
724 * This is a potentially blocking operation, it returns when the
725 * system has either rejected the contract, or admitted it and made it
726 * effective. No thread is bound to the newly created vres, which
727 * will be idle until a thread is bound to it via frsh_thread_bind()
728 * or frsh_thread_create_and_bind().
730 * This operation can only be executed by threads that are already
731 * bound to an active vres and therefore are being scheduled by the
734 * @return 0 if successful \n
735 * FRSH_ERR_CONTRACT_REJECTED: The contract is not accepted.\n
736 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
738 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
740 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not scheduled
741 * under FRSH scheduler \n
742 * FRSH_ERR_BAD_ARGUMENT : if the contract or vres arguments are NULL \n
743 * FRSH_ERR_TOO_MANY_VRES : if there is no space for more vres
744 * (the maximum number of them is already reached) \n
745 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS : contract_label is not unique.
748 int frsh_contract_negotiate
749 (const frsh_contract_t *contract,
750 frsh_vres_id_t *vres);
753 * frsh_thread_create_and_bind()
755 * This operation creates a thread and binds it to an existing vres.
757 * This is the preferred way to add threads to the application because
758 * we make sure that the thread won't become unbound.
760 * The vres must not have any thread binded to it. If you want to
761 * bind more than one thread to the vres you must use the
762 * hierarchical module.
764 * The frsh_thread_attr_t parameter is overwritten as necessary to
765 * introduce the adequate scheduling policy and priority, according
766 * to the preemption level given in the contract and the
767 * frsh_priority_map() function defined by the user.
769 * @param[in] vres_id vres with which the thread will be bound.
770 * @param[out] thread frsh_thread_id returned by the system.
771 * @param attr pthread_attr taken and maybe corrected
772 * by the system. Ignored if NULL
773 * @param[in] thread_code Thread function (void func(void *) )
774 * that will constitute the main of the
776 * @param[in] arg Argument for data to be passed at the
777 * thread. Set to NUL if you don't want
778 * to do anything like this.
780 * @return 0 if successful \n
781 * FRSH_ERR_BAD_ARGUMENT : if the contract or vres arguments are
783 * FRSH_ERR_CONTRACT_REJECTED : if the contract is rejected. \n
785 * It may also return all the errors that may be returned by the
786 * fosa_thread_create() function call
789 int frsh_thread_create_and_bind
790 (const frsh_vres_id_t vres,
791 frsh_thread_id_t *thread,
792 frsh_thread_attr_t *attr,
793 frsh_thread_code_t thread_code,
798 * frsh_thread_create_in_background()
800 * This function creates a "background contract" that does not need to
801 * be negotiated, creates a threads and binds to the new vres.
803 * This method is suggested as a way to initate components and
804 * plugins. The event that triggers the component activation should
805 * arrive to an application thread that could use this function to
806 * create a thread used in its initialisation.
808 * The attribute parameter is overwritten as necessary to introduce
809 * the adequate scheduling policy and priority.
811 * @param[in] thread_code Function to be executed by the new
813 * @param[in] thread_arg General pointer that will be passed to
814 * the new thread as initialisation data.
815 * @param attr Pthread attribute with thread params
816 * @param[in] contract_label Contract label for the new vres.
817 * @param[out] thread_id Id of the new thread.
818 * @param[out] vres_id vres_id of the new vres.
820 * @return 0 if successful \n
821 * FRSH_ERR_BAD_ARGUMENT : Any problems with the argument \n
822 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is
823 * not scheduled under FRSH \n
824 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS : contract_label is not unique \n
825 * FRSH_ERR_TOO_MANY_VRES : if there is no space for more vres
826 * (the maximum number of them is already reached)
829 int frsh_thread_create_in_background
830 (frsh_thread_code_t thread_code,
831 const void *thread_arg,
832 const char *contract_label,
833 frsh_thread_attr_t *attr,
834 frsh_thread_id_t *thread_id,
835 frsh_vres_id_t *vres_id);
840 * frsh_thread_join_in_background()
842 * This function is aimed for external threads to join FRSH in the
843 * least disturbing possible mode.
845 * Upon calling this function by a thread which has been created
846 * natively in the OS, it joins the framework and gets inmediately
847 * bound to an on-the-fly generated background contract.
849 * In order to gain a higher priority then it can renegotiate a
850 * contract for its vres with the needed parameters.
852 * @param[in] resource_id: Resource (CPU) in which the vres will
855 * @param[in] resource_type: Resource type (should be CPU) for the
858 * @param[in] label: Label to be added to the contract.
860 * @param[out] vres_id: Resulting vres_id from the on-the-fly
861 * generated background contract.
863 * @return 0 if successful\n
864 * FRSH_ERR_NOT_CONTRACTED_VRES if the thread is already
867 int frsh_thread_join_in_background(frsh_resource_id_t resource_id,
868 frsh_resource_type_t resource_type,
870 frsh_vres_id_t *vres_id);
877 * This operation associates a thread with a vres, which means that
878 * it starts consuming the vres's budget and is executed according
879 * to the contract established for that vres. If the thread is
880 * already bound to another vres, it is effectively unbound from it
881 * and bound to the specified one.
883 * It fails if the vres's policy is different than FRSH_NONE, or if
884 * there is already a thread bound to this vres. In order to bind
885 * more than one vres to the same thread you must use the
886 * hierarchical module.
888 * Implementation dependent issue: In order to allow the usage of
889 * application defined schedulers, the given thread must not have the
890 * scheduling policy SCHED_APP and at the same time be attached to an
891 * application scheduler different than the frsh scheduler.
893 * @return 0 if successful \n
894 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
896 * FRSH_ERR_UNKNOWN_APPSCHEDULED_THREAD : if the thread is attached to
897 * an application defined scheduler different than the frsh
899 * FRSH_ERR_BAD_ARGUMENT : if the vres value does not complain with the
900 * expected format or valid range or the given thread does not
902 * FRSH_ERR_NOT_CONTRACTED_VRES : if the referenced vres is not
904 * FRSH_ERR_VRES_WORKLOAD_NOT_COMPATIBLE: if the kind of workload
905 * of the vres is FRSH_OVERHEAD \n
906 * FRSH_ERR_ALREADY_BOUND : if the given vres has a thread already
911 (const frsh_vres_id_t vres,
912 const frsh_thread_id_t thread);
916 * frsh_thread_unbind()
918 * This operation unbinds a thread from a vres. Since threads with
919 * no vres associated are not allowed to execute, they remain in a
920 * dormant state until they are either eliminated or bound again.
922 * If the thread is inside a critical section the effects of this call
923 * are deferred until the critical section is ended
925 * Implementation dependent issue: in the implementation with an
926 * application scheduler, the thread is still attached to the frsh
927 * scheduler, but suspended.
929 * @return 0 if successful \n
930 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
932 * FRSH_ERR_BAD_ARGUMENT : if the given thread does not exist \n
933 * FRSH_ERR_NOT_SCHEDULED_THREAD : if the given thread is not scheduled
935 * FRSH_ERR_UNKNOWN_APPSCHEDULED_THREAD : if the thread is attached to
936 * an application defined scheduler different than the frsh
938 * FRSH_ERR_NOT_BOUND : if the given thread does not have a valid
941 int frsh_thread_unbind(const frsh_thread_id_t thread);
944 * frsh_vres_set_notification()
946 * This function setups notification signals for CPU vres. It is
947 * necessary to call this function before bounding the thread to the
950 * @param [in] budget_overrun_signal contains the number of the signal
951 * that must be raised if the budget of the vres is
952 * overrun by the thread.
953 * If the value of this parameter is FRSH_NULL_SIGNAL, no signal will
955 * @param [in] budget_overrun_siginfo contains the value that will be
956 * passed to the signal "catcher" when the signal is raised.
957 * This parameters is not used if the budget_overrun_signal
958 * parameter is set to FRSH_NULL_SIGNAL.
959 * @param [in] deadline_miss_signal contains the number of the
960 * signal that must be raised if the deadline of the
961 * vres is missed. If the value of this parameter is
962 * FRSH_NULL_SIGNAL, no signal is raised.
963 * @param [in] deadline_miss_siginfo contains the value that will be
964 * passed to the signal "catcher" when the signal is
965 * raised. This parameter is not used if the
966 * deadline_signal parameter is set to NULL_SIGNAL
968 int frsh_vres_set_notification(
970 const frsh_signal_t budget_overrun_signal,
971 const frsh_signal_info_t budget_overrun_siginfo,
972 const frsh_signal_t deadline_miss_signal,
973 const frsh_signal_info_t deadline_miss_siginfo);
976 * frsh_thread_get_vres_id()
978 * This operation stores the Id of the vres associated with the
979 * specified thread in the variable pointed to by vres. It returns
980 * an error if the thread does not exist, it is not under the control
981 * of the scheduling framework, or is not bound.
983 * @return 0 if no error \n
984 * FRSH_ERR_NOT_SCHEDULED_THREAD : if the given thread is not scheduled
986 * FRSH_ERR_NOT_BOUND : if the given thread does not have a valid
987 * vres bound to it \n
988 * FRSH_ERR_BAD_ARGUMENT : if the given thread does not exist or the
989 * vres argument is NULL
992 int frsh_thread_get_vres_id(const frsh_thread_id_t thread,
993 frsh_vres_id_t *vres_id);
996 * frsh_vres_get_priority()
998 * This operation stores the priority currently associated
999 * with the specified vres in the variable pointed to by
1000 * priority. It returns an error if the vres_id is not recognised.
1002 * @return 0 if no error \n
1003 * FRSH_ERR_BAD_ARGUMENT : if the contract argument is NULL or the value
1004 * of the vres argument is not in range \n
1005 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1006 * scheduled under FRSH \n
1007 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1009 * FRSH_ERR_NOT_CONTRACTED_VRES: if the vres of the calling thread
1010 * has been cancelled or it is not valid
1013 int frsh_vres_get_priority
1014 (frsh_vres_id_t vres_id,
1018 * frsh_vres_get_contract()
1020 * This operation stores the contract parameters currently associated
1021 * with the specified vres in the variable pointed to by
1022 * contract. It returns an error if the vres_id is not recognised.
1024 * @return 0 if no error \n
1025 * FRSH_ERR_BAD_ARGUMENT : if the contract argument is NULL or the value
1026 * of the vres argument is not in range \n
1027 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1028 * scheduled under FRSH \n
1029 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1031 * FRSH_ERR_NOT_CONTRACTED_VRES: if the vres of the calling thread
1032 * has been cancelled or it is not valid
1035 int frsh_vres_get_contract
1036 (const frsh_vres_id_t vres,
1037 frsh_contract_t *contract);
1040 * frsh_resource_get_vres_from_label()
1042 * This operation retrieves the vres_id whose contract_label
1043 * corresponds to the parameter in the resource_id and resource_type
1046 * The contract label must refer to a contract negotiated
1047 * in the same processing node in which the call is being
1048 * made. Otherwise an error is returned.
1050 * @return 0 if no error \n
1051 * FRSH_ERR_BAD_ARGUMENT : if the contract argument is NULL or the
1052 * contract_label is NULL \n
1053 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1054 * scheduled under FRSH \n
1055 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1057 * FRSH_ERR_CONTRACT_LABEL_UNKNOWN: if the contract_label is not known
1059 int frsh_resource_get_vres_from_label
1060 (const char *contract_label,
1061 const frsh_resource_type_t resource_type,
1062 const frsh_resource_id_t resource_id,
1063 frsh_vres_id_t *vres);
1068 * frsh_contract_cancel()
1070 * The operation eliminates the specified vres
1071 * and recalculates all necessary parameters for the contracts
1072 * remaining in the system. This is a potentially blocking operation;
1073 * it returns when the system has made the changes effective.
1075 * Note that the thread is not eliminated. We leave the application
1076 * the option to either freeze it for a later use or bind it to
1079 * @return 0 if successful \n
1080 * FRSH_ERR_BAD_ARGUMENT : if the value of vres is not in range \n
1081 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1082 * scheduled under FRSH \n
1083 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1085 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1086 * has been cancelled or it is not valid
1089 int frsh_contract_cancel (const frsh_vres_id_t vres);
1093 * frsh_contract_renegotiate_sync()
1095 * The operation renegotiates a contract for an existing vres. If
1096 * the on-line admission test is enabled it determines whether the
1097 * contract can be admitted or not based on the current contracts
1098 * established in the system. If it cannot be admitted, the old
1099 * contract remains in effect and an error is returned. If it can be
1100 * admitted, it recalculates all necessary parameters for the
1101 * contracts already present in the system and returns zero. This is a
1102 * potentially blocking operation; it returns when the system has
1103 * either rejected the new contract, or admitted it and made it
1106 * @return 0 if successful \n
1107 * FRSH_ERR_BAD_ARGUMENT : if the new_contract argument is NULL or the
1108 * 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 \n
1115 * FRSH_ERR_CONTRACT_REJECTED : if the renegotiation fails
1118 int frsh_contract_renegotiate_sync
1119 (const frsh_contract_t *new_contract,
1120 const frsh_vres_id_t vres);
1124 * frsh_contract_renegotiate_async()
1126 * The operation enqueues a renegotiate operation for an existing
1127 * vres, and returns immediately. The renegotiate operation is
1128 * performed asynchronously, as soon as it is practical; meanwhile the
1129 * system operation will continue normally. When the renegotiation is
1130 * made, if the on-line admission test is enabled it determines
1131 * whether the contract can be admitted or not based on the current
1132 * contracts established in the system. If it cannot be admitted, the
1133 * old contract remains in effect. If it can be admitted, it
1134 * recalculates all necessary parameters for the contracts already
1135 * present in the system.
1137 * When the operation is completed, notification is made to the
1138 * caller, if requested, via a signal. The status of the operation (in
1139 * progress, admitted, rejected) can be checked with the
1140 * frsh_vres_get_renegotiation_status() operation. The argument
1141 * sig_notify can be FRSH_NULL_SIGNAL (no notification), or any FRSH
1142 * signal value and in this case signal_info is to be sent with the signal.
1144 * @param[in] new_contract New contract parameters for the new
1145 * situation if approved.
1146 * @param[in] vres vres_id on which to do the renegotiation.
1147 * @param[in] signal_to_notify Signal number to use to notify vres of
1148 * the negotiation result. If
1149 * FRSH_NULL_SIGNAL, no signal will be raised.
1150 * @param[in] signal_info: Associated info that will come with the
1151 * signal. This parameter will be ignored
1152 * if signal_to_notify == FRSH_NULL_SIGNAL.
1154 * @return 0 if no error \n
1155 * FRSH_ERR_BAD_ARGUMENT : if the new_contract argument is NULL, the
1156 * value of the vres argument is not in range or sig_notify is
1157 * neither NULL nor a valid POSIX signal \n
1158 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1159 * scheduled under FRSH \n
1160 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1162 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1163 * has been cancelled or it is not valid
1166 int frsh_contract_renegotiate_async
1167 (const frsh_contract_t *new_contract,
1168 const frsh_vres_id_t vres,
1169 const frsh_signal_t signal_to_notify,
1170 const frsh_signal_info_t signal_info);
1174 * frsh_vres_get_renegotiation_status()
1176 * The operation reports on the status of the last renegotiation
1177 * operation enqueued for the specified vres. It is callable even
1178 * after notification of the completion of such operation, if
1181 * If the vres is not and has not been involved in any of the
1182 * frsh_contract_renegotiate_async() or frsh_group_change_mode_async()
1183 * operations, the status returned is FRSH_RS_NOT_REQUESTED
1185 * @return 0 if no error \n
1186 * FRSH_ERR_BAD_ARGUMENT : if the renegotiation_status argument is
1187 * NULL or the value of the vres argument is not in range \n
1188 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1189 * scheduled under FRSH \n
1190 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1192 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1193 * has been cancelled or it is not valid
1196 int frsh_vres_get_renegotiation_status
1197 (const frsh_vres_id_t vres,
1198 frsh_renegotiation_status_t *renegotiation_status);
1202 ////////////////////////////////////////////////////////////////////////
1203 // CHANGE OF MODE: GROUPS OF CONTRACTS
1204 ////////////////////////////////////////////////////////////////////////
1206 * @defgroup groupofcontracts Group of contracts
1209 * The following functions are used to negotiate atomically more than
1210 * one contract. This allows to build complex applications by
1211 * splitting them in individual contracts that are negotiated
1212 * simultaneously and atomically.
1218 * frsh_group_change_mode_sync()
1220 * This function performs a set of negotiation operations which can
1221 * include: adding new contracts (neg), modifying existing vres (reneg)
1222 * or cancelling existing vres (cancel).
1224 * If one of the group operations has a NULL value, unless it causes an
1225 * inconsistency the system will suppose that no operation of that
1226 * type (neg, reneg or cancel) should be done.
1228 * The virtual resources resulting from negotiations of new contracts are
1229 * returned in the parameter 'new_vres' which must be provided by the user.
1231 * If the on-line admission test is enabled, FRSH analizes the
1232 * schedulability of the context that would result in the new
1233 * contract situation with removed, changed and added contracts.
1235 * A successful return code will mean that all contracts have been
1236 * accepted and all required operations (creation, cancellation or
1237 * update of vres) have been carried out to reach the new running
1240 * If any of the contracts is not accepted a corresponding error shall be
1241 * returned and no changes will be made to the previously running context.
1243 * This call is a synchronous, potentially blocking operation. It
1244 * returns when the system has rejected the contracts or accepted
1245 * and made them effective.
1247 * @param[in] contracts_to_neg List of new contracts to negotiate
1248 * @param[in] contracts_to_reneg List of contracts to renegotiate
1249 * @param[in] vres_to_reneg List of vres to renegotiate
1250 * @param[in] vres_to_cancel List of vres to cancel
1251 * @param[out] new_vres List of vres of new contracts.
1253 * @return 0 if no error \n
1254 * FRSH_ERR_BAD_ARGUMENT Invalid pointer or group identifier. \n
1255 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS contract_label not unique. \n
1256 * FRSH_ERR_NOT_CONTRACTED_VRES: One of the provided vres_ids
1257 * is not recognised. \n
1258 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD The calling thread
1259 * is not scheduled under FRSH. \n
1260 * FRSH_ERR_INVALID_SCHEDULER_REPLY: The scheduler is wrong or
1262 * FRSH_ERR_INTERNAL_ERROR: Erroneous binding or malfunction of
1263 * FRSH main scheduler. \n
1264 * FRSH_ERR_REJECTED_CONTRACT: The negotiation of one of the
1265 * proposed contracts has failed.
1267 int frsh_group_change_mode_sync
1268 (const frsh_contracts_group_t *contracts_to_neg,
1269 const frsh_contracts_group_t *contracts_to_reneg,
1270 const frsh_vres_group_t *vres_to_reneg,
1271 const frsh_vres_group_t *vres_to_cancel,
1272 frsh_vres_group_t *new_vres);
1275 * frsh_group_change_mode_async()
1277 * This is an asynchronous (non-blocking) version of the previous function,
1278 * frsh_group_change_mode_sync() and thus, it returns inmediately.
1280 * The status of the change of mode and the identifiers for new virtual
1281 * resources must be requested with the function 'frsh_group_get_status'
1282 * by using the return parameter 'group'.
1284 * As in the asynchronous renegotiations, when the operation is completed,
1285 * the user is notified with a signal so he can check the final result with
1286 * 'frsh_group_get_status'. In case that FRSH_NULL_SIGNAL is used, no
1287 * signal will be sent to the user.
1289 * @param[in] contracts_to_neg List of new contracts to negotiate
1290 * @param[in] contracts_to_reneg List of contracts to renegotiate
1291 * @param[in] vres_to_reneg List of vres to renegotiate
1292 * @param[in] vres_to_cancel List of vres to cancel
1293 * @param[in] signal Signal number to notify completion of
1294 * the change of mode. If FRSH_NULL_SIGNAL,
1295 * no signal will be raised.
1296 * @param[in] signal_info Data associated to the signal
1297 * @param[out] group The group identifier to get the status
1299 * @return 0 if no error \n
1300 * FRSH_ERR_BAD_ARGUMENT Invalid pointer, signal or group identifier. \n
1301 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS contract_label not unique. \n
1302 * FRSH_ERR_NOT_CONTRACTED_VRES: One of the provided vres_ids
1303 * is not recognised. \n
1304 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD The calling thread
1305 * is not scheduled under FRSH. \n
1306 * FRSH_ERR_INVALID_SCHEDULER_REPLY: The scheduler is wrong or
1308 * FRSH_ERR_INTERNAL_ERROR: Erroneous binding or malfunction of
1309 * FRSH main scheduler.
1311 int frsh_group_change_mode_async
1312 (const frsh_contracts_group_t *contracts_to_neg,
1313 const frsh_contracts_group_t *contracts_to_reneg,
1314 const frsh_vres_group_t *vres_to_reneg,
1315 const frsh_vres_group_t *vres_to_cancel,
1316 const frsh_signal_t signal,
1317 const frsh_signal_info_t signal_info,
1318 frsh_group_id_t *group);
1321 * frsh_group_get_status()
1323 * This function is similar to 'frsh_vres_get_renegotiation_status' but it
1324 * is intented for group negotiations (changes of mode).
1326 * The operation reports on the status of the last negotiation
1327 * operation enqueued for the specified group identifier.
1329 * The status value can be one of the following values:
1331 * - FRSH_RS_IN_PROGRESS: the change of mode is in progress
1332 * - FRSH_RS_REJECTED: the change of mode was not accepted
1333 * - FRSH_RS_ADMITTED: the change of mode was accepted
1334 * - FRSH_RS_NOT_REQUESTED: no change of mode has been requested yet
1336 * When status returns 'FRSH_RS_ADMITTED', the array 'new_vres' contains
1337 * the values for the new virtual resources (if there was any).
1339 * This function frees the group identifier when status returns something
1340 * different than FRSH_RS_IN_PROGRESS so further calls to this function may
1341 * return inconsistent values.
1343 * @param[in] group The group identifier
1344 * @param[out] status The status of the change of mode
1345 * @param[out] new_vres List of vres for the negotiation of new contracts.
1347 * @return 0 if no error \n
1348 * FRSH_ERR_BAD_ARGUMENT Invalid pointer, signal or group identifier. \n
1349 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS contract_label not unique. \n
1350 * FRSH_ERR_NOT_CONTRACTED_VRES: One of the provided vres_ids
1351 * is not recognised. \n
1352 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD The calling thread
1353 * is not scheduled under FRSH. \n
1354 * FRSH_ERR_INVALID_SCHEDULER_REPLY: The scheduler is wrong or
1356 * FRSH_ERR_INTERNAL_ERROR: Erroneous binding or malfunction of
1357 * FRSH main scheduler.
1359 int frsh_group_get_status(const frsh_group_id_t group,
1360 frsh_renegotiation_status_t *status,
1361 frsh_vres_group_t *new_vres);
1367 ////////////////////////////////////////////////////
1368 // OBTAINING INFORMATION FROM THE SCHEDULER
1369 ////////////////////////////////////////////////////
1372 * @defgroup getschedinfo Obtaining information from the scheduler
1376 * The following functions are used to obtain available budget and
1377 * resource usage in the system. They can be used to adapt the
1378 * execution of threads according to the load of the system.
1385 * frsh_config_is_admission_test_enabled()
1387 * Returns true if the system is
1388 * configured with the on-line admission test enabled, or false
1389 * otherwise. This situation can only be changed at compile time.
1391 bool frsh_config_is_admission_test_enabled();
1394 * frsh_vres_get_usage()
1396 * This function stores the current execution time spent by the
1397 * threads bound to the specified vres in the variable pointed to by
1400 * @return 0 if successful \n
1401 * FRSH_ERR_BAD_ARGUMENT : if the value of the vres argument is not in range or
1402 * cpu_time is NULL \n
1403 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1404 * scheduled under FRSH \n
1405 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1407 * FRSH_ERR_NOT_CONTRACTED_VRESR : if the vres of the calling thread
1408 * has been cancelled or it is not valid
1411 int frsh_vres_get_usage
1412 (const frsh_vres_id_t vres,
1413 frsh_rel_time_t *spent);
1417 * frsh_vres_get_job_usage()
1419 * Get the execution time of the current job of the specified virtual
1420 * resource for a bounded or synchronized workload.
1422 int frsh_vres_get_job_usage
1423 (const frsh_vres_id_t vres,
1424 frsh_rel_time_t *spent);
1428 * frsh_vres_get_remaining_budget()
1430 * This function stores in the variable pointed to by budget the
1431 * remaining execution-time budget associated with the specified
1434 * @return 0 if successful \n
1435 * FRSH_ERR_BAD_ARGUMENT : if the value of the vres argument is not in range or
1437 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1438 * scheduled under FRSH \n
1439 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1441 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1442 * has been cancelled or it is not valid
1445 int frsh_vres_get_remaining_budget
1446 (const frsh_vres_id_t vres,
1447 frsh_rel_time_t *budget);
1451 * frsh_vres_get_budget_and_period()
1453 * This function stores in the variables
1454 * pointed to by budget and period, the execution-time budget and the
1455 * period respectively associated with the specified vres. If any of
1456 * these pointers is NULL, the corresponding information is not stored.
1458 * @return 0 if successful \n
1459 * FRSH_ERR_BAD_ARGUMENT : if the value of the vres argument is not in range,
1460 * or budget and period are both NULL \n
1461 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1462 * scheduled under FRSH \n
1463 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1465 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1466 * has been cancelled or it is not valid
1469 int frsh_vres_get_budget_and_period
1470 (const frsh_vres_id_t vres,
1471 frsh_rel_time_t *budget,
1472 frsh_rel_time_t *period);
1476 /////////////////////////////////////////////////////////////////////
1477 // SERVICE THREAD TUNING
1478 /////////////////////////////////////////////////////////////////////
1480 * @defgroup servthtuning Service thread tuning
1484 * The following functions are used to obtain available budget and
1485 * resource usage in the system. They can be used to adapt the
1486 * execution of threads to the load of the system.
1492 * frsh_service_thread_set_data()
1494 * This function allows the application to change the period and
1495 * budget of the service thread that makes the
1496 * negotiations. Increasing the utilization of this thread makes the
1497 * negotiations faster, but introduces additional load in the system
1498 * that may decrease the bandwidth available for the vres. For this
1499 * call, the system will make a schedulability analysis to determine
1500 * if the new situation is acceptable or not. This is reported back in
1501 * the variable pointed to by accepted. If the new service thread data
1502 * is accepted, the system will reassign budgets and periods to the
1503 * vres according to the new bandwidth available, in the same way
1504 * as it does for a regular contract negotiation.
1506 * When its budget is exhausted, the service thread may run in the
1509 * The service thread starts with a default budget and period that are
1512 * Implementation dependency: in the fixed priority implementtaion of
1513 * frsh, the default priority is lower than the priority of any vres,
1514 * but higher than the background. According to the
1515 * implementation-dependent module the priority is adjustable by means
1516 * of a function that changes its preemption level
1518 * @return 0 if successful \n
1519 * FRSH_ERR_BAD_ARGUMENT : if any of the pointer arguments is NULL or
1520 * the budget value is greater than the period value \n
1521 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1522 * scheduled under FRSH \n
1523 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1525 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1526 * has been cancelled or it is not valid
1529 int frsh_service_thread_set_data (const frsh_rel_time_t *budget,
1530 const frsh_rel_time_t *period,
1534 * frsh_service_thread_get_data()
1536 * this function returns in the variables pointed by budget and
1537 * period, respectively, the current budget and period of the service
1540 * @return 0 if successful \n
1541 * FRSH_ERR_BAD_ARGUMENT : if any of the pointer arguments is NULL \n
1542 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1543 * scheduled under FRSH \n
1544 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1546 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1547 * has been cancelled or it is not valid
1550 int frsh_service_thread_get_data
1551 (frsh_rel_time_t *budget,
1552 frsh_rel_time_t *period);
1558 ////////////////////////////////////////////////////////////////////////
1559 // BACKGROUND MANAGEMENT
1560 ////////////////////////////////////////////////////////////////////////
1562 //A round-robin background scheduling policy is available for those
1563 //threads that do not have real-time requirements. Because some of
1564 //these threads may require sharing information with other threads run
1565 //by regular vres. Special background contracts may be created for
1566 //specifying the synchronization requirements.
1568 //The way of specifying a background contract is by setting
1569 //contract_type to FRSH_CT_BACKGROUND. Negotiation may fail if the contract uses
1570 //shared_objects. If the contract has no shared_objects the returned
1571 //vres id represents the background and may be used to bind more
1572 //than one thread. If the contract has shared objects a vres is
1573 //created to keep track of them, but the associated threads are
1574 //executed in the background, together with the other background
1578 ////////////////////////////////////////////////////////////////////////
1580 ////////////////////////////////////////////////////////////////////////
1583 * Returns resource id of local CPU.
1585 * The ID is determined from environment variable FRSH_CPU_ID or, if
1586 * that is not defined, the compile time default (defined in
1587 * config.target/omk).
1589 frsh_resource_id_t frsh_get_local_cpu_id(void);
1593 #endif // _FRSH_CORE_H_