1 /**************************************************************************/
2 /* CAN latency tester */
3 /* Copyright (C) 2010 Michal Sojka, DCE FEE CTU Prague */
5 /**************************************************************************/
16 #include <semaphore.h>
24 #include <sys/ioctl.h>
26 #include <sys/socket.h>
29 #include <sys/types.h>
33 #include <linux/can.h>
34 #include <linux/can/raw.h>
36 #include "histogram.h"
39 #define dbg(level, fmt, arg...) do {} while (0)
41 #define dbg(level, fmt, arg...) do { if (level <= DEBUG) { printf("candping: " fmt, ## arg); } } while (0)
44 #define INTERRUPTED_SYSCALL(errno) (errno == EINTR || errno == ERESTART)
46 #define MEMSET_ZERO(obj) memset(&(obj), 0, sizeof(obj))
48 /* Global variables */
49 volatile sig_atomic_t finish_flag = 0; /* Threads should terminate. */
50 sem_t finish_sem; /* Thread signals a termination */
52 /* Command line options */
66 struct options opt = {
73 int num_interfaces = 0;
74 int count = 0; /* Number of sent messages */
75 int completion_pipe[2];
80 struct timespec ts_sent, ts_sent_kern;
81 struct timespec ts_rx_onwire, ts_rx_onwire_kern;
82 struct timespec ts_rx_final, ts_rx_final_kern;
83 struct can_frame sent, received;
86 #define MAX_INFOS 10000
87 struct msg_info msg_infos[MAX_INFOS];
89 struct histogram histogram;
91 void sprint_canframe(char *buf , struct can_frame *cf, int sep) {
92 /* documentation see lib.h */
95 int dlc = (cf->can_dlc > 8)? 8 : cf->can_dlc;
97 if (cf->can_id & CAN_ERR_FLAG) {
98 sprintf(buf, "%08X#", cf->can_id & (CAN_ERR_MASK|CAN_ERR_FLAG));
100 } else if (cf->can_id & CAN_EFF_FLAG) {
101 sprintf(buf, "%08X#", cf->can_id & CAN_EFF_MASK);
104 sprintf(buf, "%03X#", cf->can_id & CAN_SFF_MASK);
108 if (cf->can_id & CAN_RTR_FLAG) /* there are no ERR frames with RTR */
109 sprintf(buf+offset, "R");
111 for (i = 0; i < dlc; i++) {
112 sprintf(buf+offset, "%02X", cf->data[i]);
114 if (sep && (i+1 < dlc))
115 sprintf(buf+offset++, ".");
119 static inline struct msg_info *frame2info(struct can_frame *frame)
122 if (frame->can_dlc >= 2) {
123 memcpy(&idx, frame->data, sizeof(idx));
124 if (idx >= MAX_INFOS)
125 error(1, 0, "%s idx too high", __FUNCTION__);
128 error(1, 0, "%s error", __FUNCTION__);
130 return &msg_infos[idx];
133 static inline char *tstamp_str(const void *ctx, struct timespec *tstamp)
135 return talloc_asprintf(ctx, "%ld.%06ld",
136 tstamp->tv_sec, tstamp->tv_nsec/1000);
139 void msg_info_print(FILE *f, struct msg_info *mi)
141 struct timespec diff;
142 void *local = talloc_new (NULL);
144 char sent[64], received[64];
146 sprint_canframe(sent, &mi->sent, true);
147 sprint_canframe(received, &mi->received, true);
149 #define S(ts) tstamp_str(local, &ts)
150 #define DIFF(a, b) (timespec_subtract(&diff, &b, &a), S(diff))
152 if (num_interfaces == 2)
153 fprintf(f, "%ld: %s %s -> %s (%s) %s = %s (%s)\n",
154 num, S(mi->ts_sent), sent, S(mi->ts_rx_final_kern), S(mi->ts_rx_final), received,
155 DIFF(mi->ts_sent, mi->ts_rx_final_kern),
156 DIFF(mi->ts_sent, mi->ts_rx_final));
158 fprintf(f, "%ld: %s %s -> %s (%s) -> %s (%s) %s = %s (%s), %s (%s)\n",
159 num, S(mi->ts_sent), sent,
160 S(mi->ts_rx_onwire_kern), S(mi->ts_rx_onwire),
161 S(mi->ts_rx_final_kern), S(mi->ts_rx_final), received,
162 DIFF(mi->ts_sent, mi->ts_rx_onwire_kern),
163 DIFF(mi->ts_sent, mi->ts_rx_onwire),
164 DIFF(mi->ts_rx_onwire_kern, mi->ts_rx_final_kern),
165 DIFF(mi->ts_rx_onwire, mi->ts_rx_final));
172 int msg_info_store(FILE *f, struct msg_info *mi)
174 struct timespec diff;
175 void *local = talloc_new (NULL);
178 #define S(ts) tstamp_str(local, &ts)
179 #define DIFF(a, b) (timespec_subtract(&diff, &b, &a), S(diff))
181 if (num_interfaces == 2)
182 fprintf(f, "%ld %d %d %s\n",
183 num, mi->id, mi->length,
184 DIFF(mi->ts_sent, mi->ts_rx_final_kern));
186 fprintf(f, "%ld %d %d %s\n",
187 num, mi->id, mi->length,
188 DIFF(mi->ts_rx_onwire_kern, mi->ts_rx_final_kern));
195 /* Subtract the `struct timespec' values X and Y, storing the result in
196 RESULT. Return 1 if the difference is negative, otherwise 0. */
198 int timespec_subtract (struct timespec *result, struct timespec *x, struct timespec *yy)
200 struct timespec ylocal = *yy, *y = &ylocal;
201 /* Perform the carry for the later subtraction by updating Y. */
202 if (x->tv_nsec < y->tv_nsec) {
203 int nsec = (y->tv_nsec - x->tv_nsec) / 1000000000 + 1;
204 y->tv_nsec -= 1000000000 * nsec;
207 if (x->tv_nsec - y->tv_nsec > 1000000000) {
208 int nsec = (x->tv_nsec - y->tv_nsec) / 1000000000;
209 y->tv_nsec += 1000000000 * nsec;
213 /* Compute the time remaining to wait.
214 `tv_nsec' is certainly positive. */
215 result->tv_sec = x->tv_sec - y->tv_sec;
216 result->tv_nsec = x->tv_nsec - y->tv_nsec;
218 /* Return 1 if result is negative. */
219 return x->tv_sec < y->tv_sec;
222 void dbg_print_timespec(char *msg, struct timespec *tv)
225 printf("%s sec=%ld nsec=%ld\n", msg, tv->tv_sec, tv->tv_nsec);
228 static inline unsigned get_msg_latency_us(struct msg_info *mi)
230 struct timespec diff;
231 if (num_interfaces == 3)
233 timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_rx_onwire_kern);
235 timespec_subtract(&diff, &mi->ts_rx_final, &mi->ts_rx_onwire);
238 timespec_subtract(&diff, &mi->ts_rx_final, &mi->ts_sent);
240 timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_sent);
241 return diff.tv_sec * 1000000 + diff.tv_nsec/1000;
244 void set_sched_policy_and_prio(int policy, int rtprio)
246 struct sched_param scheduling_parameters;
247 int maxprio=sched_get_priority_max(policy);
248 int minprio=sched_get_priority_min(policy);
250 if((rtprio < minprio) || (rtprio > maxprio))
251 error(1, 0, "The priority for requested policy is out of <%d, %d> range\n",
254 scheduling_parameters.sched_priority = rtprio;
256 if (0 != pthread_setschedparam(pthread_self(), policy, &scheduling_parameters))
257 error(1, errno, "pthread_setschedparam error");
260 void term_handler(int signum)
265 static inline int sock_get_if_index(int s, const char *if_name)
270 strcpy(ifr.ifr_name, if_name);
271 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0)
272 error(1, errno, "SIOCGIFINDEX '%s'", if_name);
273 return ifr.ifr_ifindex;
276 static inline get_tstamp(struct timespec *ts)
278 clock_gettime(CLOCK_REALTIME, ts);
281 int send_frame(int socket)
283 struct can_frame frame;
286 static int curr_msg = -1;
292 while (msg_infos[i].id != -1 && i != curr_msg) {
298 error(1, 0, "Msg info table is full! Probably, many packets were lost.");
302 frame.can_id = opt.id;
304 error(1, 0, "Length < 2 is not yet supported");
305 frame.can_dlc = opt.length;
307 memcpy(frame.data, &idx, sizeof(idx));
308 mi = frame2info(&frame);
310 mi->id = frame.can_id;
311 mi->length = frame.can_dlc;
312 get_tstamp(&mi->ts_sent);
314 ret = write(socket, &frame, sizeof(frame));
318 void msg_info_free(struct msg_info *mi)
323 static inline void get_next_timeout(struct timespec *timeout)
326 static struct timespec last = {-1, 0 };
328 clock_gettime(CLOCK_MONOTONIC, &now);
330 if (last.tv_sec == -1)
332 if (opt.period_us != 0) {
333 last.tv_sec += opt.period_us/1000000;
334 last.tv_nsec += (opt.period_us%1000000)*1000;
335 while (last.tv_nsec >= 1000000000) {
336 last.tv_nsec -= 1000000000;
339 timespec_subtract(timeout, &last, &now);
340 } else if (opt.timeout_ms != 0) {
341 timeout->tv_sec = opt.timeout_ms/1000;
342 timeout->tv_nsec = (opt.timeout_ms%1000)*1000000;
344 error(1, 0, "Timeout and period cannot be both zero");
347 void receive(int s, struct can_frame *frame, struct timespec *ts_kern, struct timespec *ts_user)
349 char ctrlmsg[CMSG_SPACE(sizeof(struct timeval)) + CMSG_SPACE(sizeof(__u32))];
352 struct cmsghdr *cmsg;
353 struct sockaddr_can addr;
355 static uint64_t dropcnt = 0;
357 iov.iov_base = frame;
358 msg.msg_name = &addr;
361 msg.msg_control = &ctrlmsg;
363 /* these settings may be modified by recvmsg() */
364 iov.iov_len = sizeof(*frame);
365 msg.msg_namelen = sizeof(addr);
366 msg.msg_controllen = sizeof(ctrlmsg);
369 nbytes = recvmsg(s, &msg, 0);
371 error(1, errno, "recvmsg");
373 if (nbytes < sizeof(struct can_frame))
374 error(1, 0, "recvmsg: incomplete CAN frame\n");
377 MEMSET_ZERO(*ts_kern);
378 for (cmsg = CMSG_FIRSTHDR(&msg);
379 cmsg && (cmsg->cmsg_level == SOL_SOCKET);
380 cmsg = CMSG_NXTHDR(&msg,cmsg)) {
381 if (cmsg->cmsg_type == SO_TIMESTAMPNS)
382 *ts_kern = *(struct timespec *)CMSG_DATA(cmsg);
383 else if (cmsg->cmsg_type == SO_RXQ_OVFL)
384 dropcnt += *(__u32 *)CMSG_DATA(cmsg);
389 void process_tx(int s)
391 error(1, 0, "%s: not implemented", __FUNCTION__);
394 void process_on_wire_rx(int s)
396 struct timespec ts_kern, ts_user, ts_diff;
397 struct can_frame frame;
399 receive(s, &frame, &ts_kern, &ts_user);
400 mi = frame2info(&frame);
401 mi->ts_rx_onwire_kern = ts_kern;
402 mi->ts_rx_onwire = ts_user;
406 void process_final_rx(int s)
408 struct timespec ts_kern, ts_user, ts_diff;
409 struct can_frame frame;
413 receive(s, &frame, &ts_kern, &ts_user);
414 mi = frame2info(&frame);
415 mi->ts_rx_final_kern = ts_kern;
416 mi->ts_rx_final = ts_user;
417 mi->received = frame;
420 histogram_add(&histogram, get_msg_latency_us(mi));
422 ret = write(completion_pipe[1], &mi, sizeof(mi));
424 error(1, errno, "completion_pipe write");
427 void *measure_thread(void *arg)
430 struct pollfd pfd[3];
431 struct timespec timeout;
432 struct sockaddr_can addr;
434 unsigned msg_in_progress = 0;
438 for (i=0; i<num_interfaces; i++) {
439 if ((s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0)
440 error(1, errno, "socket");
442 addr.can_family = AF_CAN;
443 addr.can_ifindex = sock_get_if_index(s, opt.interface[i]);
445 if (i == 0) { /* TX socket */
446 /* disable default receive filter on this RAW socket */
447 /* This is obsolete as we do not read from the socket at all, but for */
448 /* this reason we can remove the receive list in the Kernel to save a */
449 /* little (really a very little!) CPU usage. */
450 if (setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0) == -1)
451 error(1, errno, "SOL_CAN_RAW");
454 if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0)
455 error(1, errno, "bind");
457 const int timestamp_on = 1;
458 if (setsockopt(s, SOL_SOCKET, SO_TIMESTAMPNS,
459 ×tamp_on, sizeof(timestamp_on)) < 0)
460 error(1, errno, "setsockopt SO_TIMESTAMP");
462 const int dropmonitor_on = 1;
463 if (setsockopt(s, SOL_SOCKET, SO_RXQ_OVFL,
464 &dropmonitor_on, sizeof(dropmonitor_on)) < 0)
465 error(1, errno, "setsockopt SO_RXQ_OVFL not supported by your Linux Kernel");
469 pfd[i].events = POLLIN | POLLERR | ((opt.period_us == 0 && !opt.oneattime) ? POLLOUT : 0);
471 pfd[i].events = POLLIN;
474 set_sched_policy_and_prio(SCHED_FIFO, 99);
478 ret = send_frame(pfd[0].fd); \
479 if (ret != sizeof(struct can_frame)) \
480 error(1, errno, "send_frame (line %d)", __LINE__); \
490 while (!finish_flag &&
491 (opt.count == 0 || count < opt.count || msg_in_progress != 0)) {
493 get_next_timeout(&timeout);
494 //printf("ppoll"); fflush(stdout);
495 ret = ppoll(pfd, num_interfaces, &timeout, NULL);
496 //printf("=%d\n", ret);
499 if (!INTERRUPTED_SYSCALL(errno))
500 error(1, errno, "ppoll");
504 if (opt.count == 0 || count < opt.count) {
508 error(1, 0, "poll timeout");
512 if (pfd[0].revents & (POLLIN|POLLERR)) {
513 process_tx(pfd[0].fd);
515 if (pfd[0].revents & POLLOUT) {
516 if (opt.count == 0 || count < opt.count)
521 if (num_interfaces == 3 && pfd[1].revents != 0) {
522 process_on_wire_rx(pfd[1].fd);
526 i = (num_interfaces == 2) ? 1 : 2;
527 if (pfd[i].revents != 0) {
528 process_final_rx(pfd[i].fd);
531 if ((opt.count == 0 || count < opt.count) &&
539 for (i=0; i<num_interfaces; i++)
545 struct poptOption optionsTable[] = {
546 { "device", 'd', POPT_ARG_ARGV, &opt.interface, 'd', "Interface to use. Must be given two times (tx, rx) or three times (tx, rx1, rx2)", "interface" },
547 { "count", 'c', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.count, 0, "The count of messages to send, zero corresponds to infinity", "num"},
548 { "id", 'i', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.id, 0, "CAN ID of sent messages", "id"},
549 { "period", 'p', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.period_us, 0, "Period for sending messages or zero (default) to send as fast as possible", "us"},
550 { "timeout",'t', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.timeout_ms,0, "Timeout when period is zero", "ms"},
551 { "oneattime",'o', POPT_ARG_NONE, &opt.oneattime,0, "Send the next message only when the previous was finally received"},
552 { "verbose",'v', POPT_ARG_NONE, NULL, 'v', "Send the next message only when the previous was finally received"},
553 { "file", 'f', POPT_ARG_STRING, NULL, 'f', "File where to store results", "filename"},
554 { "histogram", 'h', POPT_ARG_STRING, NULL, 'h', "Store histogram in file", "filename"},
555 { "length", 'l', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.length, 0, "The length of generated messages", "bytes"},
556 { "userhist", 'u', POPT_ARG_NONE, &opt.userhist, 0, "Generate histogram from userspace timestamps"},
558 { NULL, 0, 0, NULL, 0 }
561 int parse_options(int argc, const char *argv[])
564 poptContext optCon; /* context for parsing command-line options */
566 optCon = poptGetContext(NULL, argc, argv, optionsTable, 0);
567 //poptSetOtherOptionHelp(optCon, "[OPTIONS]* <port>");
569 /* Now do options processing */
570 while ((c = poptGetNextOpt(optCon)) >= 0) {
576 opt.file = fopen(poptGetOptArg(optCon), "w");
578 error(1, errno, "fopen: %s", poptGetOptArg(optCon));
581 opt.histogram = fopen(poptGetOptArg(optCon), "w");
583 error(1, errno, "fopen: %s", poptGetOptArg(optCon));
588 error(1, 0, "%s: %s\n",
589 poptBadOption(optCon, POPT_BADOPTION_NOALIAS),
592 if (num_interfaces < 2 || num_interfaces > 3)
593 error(1, 0, "-d option must be given exactly 2 or 3 times");
595 if (opt.oneattime && opt.period_us)
596 error(1, 0, "oneattime and period cannot be specified at the same time");
598 poptFreeContext(optCon);
604 int main(int argc, const char *argv[])
610 parse_options(argc, argv);
612 mlockall(MCL_CURRENT | MCL_FUTURE);
614 signal(SIGINT, term_handler);
615 signal(SIGTERM, term_handler);
617 for (i=0; i<MAX_INFOS; i++)
618 msg_infos[i].id = -1;
621 histogram_init(&histogram, 5000000, 1);
624 ret = pipe(completion_pipe);
626 error(1, errno, "pipe");
627 ret = fcntl(completion_pipe[1], F_SETFL, O_NONBLOCK);
629 error(1, errno, "pipe fcntl");
631 pthread_create(&thread, 0, measure_thread, NULL);
633 struct timespec next, now, diff;
634 clock_gettime(CLOCK_MONOTONIC, &next);
636 while (!finish_flag && (opt.count == 0 || completed < opt.count)) {
637 struct pollfd pfd[1];
638 pfd[0].fd = completion_pipe[0];
639 pfd[0].events = POLLIN;
640 ret = poll(pfd, 1, 100);
641 if (ret == -1 && !INTERRUPTED_SYSCALL(errno))
642 error(1, errno, "poll main");
643 if (ret > 0 && (pfd[0].revents & POLLIN)) {
646 ret = read(completion_pipe[0], &mi, sizeof(mi));
647 if (ret < sizeof(mi))
648 error(1, errno, "read completion returned %d", ret);
650 msg_info_print(opt.file, mi);
655 clock_gettime(CLOCK_MONOTONIC, &now);
656 if (timespec_subtract(&diff, &next, &now)) {
657 printf("\rMessage %d", count);
659 next.tv_nsec += 100000000;
660 while (next.tv_nsec >= 1000000000) {
661 next.tv_nsec -= 1000000000;
666 printf("\rMessage %d\n", count);
668 pthread_join(thread, NULL);
670 close(completion_pipe[0]);
671 close(completion_pipe[1]);
674 histogram_fprint(&histogram, opt.histogram);
675 fclose(opt.histogram);