1 //----------------------------------------------------------------------
2 // Copyright (C) 2006 - 2007 by the FRESCOR consortium:
4 // Universidad de Cantabria, SPAIN
5 // University of York, UK
6 // Scuola Superiore Sant'Anna, ITALY
7 // Kaiserslautern University, GERMANY
8 // Univ. Politecnica 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
18 // The 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 // This file is part of FOSA (Frsh Operating System Abstraction)
33 // FOSA is free software; you can redistribute it and/or modify it
34 // under terms of the GNU General Public License as published by the
35 // Free Software Foundation; either version 2, or (at your option) any
36 // later version. FOSA is distributed in the hope that it will be
37 // useful, but WITHOUT ANY WARRANTY; without even the implied warranty
38 // of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
39 // General Public License for more details. You should have received a
40 // copy of the GNU General Public License along with FOSA; see file
41 // COPYING. If not, write to the Free Software Foundation, 675 Mass Ave,
42 // Cambridge, MA 02139, USA.
44 // As a special exception, including FOSA header files in a file,
45 // instantiating FOSA generics or templates, or linking other files
46 // with FOSA objects to produce an executable application, does not
47 // by itself cause the resulting executable application to be covered
48 // by the GNU General Public License. This exception does not
49 // however invalidate any other reasons why the executable file might be
50 // covered by the GNU Public License.
51 // -----------------------------------------------------------------------
52 //fosa_clocks_and_timers.c
53 //==============================================
54 // ******** ****** ******** **********
55 // **///// /** ** **////// /** /**
56 // ** /** ** /** /** /**
57 // ******* /** ** /********* /**********
58 // **//// /** ** ////////** /**//////**
59 // ** /** ** /** /** /**
60 // ** /** ** ******** /** /**
61 // // /******/ //////// // //
63 // FOSA(Frescor Operating System Adaptation layer)
64 //================================================
67 #include "fosa_clocks_and_timers.h"
72 static const struct timespec zero_time={0,0};
75 /*************************
77 *************************/
82 * Get the time from a clock
84 * This function sets the variable pointed to by current_time to the
85 * current value of the clock specified by clockid, which may be the
86 * FOSA_CLOCK_REALTIME constant or a value obtained with
87 * fosa_get_cputime_clock()
89 * Returns 0 if successful; otherwise it returns an error code:
90 * EINVAL: the value of clockid is invalid
92 * Alternatively, in case of error the implementation is allowed to
93 * notify it to the system console and then terminate the FRSH
94 * implementation and dependant applications
96 int fosa_clock_get_time(fosa_clock_id_t clockid, struct timespec *current_time)
98 return clock_gettime(clockid,current_time);
103 * fosa_get_cputime_clock()
105 * Get the identifier of a cpu-time clock
107 * This function stores in the variable pointed to by clockid the
108 * identifier of a cpu-time clock for the thread specified by tid.
110 * Returns 0 if successful; otherwise it returns an error code:
111 * EINVAL: the value of tid is invalid
113 * Alternatively, in case of error the implementation is allowed to
114 * notify it to the system console and then terminate the FRSH
115 * implementation and dependant applications
117 int fosa_thread_get_cputime_clock
118 (fosa_thread_id_t tid, fosa_clock_id_t *clockid)
120 return pthread_getcpuclockid(tid,clockid);
124 /*************************
126 *************************/
129 * fosa_create_timer()
131 * Create a one-shot timer
133 * This function creates a timer based on the clock specified by clock,
134 * and associates to this timer a notification mechanism consisting of
135 * a signal and associated information. Initially, the timer is in the
136 * disarmed state, i.e., not counting time. It can be armed to start
137 * counting time with fosa_timer_arm().
139 * The function stores the identifier of the newly created timer in the
140 * variable pointed to by timerid.
142 * When the timer expires, the signal number specified by signal will be
143 * sent together with the information specified by info, to the thread
144 * that armed the timer (@see fosa_timer_arm()).
146 * In those implementations that do not support queueing a
147 * signal with information to a thread (such as POSIX), the signal may
148 * be sent to any thread that is waiting for this signal via
149 * fosa_signal_wait(). Portability can be ensured by having the receiver
150 * thread be the one who is waiting for the signal.
152 * Returns 0 if successful; otherwise it returns an error code:
153 * EINVAL: the value of clockid or signal is invalid
155 * EAGAIN: the system lacks enough resources to create the timer
157 * Alternatively, in case of error the implementation is allowed to
158 * notify it to the system console and then terminate the FRSH
159 * implementation and dependant applications
161 int fosa_timer_create
162 (fosa_clock_id_t clockid, fosa_signal_t signal, fosa_signal_info_t info,
163 fosa_timer_id_t *timerid)
166 evp.sigev_notify=SIGEV_SIGNAL;
167 evp.sigev_signo=signal;
168 evp.sigev_value=* ((union sigval *) &info);
169 // the above casting construct is used to overcome the compiler
170 // restriction that does not allow casts between unions
171 return timer_create(clockid,&evp,timerid);
175 * fosa_timer_create_with_receiver()
177 * Create a one-shot timer with a specific signal receiver thread
179 * This function creates a timer in the same way as fosa_timer_create,
180 * except that the signal generated when the timer expires is sent to
181 * the thread specified by receiver
183 * Returns 0 if successful; otherwise it returns an error code:
184 * FOSA_EINVAL: the value of clockid or signal is invalid
186 * FOSA_EAGAIN: the system lacks enough resources to create the timer
188 * Alternatively, in case of error the implementation is allowed to
189 * notify it to the system console and then terminate the FRSH
190 * implementation and dependant applications
192 int fosa_timer_create_with_receiver
193 (fosa_clock_id_t clockid, fosa_signal_t signal, fosa_signal_info_t info,
194 fosa_timer_id_t *timerid, fosa_thread_id_t receiver)
196 // in POSIX the receiver thread cannot be specified
197 return fosa_timer_create(clockid,signal,info,timerid);
204 * The function deletes the timer specified by timerid, which becomes
205 * unusable. If the timer was armed, it is automatically disarmed before
208 * Returns 0 if successful; otherwise it returns an error code:
209 * EINVAL: the value of timerid is not valid
211 * Alternatively, in case of error the implementation is allowed to
212 * notify it to the system console and then terminate the FRSH
213 * implementation and dependant applications
215 int fosa_timer_delete(fosa_timer_id_t timerid)
217 return timer_delete(timerid);
225 * The timer specified by timer is armed and starts counting time.
227 * If abstime is true, the value pointed to by value is the absolute
228 * time at which the timer will expire. If value specifies a time instant
229 * in the past, the timer expires immediately.
231 * If abstime is false, the value pointed to by value is the relative interval
232 * that must elapse for the timer to expire.
234 * In both cases, absolute or relative, the time is measured with the clock
235 * associated with the timer when it was created.
237 * If the timer was already armed, the previous time or interval is discarded
238 * and the timer is rearmed with the new value.
240 * When the timer expires, it is disarmed.
242 * Returns 0 if successful; otherwise it returns an error code:
243 * EINVAL: the value of timerid or value is invalid
245 * Alternatively, in case of error the implementation is allowed to
246 * notify it to the system console and then terminate the FRSH
247 * implementation and dependant applications
250 (fosa_timer_id_t timerid, bool abstime,
251 const struct timespec *value)
254 struct itimerspec timer_value;
256 // set the abstime flag if necessary
258 timer_abstime=TIMER_ABSTIME;
261 // set the timer to the specified value, one shot only
262 timer_value.it_value=*value;
263 timer_value.it_interval=zero_time;
266 return timer_settime(timerid,timer_abstime,&timer_value,NULL);
270 * fosa_timer_get_remaining_time()
272 * Get the remaining time for timer expiration
274 * Returns the relative remaining time for timer expiration. If the
275 * clock is a CPU clock it returns the time as if the thread was
276 * executing constantly.
278 * If the timer is disarmed it returns 0.
280 * Returns 0 if successful; otherwise it returns an error code:
281 * EINVAL: the value of timerid or value is invalid
283 * Alternatively, in case of error the implementation is allowed to
284 * notify it to the system console and then terminate the FRSH
285 * implementation and dependant applications
287 int fosa_timer_get_remaining_time
288 (fosa_timer_id_t timerid, struct timespec *remaining_time)
290 struct itimerspec timer_value;
293 if (remaining_time!=NULL) {
294 error_code=timer_gettime(timerid,&timer_value);
295 if (error_code==-1) return errno;
296 *remaining_time=timer_value.it_value;
304 * fosa_timer_disarm()
308 * The timer specified by timer is disarmed, and will not expire unless
309 * it is rearmed. If the timer was already disramed, the function has
312 * If the pointer remaining_time is != NULL, the remaining time before
313 * expiration will be returned in that pointer. If the timer was
314 * disarmed a 0 value will be set.
316 * Returns 0 if successful; otherwise it returns an error code:
317 * EINVAL: the value of timerid or value is invalid
319 * Alternatively, in case of error the implementation is allowed to
320 * notify it to the system console and then terminate the FRSH
321 * implementation and dependant applications
323 int fosa_timer_disarm
324 (fosa_timer_id_t timerid,
325 struct timespec *remaining_time)
327 struct itimerspec timer_value;
330 if (remaining_time!=NULL) {
331 error_code=timer_gettime(timerid,&timer_value);
332 if (error_code==-1) return errno;
333 *remaining_time=timer_value.it_value;
335 timer_value.it_value=zero_time;
336 timer_value.it_interval=zero_time;
337 return timer_settime(timerid,0,&timer_value,NULL);