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, for a synchronized workload.
677 * Virtual resource periods are numbered. The number of the current
678 * period can be obtained through the frsh_vres_get_period_number()
681 int frsh_vresperiod_wait
682 (const frsh_vres_id_t vres,
687 * frsh_vres_get_period()
689 * Return the current period number, for a virtual resource of
690 * synchronized workload.
692 int frsh_vres_get_period_number
693 (const frsh_vres_id_t vres,
701 ///////////////////////////////////////////////////////////////////
702 // CONTRACT NEGOCIATION OPERATIONS
703 ///////////////////////////////////////////////////////////////////
706 * @defgroup negotiate Negotiate contract functions
709 * The following functions are used to negotiate contracts and thus
710 * creating vres which are the execution image of a contract.
711 * Besides, these functions allow to assign and unassign threads to
714 * In the case of more than one thread per vres please refer to the
715 * hierarchical module.
723 * frsh_contract_negotiate()
725 * The operation negotiates a contract and if accepted it will return
726 * a vres_id. It will also check that the given contract_label is unique
729 * If the on-line admission test is enabled, it determines whether the
730 * contract can be admitted or not based on the current contracts
731 * established in the system. Then it creates the vres and
732 * recalculates all necessary parameters for the contracts already
733 * present in the system.
735 * This is a potentially blocking operation, it returns when the
736 * system has either rejected the contract, or admitted it and made it
737 * effective. No thread is bound to the newly created vres, which
738 * will be idle until a thread is bound to it via frsh_thread_bind()
739 * or frsh_thread_create_and_bind().
741 * This operation can only be executed by threads that are already
742 * bound to an active vres and therefore are being scheduled by the
745 * @return 0 if successful \n
746 * FRSH_ERR_CONTRACT_REJECTED: The contract is not accepted.\n
747 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
749 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
751 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not scheduled
752 * under FRSH scheduler \n
753 * FRSH_ERR_BAD_ARGUMENT : if the contract or vres arguments are NULL \n
754 * FRSH_ERR_TOO_MANY_VRES : if there is no space for more vres
755 * (the maximum number of them is already reached) \n
756 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS : contract_label is not unique.
759 int frsh_contract_negotiate
760 (const frsh_contract_t *contract,
761 frsh_vres_id_t *vres);
764 * frsh_thread_create_and_bind()
766 * This operation creates a thread and binds it to an existing vres.
768 * This is the preferred way to add threads to the application because
769 * we make sure that the thread won't become unbound.
771 * The vres must not have any thread binded to it. If you want to
772 * bind more than one thread to the vres you must use the
773 * hierarchical module.
775 * The frsh_thread_attr_t parameter is overwritten as necessary to
776 * introduce the adequate scheduling policy and priority, according
777 * to the preemption level given in the contract and the
778 * frsh_priority_map() function defined by the user.
780 * @param[in] vres_id vres with which the thread will be bound.
781 * @param[out] thread frsh_thread_id returned by the system.
782 * @param attr pthread_attr taken and maybe corrected
783 * by the system. Ignored if NULL
784 * @param[in] thread_code Thread function (void func(void *) )
785 * that will constitute the main of the
787 * @param[in] arg Argument for data to be passed at the
788 * thread. Set to NUL if you don't want
789 * to do anything like this.
791 * @return 0 if successful \n
792 * FRSH_ERR_BAD_ARGUMENT : if the contract or vres arguments are
794 * FRSH_ERR_CONTRACT_REJECTED : if the contract is rejected. \n
796 * It may also return all the errors that may be returned by the
797 * fosa_thread_create() function call
800 int frsh_thread_create_and_bind
801 (const frsh_vres_id_t vres,
802 frsh_thread_id_t *thread,
803 frsh_thread_attr_t *attr,
804 frsh_thread_code_t thread_code,
809 * frsh_thread_create_in_background()
811 * This function creates a "background contract" that does not need to
812 * be negotiated, creates a threads and binds to the new vres.
814 * This method is suggested as a way to initate components and
815 * plugins. The event that triggers the component activation should
816 * arrive to an application thread that could use this function to
817 * create a thread used in its initialisation.
819 * The attribute parameter is overwritten as necessary to introduce
820 * the adequate scheduling policy and priority.
822 * @param[in] thread_code Function to be executed by the new
824 * @param[in] thread_arg General pointer that will be passed to
825 * the new thread as initialisation data.
826 * @param attr Pthread attribute with thread params
827 * @param[in] contract_label Contract label for the new vres.
828 * @param[out] thread_id Id of the new thread.
829 * @param[out] vres_id vres_id of the new vres.
831 * @return 0 if successful \n
832 * FRSH_ERR_BAD_ARGUMENT : Any problems with the argument \n
833 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is
834 * not scheduled under FRSH \n
835 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS : contract_label is not unique \n
836 * FRSH_ERR_TOO_MANY_VRES : if there is no space for more vres
837 * (the maximum number of them is already reached)
840 int frsh_thread_create_in_background
841 (frsh_thread_code_t thread_code,
842 const void *thread_arg,
843 const char *contract_label,
844 frsh_thread_attr_t *attr,
845 frsh_thread_id_t *thread_id,
846 frsh_vres_id_t *vres_id);
849 int frsh_thread_join_in_background(frsh_resource_id_t resource_id,
850 frsh_resource_type_t resource_type,
852 frsh_vres_id_t *vres_id);
859 * This operation associates a thread with a vres, which means that
860 * it starts consuming the vres's budget and is executed according
861 * to the contract established for that vres. If the thread is
862 * already bound to another vres, it is effectively unbound from it
863 * and bound to the specified one.
865 * It fails if the vres's policy is different than FRSH_NONE, or if
866 * there is already a thread bound to this vres. In order to bind
867 * more than one vres to the same thread you must use the
868 * hierarchical module.
870 * Implementation dependent issue: In order to allow the usage of
871 * application defined schedulers, the given thread must not have the
872 * scheduling policy SCHED_APP and at the same time be attached to an
873 * application scheduler different than the frsh scheduler.
875 * @return 0 if successful \n
876 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
878 * FRSH_ERR_UNKNOWN_APPSCHEDULED_THREAD : if the thread is attached to
879 * an application defined scheduler different than the frsh
881 * FRSH_ERR_BAD_ARGUMENT : if the vres value does not complain with the
882 * expected format or valid range or the given thread does not
884 * FRSH_ERR_NOT_CONTRACTED_VRES : if the referenced vres is not
886 * FRSH_ERR_VRES_WORKLOAD_NOT_COMPATIBLE: if the kind of workload
887 * of the vres is FRSH_OVERHEAD \n
888 * FRSH_ERR_ALREADY_BOUND : if the given vres has a thread already
893 (const frsh_vres_id_t vres,
894 const frsh_thread_id_t thread);
898 * frsh_thread_unbind()
900 * This operation unbinds a thread from a vres. Since threads with
901 * no vres associated are not allowed to execute, they remain in a
902 * dormant state until they are either eliminated or bound again.
904 * If the thread is inside a critical section the effects of this call
905 * are deferred until the critical section is ended
907 * Implementation dependent issue: in the implementation with an
908 * application scheduler, the thread is still attached to the frsh
909 * scheduler, but suspended.
911 * @return 0 if successful \n
912 * FRSH_ERR_INTERNAL_ERROR : erroneous binding or malfunction of the FRSH
914 * FRSH_ERR_BAD_ARGUMENT : if the given thread does not exist \n
915 * FRSH_ERR_NOT_SCHEDULED_THREAD : if the given thread is not scheduled
917 * FRSH_ERR_UNKNOWN_APPSCHEDULED_THREAD : if the thread is attached to
918 * an application defined scheduler different than the frsh
920 * FRSH_ERR_NOT_BOUND : if the given thread does not have a valid
923 int frsh_thread_unbind(const frsh_thread_id_t thread);
926 * frsh_thread_get_vres_id()
928 * This operation stores the Id of the vres associated with the
929 * specified thread in the variable pointed to by vres. It returns
930 * an error if the thread does not exist, it is not under the control
931 * of the scheduling framework, or is not bound.
933 * @return 0 if no error \n
934 * FRSH_ERR_NOT_SCHEDULED_THREAD : if the given thread is not scheduled
936 * FRSH_ERR_NOT_BOUND : if the given thread does not have a valid
937 * vres bound to it \n
938 * FRSH_ERR_BAD_ARGUMENT : if the given thread does not exist or the
939 * vres argument is NULL
942 int frsh_thread_get_vres_id(const frsh_thread_id_t thread,
943 frsh_vres_id_t *vres_id);
946 * frsh_vres_get_priority()
948 * This operation stores the priority currently associated
949 * with the specified vres in the variable pointed to by
950 * priority. It returns an error if the vres_id is not recognised.
952 * @return 0 if no error \n
953 * FRSH_ERR_BAD_ARGUMENT : if the contract argument is NULL or the value
954 * of the vres argument is not in range \n
955 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
956 * scheduled under FRSH \n
957 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
959 * FRSH_ERR_NOT_CONTRACTED_VRES: if the vres of the calling thread
960 * has been cancelled or it is not valid
963 int frsh_vres_get_priority
964 (frsh_vres_id_t vres_id,
968 * frsh_vres_get_contract()
970 * This operation stores the contract parameters currently associated
971 * with the specified vres in the variable pointed to by
972 * contract. It returns an error if the vres_id is not recognised.
974 * @return 0 if no error \n
975 * FRSH_ERR_BAD_ARGUMENT : if the contract argument is NULL or the value
976 * of the vres argument is not in range \n
977 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
978 * scheduled under FRSH \n
979 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
981 * FRSH_ERR_NOT_CONTRACTED_VRES: if the vres of the calling thread
982 * has been cancelled or it is not valid
985 int frsh_vres_get_contract
986 (const frsh_vres_id_t vres,
987 frsh_contract_t *contract);
990 * frsh_resource_get_vres_from_label()
992 * This operation retrieves the vres_id whose contract_label
993 * corresponds to the parameter in the resource_id and resource_type
996 * The contract label must refer to a contract negotiated
997 * in the same processing node in which the call is being
998 * made. Otherwise an error is returned.
1000 * @return 0 if no error \n
1001 * FRSH_ERR_BAD_ARGUMENT : if the contract argument is NULL or the
1002 * contract_label is NULL \n
1003 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1004 * scheduled under FRSH \n
1005 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1007 * FRSH_ERR_CONTRACT_LABEL_UNKNOWN: if the contract_label is not known
1009 int frsh_resource_get_vres_from_label
1010 (const char *contract_label,
1011 const frsh_resource_type_t resource_type,
1012 const frsh_resource_id_t resource_id,
1013 frsh_vres_id_t *vres);
1018 * frsh_contract_cancel()
1020 * The operation eliminates the specified vres
1021 * and recalculates all necessary parameters for the contracts
1022 * remaining in the system. This is a potentially blocking operation;
1023 * it returns when the system has made the changes effective.
1025 * Note that the thread is not eliminated. We leave the application
1026 * the option to either freeze it for a later use or bind it to
1029 * @return 0 if successful \n
1030 * FRSH_ERR_BAD_ARGUMENT : if the value of vres is not in range \n
1031 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1032 * scheduled under FRSH \n
1033 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1035 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1036 * has been cancelled or it is not valid
1039 int frsh_contract_cancel (const frsh_vres_id_t vres);
1043 * frsh_contract_renegotiate_sync()
1045 * The operation renegotiates a contract for an existing vres. If
1046 * the on-line admission test is enabled it determines whether the
1047 * contract can be admitted or not based on the current contracts
1048 * established in the system. If it cannot be admitted, the old
1049 * contract remains in effect and an error is returned. If it can be
1050 * admitted, it recalculates all necessary parameters for the
1051 * contracts already present in the system and returns zero. This is a
1052 * potentially blocking operation; it returns when the system has
1053 * either rejected the new contract, or admitted it and made it
1056 * @return 0 if successful \n
1057 * FRSH_ERR_BAD_ARGUMENT : if the new_contract argument is NULL or the
1058 * value of the vres argument is not in range \n
1059 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1060 * scheduled under FRSH \n
1061 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1063 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1064 * has been cancelled or it is not valid \n
1065 * FRSH_ERR_REJECTED_CONTRACT : if the renegotiation fails
1068 int frsh_contract_renegotiate_sync
1069 (const frsh_contract_t *new_contract,
1070 const frsh_vres_id_t vres);
1074 * frsh_contract_renegotiate_async()
1076 * The operation enqueues a renegotiate operation for an existing
1077 * vres, and returns immediately. The renegotiate operation is
1078 * performed asynchronously, as soon as it is practical; meanwhile the
1079 * system operation will continue normally. When the renegotiation is
1080 * made, if the on-line admission test is enabled it determines
1081 * whether the contract can be admitted or not based on the current
1082 * contracts established in the system. If it cannot be admitted, the
1083 * old contract remains in effect. If it can be admitted, it
1084 * recalculates all necessary parameters for the contracts already
1085 * present in the system.
1087 * When the operation is completed, notification is made to the
1088 * caller, if requested, via a signal. The status of the operation (in
1089 * progress, admitted, rejected) can be checked with the
1090 * frsh_vres_get_renegotiation_status() operation. The argument
1091 * sig_notify can be FRSH_NULL_SIGNAL (no notification), or any FRSH
1092 * signal value and in this case signal_info is to be sent with the signal.
1094 * @param[in] new_contract New contract parameters for the new
1095 * situation if approved.
1096 * @param[in] vres vres_id on which to do the renegotiation.
1097 * @param[in] signal_to_notify Signal number to use to notify vres of
1098 * the negotiation result. If
1099 * FRSH_NULL_SIGNAL, no signal will be raised.
1100 * @param[in] signal_info: Associated info that will come with the
1101 * signal. This parameter will be ignored
1102 * if signal_to_notify == FRSH_NULL_SIGNAL.
1104 * @return 0 if no error \n
1105 * FRSH_ERR_BAD_ARGUMENT : if the new_contract argument is NULL, the
1106 * value of the vres argument is not in range or sig_notify is
1107 * neither NULL nor a valid POSIX signal \n
1108 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1109 * scheduled under FRSH \n
1110 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1112 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1113 * has been cancelled or it is not valid
1116 int frsh_contract_renegotiate_async
1117 (const frsh_contract_t *new_contract,
1118 const frsh_vres_id_t vres,
1119 const frsh_signal_t signal_to_notify,
1120 const frsh_signal_info_t signal_info);
1124 * frsh_vres_get_renegotiation_status()
1126 * The operation reports on the status of the last renegotiation
1127 * operation enqueued for the specified vres. It is callable even
1128 * after notification of the completion of such operation, if
1131 * If the vres is not and has not been involved in any of the
1132 * frsh_contract_renegotiate_async() or frsh_group_change_mode_async()
1133 * operations, the status returned is FRSH_RS_NOT_REQUESTED
1135 * @return 0 if no error \n
1136 * FRSH_ERR_BAD_ARGUMENT : if the renegotiation_status argument is
1137 * NULL or the value of the vres argument is not in range \n
1138 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1139 * scheduled under FRSH \n
1140 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1142 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1143 * has been cancelled or it is not valid
1146 int frsh_vres_get_renegotiation_status
1147 (const frsh_vres_id_t vres,
1148 frsh_renegotiation_status_t *renegotiation_status);
1152 ////////////////////////////////////////////////////////////////////////
1153 // CHANGE OF MODE: GROUPS OF CONTRACTS
1154 ////////////////////////////////////////////////////////////////////////
1156 * @defgroup groupofcontracts Group of contracts
1159 * The following functions are used to negotiate atomically more than
1160 * one contract. This allows to build complex applications by
1161 * splitting them in individual contracts that are negotiated
1162 * simultaneously and atomically.
1168 * frsh_group_change_mode_sync()
1170 * This function performs a set of negotiation operations which can
1171 * include: adding new contracts (neg), modifying existing vres (reneg)
1172 * or cancelling existing vres (cancel).
1174 * If one of the group operations has a NULL value, unless it causes an
1175 * inconsistency the system will suppose that no operation of that
1176 * type (neg, reneg or cancel) should be done.
1178 * The virtual resources resulting from negotiations of new contracts are
1179 * returned in the parameter 'new_vres' which must be provided by the user.
1181 * If the on-line admission test is enabled, FRSH analizes the
1182 * schedulability of the context that would result in the new
1183 * contract situation with removed, changed and added contracts.
1185 * A successful return code will mean that all contracts have been
1186 * accepted and all required operations (creation, cancellation or
1187 * update of vres) have been carried out to reach the new running
1190 * If any of the contracts is not accepted a corresponding error shall be
1191 * returned and no changes will be made to the previously running context.
1193 * This call is a synchronous, potentially blocking operation. It
1194 * returns when the system has rejected the contracts or accepted
1195 * and made them effective.
1197 * @param[in] contracts_to_neg List of new contracts to negotiate
1198 * @param[in] contracts_to_reneg List of contracts to renegotiate
1199 * @param[in] vres_to_reneg List of vres to renegotiate
1200 * @param[in] vres_to_cancel List of vres to cancel
1201 * @param[out] new_vres List of vres of new contracts.
1203 * @return 0 if no error \n
1204 * FRSH_ERR_BAD_ARGUMENT Invalid pointer or group identifier. \n
1205 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS contract_label not unique. \n
1206 * FRSH_ERR_NOT_CONTRACTED_VRES: One of the provided vres_ids
1207 * is not recognised. \n
1208 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD The calling thread
1209 * is not scheduled under FRSH. \n
1210 * FRSH_ERR_INVALID_SCHEDULER_REPLY: The scheduler is wrong or
1212 * FRSH_ERR_INTERNAL_ERROR: Erroneous binding or malfunction of
1213 * FRSH main scheduler. \n
1214 * FRSH_ERR_REJECTED_CONTRACT: The negotiation of one of the
1215 * proposed contracts has failed.
1217 int frsh_group_change_mode_sync
1218 (const frsh_contracts_group_t *contracts_to_neg,
1219 const frsh_contracts_group_t *contracts_to_reneg,
1220 const frsh_vres_group_t *vres_to_reneg,
1221 const frsh_vres_group_t *vres_to_cancel,
1222 frsh_vres_group_t *new_vres);
1225 * frsh_group_change_mode_async()
1227 * This is an asynchronous (non-blocking) version of the previous function,
1228 * frsh_group_change_mode_sync() and thus, it returns inmediately.
1230 * The status of the change of mode and the identifiers for new virtual
1231 * resources must be requested with the function 'frsh_group_get_status'
1232 * by using the return parameter 'group'.
1234 * As in the asynchronous renegotiations, when the operation is completed,
1235 * the user is notified with a signal so he can check the final result with
1236 * 'frsh_group_get_status'. In case that FRSH_NULL_SIGNAL is used, no
1237 * signal will be sent to the user.
1239 * @param[in] contracts_to_neg List of new contracts to negotiate
1240 * @param[in] contracts_to_reneg List of contracts to renegotiate
1241 * @param[in] vres_to_reneg List of vres to renegotiate
1242 * @param[in] vres_to_cancel List of vres to cancel
1243 * @param[in] signal Signal number to notify completion of
1244 * the change of mode. If FRSH_NULL_SIGNAL,
1245 * no signal will be raised.
1246 * @param[in] signal_info Data associated to the signal
1247 * @param[out] group The group identifier to get the status
1249 * @return 0 if no error \n
1250 * FRSH_ERR_BAD_ARGUMENT Invalid pointer, signal or group identifier. \n
1251 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS contract_label not unique. \n
1252 * FRSH_ERR_NOT_CONTRACTED_VRES: One of the provided vres_ids
1253 * is not recognised. \n
1254 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD The calling thread
1255 * is not scheduled under FRSH. \n
1256 * FRSH_ERR_INVALID_SCHEDULER_REPLY: The scheduler is wrong or
1258 * FRSH_ERR_INTERNAL_ERROR: Erroneous binding or malfunction of
1259 * FRSH main scheduler.
1261 int frsh_group_change_mode_async
1262 (const frsh_contracts_group_t *contracts_to_neg,
1263 const frsh_contracts_group_t *contracts_to_reneg,
1264 const frsh_vres_group_t *vres_to_reneg,
1265 const frsh_vres_group_t *vres_to_cancel,
1266 const frsh_signal_t signal,
1267 const frsh_signal_info_t signal_info,
1268 frsh_group_id_t *group);
1271 * frsh_group_get_status()
1273 * This function is similar to 'frsh_vres_get_renegotiation_status' but it
1274 * is intented for group negotiations (changes of mode).
1276 * The operation reports on the status of the last negotiation
1277 * operation enqueued for the specified group identifier.
1279 * The status value can be one of the following values:
1281 * - FRSH_RS_IN_PROGRESS: the change of mode is in progress
1282 * - FRSH_RS_REJECTED: the change of mode was not accepted
1283 * - FRSH_RS_ADMITTED: the change of mode was accepted
1284 * - FRSH_RS_NOT_REQUESTED: no change of mode has been requested yet
1286 * When status returns 'FRSH_RS_ADMITTED', the array 'new_vres' contains
1287 * the values for the new virtual resources (if there was any).
1289 * This function frees the group identifier when status returns something
1290 * different than FRSH_RS_IN_PROGRESS so further calls to this function may
1291 * return inconsistent values.
1293 * @param[in] group The group identifier
1294 * @param[out] status The status of the change of mode
1295 * @param[out] new_vres List of vres for the negotiation of new contracts.
1297 * @return 0 if no error \n
1298 * FRSH_ERR_BAD_ARGUMENT Invalid pointer, signal or group identifier. \n
1299 * FRSH_ERR_CONTRACT_LABEL_ALREADY_EXISTS contract_label not unique. \n
1300 * FRSH_ERR_NOT_CONTRACTED_VRES: One of the provided vres_ids
1301 * is not recognised. \n
1302 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD The calling thread
1303 * is not scheduled under FRSH. \n
1304 * FRSH_ERR_INVALID_SCHEDULER_REPLY: The scheduler is wrong or
1306 * FRSH_ERR_INTERNAL_ERROR: Erroneous binding or malfunction of
1307 * FRSH main scheduler.
1309 int frsh_group_get_status(const frsh_group_id_t group,
1310 frsh_renegotiation_status_t *status,
1311 frsh_vres_group_t *new_vres);
1317 ////////////////////////////////////////////////////
1318 // OBTAINING INFORMATION FROM THE SCHEDULER
1319 ////////////////////////////////////////////////////
1322 * @defgroup getschedinfo Obtaining information from the scheduler
1326 * The following functions are used to obtain available budget and
1327 * resource usage in the system. They can be used to adapt the
1328 * execution of threads according to the load of the system.
1335 * frsh_config_is_admission_test_enabled()
1337 * Returns true if the system is
1338 * configured with the on-line admission test enabled, or false
1339 * otherwise. This situation can only be changed at compile time.
1341 bool frsh_config_is_admission_test_enabled();
1344 * frsh_vres_get_usage()
1346 * This function stores the current execution time spent by the
1347 * threads bound to the specified vres in the variable pointed to by
1350 * @return 0 if successful \n
1351 * FRSH_ERR_BAD_ARGUMENT : if the value of the vres argument is not in range or
1352 * cpu_time is NULL \n
1353 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1354 * scheduled under FRSH \n
1355 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1357 * FRSH_ERR_NOT_CONTRACTED_VRESR : if the vres of the calling thread
1358 * has been cancelled or it is not valid
1361 int frsh_vres_get_usage
1362 (const frsh_vres_id_t vres,
1363 frsh_rel_time_t *spent);
1367 * frsh_vres_get_job_usage()
1369 * Get the execution time of the current job of the specified virtual
1370 * resource for a bounded or synchronized workload.
1372 int frsh_vres_get_job_usage
1373 (const frsh_vres_id_t vres,
1374 frsh_rel_time_t *spent);
1378 * frsh_vres_get_remaining_budget()
1380 * This function stores in the variable pointed to by budget the
1381 * remaining execution-time budget associated with the specified
1384 * @return 0 if successful \n
1385 * FRSH_ERR_BAD_ARGUMENT : if the value of the vres argument is not in range or
1387 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1388 * scheduled under FRSH \n
1389 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1391 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1392 * has been cancelled or it is not valid
1395 int frsh_vres_get_remaining_budget
1396 (const frsh_vres_id_t vres,
1397 frsh_rel_time_t *budget);
1401 * frsh_vres_get_budget_and_period()
1403 * This function stores in the variables
1404 * pointed to by budget and period, the execution-time budget and the
1405 * period respectively associated with the specified vres. If any of
1406 * these pointers is NULL, the corresponding information is not stored.
1408 * @return 0 if successful \n
1409 * FRSH_ERR_BAD_ARGUMENT : if the value of the vres argument is not in range,
1410 * or budget and period are both NULL \n
1411 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1412 * scheduled under FRSH \n
1413 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1415 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1416 * has been cancelled or it is not valid
1419 int frsh_vres_get_budget_and_period
1420 (const frsh_vres_id_t vres,
1421 frsh_rel_time_t *budget,
1422 frsh_rel_time_t *period);
1426 /////////////////////////////////////////////////////////////////////
1427 // SERVICE THREAD TUNING
1428 /////////////////////////////////////////////////////////////////////
1430 * @defgroup servthtuning Service thread tuning
1434 * The following functions are used to obtain available budget and
1435 * resource usage in the system. They can be used to adapt the
1436 * execution of threads to the load of the system.
1442 * frsh_service_thread_set_data()
1444 * This function allows the application to change the period and
1445 * budget of the service thread that makes the
1446 * negotiations. Increasing the utilization of this thread makes the
1447 * negotiations faster, but introduces additional load in the system
1448 * that may decrease the bandwidth available for the vres. For this
1449 * call, the system will make a schedulability analysis to determine
1450 * if the new situation is acceptable or not. This is reported back in
1451 * the variable pointed to by accepted. If the new service thread data
1452 * is accepted, the system will reassign budgets and periods to the
1453 * vres according to the new bandwidth available, in the same way
1454 * as it does for a regular contract negotiation.
1456 * When its budget is exhausted, the service thread may run in the
1459 * The service thread starts with a default budget and period that are
1462 * Implementation dependency: in the fixed priority implementtaion of
1463 * frsh, the default priority is lower than the priority of any vres,
1464 * but higher than the background. According to the
1465 * implementation-dependent module the priority is adjustable by means
1466 * of a function that changes its preemption level
1468 * @return 0 if successful \n
1469 * FRSH_ERR_BAD_ARGUMENT : if any of the pointer arguments is NULL or
1470 * the budget value is greater than the period value \n
1471 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1472 * scheduled under FRSH \n
1473 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1475 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1476 * has been cancelled or it is not valid
1479 int frsh_service_thread_set_data (const frsh_rel_time_t *budget,
1480 const frsh_rel_time_t *period,
1484 * frsh_service_thread_get_data()
1486 * this function returns in the variables pointed by budget and
1487 * period, respectively, the current budget and period of the service
1490 * @return 0 if successful \n
1491 * FRSH_ERR_BAD_ARGUMENT : if any of the pointer arguments is NULL \n
1492 * FRSH_ERR_NOT_SCHEDULED_CALLING_THREAD : if the calling thread is not
1493 * scheduled under FRSH \n
1494 * FRSH_ERR_INVALID_SCHEDULER_REPLY : the scheduler is wrong or not
1496 * FRSH_ERR_NOT_CONTRACTED_VRES : if the vres of the calling thread
1497 * has been cancelled or it is not valid
1500 int frsh_service_thread_get_data
1501 (frsh_rel_time_t *budget,
1502 frsh_rel_time_t *period);
1508 ////////////////////////////////////////////////////////////////////////
1509 // BACKGROUND MANAGEMENT
1510 ////////////////////////////////////////////////////////////////////////
1512 //A round-robin background scheduling policy is available for those
1513 //threads that do not have real-time requirements. Because some of
1514 //these threads may require sharing information with other threads run
1515 //by regular vres. Special background contracts may be created for
1516 //specifying the synchronization requirements.
1518 //The way of specifying a background contract is by setting
1519 //contract_type to FRSH_CT_BACKGROUND. Negotiation may fail if the contract uses
1520 //shared_objects. If the contract has no shared_objects the returned
1521 //vres id represents the background and may be used to bind more
1522 //than one thread. If the contract has shared objects a vres is
1523 //created to keep track of them, but the associated threads are
1524 //executed in the background, together with the other background
1530 #endif // _FRSH_CORE_H_