1 // -----------------------------------------------------------------------
2 // Copyright (C) 2006 - 2008 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_set_basic_params()
200 * The operation updates the specified contract parameters object by
201 * setting its budget, period, workload and type to the specified
202 * input parameters. (Note: the workload is a basic parameter because
203 * bounded tasks are triggered by the scheduler (see the
204 * frsh_timed_wait() and frsh_synchobj_wait* operations), while
205 * indeterminate tasks are not; therefore, their programming model is
208 * @param contract the pointer to the contract object
209 * @param[in] budget_min the minimum budget for the contract
210 * @param[in] period_max the maximum period for the contract
211 * @param[in] workload the kind of workload (can be FRSH_WT_BOUNDED,
212 * FRSH_WT_INDETERMINATE or FRSH_OVERHEAD)
213 * @param[in] contract_type can be FRSH_CT_REGULAR,
214 * FRSH_CT_BACKGROUND, FRSH_CT_DUMMY.
216 * @return 0 if no error \n
217 * FRSH_ERR_BAD_ARGUMENT : if any of the pointers is NULL
218 * or if only one of the time values is 0, and also if the
219 * workload or the contract type values are unknown in the
222 int frsh_contract_set_basic_params
223 (frsh_contract_t *contract,
224 const frsh_rel_time_t *budget_min,
225 const frsh_rel_time_t *period_max,
226 const frsh_workload_t workload,
227 const frsh_contract_type_t contract_type);
230 * frsh_contract_get_basic_params()
232 * This operation obtains from the specified contract object its
233 * budget, period, and workload, and copies them to the places pointed
234 * to by the corresponding output parameters.
236 * @param[in] contract the pointer to the contract object
237 * @param[out] budget_min pointer to preallocated space
238 * @param[out] period_max pointer to preallocated space
239 * @param[out] workload pointer to preallocated space
240 * @param[out] contract_type pointer to preallocated space
242 * @return 0 if no error \n
243 * FRSH_ERR_BAD_ARGUMENT : if one of the contract or
247 int frsh_contract_get_basic_params
248 (const frsh_contract_t *contract,
249 frsh_rel_time_t *budget_min,
250 frsh_rel_time_t *period_max,
251 frsh_workload_t *workload,
252 frsh_contract_type_t *contract_type);
255 * frsh_contract_set_resource_and_label()
257 * Specify resource_id and type, and the contract label. Otherwise
258 * default values will apply. If the contract label is too long it is truncated
260 * @return 0 if no error \n
261 * FRSH_ERR_BAD_ARGUMENT : if the contract pointer is NULL.
263 int frsh_contract_set_resource_and_label
264 (frsh_contract_t *contract,
265 const frsh_resource_type_t resource_type,
266 const frsh_resource_id_t resource_id,
267 const char *contract_label);
271 * frsh_contract_get_resource_and_label()
273 * Obtain the resource_id and type, and the contract label.
275 * @return 0 if no error \n
276 * FRSH_ERR_BAD_ARGUMENT : if the contract or the contract_label
279 int frsh_contract_get_resource_and_label
280 (const frsh_contract_t *contract,
281 frsh_resource_type_t *resource_type,
282 frsh_resource_id_t *resource_id,
283 char *contract_label);
287 * frsh_contract_set_timing_reqs()
289 * The operation updates the specified contract object, specifying
290 * additional time-related requirements.
292 * @param contract The pointer to the contract object
294 * @param [in] d_equals_t It is a boolean value, set to true (1) if
295 * we want to specify a deadline different from
296 * the period for the contract.
297 * @param [in] deadline If the previous parameter is set to true,
298 * this parameter is ignored (the contract value
299 * will be NULL_DEADLINE internally). Otherwise, it
300 * contains the desired deadline value.
301 * @param [in] budget_overrun_signal contains the number of the signal
302 * that must be raised if the budget of the vres is overrun.
303 * If the value of this parameter is FRSH_NULL_SIGNAL, no signal will
305 * @param [in] budget_overrun_siginfo contains the value that will be
306 * passed to the signal "catcher" when the signal is raised.
307 * This parameters is not used if the budget_overrun_signal
308 * parameter is set to FRSH_NULL_SIGNAL.
309 * @param [in] deadline_miss_signal contains the number of the
310 * signal that must be raised if the deadline of the
311 * vres is missed. If the value of this parameter is
312 * FRSH_NULL_SIGNAL, no signal is raised.
313 * @param [in] deadline_miss_siginfo contains the value that will be
314 * passed to the signal "catcher" when the signal is
315 * raised. This parameter is not used if the
316 * deadline_signal parameter is set to NULL_SIGNAL
318 * @return 0 if successful\n
319 * FRSH_ERR_BAD_ARGUMENT : if contract is NULL \b or \n
320 * (d_equals_t is true and deadline is not FRSH_NULL_DEADLINE) \b or \n
321 * (budget_overrun_signal is not a valid signal) \b or \n
322 * (deadline_miss_signal is not a valid signal) \b or \n
323 * (d_equals_t is false but (deadline is FRSH_NULL_DEADLINE or its value
324 * is grater than the contract's maximum period))
327 int frsh_contract_set_timing_reqs
328 (frsh_contract_t *contract,
329 const bool d_equals_t,
330 const frsh_rel_time_t *deadline,
331 const frsh_signal_t budget_overrun_signal,
332 const frsh_signal_info_t budget_overrun_siginfo,
333 const frsh_signal_t deadline_miss_signal,
334 const frsh_signal_info_t deadline_miss_siginfo);
337 * frsh_contract_get_timing_reqs()
339 * The operation obtains the corresponding input parameters from the
340 * specified contract object. If d_equals_t is true, the deadline will
341 * be set to FRSH_NULL_DEADLINE.
343 * @return 0 if no error \n
344 * FRSH_ERR_BAD_ARGUMENT : if contract is NULL
347 int frsh_contract_get_timing_reqs
348 (const frsh_contract_t *contract,
350 frsh_rel_time_t *deadline,
351 frsh_signal_t *budget_overrun_signal,
352 frsh_signal_info_t *budget_overrun_siginfo,
353 frsh_signal_t *deadline_miss_signal,
354 frsh_signal_info_t *deadline_miss_siginfo);
359 //////////////////////////////////////////////////////////////////
360 // SYNCHRONIZATION OBJECTS
361 //////////////////////////////////////////////////////////////////
363 * @defgroup synch Synchronization objects
366 * Synchronisation objects provide an alternative to timers for
367 * bounded-workload vres to signal the end of their current job and
368 * return their remaining budget to FRSH.
370 * Instead of asking to be reactivated based on an absolute time, they
371 * queue themselves in a synchronisation object and will wait there
372 * until another vres (bounded-workload or indeterminate-workload)
373 * wakes them up with a signal call the earliest at the beginning of
376 * Indeterminate-workload vres cannot queue themselves here because
377 * they don't have any budget to return. However they can signal on
378 * the objects to activate a waiting workload vres.
380 * For classical signal/wait synchronisation paradigms the application
381 * must use whatever mechanism the underlying OS provides.
383 * In the future we may add a broadcast operation that would signal a
384 * group of synchronization objects. We have not included a broadcast
385 * service in this version because it can be easily created by the
386 * user by signalling individual synchronization objects inside a
389 * Notice that for synchronization objects there is no naming service
390 * like in shared objects because tasks that use synchronization are
391 * not developed independently, as they are closely coupled.
398 * frsh_synchobj_create()
400 * This operation creates and initializes a synchronization object
401 * variable managed by the scheduler, and returns a handle to it in
402 * the variable pointed to by synch_handle.
404 * @param[out] synch_handle pointer to the variable that will contain
405 * the handle to the newly created synchronization object
407 * @return 0 if the operation is succesful
408 * FRSH_ERR_TOO_MANY_SYNCH_OBJS if the number of synchronization
409 * objects in the system has already exceeded the maximum
411 * FRSH_ERR_TOO_MANY_SYNCH_OBJS : if the number of synchronization
412 * objects in the system has already exceeded the maximum\n
414 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
415 * scheduled under FRSH\n
417 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not running
420 int frsh_synchobj_create
421 (frsh_synchobj_handle_t *synch_handle);
425 * frsh_synchobj_destroy()
427 * This operation destroys the synchronization object (created by a
428 * previous call to frsh_synchobj_create) that is referenced by the
429 * synch_handle variable. After calling this operation, the
430 * synch_handle variable can not be used until it is initialized again
431 * by a call to frsh_synchobj_create.
433 * @param synch_handle the handle to the synchronization object
436 * @return 0 if no error \n
437 * FRSH_ERR_BAD_ARGUMENT : if synch_handle is 0\n
438 * FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE if the handle is not valid\n
439 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
440 * scheduled under FRSH \n
441 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
444 * @sa frsh_synchobj_create
446 int frsh_synchobj_destroy
447 (const frsh_synchobj_handle_t synchobj_handle);
450 * frsh_synchobj_wait()
452 * This operation is invoked by threads associated with bounded
453 * workload vres to indicate that a job has been completed (and
454 * that the scheduler may reassign the unused capacity of the current
455 * job to other vres).
457 * As a difference with frsh_timed_wait(), here the vres
458 * specifies to be awakened by the arrival of a signal operation
459 * instead of at a precise point of time.
461 * This function can also be called to schedule the first job of a
462 * recently created vres and make it start when a signal operation
463 * has been sent from another thread.
465 * The vres' budget will be made zero for the remainder of the vres'
466 * period, and FRSH will not replenish it until an event has been
467 * notified to the synchronisation object by another vres.
469 * It can happen that the synchronisation object has notification
470 * events queued from the past, in this case one of the events is
471 * dequeued immediately and the vres won't have to wait for another
474 * At the time of reception of a notification event (wether in the
475 * future or in the past), all pending budget replenishments (if any)
476 * are made effective. Once the vres has a positive budget and the
477 * scheduler schedules the calling thread again, the call returns and
478 * the vres continues executing.
480 * If the synchronisation object is destroyed while the vres was
481 * waiting on it, the vres will be awaken and the function will
482 * return with a code FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE
484 * Except for those parameters equal to NULL pointers, the system
485 * reports the current period and budget for the current job, it informs
486 * if the deadline of the previous job was missed or not, and whether the
487 * budget of the previous job was overrun or not.
489 * In a system with hierarchical scheduling, since this call makes the
490 * budget of the current period zero, the other threads in the same
491 * vres are not run. As mentioned above, only when the call finishes
492 * the budget may be replenished.
494 * @param synch_handle Synchronisation object upon which the vres
496 * @param next_budget[out] Upon return of this function, the variable
497 * pointed by this function will be equal to
498 * the current vres budget. If this parameter is
499 * set to NULL, no action is taken
500 * @param next_period[out] The vres period upon return (ignored if NULL).
501 * @param was_deadline_missed Upon return whether the deadline was
502 * missed in the previous period.
503 * @param was_budget_overran
506 * @return 0 if success \n
507 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
509 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
511 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not scheduled
513 * FRSH_ERR_NOT_BOUND : if the calling thread does not have a valid
514 * vres bound to it \n
515 * FRSH_ERR_BAD_ARGUMENT : if synch_handle is 0 \n
516 * FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE if the synch_handle is not
517 * valid or was destroyed while the vres was waiting on it. \n
518 * FRSH_ERR_VRES_WORKLOAD_NOT_COMPATIBLE: if the kind of workload of the vres
519 * is not FRSH_BOUNDED
522 int frsh_synchobj_wait
523 (const frsh_synchobj_handle_t synch_handle,
524 frsh_rel_time_t *next_budget,
525 frsh_rel_time_t *next_period,
526 bool *was_deadline_missed,
527 bool *was_budget_overran);
531 * frsh_synchobj_wait_with_timeout()
533 * This call is the same as frsh_synchobj_wait() but with an extra
534 * absolute timeout. The timed_out argument, indicates whether the
535 * function returned because of the expiration of the timeout or not.
537 * @return 0 if no error \n
538 * FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE if the synch_handle is not
540 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
542 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
544 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not scheduled
546 * FRSH_ERR_NOT_BOUND : if the calling thread does not have a valid
547 * vres bound to it \n
548 * FRSH_ERR_BAD_ARGUMENT : if the synch_handle given is not valid or the
549 * abs_timeout argument is NULL or its value is in the past\n
550 * FRSH_ERR_VRES_WORKLOAD_NOT_COMPATIBLE: if the kind of workload of the vres
551 * is not FRSH_BOUNDED
554 int frsh_synchobj_wait_with_timeout
555 (const frsh_synchobj_handle_t synch_handle,
556 const frsh_abs_time_t *abs_timeout,
558 frsh_rel_time_t *next_budget,
559 frsh_rel_time_t *next_period,
560 bool *was_deadline_missed,
561 bool *was_budget_overran);
564 * frsh_synchobj_signal()
566 * This function sends a notification event to the synchronization object
567 * specified as parameter. If there is at least one vres waiting on
568 * the synchronization object, it is awaken. If more than one vres
569 * are waiting, just one of them is awaken. However, which one is
570 * awaken is implementation dependent. If no vres is waiting on the
571 * synchronization object, the notification event is queued.
573 * @param [in] synch_handle the handle of the synchronization object to
576 * @return 0 if no error \n
577 * FRSH_ERR_BAD_ARGUMENT : if synch_handle is 0 \n
578 * FRSH_ERR_INVALID_SYNCH_OBJ_HANDLE if the handle is not valid \n
579 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
580 * scheduled under FRSH \n
581 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
583 * FRSH_ERR_TOO_MANY_EVENTS_IN_SYNCH_OBJ : if the number of events stored
584 * in the synchronization object reaches the maximum defined in the
585 * configuration parameter header file
587 * @sa frsh_synchobj_wait, frsh_synchobj_wait_with_timeout
589 int frsh_synchobj_signal
590 (const frsh_synchobj_handle_t synch_handle);
595 * This operation is invoked by threads associated with bounded
596 * workload vres to indicate that a job has been completed (and
597 * that the scheduler may reassign the unused capacity of the current
598 * job to other vres). It is also invoked when the first job of
599 * such threads has to be scheduled.
601 * As an effect, the system will make the current vres's budget zero
602 * for the remainder of the vres's period, and will not replenish
603 * the budget until the specified absolute time. At that time, all
604 * pending budget replenishments (if any) are made effective. Once the
605 * vres has a positive budget and the scheduler schedules the
606 * calling thread again, the call returns and at that time, except for
607 * those parameters equal to NULL pointers, the system reports the
608 * current period and budget for the current job, whether the deadline
609 * of the previous job was missed or not, and whether the budget of
610 * the previous job was overrun or not.
612 * In a system with hierarchical scheduling, since this call makes the
613 * budget zero, the other threads in the same vres are not run. As
614 * mentioned abobe, only when the call finishes the budget may be
617 * @param [in] abs_time absolute time at which the budget will be
620 * @param [out] next_budget upon return of this function, the variable
621 * pointed by this function will be equal to
622 * the current vres budget. If this parameter is
623 * set to NULL, no action is taken.
625 * @param [out] next_period upon return of this function, the variable
626 * pointed by this function will be equal to
627 * the current vres period. If this parameter is
628 * set to NULL, no action is taken.
630 * @param [out] was_deadline_missed upon return of this function, the
631 * variable pointed by this function will be
632 * equal to true if the previous vres deadline
633 * was missed, to false otherwise. If this
634 * parameter is set to NULL, no action is
637 * @param [out] was_budget_overrun upon return of this function, the
638 * variable pointed by this function will be
639 * equal to true if the previous vres budget was
640 * overrun, to false otherwise. If this
641 * parameter is set to NULL, no action is
644 * @return 0 if the operation is successful \n
645 * FRSH_ERR_TIME_SPEC_IN_THE_PAST if the absolute time specification
647 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong
649 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
651 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling
652 * thread is not scheduled under FRSH \n
653 * FRSH_ERR_NOT_BOUND : if the calling thread does not have a valid
654 * vres bound to it \n
655 * FRSH_ERR_BAD_ARGUMENT : if abs_time is NULL \n
656 * FRSH_ERR_VRES_WORKLOAD_NOT_COMPATIBLE: if the kind of workload of the vres
657 * is not FRSH_BOUNDED
660 * @sa frsh_synchobj_wait, frsh_synchobj_wait_with_timeout
663 (const frsh_abs_time_t *abs_time,
664 frsh_rel_time_t *next_budget,
665 frsh_rel_time_t *next_period,
666 bool *was_deadline_missed,
667 bool *was_budget_overran);
672 * frsh_vresperiod_wait()
674 * Suspend the calling thread until the start of the specified virtual
675 * resource period of a vres_id, for a synchronized workload.
677 * Virtual resource periods are numbered. The number of the current
678 * period can be obtained through the frsh_vres_get_period_number()
681 int frsh_vresperiod_wait(unsigned long period_num,
682 frsh_rel_time_t *next_budget,
683 frsh_rel_time_t *next_period,
684 bool *was_deadline_missed,
685 bool *was_budget_overran);
689 * frsh_vres_get_period()
691 * Return the current period number, for a virtual resource of
692 * synchronized workload.
694 int frsh_vres_get_period_number
695 (const frsh_vres_id_t vres,
703 ///////////////////////////////////////////////////////////////////
704 // CONTRACT NEGOCIATION OPERATIONS
705 ///////////////////////////////////////////////////////////////////
708 * @defgroup negotiate Negotiate contract functions
711 * The following functions are used to negotiate contracts and thus
712 * creating vres which are the execution image of a contract.
713 * Besides, these functions allow to assign and unassign threads to
716 * In the case of more than one thread per vres please refer to the
717 * hierarchical module.
725 * frsh_contract_negotiate()
727 * The operation negotiates a contract and if accepted it will return
728 * a vres_id. It will also check that the given contract_label is unique
731 * If the on-line admission test is enabled, it determines whether the
732 * contract can be admitted or not based on the current contracts
733 * established in the system. Then it creates the vres and
734 * recalculates all necessary parameters for the contracts already
735 * present in the system.
737 * This is a potentially blocking operation, it returns when the
738 * system has either rejected the contract, or admitted it and made it
739 * effective. No thread is bound to the newly created vres, which
740 * will be idle until a thread is bound to it via frsh_thread_bind()
741 * or frsh_thread_create_and_bind().
743 * This operation can only be executed by threads that are already
744 * bound to an active vres and therefore are being scheduled by the
747 * @return 0 if successful \n
748 * FRSH_ERR_CONTRACT_REJECTED: The contract is not accepted.\n
749 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
751 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
753 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not scheduled
754 * under FRSH scheduler \n
755 * FRSH_ERR_BAD_ARGUMENT : if the contract or vres arguments are NULL \n
756 * FRSH_ERR_TOO_MANY_VRES : if there is no space for more vres
757 * (the maximum number of them is already reached) \n
758 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS : contract_label is not unique.
761 int frsh_contract_negotiate
762 (const frsh_contract_t *contract,
763 frsh_vres_id_t *vres);
766 * frsh_thread_create_and_bind()
768 * This operation creates a thread and binds it to an existing vres.
770 * This is the preferred way to add threads to the application because
771 * we make sure that the thread won't become unbound.
773 * The vres must not have any thread binded to it. If you want to
774 * bind more than one thread to the vres you must use the
775 * hierarchical module.
777 * The frsh_thread_attr_t parameter is overwritten as necessary to
778 * introduce the adequate scheduling policy and priority, according
779 * to the preemption level given in the contract and the
780 * frsh_priority_map() function defined by the user.
782 * @param[in] vres_id vres with which the thread will be bound.
783 * @param[out] thread frsh_thread_id returned by the system.
784 * @param attr pthread_attr taken and maybe corrected
785 * by the system. Ignored if NULL
786 * @param[in] thread_code Thread function (void func(void *) )
787 * that will constitute the main of the
789 * @param[in] arg Argument for data to be passed at the
790 * thread. Set to NUL if you don't want
791 * to do anything like this.
793 * @return 0 if successful \n
794 * FRSH_ERR_BAD_ARGUMENT : if the contract or vres arguments are
796 * FRSH_ERR_CONTRACT_REJECTED : if the contract is rejected. \n
798 * It may also return all the errors that may be returned by the
799 * fosa_thread_create() function call
802 int frsh_thread_create_and_bind
803 (const frsh_vres_id_t vres,
804 frsh_thread_id_t *thread,
805 frsh_thread_attr_t *attr,
806 frsh_thread_code_t thread_code,
811 * frsh_thread_create_in_background()
813 * This function creates a "background contract" that does not need to
814 * be negotiated, creates a threads and binds to the new vres.
816 * This method is suggested as a way to initate components and
817 * plugins. The event that triggers the component activation should
818 * arrive to an application thread that could use this function to
819 * create a thread used in its initialisation.
821 * The attribute parameter is overwritten as necessary to introduce
822 * the adequate scheduling policy and priority.
824 * @param[in] thread_code Function to be executed by the new
826 * @param[in] thread_arg General pointer that will be passed to
827 * the new thread as initialisation data.
828 * @param attr Pthread attribute with thread params
829 * @param[in] contract_label Contract label for the new vres.
830 * @param[out] thread_id Id of the new thread.
831 * @param[out] vres_id vres_id of the new vres.
833 * @return 0 if successful \n
834 * FRSH_ERR_BAD_ARGUMENT : Any problems with the argument \n
835 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is
836 * not scheduled under FRSH \n
837 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS : contract_label is not unique \n
838 * FRSH_ERR_TOO_MANY_VRES : if there is no space for more vres
839 * (the maximum number of them is already reached)
842 int frsh_thread_create_in_background
843 (frsh_thread_code_t thread_code,
844 const void *thread_arg,
845 const char *contract_label,
846 frsh_thread_attr_t *attr,
847 frsh_thread_id_t *thread_id,
848 frsh_vres_id_t *vres_id);
851 int frsh_thread_join_in_background(frsh_resource_id_t resource_id,
852 frsh_resource_type_t resource_type,
854 frsh_vres_id_t *vres_id);
861 * This operation associates a thread with a vres, which means that
862 * it starts consuming the vres's budget and is executed according
863 * to the contract established for that vres. If the thread is
864 * already bound to another vres, it is effectively unbound from it
865 * and bound to the specified one.
867 * It fails if the vres's policy is different than FRSH_NONE, or if
868 * there is already a thread bound to this vres. In order to bind
869 * more than one vres to the same thread you must use the
870 * hierarchical module.
872 * Implementation dependent issue: In order to allow the usage of
873 * application defined schedulers, the given thread must not have the
874 * scheduling policy SCHED_APP and at the same time be attached to an
875 * application scheduler different than the frsh scheduler.
877 * @return 0 if successful \n
878 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
880 * FRSH_ERR_UNKNOWN_APPSCHEDULED_THREAD : if the thread is attached to
881 * an application defined scheduler different than the frsh
883 * FRSH_ERR_BAD_ARGUMENT : if the vres value does not complain with the
884 * expected format or valid range or the given thread does not
886 * FRSH_ERR_NOT_CONTRACTED_VRES : if the referenced vres is not
888 * FRSH_ERR_VRES_WORKLOAD_NOT_COMPATIBLE: if the kind of workload
889 * of the vres is FRSH_OVERHEAD \n
890 * FRSH_ERR_ALREADY_BOUND : if the given vres has a thread already
895 (const frsh_vres_id_t vres,
896 const frsh_thread_id_t thread);
900 * frsh_thread_unbind()
902 * This operation unbinds a thread from a vres. Since threads with
903 * no vres associated are not allowed to execute, they remain in a
904 * dormant state until they are either eliminated or bound again.
906 * If the thread is inside a critical section the effects of this call
907 * are deferred until the critical section is ended
909 * Implementation dependent issue: in the implementation with an
910 * application scheduler, the thread is still attached to the frsh
911 * scheduler, but suspended.
913 * @return 0 if successful \n
914 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
916 * FRSH_ERR_BAD_ARGUMENT : if the given thread does not exist \n
917 * FRSH_ERR_NOT_SCHEDULED_THREAD : if the given thread is not scheduled
919 * FRSH_ERR_UNKNOWN_APPSCHEDULED_THREAD : if the thread is attached to
920 * an application defined scheduler different than the frsh
922 * FRSH_ERR_NOT_BOUND : if the given thread does not have a valid
925 int frsh_thread_unbind(const frsh_thread_id_t thread);
928 * frsh_thread_get_vres_id()
930 * This operation stores the Id of the vres associated with the
931 * specified thread in the variable pointed to by vres. It returns
932 * an error if the thread does not exist, it is not under the control
933 * of the scheduling framework, or is not bound.
935 * @return 0 if no error \n
936 * FRSH_ERR_NOT_SCHEDULED_THREAD : if the given thread is not scheduled
938 * FRSH_ERR_NOT_BOUND : if the given thread does not have a valid
939 * vres bound to it \n
940 * FRSH_ERR_BAD_ARGUMENT : if the given thread does not exist or the
941 * vres argument is NULL
944 int frsh_thread_get_vres_id(const frsh_thread_id_t thread,
945 frsh_vres_id_t *vres_id);
948 * frsh_vres_get_priority()
950 * This operation stores the priority currently associated
951 * with the specified vres in the variable pointed to by
952 * priority. It returns an error if the vres_id is not recognised.
954 * @return 0 if no error \n
955 * FRSH_ERR_BAD_ARGUMENT : if the contract argument is NULL or the value
956 * of the vres argument is not in range \n
957 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
958 * scheduled under FRSH \n
959 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
961 * FRSH_ERR_NOT_CONTRACTED_VRES: if the vres of the calling thread
962 * has been cancelled or it is not valid
965 int frsh_vres_get_priority
966 (frsh_vres_id_t vres_id,
970 * frsh_vres_get_contract()
972 * This operation stores the contract parameters currently associated
973 * with the specified vres in the variable pointed to by
974 * contract. It returns an error if the vres_id is not recognised.
976 * @return 0 if no error \n
977 * FRSH_ERR_BAD_ARGUMENT : if the contract argument is NULL or the value
978 * of the vres argument is not in range \n
979 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
980 * scheduled under FRSH \n
981 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
983 * FRSH_ERR_NOT_CONTRACTED_VRES: if the vres of the calling thread
984 * has been cancelled or it is not valid
987 int frsh_vres_get_contract
988 (const frsh_vres_id_t vres,
989 frsh_contract_t *contract);
992 * frsh_resource_get_vres_from_label()
994 * This operation retrieves the vres_id whose contract_label
995 * corresponds to the parameter in the resource_id and resource_type
998 * The contract label must refer to a contract negotiated
999 * in the same processing node in which the call is being
1000 * made. Otherwise an error is returned.
1002 * @return 0 if no error \n
1003 * FRSH_ERR_BAD_ARGUMENT : if the contract argument is NULL or the
1004 * contract_label is NULL \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_CONTRACT_LABEL_UNKNOWN: if the contract_label is not known
1011 int frsh_resource_get_vres_from_label
1012 (const char *contract_label,
1013 const frsh_resource_type_t resource_type,
1014 const frsh_resource_id_t resource_id,
1015 frsh_vres_id_t *vres);
1020 * frsh_contract_cancel()
1022 * The operation eliminates the specified vres
1023 * and recalculates all necessary parameters for the contracts
1024 * remaining in the system. This is a potentially blocking operation;
1025 * it returns when the system has made the changes effective.
1027 * Note that the thread is not eliminated. We leave the application
1028 * the option to either freeze it for a later use or bind it to
1031 * @return 0 if successful \n
1032 * FRSH_ERR_BAD_ARGUMENT : if the value of vres is not in range \n
1033 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1034 * scheduled under FRSH \n
1035 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1037 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1038 * has been cancelled or it is not valid
1041 int frsh_contract_cancel (const frsh_vres_id_t vres);
1045 * frsh_contract_renegotiate_sync()
1047 * The operation renegotiates a contract for an existing vres. If
1048 * the on-line admission test is enabled it determines whether the
1049 * contract can be admitted or not based on the current contracts
1050 * established in the system. If it cannot be admitted, the old
1051 * contract remains in effect and an error is returned. If it can be
1052 * admitted, it recalculates all necessary parameters for the
1053 * contracts already present in the system and returns zero. This is a
1054 * potentially blocking operation; it returns when the system has
1055 * either rejected the new contract, or admitted it and made it
1058 * @return 0 if successful \n
1059 * FRSH_ERR_BAD_ARGUMENT : if the new_contract argument is NULL or the
1060 * value of the vres argument is not in range \n
1061 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1062 * scheduled under FRSH \n
1063 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1065 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1066 * has been cancelled or it is not valid \n
1067 * FRSH_ERR_REJECTED_CONTRACT : if the renegotiation fails
1070 int frsh_contract_renegotiate_sync
1071 (const frsh_contract_t *new_contract,
1072 const frsh_vres_id_t vres);
1076 * frsh_contract_renegotiate_async()
1078 * The operation enqueues a renegotiate operation for an existing
1079 * vres, and returns immediately. The renegotiate operation is
1080 * performed asynchronously, as soon as it is practical; meanwhile the
1081 * system operation will continue normally. When the renegotiation is
1082 * made, if the on-line admission test is enabled it determines
1083 * whether the contract can be admitted or not based on the current
1084 * contracts established in the system. If it cannot be admitted, the
1085 * old contract remains in effect. If it can be admitted, it
1086 * recalculates all necessary parameters for the contracts already
1087 * present in the system.
1089 * When the operation is completed, notification is made to the
1090 * caller, if requested, via a signal. The status of the operation (in
1091 * progress, admitted, rejected) can be checked with the
1092 * frsh_vres_get_renegotiation_status() operation. The argument
1093 * sig_notify can be FRSH_NULL_SIGNAL (no notification), or any FRSH
1094 * signal value and in this case signal_info is to be sent with the signal.
1096 * @param[in] new_contract New contract parameters for the new
1097 * situation if approved.
1098 * @param[in] vres vres_id on which to do the renegotiation.
1099 * @param[in] signal_to_notify Signal number to use to notify vres of
1100 * the negotiation result. If
1101 * FRSH_NULL_SIGNAL, no signal will be raised.
1102 * @param[in] signal_info: Associated info that will come with the
1103 * signal. This parameter will be ignored
1104 * if signal_to_notify == FRSH_NULL_SIGNAL.
1106 * @return 0 if no error \n
1107 * FRSH_ERR_BAD_ARGUMENT : if the new_contract argument is NULL, the
1108 * value of the vres argument is not in range or sig_notify is
1109 * neither NULL nor a valid POSIX signal \n
1110 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1111 * scheduled under FRSH \n
1112 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1114 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1115 * has been cancelled or it is not valid
1118 int frsh_contract_renegotiate_async
1119 (const frsh_contract_t *new_contract,
1120 const frsh_vres_id_t vres,
1121 const frsh_signal_t signal_to_notify,
1122 const frsh_signal_info_t signal_info);
1126 * frsh_vres_get_renegotiation_status()
1128 * The operation reports on the status of the last renegotiation
1129 * operation enqueued for the specified vres. It is callable even
1130 * after notification of the completion of such operation, if
1133 * If the vres is not and has not been involved in any of the
1134 * frsh_contract_renegotiate_async() or frsh_group_change_mode_async()
1135 * operations, the status returned is FRSH_RS_NOT_REQUESTED
1137 * @return 0 if no error \n
1138 * FRSH_ERR_BAD_ARGUMENT : if the renegotiation_status argument is
1139 * NULL or the value of the vres argument is not in range \n
1140 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1141 * scheduled under FRSH \n
1142 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1144 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1145 * has been cancelled or it is not valid
1148 int frsh_vres_get_renegotiation_status
1149 (const frsh_vres_id_t vres,
1150 frsh_renegotiation_status_t *renegotiation_status);
1154 ////////////////////////////////////////////////////////////////////////
1155 // CHANGE OF MODE: GROUPS OF CONTRACTS
1156 ////////////////////////////////////////////////////////////////////////
1158 * @defgroup groupofcontracts Group of contracts
1161 * The following functions are used to negotiate atomically more than
1162 * one contract. This allows to build complex applications by
1163 * splitting them in individual contracts that are negotiated
1164 * simultaneously and atomically.
1170 * frsh_group_change_mode_sync()
1172 * This function performs a set of negotiation operations which can
1173 * include: adding new contracts (neg), modifying existing vres (reneg)
1174 * or cancelling existing vres (cancel).
1176 * If one of the group operations has a NULL value, unless it causes an
1177 * inconsistency the system will suppose that no operation of that
1178 * type (neg, reneg or cancel) should be done.
1180 * The virtual resources resulting from negotiations of new contracts are
1181 * returned in the parameter 'new_vres' which must be provided by the user.
1183 * If the on-line admission test is enabled, FRSH analizes the
1184 * schedulability of the context that would result in the new
1185 * contract situation with removed, changed and added contracts.
1187 * A successful return code will mean that all contracts have been
1188 * accepted and all required operations (creation, cancellation or
1189 * update of vres) have been carried out to reach the new running
1192 * If any of the contracts is not accepted a corresponding error shall be
1193 * returned and no changes will be made to the previously running context.
1195 * This call is a synchronous, potentially blocking operation. It
1196 * returns when the system has rejected the contracts or accepted
1197 * and made them effective.
1199 * @param[in] contracts_to_neg List of new contracts to negotiate
1200 * @param[in] contracts_to_reneg List of contracts to renegotiate
1201 * @param[in] vres_to_reneg List of vres to renegotiate
1202 * @param[in] vres_to_cancel List of vres to cancel
1203 * @param[out] new_vres List of vres of new contracts.
1205 * @return 0 if no error \n
1206 * FRSH_ERR_BAD_ARGUMENT Invalid pointer or group identifier. \n
1207 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS contract_label not unique. \n
1208 * FRSH_ERR_NOT_CONTRACTED_VRES: One of the provided vres_ids
1209 * is not recognised. \n
1210 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD The calling thread
1211 * is not scheduled under FRSH. \n
1212 * FRSH_ERR_INVALID_SCHEDULER_REPLY: The scheduler is wrong or
1214 * FRSH_ERR_INTERNAL_ERROR: Erroneous binding or malfunction of
1215 * FRSH main scheduler. \n
1216 * FRSH_ERR_REJECTED_CONTRACT: The negotiation of one of the
1217 * proposed contracts has failed.
1219 int frsh_group_change_mode_sync
1220 (const frsh_contracts_group_t *contracts_to_neg,
1221 const frsh_contracts_group_t *contracts_to_reneg,
1222 const frsh_vres_group_t *vres_to_reneg,
1223 const frsh_vres_group_t *vres_to_cancel,
1224 frsh_vres_group_t *new_vres);
1227 * frsh_group_change_mode_async()
1229 * This is an asynchronous (non-blocking) version of the previous function,
1230 * frsh_group_change_mode_sync() and thus, it returns inmediately.
1232 * The status of the change of mode and the identifiers for new virtual
1233 * resources must be requested with the function 'frsh_group_get_status'
1234 * by using the return parameter 'group'.
1236 * As in the asynchronous renegotiations, when the operation is completed,
1237 * the user is notified with a signal so he can check the final result with
1238 * 'frsh_group_get_status'. In case that FRSH_NULL_SIGNAL is used, no
1239 * signal will be sent to the user.
1241 * @param[in] contracts_to_neg List of new contracts to negotiate
1242 * @param[in] contracts_to_reneg List of contracts to renegotiate
1243 * @param[in] vres_to_reneg List of vres to renegotiate
1244 * @param[in] vres_to_cancel List of vres to cancel
1245 * @param[in] signal Signal number to notify completion of
1246 * the change of mode. If FRSH_NULL_SIGNAL,
1247 * no signal will be raised.
1248 * @param[in] signal_info Data associated to the signal
1249 * @param[out] group The group identifier to get the status
1251 * @return 0 if no error \n
1252 * FRSH_ERR_BAD_ARGUMENT Invalid pointer, signal or group identifier. \n
1253 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS contract_label not unique. \n
1254 * FRSH_ERR_NOT_CONTRACTED_VRES: One of the provided vres_ids
1255 * is not recognised. \n
1256 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD The calling thread
1257 * is not scheduled under FRSH. \n
1258 * FRSH_ERR_INVALID_SCHEDULER_REPLY: The scheduler is wrong or
1260 * FRSH_ERR_INTERNAL_ERROR: Erroneous binding or malfunction of
1261 * FRSH main scheduler.
1263 int frsh_group_change_mode_async
1264 (const frsh_contracts_group_t *contracts_to_neg,
1265 const frsh_contracts_group_t *contracts_to_reneg,
1266 const frsh_vres_group_t *vres_to_reneg,
1267 const frsh_vres_group_t *vres_to_cancel,
1268 const frsh_signal_t signal,
1269 const frsh_signal_info_t signal_info,
1270 frsh_group_id_t *group);
1273 * frsh_group_get_status()
1275 * This function is similar to 'frsh_vres_get_renegotiation_status' but it
1276 * is intented for group negotiations (changes of mode).
1278 * The operation reports on the status of the last negotiation
1279 * operation enqueued for the specified group identifier.
1281 * The status value can be one of the following values:
1283 * - FRSH_RS_IN_PROGRESS: the change of mode is in progress
1284 * - FRSH_RS_REJECTED: the change of mode was not accepted
1285 * - FRSH_RS_ADMITTED: the change of mode was accepted
1286 * - FRSH_RS_NOT_REQUESTED: no change of mode has been requested yet
1288 * When status returns 'FRSH_RS_ADMITTED', the array 'new_vres' contains
1289 * the values for the new virtual resources (if there was any).
1291 * This function frees the group identifier when status returns something
1292 * different than FRSH_RS_IN_PROGRESS so further calls to this function may
1293 * return inconsistent values.
1295 * @param[in] group The group identifier
1296 * @param[out] status The status of the change of mode
1297 * @param[out] new_vres List of vres for the negotiation of new contracts.
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_get_status(const frsh_group_id_t group,
1312 frsh_renegotiation_status_t *status,
1313 frsh_vres_group_t *new_vres);
1319 ////////////////////////////////////////////////////
1320 // OBTAINING INFORMATION FROM THE SCHEDULER
1321 ////////////////////////////////////////////////////
1324 * @defgroup getschedinfo Obtaining information from the scheduler
1328 * The following functions are used to obtain available budget and
1329 * resource usage in the system. They can be used to adapt the
1330 * execution of threads according to the load of the system.
1337 * frsh_config_is_admission_test_enabled()
1339 * Returns true if the system is
1340 * configured with the on-line admission test enabled, or false
1341 * otherwise. This situation can only be changed at compile time.
1343 bool frsh_config_is_admission_test_enabled();
1346 * frsh_vres_get_usage()
1348 * This function stores the current execution time spent by the
1349 * threads bound to the specified vres in the variable pointed to by
1352 * @return 0 if successful \n
1353 * FRSH_ERR_BAD_ARGUMENT : if the value of the vres argument is not in range or
1354 * cpu_time is NULL \n
1355 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1356 * scheduled under FRSH \n
1357 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1359 * FRSH_ERR_NOT_CONTRACTED_VRESR : if the vres of the calling thread
1360 * has been cancelled or it is not valid
1363 int frsh_vres_get_usage
1364 (const frsh_vres_id_t vres,
1365 frsh_rel_time_t *spent);
1369 * frsh_vres_get_job_usage()
1371 * Get the execution time of the current job of the specified virtual
1372 * resource for a bounded or synchronized workload.
1374 int frsh_vres_get_job_usage
1375 (const frsh_vres_id_t vres,
1376 frsh_rel_time_t *spent);
1380 * frsh_vres_get_remaining_budget()
1382 * This function stores in the variable pointed to by budget the
1383 * remaining execution-time budget associated with the specified
1386 * @return 0 if successful \n
1387 * FRSH_ERR_BAD_ARGUMENT : if the value of the vres argument is not in range or
1389 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1390 * scheduled under FRSH \n
1391 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1393 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1394 * has been cancelled or it is not valid
1397 int frsh_vres_get_remaining_budget
1398 (const frsh_vres_id_t vres,
1399 frsh_rel_time_t *budget);
1403 * frsh_vres_get_budget_and_period()
1405 * This function stores in the variables
1406 * pointed to by budget and period, the execution-time budget and the
1407 * period respectively associated with the specified vres. If any of
1408 * these pointers is NULL, the corresponding information is not stored.
1410 * @return 0 if successful \n
1411 * FRSH_ERR_BAD_ARGUMENT : if the value of the vres argument is not in range,
1412 * or budget and period are both NULL \n
1413 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1414 * scheduled under FRSH \n
1415 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1417 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1418 * has been cancelled or it is not valid
1421 int frsh_vres_get_budget_and_period
1422 (const frsh_vres_id_t vres,
1423 frsh_rel_time_t *budget,
1424 frsh_rel_time_t *period);
1428 /////////////////////////////////////////////////////////////////////
1429 // SERVICE THREAD TUNING
1430 /////////////////////////////////////////////////////////////////////
1432 * @defgroup servthtuning Service thread tuning
1436 * The following functions are used to obtain available budget and
1437 * resource usage in the system. They can be used to adapt the
1438 * execution of threads to the load of the system.
1444 * frsh_service_thread_set_data()
1446 * This function allows the application to change the period and
1447 * budget of the service thread that makes the
1448 * negotiations. Increasing the utilization of this thread makes the
1449 * negotiations faster, but introduces additional load in the system
1450 * that may decrease the bandwidth available for the vres. For this
1451 * call, the system will make a schedulability analysis to determine
1452 * if the new situation is acceptable or not. This is reported back in
1453 * the variable pointed to by accepted. If the new service thread data
1454 * is accepted, the system will reassign budgets and periods to the
1455 * vres according to the new bandwidth available, in the same way
1456 * as it does for a regular contract negotiation.
1458 * When its budget is exhausted, the service thread may run in the
1461 * The service thread starts with a default budget and period that are
1464 * Implementation dependency: in the fixed priority implementtaion of
1465 * frsh, the default priority is lower than the priority of any vres,
1466 * but higher than the background. According to the
1467 * implementation-dependent module the priority is adjustable by means
1468 * of a function that changes its preemption level
1470 * @return 0 if successful \n
1471 * FRSH_ERR_BAD_ARGUMENT : if any of the pointer arguments is NULL or
1472 * the budget value is greater than the period value \n
1473 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1474 * scheduled under FRSH \n
1475 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1477 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1478 * has been cancelled or it is not valid
1481 int frsh_service_thread_set_data (const frsh_rel_time_t *budget,
1482 const frsh_rel_time_t *period,
1486 * frsh_service_thread_get_data()
1488 * this function returns in the variables pointed by budget and
1489 * period, respectively, the current budget and period of the service
1492 * @return 0 if successful \n
1493 * FRSH_ERR_BAD_ARGUMENT : if any of the pointer arguments is NULL \n
1494 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1495 * scheduled under FRSH \n
1496 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1498 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1499 * has been cancelled or it is not valid
1502 int frsh_service_thread_get_data
1503 (frsh_rel_time_t *budget,
1504 frsh_rel_time_t *period);
1510 ////////////////////////////////////////////////////////////////////////
1511 // BACKGROUND MANAGEMENT
1512 ////////////////////////////////////////////////////////////////////////
1514 //A round-robin background scheduling policy is available for those
1515 //threads that do not have real-time requirements. Because some of
1516 //these threads may require sharing information with other threads run
1517 //by regular vres. Special background contracts may be created for
1518 //specifying the synchronization requirements.
1520 //The way of specifying a background contract is by setting
1521 //contract_type to FRSH_CT_BACKGROUND. Negotiation may fail if the contract uses
1522 //shared_objects. If the contract has no shared_objects the returned
1523 //vres id represents the background and may be used to bind more
1524 //than one thread. If the contract has shared objects a vres is
1525 //created to keep track of them, but the associated threads are
1526 //executed in the background, together with the other background
1532 #endif // _FRSH_CORE_H_