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 */
66 /* Temporary variables */
72 struct options opt = {
85 int num_interfaces = 0;
86 int count = 0; /* Number of sent messages */
87 unsigned msg_in_progress = 0;
88 int completion_pipe[2];
93 struct timespec ts_sent, ts_sent_kern;
94 struct timespec ts_rx_onwire, ts_rx_onwire_kern;
95 struct timespec ts_rx_final, ts_rx_final_kern;
96 struct can_frame sent, received;
99 #define MAX_INFOS 10000
100 struct msg_info msg_infos[MAX_INFOS];
102 struct histogram histogram;
104 void sprint_canframe(char *buf , struct can_frame *cf, int sep) {
105 /* documentation see lib.h */
108 int dlc = (cf->can_dlc > 8)? 8 : cf->can_dlc;
110 if (cf->can_id & CAN_ERR_FLAG) {
111 sprintf(buf, "%08X#", cf->can_id & (CAN_ERR_MASK|CAN_ERR_FLAG));
113 } else if (cf->can_id & CAN_EFF_FLAG) {
114 sprintf(buf, "%08X#", cf->can_id & CAN_EFF_MASK);
117 sprintf(buf, "%03X#", cf->can_id & CAN_SFF_MASK);
121 if (cf->can_id & CAN_RTR_FLAG) /* there are no ERR frames with RTR */
122 sprintf(buf+offset, "R");
124 for (i = 0; i < dlc; i++) {
125 sprintf(buf+offset, "%02X", cf->data[i]);
127 if (sep && (i+1 < dlc))
128 sprintf(buf+offset++, ".");
132 static inline struct msg_info *frame2info(struct can_frame *frame)
135 if (frame->can_dlc >= 2) {
136 memcpy(&idx, frame->data, sizeof(idx));
137 if (idx >= MAX_INFOS)
138 error(1, 0, "%s idx too high", __FUNCTION__);
141 error(1, 0, "%s error", __FUNCTION__);
143 return &msg_infos[idx];
146 static inline char *tstamp_str(const void *ctx, struct timespec *tstamp)
148 return talloc_asprintf(ctx, "%ld.%06ld",
149 tstamp->tv_sec, tstamp->tv_nsec/1000);
152 void msg_info_print(FILE *f, struct msg_info *mi)
154 struct timespec diff;
155 void *local = talloc_new (NULL);
157 char sent[64], received[64];
159 sprint_canframe(sent, &mi->sent, true);
160 sprint_canframe(received, &mi->received, true);
162 #define S(ts) tstamp_str(local, &ts)
163 #define DIFF(a, b) (timespec_subtract(&diff, &b, &a), S(diff))
165 if (num_interfaces == 2)
166 fprintf(f, "%ld: %s %s -> %s (%s) %s = %s (%s)\n",
167 num, S(mi->ts_sent), sent, S(mi->ts_rx_final_kern), S(mi->ts_rx_final), received,
168 DIFF(mi->ts_sent, mi->ts_rx_final_kern),
169 DIFF(mi->ts_sent, mi->ts_rx_final));
171 fprintf(f, "%ld: %s %s -> %s (%s) -> %s (%s) %s = %s (%s), %s (%s)\n",
172 num, S(mi->ts_sent), sent,
173 S(mi->ts_rx_onwire_kern), S(mi->ts_rx_onwire),
174 S(mi->ts_rx_final_kern), S(mi->ts_rx_final), received,
175 DIFF(mi->ts_sent, mi->ts_rx_onwire_kern),
176 DIFF(mi->ts_sent, mi->ts_rx_onwire),
177 DIFF(mi->ts_rx_onwire_kern, mi->ts_rx_final_kern),
178 DIFF(mi->ts_rx_onwire, mi->ts_rx_final));
185 int msg_info_store(FILE *f, struct msg_info *mi)
187 struct timespec diff;
188 void *local = talloc_new (NULL);
191 #define S(ts) tstamp_str(local, &ts)
192 #define DIFF(a, b) (timespec_subtract(&diff, &b, &a), S(diff))
194 if (num_interfaces == 2)
195 fprintf(f, "%ld %d %d %s\n",
196 num, mi->id, mi->length,
197 DIFF(mi->ts_sent, mi->ts_rx_final_kern));
199 fprintf(f, "%ld %d %d %s\n",
200 num, mi->id, mi->length,
201 DIFF(mi->ts_rx_onwire_kern, mi->ts_rx_final_kern));
208 /* Subtract the `struct timespec' values X and Y, storing the result in
209 RESULT. Return 1 if the difference is negative, otherwise 0. */
211 int timespec_subtract (struct timespec *result, struct timespec *x, struct timespec *yy)
213 struct timespec ylocal = *yy, *y = &ylocal;
214 /* Perform the carry for the later subtraction by updating Y. */
215 if (x->tv_nsec < y->tv_nsec) {
216 int nsec = (y->tv_nsec - x->tv_nsec) / 1000000000 + 1;
217 y->tv_nsec -= 1000000000 * nsec;
220 if (x->tv_nsec - y->tv_nsec > 1000000000) {
221 int nsec = (x->tv_nsec - y->tv_nsec) / 1000000000;
222 y->tv_nsec += 1000000000 * nsec;
226 /* Compute the time remaining to wait.
227 `tv_nsec' is certainly positive. */
228 result->tv_sec = x->tv_sec - y->tv_sec;
229 result->tv_nsec = x->tv_nsec - y->tv_nsec;
231 /* Return 1 if result is negative. */
232 return x->tv_sec < y->tv_sec;
235 void dbg_print_timespec(char *msg, struct timespec *tv)
238 printf("%s sec=%ld nsec=%ld\n", msg, tv->tv_sec, tv->tv_nsec);
241 static inline unsigned get_msg_latency_us(struct msg_info *mi)
243 struct timespec diff;
244 if (num_interfaces == 3)
246 timespec_subtract(&diff, &mi->ts_rx_final, &mi->ts_rx_onwire);
248 timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_rx_onwire_kern);
251 timespec_subtract(&diff, &mi->ts_rx_final, &mi->ts_sent);
253 timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_sent);
254 return diff.tv_sec * 1000000 + diff.tv_nsec/1000;
257 void set_sched_policy_and_prio(int policy, int rtprio)
259 struct sched_param scheduling_parameters;
260 int maxprio=sched_get_priority_max(policy);
261 int minprio=sched_get_priority_min(policy);
263 if((rtprio < minprio) || (rtprio > maxprio))
264 error(1, 0, "The priority for requested policy is out of <%d, %d> range\n",
267 scheduling_parameters.sched_priority = rtprio;
269 if (0 != pthread_setschedparam(pthread_self(), policy, &scheduling_parameters))
270 error(1, errno, "pthread_setschedparam error");
273 void term_handler(int signum)
278 static inline int sock_get_if_index(int s, const char *if_name)
283 strcpy(ifr.ifr_name, if_name);
284 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0)
285 error(1, errno, "SIOCGIFINDEX '%s'", if_name);
286 return ifr.ifr_ifindex;
289 static inline get_tstamp(struct timespec *ts)
291 clock_gettime(CLOCK_REALTIME, ts);
305 debugfs = "/sys/kernel/debug";
307 strcpy(path, debugfs);
308 strcat(path,"/tracing/tracing_on");
309 trace_fd = open(path, O_WRONLY);
311 write(trace_fd, "1", 1);
313 strcpy(path, debugfs);
314 strcat(path,"/tracing/trace_marker");
315 marker_fd = open(path, O_WRONLY);
317 strcpy(path, debugfs);
318 strcat(path,"/tracing/set_ftrace_pid");
319 f = fopen(path, "w");
320 fprintf(f, "%d\n", getpid());
322 system("echo function_graph > /sys/kernel/debug/tracing/current_tracer");
323 system("echo can_send > /sys/kernel/debug/tracing/set_graph_function");
324 system("echo > /sys/kernel/debug/tracing/trace");
325 system("echo 1 > /sys/kernel/debug/tracing/tracing_enabled");
330 static inline void trace_on()
333 write(trace_fd, "1", 1);
336 static inline void trace_off(int ret)
338 if (marker_fd >= 0) {
340 sprintf(marker, "write returned %d\n", ret);
341 write(marker_fd, marker, strlen(marker));
344 write(trace_fd, "0", 1);
347 void msg_info_free(struct msg_info *mi)
352 int send_frame(int socket)
354 struct can_frame frame;
357 static int curr_msg = -1;
363 while (msg_infos[i].id != -1 && i != curr_msg) {
369 error(1, 0, "Msg info table is full! Probably, many packets were lost.");
373 frame.can_id = opt.id;
375 error(1, 0, "Length < 2 is not yet supported");
376 frame.can_dlc = opt.length;
378 memcpy(frame.data, &idx, sizeof(idx));
379 mi = frame2info(&frame);
381 mi->id = frame.can_id;
382 mi->length = frame.can_dlc;
383 get_tstamp(&mi->ts_sent);
387 ret = write(socket, &frame, sizeof(frame));
395 static inline send_and_check(int s)
399 if (ret != sizeof(struct can_frame)) {
400 /* if (ret == -1 && errno == ENOBUFS && opt.period_us == 0 && !opt.oneattime) { */
401 /* stats.enobufs++; */
402 /* /\* Ignore this error - pfifo_fast qeuue is full *\/ */
404 error(1, errno, "send_frame (line %d)", __LINE__);
411 static inline void get_next_timeout(struct timespec *timeout)
414 static struct timespec last = {-1, 0 };
416 clock_gettime(CLOCK_MONOTONIC, &now);
418 if (last.tv_sec == -1)
420 if (opt.period_us != 0) {
421 last.tv_sec += opt.period_us/1000000;
422 last.tv_nsec += (opt.period_us%1000000)*1000;
423 while (last.tv_nsec >= 1000000000) {
424 last.tv_nsec -= 1000000000;
427 if (timespec_subtract(timeout, &last, &now) /* is negative */) {
429 memset(timeout, 0, sizeof(*timeout));
431 } else if (opt.timeout_ms != 0) {
432 timeout->tv_sec = opt.timeout_ms/1000;
433 timeout->tv_nsec = (opt.timeout_ms%1000)*1000000;
435 error(1, 0, "Timeout and period cannot be both zero");
438 void receive(int s, struct can_frame *frame, struct timespec *ts_kern, struct timespec *ts_user)
440 char ctrlmsg[CMSG_SPACE(sizeof(struct timeval)) + CMSG_SPACE(sizeof(__u32))];
443 struct cmsghdr *cmsg;
444 struct sockaddr_can addr;
446 static uint64_t dropcnt = 0;
448 iov.iov_base = frame;
449 msg.msg_name = &addr;
452 msg.msg_control = &ctrlmsg;
454 /* these settings may be modified by recvmsg() */
455 iov.iov_len = sizeof(*frame);
456 msg.msg_namelen = sizeof(addr);
457 msg.msg_controllen = sizeof(ctrlmsg);
460 nbytes = recvmsg(s, &msg, 0);
462 error(1, errno, "recvmsg");
464 if (nbytes < sizeof(struct can_frame))
465 error(1, 0, "recvmsg: incomplete CAN frame\n");
468 MEMSET_ZERO(*ts_kern);
469 for (cmsg = CMSG_FIRSTHDR(&msg);
470 cmsg && (cmsg->cmsg_level == SOL_SOCKET);
471 cmsg = CMSG_NXTHDR(&msg,cmsg)) {
472 if (cmsg->cmsg_type == SO_TIMESTAMPNS)
473 *ts_kern = *(struct timespec *)CMSG_DATA(cmsg);
474 else if (cmsg->cmsg_type == SO_RXQ_OVFL)
475 dropcnt += *(__u32 *)CMSG_DATA(cmsg);
480 void process_tx(int s)
482 error(1, 0, "%s: not implemented", __FUNCTION__);
485 void process_on_wire_rx(int s)
487 struct timespec ts_kern, ts_user, ts_diff;
488 struct can_frame frame;
490 receive(s, &frame, &ts_kern, &ts_user);
491 mi = frame2info(&frame);
492 mi->ts_rx_onwire_kern = ts_kern;
493 mi->ts_rx_onwire = ts_user;
497 void process_final_rx(int s)
499 struct timespec ts_kern, ts_user, ts_diff;
500 struct can_frame frame;
504 receive(s, &frame, &ts_kern, &ts_user);
505 mi = frame2info(&frame);
506 mi->ts_rx_final_kern = ts_kern;
507 mi->ts_rx_final = ts_user;
508 mi->received = frame;
510 histogram_add(&histogram, get_msg_latency_us(mi));
512 ret = write(completion_pipe[1], &mi, sizeof(mi));
514 error(1, errno, "completion_pipe write");
517 void *measure_thread(void *arg)
520 struct pollfd pfd[3];
521 struct timespec timeout;
522 struct sockaddr_can addr;
527 for (i=0; i<num_interfaces; i++) {
528 if ((s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0)
529 error(1, errno, "socket");
531 addr.can_family = AF_CAN;
532 addr.can_ifindex = sock_get_if_index(s, opt.interface[i]);
534 if (i == 0) { /* TX socket */
535 /* disable default receive filter on this RAW socket */
536 /* This is obsolete as we do not read from the socket at all, but for */
537 /* this reason we can remove the receive list in the Kernel to save a */
538 /* little (really a very little!) CPU usage. */
539 if (setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0) == -1)
540 error(1, errno, "SOL_CAN_RAW");
543 if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0)
544 error(1, errno, "bind");
546 const int timestamp_on = 1;
547 if (setsockopt(s, SOL_SOCKET, SO_TIMESTAMPNS,
548 ×tamp_on, sizeof(timestamp_on)) < 0)
549 error(1, errno, "setsockopt SO_TIMESTAMP");
551 const int dropmonitor_on = 1;
552 if (setsockopt(s, SOL_SOCKET, SO_RXQ_OVFL,
553 &dropmonitor_on, sizeof(dropmonitor_on)) < 0)
554 error(1, errno, "setsockopt SO_RXQ_OVFL not supported by your Linux Kernel");
558 pfd[i].events = POLLIN | POLLERR | ((opt.period_us == 0 && !opt.oneattime) ? POLLOUT : 0);
560 pfd[i].events = POLLIN;
563 set_sched_policy_and_prio(SCHED_FIFO, 40);
565 #define SEND() send_and_check(pfd[0].fd)
570 while (!finish_flag &&
571 (opt.count == 0 || count < opt.count || msg_in_progress != 0)) {
573 get_next_timeout(&timeout);
574 //printf("ppoll"); fflush(stdout);
575 ret = ppoll(pfd, num_interfaces, &timeout, NULL);
576 //printf("=%d\n", ret);
579 if (!INTERRUPTED_SYSCALL(errno))
580 error(1, errno, "ppoll");
584 if (opt.count == 0 || count < opt.count) {
588 error(1, 0, "poll timeout");
592 if (pfd[0].revents & (POLLIN|POLLERR)) {
593 process_tx(pfd[0].fd);
595 if (pfd[0].revents & POLLOUT) {
596 if (opt.count == 0 || count < opt.count)
601 if (num_interfaces == 3 && pfd[1].revents != 0) {
602 process_on_wire_rx(pfd[1].fd);
606 i = (num_interfaces == 2) ? 1 : 2;
607 if (pfd[i].revents != 0) {
608 process_final_rx(pfd[i].fd);
611 if ((opt.count == 0 || count < opt.count) &&
619 for (i=0; i<num_interfaces; i++)
625 struct poptOption optionsTable[] = {
626 { "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" },
627 { "count", 'c', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.count, 0, "The count of messages to send, zero corresponds to infinity", "num"},
628 { "id", 'i', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.id, 0, "CAN ID of sent messages", "id"},
629 { "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"},
630 { "timeout",'t', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.timeout_ms,0, "Timeout when period is zero", "ms"},
631 { "oneattime",'o', POPT_ARG_NONE, &opt.oneattime,0, "Send the next message only when the previous was finally received"},
632 { "verbose",'v', POPT_ARG_NONE, NULL, 'v', "Send the next message only when the previous was finally received"},
633 { "name", 'n', POPT_ARG_STRING, &opt.name, 0, "Prefix of the generated files"},
634 { "length", 'l', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.length, 0, "The length of generated messages", "bytes"},
635 { "userhist", 'u', POPT_ARG_NONE, &opt.userhist, 0, "Generate histogram from userspace timestamps"},
637 { NULL, 0, 0, NULL, 0 }
640 int parse_options(int argc, const char *argv[])
643 poptContext optCon; /* context for parsing command-line options */
644 void *local = talloc_new (NULL);
646 optCon = poptGetContext(NULL, argc, argv, optionsTable, 0);
647 //poptSetOtherOptionHelp(optCon, "[OPTIONS]* <port>");
649 /* Now do options processing */
650 while ((c = poptGetNextOpt(optCon)) >= 0) {
658 error(1, 0, "%s: %s\n",
659 poptBadOption(optCon, POPT_BADOPTION_NOALIAS),
662 if (num_interfaces < 2 || num_interfaces > 3)
663 error(1, 0, "-d option must be given exactly 2 or 3 times");
665 if (opt.oneattime && opt.period_us)
666 error(1, 0, "oneattime and period cannot be specified at the same time");
669 char *f = talloc_asprintf(local, "%s-msgs.txt", opt.name);
670 opt.f_msgs = fopen(f, "w");
672 error(1, errno, "fopen: %s", f);
676 char *f = talloc_asprintf(local, "%s-hist.txt", opt.name);
677 opt.f_hist = fopen(f, "w");
679 error(1, errno, "fopen: %s", f);
683 char *f = talloc_asprintf(local, "%s-stat.txt", opt.name);
684 opt.f_stat = fopen(f, "w");
686 error(1, errno, "fopen: %s", f);
689 poptFreeContext(optCon);
694 void print_progress()
696 printf("\rSent %5d, in progress %5d", count, msg_in_progress);
700 int main(int argc, const char *argv[])
706 parse_options(argc, argv);
708 mlockall(MCL_CURRENT | MCL_FUTURE);
710 signal(SIGINT, term_handler);
711 signal(SIGTERM, term_handler);
713 for (i=0; i<MAX_INFOS; i++)
714 msg_infos[i].id = -1;
716 histogram_init(&histogram, 5000000, 1);
718 ret = pipe(completion_pipe);
720 error(1, errno, "pipe");
721 ret = fcntl(completion_pipe[1], F_SETFL, O_NONBLOCK);
723 error(1, errno, "pipe fcntl");
727 pthread_create(&thread, 0, measure_thread, NULL);
729 struct timespec next, now, diff, allsent = {0,0};
730 clock_gettime(CLOCK_MONOTONIC, &next);
732 while (!finish_flag && (opt.count == 0 || completed < opt.count)) {
733 struct pollfd pfd[1];
734 pfd[0].fd = completion_pipe[0];
735 pfd[0].events = POLLIN;
736 ret = poll(pfd, 1, 100);
737 if (ret == -1 && !INTERRUPTED_SYSCALL(errno))
738 error(1, errno, "poll main");
739 if (ret > 0 && (pfd[0].revents & POLLIN)) {
742 ret = read(completion_pipe[0], &mi, sizeof(mi));
743 if (ret < sizeof(mi))
744 error(1, errno, "read completion returned %d", ret);
745 msg_info_print(opt.f_msgs, mi);
750 clock_gettime(CLOCK_MONOTONIC, &now);
751 if (timespec_subtract(&diff, &next, &now)) {
753 next.tv_nsec += 100000000;
754 while (next.tv_nsec >= 1000000000) {
755 next.tv_nsec -= 1000000000;
759 if (opt.count != 0 && count >= opt.count) {
760 if (allsent.tv_sec == 0)
762 timespec_subtract(&diff, &now, &allsent);
763 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, "sent=%d\n", count);
783 fprintf(opt.f_stat, "overrun=%d\n", stats.overrun);
785 printf("overrun=%d\n", stats.overrun);
786 fprintf(opt.f_stat, "enobufs=%d\n", stats.enobufs);
788 printf("enobufs=%d\n", stats.enobufs);
789 fprintf(opt.f_stat, "lost=%d\n", stats.lost);
791 printf("lost=%d\n", stats.lost);