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"
41 #define dbg(level, fmt, arg...) do {} while (0)
43 #define dbg(level, fmt, arg...) do { if (level <= DEBUG) { printf("candping: " fmt, ## arg); } } while (0)
46 #define INTERRUPTED_SYSCALL(errno) (errno == EINTR || errno == ERESTART)
48 #define MEMSET_ZERO(obj) memset(&(obj), 0, sizeof(obj))
50 /* Global variables */
51 volatile sig_atomic_t finish_flag = 0; /* Threads should terminate. */
52 sem_t finish_sem; /* Thread signals a termination */
54 /* Command line options */
67 /* Temporary variables */
73 struct options opt = {
84 struct timespec tic, tac;
87 int num_interfaces = 0;
88 int count = 0; /* Number of sent messages */
89 unsigned msg_in_progress = 0;
90 int completion_pipe[2];
95 struct timespec ts_sent, ts_sent_kern;
96 struct timespec ts_rx_onwire, ts_rx_onwire_kern;
97 struct timespec ts_rx_final, ts_rx_final_kern;
98 struct can_frame sent, received;
101 #define MAX_INFOS 10000
102 struct msg_info msg_infos[MAX_INFOS];
104 struct histogram histogram;
106 void sprint_canframe(char *buf , struct can_frame *cf, int sep) {
107 /* documentation see lib.h */
110 int dlc = (cf->can_dlc > 8)? 8 : cf->can_dlc;
112 if (cf->can_id & CAN_ERR_FLAG) {
113 sprintf(buf, "%08X#", cf->can_id & (CAN_ERR_MASK|CAN_ERR_FLAG));
115 } else if (cf->can_id & CAN_EFF_FLAG) {
116 sprintf(buf, "%08X#", cf->can_id & CAN_EFF_MASK);
119 sprintf(buf, "%03X#", cf->can_id & CAN_SFF_MASK);
123 if (cf->can_id & CAN_RTR_FLAG) /* there are no ERR frames with RTR */
124 sprintf(buf+offset, "R");
126 for (i = 0; i < dlc; i++) {
127 sprintf(buf+offset, "%02X", cf->data[i]);
129 if (sep && (i+1 < dlc))
130 sprintf(buf+offset++, ".");
134 static inline struct msg_info *frame2info(struct can_frame *frame)
137 if (frame->can_dlc >= 2) {
138 memcpy(&idx, frame->data, sizeof(idx));
139 if (idx >= MAX_INFOS)
140 error(1, 0, "%s idx too high", __FUNCTION__);
143 error(1, 0, "%s error", __FUNCTION__);
145 return &msg_infos[idx];
148 static inline char *tstamp_str(const void *ctx, struct timespec *tstamp)
150 return talloc_asprintf(ctx, "%ld.%06ld",
151 tstamp->tv_sec, tstamp->tv_nsec/1000);
154 void msg_info_print(FILE *f, struct msg_info *mi)
156 struct timespec diff;
157 void *local = talloc_new (NULL);
159 char sent[64], received[64];
161 sprint_canframe(sent, &mi->sent, true);
162 sprint_canframe(received, &mi->received, true);
164 #define S(ts) tstamp_str(local, &ts)
165 #define DIFF(a, b) (timespec_subtract(&diff, &b, &a), S(diff))
167 switch (num_interfaces) {
169 fprintf(f, "%ld: %s %s -> %s (%s) %s = %s (%s)\n",
170 num, S(mi->ts_sent), sent, S(mi->ts_rx_final_kern), S(mi->ts_rx_final), received,
171 DIFF(mi->ts_sent, mi->ts_rx_final_kern),
172 DIFF(mi->ts_sent, mi->ts_rx_final));
175 fprintf(f, "%ld: %s %s -> %s (%s) -> %s (%s) %s = %s (%s), %s (%s)\n",
176 num, S(mi->ts_sent), sent,
177 S(mi->ts_rx_onwire_kern), S(mi->ts_rx_onwire),
178 S(mi->ts_rx_final_kern), S(mi->ts_rx_final), received,
179 DIFF(mi->ts_sent, mi->ts_rx_onwire_kern),
180 DIFF(mi->ts_sent, mi->ts_rx_onwire),
181 DIFF(mi->ts_rx_onwire_kern, mi->ts_rx_final_kern),
182 DIFF(mi->ts_rx_onwire, mi->ts_rx_final));
191 /* Subtract the `struct timespec' values X and Y, storing the result in
192 RESULT. Return 1 if the difference is negative, otherwise 0. */
194 int timespec_subtract (struct timespec *result, struct timespec *x, struct timespec *yy)
196 struct timespec ylocal = *yy, *y = &ylocal;
197 /* Perform the carry for the later subtraction by updating Y. */
198 if (x->tv_nsec < y->tv_nsec) {
199 int nsec = (y->tv_nsec - x->tv_nsec) / 1000000000 + 1;
200 y->tv_nsec -= 1000000000 * nsec;
203 if (x->tv_nsec - y->tv_nsec > 1000000000) {
204 int nsec = (x->tv_nsec - y->tv_nsec) / 1000000000;
205 y->tv_nsec += 1000000000 * nsec;
209 /* Compute the time remaining to wait.
210 `tv_nsec' is certainly positive. */
211 result->tv_sec = x->tv_sec - y->tv_sec;
212 result->tv_nsec = x->tv_nsec - y->tv_nsec;
214 /* Return 1 if result is negative. */
215 return x->tv_sec < y->tv_sec;
218 void dbg_print_timespec(char *msg, struct timespec *tv)
221 printf("%s sec=%ld nsec=%ld\n", msg, tv->tv_sec, tv->tv_nsec);
224 static inline unsigned get_msg_latency_us(struct msg_info *mi)
226 struct timespec diff;
227 switch (num_interfaces) {
230 timespec_subtract(&diff, &mi->ts_rx_final, &mi->ts_rx_onwire);
232 timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_rx_onwire_kern);
236 timespec_subtract(&diff, &mi->ts_rx_final, &mi->ts_sent);
238 timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_sent);
243 return diff.tv_sec * 1000000 + diff.tv_nsec/1000;
246 void set_sched_policy_and_prio(int policy, int rtprio)
248 struct sched_param scheduling_parameters;
249 int maxprio=sched_get_priority_max(policy);
250 int minprio=sched_get_priority_min(policy);
252 if((rtprio < minprio) || (rtprio > maxprio))
253 error(1, 0, "The priority for requested policy is out of <%d, %d> range\n",
256 scheduling_parameters.sched_priority = rtprio;
258 if (0 != pthread_setschedparam(pthread_self(), policy, &scheduling_parameters))
259 error(1, errno, "pthread_setschedparam error");
262 void term_handler(int signum)
267 static inline int sock_get_if_index(int s, const char *if_name)
272 strcpy(ifr.ifr_name, if_name);
273 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0)
274 error(1, errno, "SIOCGIFINDEX '%s'", if_name);
275 return ifr.ifr_ifindex;
278 static inline get_tstamp(struct timespec *ts)
280 clock_gettime(CLOCK_REALTIME, ts);
294 debugfs = "/sys/kernel/debug";
296 strcpy(path, debugfs);
297 strcat(path,"/tracing/tracing_on");
298 trace_fd = open(path, O_WRONLY);
300 write(trace_fd, "1", 1);
302 strcpy(path, debugfs);
303 strcat(path,"/tracing/trace_marker");
304 marker_fd = open(path, O_WRONLY);
306 strcpy(path, debugfs);
307 strcat(path,"/tracing/set_ftrace_pid");
308 f = fopen(path, "w");
309 fprintf(f, "%d\n", getpid());
311 system("echo function_graph > /sys/kernel/debug/tracing/current_tracer");
312 system("echo can_send > /sys/kernel/debug/tracing/set_graph_function");
313 system("echo > /sys/kernel/debug/tracing/trace");
314 system("echo 1 > /sys/kernel/debug/tracing/tracing_enabled");
319 static inline void trace_on()
322 write(trace_fd, "1", 1);
325 static inline void trace_off(int ret)
327 if (marker_fd >= 0) {
329 sprintf(marker, "write returned %d\n", ret);
330 write(marker_fd, marker, strlen(marker));
333 write(trace_fd, "0", 1);
336 void msg_info_free(struct msg_info *mi)
341 int send_frame(int socket)
343 struct can_frame frame;
346 static int curr_msg = -1;
352 while (msg_infos[i].id != -1 && i != curr_msg) {
358 error(1, 0, "Msg info table is full! Probably, many packets were lost.");
362 frame.can_id = opt.id;
364 error(1, 0, "Length < 2 is not yet supported");
365 frame.can_dlc = opt.length;
367 memcpy(frame.data, &idx, sizeof(idx));
368 mi = frame2info(&frame);
370 mi->id = frame.can_id;
371 mi->length = frame.can_dlc;
372 get_tstamp(&mi->ts_sent);
376 ret = write(socket, &frame, sizeof(frame));
379 if (ret == -1 || num_interfaces == 1)
384 static inline send_and_check(int s)
388 if (ret != sizeof(struct can_frame)) {
389 /* if (ret == -1 && errno == ENOBUFS && opt.period_us == 0 && !opt.oneattime) { */
390 /* stats.enobufs++; */
391 /* /\* Ignore this error - pfifo_fast qeuue is full *\/ */
393 error(1, errno, "send_frame (line %d)", __LINE__);
400 static inline void get_next_timeout(struct timespec *timeout)
403 static struct timespec last = {-1, 0 };
405 clock_gettime(CLOCK_MONOTONIC, &now);
407 if (last.tv_sec == -1)
409 if (opt.period_us != 0) {
410 last.tv_sec += opt.period_us/1000000;
411 last.tv_nsec += (opt.period_us%1000000)*1000;
412 while (last.tv_nsec >= 1000000000) {
413 last.tv_nsec -= 1000000000;
416 if (timespec_subtract(timeout, &last, &now) /* is negative */) {
418 memset(timeout, 0, sizeof(*timeout));
420 } else if (opt.timeout_ms != 0) {
421 timeout->tv_sec = opt.timeout_ms/1000;
422 timeout->tv_nsec = (opt.timeout_ms%1000)*1000000;
424 error(1, 0, "Timeout and period cannot be both zero");
427 void receive(int s, struct can_frame *frame, struct timespec *ts_kern, struct timespec *ts_user)
429 char ctrlmsg[CMSG_SPACE(sizeof(struct timeval)) + CMSG_SPACE(sizeof(__u32))];
432 struct cmsghdr *cmsg;
433 struct sockaddr_can addr;
435 static uint64_t dropcnt = 0;
437 iov.iov_base = frame;
438 msg.msg_name = &addr;
441 msg.msg_control = &ctrlmsg;
443 /* these settings may be modified by recvmsg() */
444 iov.iov_len = sizeof(*frame);
445 msg.msg_namelen = sizeof(addr);
446 msg.msg_controllen = sizeof(ctrlmsg);
449 nbytes = recvmsg(s, &msg, 0);
451 error(1, errno, "recvmsg");
453 if (nbytes < sizeof(struct can_frame))
454 error(1, 0, "recvmsg: incomplete CAN frame\n");
457 MEMSET_ZERO(*ts_kern);
458 for (cmsg = CMSG_FIRSTHDR(&msg);
459 cmsg && (cmsg->cmsg_level == SOL_SOCKET);
460 cmsg = CMSG_NXTHDR(&msg,cmsg)) {
461 if (cmsg->cmsg_type == SO_TIMESTAMPNS)
462 *ts_kern = *(struct timespec *)CMSG_DATA(cmsg);
463 else if (cmsg->cmsg_type == SO_RXQ_OVFL)
464 dropcnt += *(__u32 *)CMSG_DATA(cmsg);
469 void process_tx(int s)
471 error(1, 0, "%s: not implemented", __FUNCTION__);
474 void process_on_wire_rx(int s)
476 struct timespec ts_kern, ts_user, ts_diff;
477 struct can_frame frame;
479 receive(s, &frame, &ts_kern, &ts_user);
480 mi = frame2info(&frame);
481 mi->ts_rx_onwire_kern = ts_kern;
482 mi->ts_rx_onwire = ts_user;
486 void process_final_rx(int s)
488 struct timespec ts_kern, ts_user, ts_diff;
489 struct can_frame frame;
493 receive(s, &frame, &ts_kern, &ts_user);
494 mi = frame2info(&frame);
495 mi->ts_rx_final_kern = ts_kern;
496 mi->ts_rx_final = ts_user;
497 mi->received = frame;
499 histogram_add(&histogram, get_msg_latency_us(mi));
501 ret = write(completion_pipe[1], &mi, sizeof(mi));
503 error(1, errno, "completion_pipe write");
506 void *measure_thread(void *arg)
509 struct pollfd pfd[3];
510 struct timespec timeout;
511 struct sockaddr_can addr;
516 for (i=0; i<num_interfaces; i++) {
517 if ((s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0)
518 error(1, errno, "socket");
520 addr.can_family = AF_CAN;
521 addr.can_ifindex = sock_get_if_index(s, opt.interface[i]);
523 if (i == 0) { /* TX socket */
524 /* disable default receive filter on this RAW socket */
525 /* This is obsolete as we do not read from the socket at all, but for */
526 /* this reason we can remove the receive list in the Kernel to save a */
527 /* little (really a very little!) CPU usage. */
528 if (setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0) == -1)
529 error(1, errno, "SOL_CAN_RAW");
532 if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0)
533 error(1, errno, "bind");
535 const int timestamp_on = 1;
536 if (setsockopt(s, SOL_SOCKET, SO_TIMESTAMPNS,
537 ×tamp_on, sizeof(timestamp_on)) < 0)
538 error(1, errno, "setsockopt SO_TIMESTAMP");
540 const int dropmonitor_on = 1;
541 if (setsockopt(s, SOL_SOCKET, SO_RXQ_OVFL,
542 &dropmonitor_on, sizeof(dropmonitor_on)) < 0)
543 error(1, errno, "setsockopt SO_RXQ_OVFL not supported by your Linux Kernel");
547 pfd[i].events = POLLIN | POLLERR | ((opt.period_us == 0 && !opt.oneattime) ? POLLOUT : 0);
549 pfd[i].events = POLLIN;
552 set_sched_policy_and_prio(SCHED_FIFO, 40);
554 #define SEND() send_and_check(pfd[0].fd)
559 get_tstamp(&stats.tic);
561 while (!finish_flag &&
562 (opt.count == 0 || count < opt.count || msg_in_progress != 0)) {
564 get_next_timeout(&timeout);
565 //printf("ppoll"); fflush(stdout);
566 ret = ppoll(pfd, num_interfaces, &timeout, NULL);
567 //printf("=%d\n", ret);
570 if (!INTERRUPTED_SYSCALL(errno))
571 error(1, errno, "ppoll");
575 if (opt.count == 0 || count < opt.count) {
579 error(1, 0, "poll timeout");
583 if (pfd[0].revents & (POLLIN|POLLERR)) {
584 process_tx(pfd[0].fd);
586 if (pfd[0].revents & POLLOUT) {
587 if (opt.count == 0 || count < opt.count)
592 if (num_interfaces == 3 && pfd[1].revents != 0) {
593 process_on_wire_rx(pfd[1].fd);
597 i = (num_interfaces == 2) ? 1 : 2;
598 if (pfd[i].revents != 0) {
599 process_final_rx(pfd[i].fd);
602 if ((opt.count == 0 || count < opt.count) &&
610 get_tstamp(&stats.tac);
612 for (i=0; i<num_interfaces; i++)
618 struct poptOption optionsTable[] = {
619 { "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" },
620 { "count", 'c', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.count, 0, "The count of messages to send, zero corresponds to infinity", "num"},
621 { "id", 'i', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.id, 0, "CAN ID of sent messages", "id"},
622 { "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"},
623 { "timeout",'t', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.timeout_ms,0, "Timeout when period is zero", "ms"},
624 { "oneattime",'o', POPT_ARG_NONE, &opt.oneattime,0, "Send the next message only when the previous was finally received"},
625 { "verbose",'v', POPT_ARG_NONE, NULL, 'v', "Send the next message only when the previous was finally received"},
626 { "name", 'n', POPT_ARG_STRING, &opt.name, 0, "Prefix of the generated files"},
627 { "length", 'l', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.length, 0, "The length of generated messages", "bytes"},
628 { "userhist", 'u', POPT_ARG_NONE, &opt.userhist, 0, "Generate histogram from userspace timestamps"},
629 { "quiet", 'q', POPT_ARG_NONE, &opt.quiet, 0, "Do not print progress and statistics"},
631 { NULL, 0, 0, NULL, 0 }
634 int parse_options(int argc, const char *argv[])
637 poptContext optCon; /* context for parsing command-line options */
638 void *local = talloc_new (NULL);
640 optCon = poptGetContext(NULL, argc, argv, optionsTable, 0);
641 //poptSetOtherOptionHelp(optCon, "[OPTIONS]* <port>");
643 /* Now do options processing */
644 while ((c = poptGetNextOpt(optCon)) >= 0) {
652 error(1, 0, "%s: %s\n",
653 poptBadOption(optCon, POPT_BADOPTION_NOALIAS),
656 if (num_interfaces < 1 || num_interfaces > 3)
657 error(1, 0, "-d option must only be given one, two or three times");
659 if (opt.oneattime && opt.period_us)
660 error(1, 0, "oneattime and period cannot be specified at the same time");
663 char *f = talloc_asprintf(local, "%s-msgs.txt", opt.name);
664 opt.f_msgs = fopen(f, "w");
666 error(1, errno, "fopen: %s", f);
670 char *f = talloc_asprintf(local, "%s-hist.txt", opt.name);
671 opt.f_hist = fopen(f, "w");
673 error(1, errno, "fopen: %s", f);
677 char *f = talloc_asprintf(local, "%s-stat.txt", opt.name);
678 opt.f_stat = fopen(f, "w");
680 error(1, errno, "fopen: %s", f);
683 poptFreeContext(optCon);
688 void print_progress()
691 if (num_interfaces > 1)
692 printf("\rSent %5d, in progress %5d", count, msg_in_progress);
694 printf("\rSent %5d", count);
699 int main(int argc, const char *argv[])
705 parse_options(argc, argv);
707 mlockall(MCL_CURRENT | MCL_FUTURE);
709 signal(SIGINT, term_handler);
710 signal(SIGTERM, term_handler);
712 for (i=0; i<MAX_INFOS; i++)
713 msg_infos[i].id = -1;
715 histogram_init(&histogram, 5000000, 1);
717 ret = pipe(completion_pipe);
719 error(1, errno, "pipe");
720 ret = fcntl(completion_pipe[1], F_SETFL, O_NONBLOCK);
722 error(1, errno, "pipe fcntl");
726 pthread_create(&thread, 0, measure_thread, NULL);
728 struct timespec next, now, diff, allsent = {0,0};
729 clock_gettime(CLOCK_MONOTONIC, &next);
731 while (!finish_flag && (opt.count == 0 || completed < opt.count)) {
732 struct pollfd pfd[1];
733 pfd[0].fd = completion_pipe[0];
734 pfd[0].events = POLLIN;
735 ret = poll(pfd, 1, 100);
736 if (ret == -1 && !INTERRUPTED_SYSCALL(errno))
737 error(1, errno, "poll main");
738 if (ret > 0 && (pfd[0].revents & POLLIN)) {
741 ret = read(completion_pipe[0], &mi, sizeof(mi));
742 if (ret < sizeof(mi))
743 error(1, errno, "read completion returned %d", ret);
744 msg_info_print(opt.f_msgs, mi);
749 clock_gettime(CLOCK_MONOTONIC, &now);
750 if (timespec_subtract(&diff, &next, &now)) {
752 next.tv_nsec += 100000000;
753 while (next.tv_nsec >= 1000000000) {
754 next.tv_nsec -= 1000000000;
758 if (opt.count != 0 && count >= opt.count) {
759 if (allsent.tv_sec == 0)
761 timespec_subtract(&diff, &now, &allsent);
762 if (diff.tv_sec >= 1)
770 stats.lost = msg_in_progress;
772 pthread_join(thread, NULL);
774 close(completion_pipe[0]);
775 close(completion_pipe[1]);
777 histogram_fprint(&histogram, opt.f_hist);
782 fprintf(opt.f_stat, "cmdline='");
783 for (i=0; i<argc; i++)
784 fprintf(opt.f_stat, "%s%s", argv[i], i < argc-1 ? " " : "");
785 fprintf(opt.f_stat, "'\n");
787 timespec_subtract(&diff, &stats.tac, &stats.tic);
788 fprintf(opt.f_stat, "duration=%s # seconds\n", tstamp_str(NULL, &diff));
790 fprintf(opt.f_stat, "sent=%d\n", count);
791 fprintf(opt.f_stat, "overrun=%d\n", stats.overrun);
792 if (stats.overrun && !opt.quiet)
793 printf("overrun=%d\n", stats.overrun);
794 fprintf(opt.f_stat, "enobufs=%d\n", stats.enobufs);
795 if (stats.enobufs && !opt.quiet)
796 printf("enobufs=%d\n", stats.enobufs);
797 fprintf(opt.f_stat, "lost=%d\n", stats.lost);
798 if (stats.lost && !opt.quiet)
799 printf("lost=%d\n", stats.lost);