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;
88 int num_interfaces = 0;
89 int count = 0; /* Number of sent messages */
90 unsigned msg_in_progress = 0;
91 int completion_pipe[2];
96 struct timespec ts_sent, ts_sent_kern;
97 struct timespec ts_rx_onwire, ts_rx_onwire_kern;
98 struct timespec ts_rx_final, ts_rx_final_kern;
99 struct can_frame sent, received;
102 #define MAX_INFOS 10000
103 struct msg_info msg_infos[MAX_INFOS];
105 struct histogram histogram;
107 void sprint_canframe(char *buf , struct can_frame *cf, int sep) {
108 /* documentation see lib.h */
111 int dlc = (cf->can_dlc > 8)? 8 : cf->can_dlc;
113 if (cf->can_id & CAN_ERR_FLAG) {
114 sprintf(buf, "%08X#", cf->can_id & (CAN_ERR_MASK|CAN_ERR_FLAG));
116 } else if (cf->can_id & CAN_EFF_FLAG) {
117 sprintf(buf, "%08X#", cf->can_id & CAN_EFF_MASK);
120 sprintf(buf, "%03X#", cf->can_id & CAN_SFF_MASK);
124 if (cf->can_id & CAN_RTR_FLAG) /* there are no ERR frames with RTR */
125 sprintf(buf+offset, "R");
127 for (i = 0; i < dlc; i++) {
128 sprintf(buf+offset, "%02X", cf->data[i]);
130 if (sep && (i+1 < dlc))
131 sprintf(buf+offset++, ".");
135 static inline struct msg_info *frame2info(struct can_frame *frame)
138 if (frame->can_dlc >= 2) {
139 memcpy(&idx, frame->data, sizeof(idx));
140 if (idx >= MAX_INFOS)
141 error(1, 0, "%s idx too high", __FUNCTION__);
144 error(1, 0, "%s error", __FUNCTION__);
146 return &msg_infos[idx];
149 static inline char *tstamp_str(const void *ctx, struct timespec *tstamp)
151 return talloc_asprintf(ctx, "%ld.%06ld",
152 tstamp->tv_sec, tstamp->tv_nsec/1000);
155 void msg_info_print(FILE *f, struct msg_info *mi)
157 struct timespec diff;
158 void *local = talloc_new (NULL);
160 char sent[64], received[64];
162 sprint_canframe(sent, &mi->sent, true);
163 sprint_canframe(received, &mi->received, true);
165 #define S(ts) tstamp_str(local, &ts)
166 #define DIFF(a, b) (timespec_subtract(&diff, &b, &a), S(diff))
168 switch (num_interfaces) {
170 fprintf(f, "%ld: %s %s -> %s (%s) %s = %s (%s)\n",
171 num, S(mi->ts_sent), sent, S(mi->ts_rx_final_kern), S(mi->ts_rx_final), received,
172 DIFF(mi->ts_sent, mi->ts_rx_final_kern),
173 DIFF(mi->ts_sent, mi->ts_rx_final));
176 fprintf(f, "%ld: %s %s -> %s (%s) -> %s (%s) %s = %s (%s), %s (%s)\n",
177 num, S(mi->ts_sent), sent,
178 S(mi->ts_rx_onwire_kern), S(mi->ts_rx_onwire),
179 S(mi->ts_rx_final_kern), S(mi->ts_rx_final), received,
180 DIFF(mi->ts_sent, mi->ts_rx_onwire_kern),
181 DIFF(mi->ts_sent, mi->ts_rx_onwire),
182 DIFF(mi->ts_rx_onwire_kern, mi->ts_rx_final_kern),
183 DIFF(mi->ts_rx_onwire, mi->ts_rx_final));
192 /* Subtract the `struct timespec' values X and Y, storing the result in
193 RESULT. Return 1 if the difference is negative, otherwise 0. */
195 int timespec_subtract (struct timespec *result, struct timespec *x, struct timespec *yy)
197 struct timespec ylocal = *yy, *y = &ylocal;
198 /* Perform the carry for the later subtraction by updating Y. */
199 if (x->tv_nsec < y->tv_nsec) {
200 int nsec = (y->tv_nsec - x->tv_nsec) / 1000000000 + 1;
201 y->tv_nsec -= 1000000000 * nsec;
204 if (x->tv_nsec - y->tv_nsec > 1000000000) {
205 int nsec = (x->tv_nsec - y->tv_nsec) / 1000000000;
206 y->tv_nsec += 1000000000 * nsec;
210 /* Compute the time remaining to wait.
211 `tv_nsec' is certainly positive. */
212 result->tv_sec = x->tv_sec - y->tv_sec;
213 result->tv_nsec = x->tv_nsec - y->tv_nsec;
215 /* Return 1 if result is negative. */
216 return x->tv_sec < y->tv_sec;
219 void dbg_print_timespec(char *msg, struct timespec *tv)
222 printf("%s sec=%ld nsec=%ld\n", msg, tv->tv_sec, tv->tv_nsec);
225 static inline unsigned get_msg_latency_us(struct msg_info *mi)
227 struct timespec diff;
228 switch (num_interfaces) {
231 timespec_subtract(&diff, &mi->ts_rx_final, &mi->ts_rx_onwire);
233 timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_rx_onwire_kern);
237 timespec_subtract(&diff, &mi->ts_rx_final, &mi->ts_sent);
239 timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_sent);
244 return diff.tv_sec * 1000000 + diff.tv_nsec/1000;
247 void set_sched_policy_and_prio(int policy, int rtprio)
249 struct sched_param scheduling_parameters;
250 int maxprio=sched_get_priority_max(policy);
251 int minprio=sched_get_priority_min(policy);
253 if((rtprio < minprio) || (rtprio > maxprio))
254 error(1, 0, "The priority for requested policy is out of <%d, %d> range\n",
257 scheduling_parameters.sched_priority = rtprio;
259 if (0 != pthread_setschedparam(pthread_self(), policy, &scheduling_parameters))
260 error(1, errno, "pthread_setschedparam error");
263 void term_handler(int signum)
268 static inline int sock_get_if_index(int s, const char *if_name)
273 strcpy(ifr.ifr_name, if_name);
274 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0)
275 error(1, errno, "SIOCGIFINDEX '%s'", if_name);
276 return ifr.ifr_ifindex;
279 static inline get_tstamp(struct timespec *ts)
281 clock_gettime(CLOCK_REALTIME, ts);
295 debugfs = "/sys/kernel/debug";
297 strcpy(path, debugfs);
298 strcat(path,"/tracing/tracing_on");
299 trace_fd = open(path, O_WRONLY);
301 write(trace_fd, "1", 1);
303 strcpy(path, debugfs);
304 strcat(path,"/tracing/trace_marker");
305 marker_fd = open(path, O_WRONLY);
307 strcpy(path, debugfs);
308 strcat(path,"/tracing/set_ftrace_pid");
309 f = fopen(path, "w");
310 fprintf(f, "%d\n", getpid());
312 system("echo function_graph > /sys/kernel/debug/tracing/current_tracer");
313 system("echo can_send > /sys/kernel/debug/tracing/set_graph_function");
314 system("echo > /sys/kernel/debug/tracing/trace");
315 system("echo 1 > /sys/kernel/debug/tracing/tracing_enabled");
320 static inline void trace_on()
323 write(trace_fd, "1", 1);
326 static inline void trace_off(int ret)
328 if (marker_fd >= 0) {
330 sprintf(marker, "write returned %d\n", ret);
331 write(marker_fd, marker, strlen(marker));
334 write(trace_fd, "0", 1);
337 void msg_info_free(struct msg_info *mi)
342 int send_frame(int socket)
344 struct can_frame frame;
347 static int curr_msg = -1;
353 while (msg_infos[i].id != -1 && i != curr_msg) {
359 error(1, 0, "Msg info table is full! Probably, many packets were lost.");
363 frame.can_id = opt.id;
365 error(1, 0, "Length < 2 is not yet supported");
366 frame.can_dlc = opt.length;
368 memcpy(frame.data, &idx, sizeof(idx));
369 mi = frame2info(&frame);
371 mi->id = frame.can_id;
372 mi->length = frame.can_dlc;
373 get_tstamp(&mi->ts_sent);
377 ret = write(socket, &frame, sizeof(frame));
380 if (ret == -1 || num_interfaces == 1)
385 static inline send_and_check(int s)
389 if (ret != sizeof(struct can_frame)) {
390 /* if (ret == -1 && errno == ENOBUFS && opt.period_us == 0 && !opt.oneattime) { */
391 /* stats.enobufs++; */
392 /* /\* Ignore this error - pfifo_fast qeuue is full *\/ */
394 error(1, errno, "send_frame (line %d)", __LINE__);
401 static inline void get_next_timeout(struct timespec *timeout)
404 static struct timespec last = {-1, 0 };
406 clock_gettime(CLOCK_MONOTONIC, &now);
408 if (last.tv_sec == -1)
410 if (opt.period_us != 0) {
411 last.tv_sec += opt.period_us/1000000;
412 last.tv_nsec += (opt.period_us%1000000)*1000;
413 while (last.tv_nsec >= 1000000000) {
414 last.tv_nsec -= 1000000000;
417 if (timespec_subtract(timeout, &last, &now) /* is negative */) {
419 memset(timeout, 0, sizeof(*timeout));
421 } else if (opt.timeout_ms != 0) {
422 timeout->tv_sec = opt.timeout_ms/1000;
423 timeout->tv_nsec = (opt.timeout_ms%1000)*1000000;
425 error(1, 0, "Timeout and period cannot be both zero");
428 void receive(int s, struct can_frame *frame, struct timespec *ts_kern, struct timespec *ts_user)
430 char ctrlmsg[CMSG_SPACE(sizeof(struct timeval)) + CMSG_SPACE(sizeof(__u32))];
433 struct cmsghdr *cmsg;
434 struct sockaddr_can addr;
436 static uint64_t dropcnt = 0;
438 iov.iov_base = frame;
439 msg.msg_name = &addr;
442 msg.msg_control = &ctrlmsg;
444 /* these settings may be modified by recvmsg() */
445 iov.iov_len = sizeof(*frame);
446 msg.msg_namelen = sizeof(addr);
447 msg.msg_controllen = sizeof(ctrlmsg);
450 nbytes = recvmsg(s, &msg, 0);
452 error(1, errno, "recvmsg");
454 if (nbytes < sizeof(struct can_frame))
455 error(1, 0, "recvmsg: incomplete CAN frame\n");
458 MEMSET_ZERO(*ts_kern);
459 for (cmsg = CMSG_FIRSTHDR(&msg);
460 cmsg && (cmsg->cmsg_level == SOL_SOCKET);
461 cmsg = CMSG_NXTHDR(&msg,cmsg)) {
462 if (cmsg->cmsg_type == SO_TIMESTAMPNS)
463 *ts_kern = *(struct timespec *)CMSG_DATA(cmsg);
464 else if (cmsg->cmsg_type == SO_RXQ_OVFL)
465 dropcnt += *(__u32 *)CMSG_DATA(cmsg);
470 void process_tx(int s)
472 error(1, 0, "%s: not implemented", __FUNCTION__);
475 void process_on_wire_rx(int s)
477 struct timespec ts_kern, ts_user, ts_diff;
478 struct can_frame frame;
480 receive(s, &frame, &ts_kern, &ts_user);
481 mi = frame2info(&frame);
482 mi->ts_rx_onwire_kern = ts_kern;
483 mi->ts_rx_onwire = ts_user;
487 void process_final_rx(int s)
489 struct timespec ts_kern, ts_user, ts_diff;
490 struct can_frame frame;
494 receive(s, &frame, &ts_kern, &ts_user);
495 mi = frame2info(&frame);
496 mi->ts_rx_final_kern = ts_kern;
497 mi->ts_rx_final = ts_user;
498 mi->received = frame;
500 histogram_add(&histogram, get_msg_latency_us(mi));
502 ret = write(completion_pipe[1], &mi, sizeof(mi));
504 error(1, errno, "completion_pipe write");
507 void *measure_thread(void *arg)
510 struct pollfd pfd[3];
511 struct timespec timeout;
512 struct sockaddr_can addr;
514 int consecutive_timeouts = 0;
518 for (i=0; i<num_interfaces; i++) {
519 if ((s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0)
520 error(1, errno, "socket");
522 addr.can_family = AF_CAN;
523 addr.can_ifindex = sock_get_if_index(s, opt.interface[i]);
525 if (i == 0) { /* TX socket */
526 /* disable default receive filter on this RAW socket */
527 /* This is obsolete as we do not read from the socket at all, but for */
528 /* this reason we can remove the receive list in the Kernel to save a */
529 /* little (really a very little!) CPU usage. */
530 if (setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0) == -1)
531 error(1, errno, "SOL_CAN_RAW");
534 if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0)
535 error(1, errno, "bind");
537 const int timestamp_on = 1;
538 if (setsockopt(s, SOL_SOCKET, SO_TIMESTAMPNS,
539 ×tamp_on, sizeof(timestamp_on)) < 0)
540 error(1, errno, "setsockopt SO_TIMESTAMP");
542 const int dropmonitor_on = 1;
543 if (setsockopt(s, SOL_SOCKET, SO_RXQ_OVFL,
544 &dropmonitor_on, sizeof(dropmonitor_on)) < 0)
545 error(1, errno, "setsockopt SO_RXQ_OVFL not supported by your Linux Kernel");
549 pfd[i].events = POLLIN | POLLERR | ((opt.period_us == 0 && !opt.oneattime) ? POLLOUT : 0);
551 pfd[i].events = POLLIN;
554 set_sched_policy_and_prio(SCHED_FIFO, 40);
556 #define SEND() send_and_check(pfd[0].fd)
561 get_tstamp(&stats.tic);
563 while (!finish_flag &&
564 (opt.count == 0 || count < opt.count || msg_in_progress != 0)) {
566 get_next_timeout(&timeout);
567 //printf("ppoll"); fflush(stdout);
568 ret = ppoll(pfd, num_interfaces, &timeout, NULL);
569 //printf("=%d\n", ret);
572 if (!INTERRUPTED_SYSCALL(errno))
573 error(1, errno, "ppoll");
577 if (opt.count == 0 || count < opt.count) {
581 /* Lost message - send a new one */
583 consecutive_timeouts++;
584 if (consecutive_timeouts < 10)
586 else /* Something is really broken */
591 if (pfd[0].revents & (POLLIN|POLLERR)) {
592 process_tx(pfd[0].fd);
594 if (pfd[0].revents & POLLOUT) {
595 if (opt.count == 0 || count < opt.count)
600 if (num_interfaces == 3 && pfd[1].revents != 0) {
601 process_on_wire_rx(pfd[1].fd);
605 i = (num_interfaces == 2) ? 1 : 2;
606 if (pfd[i].revents != 0) {
607 consecutive_timeouts = 0;
608 process_final_rx(pfd[i].fd);
611 if ((opt.count == 0 || count < opt.count) &&
619 get_tstamp(&stats.tac);
621 for (i=0; i<num_interfaces; i++)
627 struct poptOption optionsTable[] = {
628 { "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" },
629 { "count", 'c', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.count, 0, "The count of messages to send, zero corresponds to infinity", "num"},
630 { "id", 'i', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.id, 0, "CAN ID of sent messages", "id"},
631 { "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"},
632 { "timeout",'t', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.timeout_ms,0, "Timeout when period is zero", "ms"},
633 { "oneattime",'o', POPT_ARG_NONE, &opt.oneattime,0, "Send the next message only when the previous was finally received"},
634 { "verbose",'v', POPT_ARG_NONE, NULL, 'v', "Send the next message only when the previous was finally received"},
635 { "name", 'n', POPT_ARG_STRING, &opt.name, 0, "Prefix of the generated files"},
636 { "length", 'l', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.length, 0, "The length of generated messages", "bytes"},
637 { "userhist", 'u', POPT_ARG_NONE, &opt.userhist, 0, "Generate histogram from userspace timestamps"},
638 { "quiet", 'q', POPT_ARG_NONE, &opt.quiet, 0, "Do not print progress and statistics"},
640 { NULL, 0, 0, NULL, 0 }
643 int parse_options(int argc, const char *argv[])
646 poptContext optCon; /* context for parsing command-line options */
647 void *local = talloc_new (NULL);
649 optCon = poptGetContext(NULL, argc, argv, optionsTable, 0);
650 //poptSetOtherOptionHelp(optCon, "[OPTIONS]* <port>");
652 /* Now do options processing */
653 while ((c = poptGetNextOpt(optCon)) >= 0) {
661 error(1, 0, "%s: %s\n",
662 poptBadOption(optCon, POPT_BADOPTION_NOALIAS),
665 if (num_interfaces < 1 || num_interfaces > 3)
666 error(1, 0, "-d option must only be given one, two or three times");
668 if (opt.oneattime && opt.period_us)
669 error(1, 0, "oneattime and period cannot be specified at the same time");
672 char *f = talloc_asprintf(local, "%s-msgs.txt", opt.name);
673 opt.f_msgs = fopen(f, "w");
675 error(1, errno, "fopen: %s", f);
679 char *f = talloc_asprintf(local, "%s-hist.txt", opt.name);
680 opt.f_hist = fopen(f, "w");
682 error(1, errno, "fopen: %s", f);
686 char *f = talloc_asprintf(local, "%s-stat.txt", opt.name);
687 opt.f_stat = fopen(f, "w");
689 error(1, errno, "fopen: %s", f);
692 poptFreeContext(optCon);
697 void print_progress()
700 if (num_interfaces > 1)
701 printf("\rSent %5d, in progress %5d", count, msg_in_progress);
703 printf("\rSent %5d", count);
708 int main(int argc, const char *argv[])
714 parse_options(argc, argv);
716 mlockall(MCL_CURRENT | MCL_FUTURE);
718 signal(SIGINT, term_handler);
719 signal(SIGTERM, term_handler);
721 for (i=0; i<MAX_INFOS; i++)
722 msg_infos[i].id = -1;
724 histogram_init(&histogram, 5000000, 1);
726 ret = pipe(completion_pipe);
728 error(1, errno, "pipe");
729 ret = fcntl(completion_pipe[1], F_SETFL, O_NONBLOCK);
731 error(1, errno, "pipe fcntl");
735 pthread_create(&thread, 0, measure_thread, NULL);
737 struct timespec next, now, diff, allsent = {0,0};
738 clock_gettime(CLOCK_MONOTONIC, &next);
740 while (!finish_flag && (opt.count == 0 || completed < opt.count)) {
741 struct pollfd pfd[1];
742 pfd[0].fd = completion_pipe[0];
743 pfd[0].events = POLLIN;
744 ret = poll(pfd, 1, 100);
745 if (ret == -1 && !INTERRUPTED_SYSCALL(errno))
746 error(1, errno, "poll main");
747 if (ret > 0 && (pfd[0].revents & POLLIN)) {
750 ret = read(completion_pipe[0], &mi, sizeof(mi));
751 if (ret < sizeof(mi))
752 error(1, errno, "read completion returned %d", ret);
753 msg_info_print(opt.f_msgs, mi);
758 clock_gettime(CLOCK_MONOTONIC, &now);
759 if (timespec_subtract(&diff, &next, &now)) {
761 next.tv_nsec += 100000000;
762 while (next.tv_nsec >= 1000000000) {
763 next.tv_nsec -= 1000000000;
767 if (opt.count != 0 && count >= opt.count) {
768 if (allsent.tv_sec == 0)
770 timespec_subtract(&diff, &now, &allsent);
771 if (diff.tv_sec >= 1)
779 stats.lost = msg_in_progress;
781 pthread_join(thread, NULL);
783 close(completion_pipe[0]);
784 close(completion_pipe[1]);
786 histogram_fprint(&histogram, opt.f_hist);
791 fprintf(opt.f_stat, "cmdline='");
792 for (i=0; i<argc; i++)
793 fprintf(opt.f_stat, "%s%s", argv[i], i < argc-1 ? " " : "");
794 fprintf(opt.f_stat, "'\n");
796 timespec_subtract(&diff, &stats.tac, &stats.tic);
797 fprintf(opt.f_stat, "duration=%s # seconds\n", tstamp_str(NULL, &diff));
799 fprintf(opt.f_stat, "sent=%d\n", count);
800 fprintf(opt.f_stat, "overrun=%d\n", stats.overrun);
801 if (stats.overrun && !opt.quiet)
802 printf("overrun=%d\n", stats.overrun);
803 fprintf(opt.f_stat, "enobufs=%d\n", stats.enobufs);
804 if (stats.enobufs && !opt.quiet)
805 printf("enobufs=%d\n", stats.enobufs);
806 fprintf(opt.f_stat, "lost=%d\n", stats.lost);
807 if (stats.lost && !opt.quiet)
808 printf("lost=%d\n", stats.lost);
809 fprintf(opt.f_stat, "timeouts=%d\n", stats.timeouts);
810 if (stats.timeouts && !opt.quiet)
811 printf("timeouts=%d\n", stats.timeouts);