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 */
68 struct options opt = {
81 int num_interfaces = 0;
82 int count = 0; /* Number of sent messages */
83 unsigned msg_in_progress = 0;
84 int completion_pipe[2];
89 struct timespec ts_sent, ts_sent_kern;
90 struct timespec ts_rx_onwire, ts_rx_onwire_kern;
91 struct timespec ts_rx_final, ts_rx_final_kern;
92 struct can_frame sent, received;
95 #define MAX_INFOS 10000
96 struct msg_info msg_infos[MAX_INFOS];
98 struct histogram histogram;
100 void sprint_canframe(char *buf , struct can_frame *cf, int sep) {
101 /* documentation see lib.h */
104 int dlc = (cf->can_dlc > 8)? 8 : cf->can_dlc;
106 if (cf->can_id & CAN_ERR_FLAG) {
107 sprintf(buf, "%08X#", cf->can_id & (CAN_ERR_MASK|CAN_ERR_FLAG));
109 } else if (cf->can_id & CAN_EFF_FLAG) {
110 sprintf(buf, "%08X#", cf->can_id & CAN_EFF_MASK);
113 sprintf(buf, "%03X#", cf->can_id & CAN_SFF_MASK);
117 if (cf->can_id & CAN_RTR_FLAG) /* there are no ERR frames with RTR */
118 sprintf(buf+offset, "R");
120 for (i = 0; i < dlc; i++) {
121 sprintf(buf+offset, "%02X", cf->data[i]);
123 if (sep && (i+1 < dlc))
124 sprintf(buf+offset++, ".");
128 static inline struct msg_info *frame2info(struct can_frame *frame)
131 if (frame->can_dlc >= 2) {
132 memcpy(&idx, frame->data, sizeof(idx));
133 if (idx >= MAX_INFOS)
134 error(1, 0, "%s idx too high", __FUNCTION__);
137 error(1, 0, "%s error", __FUNCTION__);
139 return &msg_infos[idx];
142 static inline char *tstamp_str(const void *ctx, struct timespec *tstamp)
144 return talloc_asprintf(ctx, "%ld.%06ld",
145 tstamp->tv_sec, tstamp->tv_nsec/1000);
148 void msg_info_print(FILE *f, struct msg_info *mi)
150 struct timespec diff;
151 void *local = talloc_new (NULL);
153 char sent[64], received[64];
155 sprint_canframe(sent, &mi->sent, true);
156 sprint_canframe(received, &mi->received, true);
158 #define S(ts) tstamp_str(local, &ts)
159 #define DIFF(a, b) (timespec_subtract(&diff, &b, &a), S(diff))
161 if (num_interfaces == 2)
162 fprintf(f, "%ld: %s %s -> %s (%s) %s = %s (%s)\n",
163 num, S(mi->ts_sent), sent, S(mi->ts_rx_final_kern), S(mi->ts_rx_final), received,
164 DIFF(mi->ts_sent, mi->ts_rx_final_kern),
165 DIFF(mi->ts_sent, mi->ts_rx_final));
167 fprintf(f, "%ld: %s %s -> %s (%s) -> %s (%s) %s = %s (%s), %s (%s)\n",
168 num, S(mi->ts_sent), sent,
169 S(mi->ts_rx_onwire_kern), S(mi->ts_rx_onwire),
170 S(mi->ts_rx_final_kern), S(mi->ts_rx_final), received,
171 DIFF(mi->ts_sent, mi->ts_rx_onwire_kern),
172 DIFF(mi->ts_sent, mi->ts_rx_onwire),
173 DIFF(mi->ts_rx_onwire_kern, mi->ts_rx_final_kern),
174 DIFF(mi->ts_rx_onwire, mi->ts_rx_final));
181 int msg_info_store(FILE *f, struct msg_info *mi)
183 struct timespec diff;
184 void *local = talloc_new (NULL);
187 #define S(ts) tstamp_str(local, &ts)
188 #define DIFF(a, b) (timespec_subtract(&diff, &b, &a), S(diff))
190 if (num_interfaces == 2)
191 fprintf(f, "%ld %d %d %s\n",
192 num, mi->id, mi->length,
193 DIFF(mi->ts_sent, mi->ts_rx_final_kern));
195 fprintf(f, "%ld %d %d %s\n",
196 num, mi->id, mi->length,
197 DIFF(mi->ts_rx_onwire_kern, mi->ts_rx_final_kern));
204 /* Subtract the `struct timespec' values X and Y, storing the result in
205 RESULT. Return 1 if the difference is negative, otherwise 0. */
207 int timespec_subtract (struct timespec *result, struct timespec *x, struct timespec *yy)
209 struct timespec ylocal = *yy, *y = &ylocal;
210 /* Perform the carry for the later subtraction by updating Y. */
211 if (x->tv_nsec < y->tv_nsec) {
212 int nsec = (y->tv_nsec - x->tv_nsec) / 1000000000 + 1;
213 y->tv_nsec -= 1000000000 * nsec;
216 if (x->tv_nsec - y->tv_nsec > 1000000000) {
217 int nsec = (x->tv_nsec - y->tv_nsec) / 1000000000;
218 y->tv_nsec += 1000000000 * nsec;
222 /* Compute the time remaining to wait.
223 `tv_nsec' is certainly positive. */
224 result->tv_sec = x->tv_sec - y->tv_sec;
225 result->tv_nsec = x->tv_nsec - y->tv_nsec;
227 /* Return 1 if result is negative. */
228 return x->tv_sec < y->tv_sec;
231 void dbg_print_timespec(char *msg, struct timespec *tv)
234 printf("%s sec=%ld nsec=%ld\n", msg, tv->tv_sec, tv->tv_nsec);
237 static inline unsigned get_msg_latency_us(struct msg_info *mi)
239 struct timespec diff;
240 if (num_interfaces == 3)
242 timespec_subtract(&diff, &mi->ts_rx_final, &mi->ts_rx_onwire);
244 timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_rx_onwire_kern);
247 timespec_subtract(&diff, &mi->ts_rx_final, &mi->ts_sent);
249 timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_sent);
250 return diff.tv_sec * 1000000 + diff.tv_nsec/1000;
253 void set_sched_policy_and_prio(int policy, int rtprio)
255 struct sched_param scheduling_parameters;
256 int maxprio=sched_get_priority_max(policy);
257 int minprio=sched_get_priority_min(policy);
259 if((rtprio < minprio) || (rtprio > maxprio))
260 error(1, 0, "The priority for requested policy is out of <%d, %d> range\n",
263 scheduling_parameters.sched_priority = rtprio;
265 if (0 != pthread_setschedparam(pthread_self(), policy, &scheduling_parameters))
266 error(1, errno, "pthread_setschedparam error");
269 void term_handler(int signum)
274 static inline int sock_get_if_index(int s, const char *if_name)
279 strcpy(ifr.ifr_name, if_name);
280 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0)
281 error(1, errno, "SIOCGIFINDEX '%s'", if_name);
282 return ifr.ifr_ifindex;
285 static inline get_tstamp(struct timespec *ts)
287 clock_gettime(CLOCK_REALTIME, ts);
301 debugfs = "/sys/kernel/debug";
303 strcpy(path, debugfs);
304 strcat(path,"/tracing/tracing_on");
305 trace_fd = open(path, O_WRONLY);
307 write(trace_fd, "1", 1);
309 strcpy(path, debugfs);
310 strcat(path,"/tracing/trace_marker");
311 marker_fd = open(path, O_WRONLY);
313 strcpy(path, debugfs);
314 strcat(path,"/tracing/set_ftrace_pid");
315 f = fopen(path, "w");
316 fprintf(f, "%d\n", getpid());
318 system("echo function_graph > /sys/kernel/debug/tracing/current_tracer");
319 system("echo can_send > /sys/kernel/debug/tracing/set_graph_function");
320 system("echo > /sys/kernel/debug/tracing/trace");
321 system("echo 1 > /sys/kernel/debug/tracing/tracing_enabled");
326 static inline void trace_on()
329 write(trace_fd, "1", 1);
332 static inline void trace_off(int ret)
334 if (marker_fd >= 0) {
336 sprintf(marker, "write returned %d\n", ret);
337 write(marker_fd, marker, strlen(marker));
340 write(trace_fd, "0", 1);
343 void msg_info_free(struct msg_info *mi)
348 int send_frame(int socket)
350 struct can_frame frame;
353 static int curr_msg = -1;
359 while (msg_infos[i].id != -1 && i != curr_msg) {
365 error(1, 0, "Msg info table is full! Probably, many packets were lost.");
369 frame.can_id = opt.id;
371 error(1, 0, "Length < 2 is not yet supported");
372 frame.can_dlc = opt.length;
374 memcpy(frame.data, &idx, sizeof(idx));
375 mi = frame2info(&frame);
377 mi->id = frame.can_id;
378 mi->length = frame.can_dlc;
379 get_tstamp(&mi->ts_sent);
383 ret = write(socket, &frame, sizeof(frame));
391 static inline send_and_check(int s)
395 if (ret != sizeof(struct can_frame)) {
396 /* if (ret == -1 && errno == ENOBUFS && opt.period_us == 0 && !opt.oneattime) { */
397 /* stats.enobufs++; */
398 /* /\* Ignore this error - pfifo_fast qeuue is full *\/ */
400 error(1, errno, "send_frame (line %d)", __LINE__);
407 static inline void get_next_timeout(struct timespec *timeout)
410 static struct timespec last = {-1, 0 };
412 clock_gettime(CLOCK_MONOTONIC, &now);
414 if (last.tv_sec == -1)
416 if (opt.period_us != 0) {
417 last.tv_sec += opt.period_us/1000000;
418 last.tv_nsec += (opt.period_us%1000000)*1000;
419 while (last.tv_nsec >= 1000000000) {
420 last.tv_nsec -= 1000000000;
423 if (timespec_subtract(timeout, &last, &now) /* is negative */) {
425 memset(timeout, 0, sizeof(*timeout));
427 } else if (opt.timeout_ms != 0) {
428 timeout->tv_sec = opt.timeout_ms/1000;
429 timeout->tv_nsec = (opt.timeout_ms%1000)*1000000;
431 error(1, 0, "Timeout and period cannot be both zero");
434 void receive(int s, struct can_frame *frame, struct timespec *ts_kern, struct timespec *ts_user)
436 char ctrlmsg[CMSG_SPACE(sizeof(struct timeval)) + CMSG_SPACE(sizeof(__u32))];
439 struct cmsghdr *cmsg;
440 struct sockaddr_can addr;
442 static uint64_t dropcnt = 0;
444 iov.iov_base = frame;
445 msg.msg_name = &addr;
448 msg.msg_control = &ctrlmsg;
450 /* these settings may be modified by recvmsg() */
451 iov.iov_len = sizeof(*frame);
452 msg.msg_namelen = sizeof(addr);
453 msg.msg_controllen = sizeof(ctrlmsg);
456 nbytes = recvmsg(s, &msg, 0);
458 error(1, errno, "recvmsg");
460 if (nbytes < sizeof(struct can_frame))
461 error(1, 0, "recvmsg: incomplete CAN frame\n");
464 MEMSET_ZERO(*ts_kern);
465 for (cmsg = CMSG_FIRSTHDR(&msg);
466 cmsg && (cmsg->cmsg_level == SOL_SOCKET);
467 cmsg = CMSG_NXTHDR(&msg,cmsg)) {
468 if (cmsg->cmsg_type == SO_TIMESTAMPNS)
469 *ts_kern = *(struct timespec *)CMSG_DATA(cmsg);
470 else if (cmsg->cmsg_type == SO_RXQ_OVFL)
471 dropcnt += *(__u32 *)CMSG_DATA(cmsg);
476 void process_tx(int s)
478 error(1, 0, "%s: not implemented", __FUNCTION__);
481 void process_on_wire_rx(int s)
483 struct timespec ts_kern, ts_user, ts_diff;
484 struct can_frame frame;
486 receive(s, &frame, &ts_kern, &ts_user);
487 mi = frame2info(&frame);
488 mi->ts_rx_onwire_kern = ts_kern;
489 mi->ts_rx_onwire = ts_user;
493 void process_final_rx(int s)
495 struct timespec ts_kern, ts_user, ts_diff;
496 struct can_frame frame;
500 receive(s, &frame, &ts_kern, &ts_user);
501 mi = frame2info(&frame);
502 mi->ts_rx_final_kern = ts_kern;
503 mi->ts_rx_final = ts_user;
504 mi->received = frame;
507 histogram_add(&histogram, get_msg_latency_us(mi));
509 ret = write(completion_pipe[1], &mi, sizeof(mi));
511 error(1, errno, "completion_pipe write");
514 void *measure_thread(void *arg)
517 struct pollfd pfd[3];
518 struct timespec timeout;
519 struct sockaddr_can addr;
524 for (i=0; i<num_interfaces; i++) {
525 if ((s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0)
526 error(1, errno, "socket");
528 addr.can_family = AF_CAN;
529 addr.can_ifindex = sock_get_if_index(s, opt.interface[i]);
531 if (i == 0) { /* TX socket */
532 /* disable default receive filter on this RAW socket */
533 /* This is obsolete as we do not read from the socket at all, but for */
534 /* this reason we can remove the receive list in the Kernel to save a */
535 /* little (really a very little!) CPU usage. */
536 if (setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0) == -1)
537 error(1, errno, "SOL_CAN_RAW");
540 if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0)
541 error(1, errno, "bind");
543 const int timestamp_on = 1;
544 if (setsockopt(s, SOL_SOCKET, SO_TIMESTAMPNS,
545 ×tamp_on, sizeof(timestamp_on)) < 0)
546 error(1, errno, "setsockopt SO_TIMESTAMP");
548 const int dropmonitor_on = 1;
549 if (setsockopt(s, SOL_SOCKET, SO_RXQ_OVFL,
550 &dropmonitor_on, sizeof(dropmonitor_on)) < 0)
551 error(1, errno, "setsockopt SO_RXQ_OVFL not supported by your Linux Kernel");
555 pfd[i].events = POLLIN | POLLERR | ((opt.period_us == 0 && !opt.oneattime) ? POLLOUT : 0);
557 pfd[i].events = POLLIN;
560 set_sched_policy_and_prio(SCHED_FIFO, 40);
562 #define SEND() send_and_check(pfd[0].fd)
567 while (!finish_flag &&
568 (opt.count == 0 || count < opt.count || msg_in_progress != 0)) {
570 get_next_timeout(&timeout);
571 //printf("ppoll"); fflush(stdout);
572 ret = ppoll(pfd, num_interfaces, &timeout, NULL);
573 //printf("=%d\n", ret);
576 if (!INTERRUPTED_SYSCALL(errno))
577 error(1, errno, "ppoll");
581 if (opt.count == 0 || count < opt.count) {
585 error(1, 0, "poll timeout");
589 if (pfd[0].revents & (POLLIN|POLLERR)) {
590 process_tx(pfd[0].fd);
592 if (pfd[0].revents & POLLOUT) {
593 if (opt.count == 0 || count < opt.count)
598 if (num_interfaces == 3 && pfd[1].revents != 0) {
599 process_on_wire_rx(pfd[1].fd);
603 i = (num_interfaces == 2) ? 1 : 2;
604 if (pfd[i].revents != 0) {
605 process_final_rx(pfd[i].fd);
608 if ((opt.count == 0 || count < opt.count) &&
616 for (i=0; i<num_interfaces; i++)
622 struct poptOption optionsTable[] = {
623 { "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" },
624 { "count", 'c', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.count, 0, "The count of messages to send, zero corresponds to infinity", "num"},
625 { "id", 'i', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.id, 0, "CAN ID of sent messages", "id"},
626 { "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"},
627 { "timeout",'t', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.timeout_ms,0, "Timeout when period is zero", "ms"},
628 { "oneattime",'o', POPT_ARG_NONE, &opt.oneattime,0, "Send the next message only when the previous was finally received"},
629 { "verbose",'v', POPT_ARG_NONE, NULL, 'v', "Send the next message only when the previous was finally received"},
630 { "file", 'f', POPT_ARG_STRING, NULL, 'f', "File where to store results", "filename"},
631 { "histogram", 'h', POPT_ARG_STRING, NULL, 'h', "Store histogram in file", "filename"},
632 { "length", 'l', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.length, 0, "The length of generated messages", "bytes"},
633 { "userhist", 'u', POPT_ARG_NONE, &opt.userhist, 0, "Generate histogram from userspace timestamps"},
635 { NULL, 0, 0, NULL, 0 }
638 int parse_options(int argc, const char *argv[])
641 poptContext optCon; /* context for parsing command-line options */
643 optCon = poptGetContext(NULL, argc, argv, optionsTable, 0);
644 //poptSetOtherOptionHelp(optCon, "[OPTIONS]* <port>");
646 /* Now do options processing */
647 while ((c = poptGetNextOpt(optCon)) >= 0) {
653 opt.file = fopen(poptGetOptArg(optCon), "w");
655 error(1, errno, "fopen: %s", poptGetOptArg(optCon));
658 opt.histogram = fopen(poptGetOptArg(optCon), "w");
660 error(1, errno, "fopen: %s", poptGetOptArg(optCon));
665 error(1, 0, "%s: %s\n",
666 poptBadOption(optCon, POPT_BADOPTION_NOALIAS),
669 if (num_interfaces < 2 || num_interfaces > 3)
670 error(1, 0, "-d option must be given exactly 2 or 3 times");
672 if (opt.oneattime && opt.period_us)
673 error(1, 0, "oneattime and period cannot be specified at the same time");
675 poptFreeContext(optCon);
680 void print_progress()
682 printf("\rSent %5d, in progress %5d", count, msg_in_progress);
686 int main(int argc, const char *argv[])
692 parse_options(argc, argv);
694 mlockall(MCL_CURRENT | MCL_FUTURE);
696 signal(SIGINT, term_handler);
697 signal(SIGTERM, term_handler);
699 for (i=0; i<MAX_INFOS; i++)
700 msg_infos[i].id = -1;
703 histogram_init(&histogram, 5000000, 1);
706 ret = pipe(completion_pipe);
708 error(1, errno, "pipe");
709 ret = fcntl(completion_pipe[1], F_SETFL, O_NONBLOCK);
711 error(1, errno, "pipe fcntl");
715 pthread_create(&thread, 0, measure_thread, NULL);
717 struct timespec next, now, diff, allsent = {0,0};
718 clock_gettime(CLOCK_MONOTONIC, &next);
720 while (!finish_flag && (opt.count == 0 || completed < opt.count)) {
721 struct pollfd pfd[1];
722 pfd[0].fd = completion_pipe[0];
723 pfd[0].events = POLLIN;
724 ret = poll(pfd, 1, 100);
725 if (ret == -1 && !INTERRUPTED_SYSCALL(errno))
726 error(1, errno, "poll main");
727 if (ret > 0 && (pfd[0].revents & POLLIN)) {
730 ret = read(completion_pipe[0], &mi, sizeof(mi));
731 if (ret < sizeof(mi))
732 error(1, errno, "read completion returned %d", ret);
734 msg_info_print(opt.file, mi);
739 clock_gettime(CLOCK_MONOTONIC, &now);
740 if (timespec_subtract(&diff, &next, &now)) {
742 next.tv_nsec += 100000000;
743 while (next.tv_nsec >= 1000000000) {
744 next.tv_nsec -= 1000000000;
748 if (opt.count != 0 && count >= opt.count) {
749 if (allsent.tv_sec == 0)
751 timespec_subtract(&diff, &now, &allsent);
752 if (diff.tv_sec >= 1)
759 stats.lost = msg_in_progress;
761 pthread_join(thread, NULL);
763 close(completion_pipe[0]);
764 close(completion_pipe[1]);
767 histogram_fprint(&histogram, opt.histogram);
768 fclose(opt.histogram);
774 printf("overrun=%d\n", stats.overrun);
776 printf("enobufs=%d\n", stats.enobufs);
778 printf("lost=%d\n", stats.lost);