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 = {
79 int num_interfaces = 0;
80 int count = 0; /* Number of sent messages */
81 int completion_pipe[2];
86 struct timespec ts_sent, ts_sent_kern;
87 struct timespec ts_rx_onwire, ts_rx_onwire_kern;
88 struct timespec ts_rx_final, ts_rx_final_kern;
89 struct can_frame sent, received;
92 #define MAX_INFOS 10000
93 struct msg_info msg_infos[MAX_INFOS];
95 struct histogram histogram;
97 void sprint_canframe(char *buf , struct can_frame *cf, int sep) {
98 /* documentation see lib.h */
101 int dlc = (cf->can_dlc > 8)? 8 : cf->can_dlc;
103 if (cf->can_id & CAN_ERR_FLAG) {
104 sprintf(buf, "%08X#", cf->can_id & (CAN_ERR_MASK|CAN_ERR_FLAG));
106 } else if (cf->can_id & CAN_EFF_FLAG) {
107 sprintf(buf, "%08X#", cf->can_id & CAN_EFF_MASK);
110 sprintf(buf, "%03X#", cf->can_id & CAN_SFF_MASK);
114 if (cf->can_id & CAN_RTR_FLAG) /* there are no ERR frames with RTR */
115 sprintf(buf+offset, "R");
117 for (i = 0; i < dlc; i++) {
118 sprintf(buf+offset, "%02X", cf->data[i]);
120 if (sep && (i+1 < dlc))
121 sprintf(buf+offset++, ".");
125 static inline struct msg_info *frame2info(struct can_frame *frame)
128 if (frame->can_dlc >= 2) {
129 memcpy(&idx, frame->data, sizeof(idx));
130 if (idx >= MAX_INFOS)
131 error(1, 0, "%s idx too high", __FUNCTION__);
134 error(1, 0, "%s error", __FUNCTION__);
136 return &msg_infos[idx];
139 static inline char *tstamp_str(const void *ctx, struct timespec *tstamp)
141 return talloc_asprintf(ctx, "%ld.%06ld",
142 tstamp->tv_sec, tstamp->tv_nsec/1000);
145 void msg_info_print(FILE *f, struct msg_info *mi)
147 struct timespec diff;
148 void *local = talloc_new (NULL);
150 char sent[64], received[64];
152 sprint_canframe(sent, &mi->sent, true);
153 sprint_canframe(received, &mi->received, true);
155 #define S(ts) tstamp_str(local, &ts)
156 #define DIFF(a, b) (timespec_subtract(&diff, &b, &a), S(diff))
158 if (num_interfaces == 2)
159 fprintf(f, "%ld: %s %s -> %s (%s) %s = %s (%s)\n",
160 num, S(mi->ts_sent), sent, S(mi->ts_rx_final_kern), S(mi->ts_rx_final), received,
161 DIFF(mi->ts_sent, mi->ts_rx_final_kern),
162 DIFF(mi->ts_sent, mi->ts_rx_final));
164 fprintf(f, "%ld: %s %s -> %s (%s) -> %s (%s) %s = %s (%s), %s (%s)\n",
165 num, S(mi->ts_sent), sent,
166 S(mi->ts_rx_onwire_kern), S(mi->ts_rx_onwire),
167 S(mi->ts_rx_final_kern), S(mi->ts_rx_final), received,
168 DIFF(mi->ts_sent, mi->ts_rx_onwire_kern),
169 DIFF(mi->ts_sent, mi->ts_rx_onwire),
170 DIFF(mi->ts_rx_onwire_kern, mi->ts_rx_final_kern),
171 DIFF(mi->ts_rx_onwire, mi->ts_rx_final));
178 int msg_info_store(FILE *f, struct msg_info *mi)
180 struct timespec diff;
181 void *local = talloc_new (NULL);
184 #define S(ts) tstamp_str(local, &ts)
185 #define DIFF(a, b) (timespec_subtract(&diff, &b, &a), S(diff))
187 if (num_interfaces == 2)
188 fprintf(f, "%ld %d %d %s\n",
189 num, mi->id, mi->length,
190 DIFF(mi->ts_sent, mi->ts_rx_final_kern));
192 fprintf(f, "%ld %d %d %s\n",
193 num, mi->id, mi->length,
194 DIFF(mi->ts_rx_onwire_kern, mi->ts_rx_final_kern));
201 /* Subtract the `struct timespec' values X and Y, storing the result in
202 RESULT. Return 1 if the difference is negative, otherwise 0. */
204 int timespec_subtract (struct timespec *result, struct timespec *x, struct timespec *yy)
206 struct timespec ylocal = *yy, *y = &ylocal;
207 /* Perform the carry for the later subtraction by updating Y. */
208 if (x->tv_nsec < y->tv_nsec) {
209 int nsec = (y->tv_nsec - x->tv_nsec) / 1000000000 + 1;
210 y->tv_nsec -= 1000000000 * nsec;
213 if (x->tv_nsec - y->tv_nsec > 1000000000) {
214 int nsec = (x->tv_nsec - y->tv_nsec) / 1000000000;
215 y->tv_nsec += 1000000000 * nsec;
219 /* Compute the time remaining to wait.
220 `tv_nsec' is certainly positive. */
221 result->tv_sec = x->tv_sec - y->tv_sec;
222 result->tv_nsec = x->tv_nsec - y->tv_nsec;
224 /* Return 1 if result is negative. */
225 return x->tv_sec < y->tv_sec;
228 void dbg_print_timespec(char *msg, struct timespec *tv)
231 printf("%s sec=%ld nsec=%ld\n", msg, tv->tv_sec, tv->tv_nsec);
234 static inline unsigned get_msg_latency_us(struct msg_info *mi)
236 struct timespec diff;
237 if (num_interfaces == 3)
239 timespec_subtract(&diff, &mi->ts_rx_final, &mi->ts_rx_onwire);
241 timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_rx_onwire_kern);
244 timespec_subtract(&diff, &mi->ts_rx_final, &mi->ts_sent);
246 timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_sent);
247 return diff.tv_sec * 1000000 + diff.tv_nsec/1000;
250 void set_sched_policy_and_prio(int policy, int rtprio)
252 struct sched_param scheduling_parameters;
253 int maxprio=sched_get_priority_max(policy);
254 int minprio=sched_get_priority_min(policy);
256 if((rtprio < minprio) || (rtprio > maxprio))
257 error(1, 0, "The priority for requested policy is out of <%d, %d> range\n",
260 scheduling_parameters.sched_priority = rtprio;
262 if (0 != pthread_setschedparam(pthread_self(), policy, &scheduling_parameters))
263 error(1, errno, "pthread_setschedparam error");
266 void term_handler(int signum)
271 static inline int sock_get_if_index(int s, const char *if_name)
276 strcpy(ifr.ifr_name, if_name);
277 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0)
278 error(1, errno, "SIOCGIFINDEX '%s'", if_name);
279 return ifr.ifr_ifindex;
282 static inline get_tstamp(struct timespec *ts)
284 clock_gettime(CLOCK_REALTIME, ts);
298 debugfs = "/sys/kernel/debug";
300 strcpy(path, debugfs);
301 strcat(path,"/tracing/tracing_on");
302 trace_fd = open(path, O_WRONLY);
304 write(trace_fd, "1", 1);
306 strcpy(path, debugfs);
307 strcat(path,"/tracing/trace_marker");
308 marker_fd = open(path, O_WRONLY);
310 strcpy(path, debugfs);
311 strcat(path,"/tracing/set_ftrace_pid");
312 f = fopen(path, "w");
313 fprintf(f, "%d\n", getpid());
315 system("echo function_graph > /sys/kernel/debug/tracing/current_tracer");
316 system("echo can_send > /sys/kernel/debug/tracing/set_graph_function");
317 system("echo > /sys/kernel/debug/tracing/trace");
318 system("echo 1 > /sys/kernel/debug/tracing/tracing_enabled");
323 static inline void trace_on()
326 write(trace_fd, "1", 1);
329 static inline void trace_off(int ret)
331 if (marker_fd >= 0) {
333 sprintf(marker, "write returned %d\n", ret);
334 write(marker_fd, marker, strlen(marker));
337 write(trace_fd, "0", 1);
340 void msg_info_free(struct msg_info *mi)
345 int send_frame(int socket)
347 struct can_frame frame;
350 static int curr_msg = -1;
356 while (msg_infos[i].id != -1 && i != curr_msg) {
362 error(1, 0, "Msg info table is full! Probably, many packets were lost.");
366 frame.can_id = opt.id;
368 error(1, 0, "Length < 2 is not yet supported");
369 frame.can_dlc = opt.length;
371 memcpy(frame.data, &idx, sizeof(idx));
372 mi = frame2info(&frame);
374 mi->id = frame.can_id;
375 mi->length = frame.can_dlc;
376 get_tstamp(&mi->ts_sent);
380 ret = write(socket, &frame, sizeof(frame));
388 static inline void get_next_timeout(struct timespec *timeout)
391 static struct timespec last = {-1, 0 };
393 clock_gettime(CLOCK_MONOTONIC, &now);
395 if (last.tv_sec == -1)
397 if (opt.period_us != 0) {
398 last.tv_sec += opt.period_us/1000000;
399 last.tv_nsec += (opt.period_us%1000000)*1000;
400 while (last.tv_nsec >= 1000000000) {
401 last.tv_nsec -= 1000000000;
404 timespec_subtract(timeout, &last, &now);
405 } else if (opt.timeout_ms != 0) {
406 timeout->tv_sec = opt.timeout_ms/1000;
407 timeout->tv_nsec = (opt.timeout_ms%1000)*1000000;
409 error(1, 0, "Timeout and period cannot be both zero");
412 void receive(int s, struct can_frame *frame, struct timespec *ts_kern, struct timespec *ts_user)
414 char ctrlmsg[CMSG_SPACE(sizeof(struct timeval)) + CMSG_SPACE(sizeof(__u32))];
417 struct cmsghdr *cmsg;
418 struct sockaddr_can addr;
420 static uint64_t dropcnt = 0;
422 iov.iov_base = frame;
423 msg.msg_name = &addr;
426 msg.msg_control = &ctrlmsg;
428 /* these settings may be modified by recvmsg() */
429 iov.iov_len = sizeof(*frame);
430 msg.msg_namelen = sizeof(addr);
431 msg.msg_controllen = sizeof(ctrlmsg);
434 nbytes = recvmsg(s, &msg, 0);
436 error(1, errno, "recvmsg");
438 if (nbytes < sizeof(struct can_frame))
439 error(1, 0, "recvmsg: incomplete CAN frame\n");
442 MEMSET_ZERO(*ts_kern);
443 for (cmsg = CMSG_FIRSTHDR(&msg);
444 cmsg && (cmsg->cmsg_level == SOL_SOCKET);
445 cmsg = CMSG_NXTHDR(&msg,cmsg)) {
446 if (cmsg->cmsg_type == SO_TIMESTAMPNS)
447 *ts_kern = *(struct timespec *)CMSG_DATA(cmsg);
448 else if (cmsg->cmsg_type == SO_RXQ_OVFL)
449 dropcnt += *(__u32 *)CMSG_DATA(cmsg);
454 void process_tx(int s)
456 error(1, 0, "%s: not implemented", __FUNCTION__);
459 void process_on_wire_rx(int s)
461 struct timespec ts_kern, ts_user, ts_diff;
462 struct can_frame frame;
464 receive(s, &frame, &ts_kern, &ts_user);
465 mi = frame2info(&frame);
466 mi->ts_rx_onwire_kern = ts_kern;
467 mi->ts_rx_onwire = ts_user;
471 void process_final_rx(int s)
473 struct timespec ts_kern, ts_user, ts_diff;
474 struct can_frame frame;
478 receive(s, &frame, &ts_kern, &ts_user);
479 mi = frame2info(&frame);
480 mi->ts_rx_final_kern = ts_kern;
481 mi->ts_rx_final = ts_user;
482 mi->received = frame;
485 histogram_add(&histogram, get_msg_latency_us(mi));
487 ret = write(completion_pipe[1], &mi, sizeof(mi));
489 error(1, errno, "completion_pipe write");
492 void *measure_thread(void *arg)
495 struct pollfd pfd[3];
496 struct timespec timeout;
497 struct sockaddr_can addr;
499 unsigned msg_in_progress = 0;
503 for (i=0; i<num_interfaces; i++) {
504 if ((s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0)
505 error(1, errno, "socket");
507 addr.can_family = AF_CAN;
508 addr.can_ifindex = sock_get_if_index(s, opt.interface[i]);
510 if (i == 0) { /* TX socket */
511 /* disable default receive filter on this RAW socket */
512 /* This is obsolete as we do not read from the socket at all, but for */
513 /* this reason we can remove the receive list in the Kernel to save a */
514 /* little (really a very little!) CPU usage. */
515 if (setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0) == -1)
516 error(1, errno, "SOL_CAN_RAW");
519 if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0)
520 error(1, errno, "bind");
522 const int timestamp_on = 1;
523 if (setsockopt(s, SOL_SOCKET, SO_TIMESTAMPNS,
524 ×tamp_on, sizeof(timestamp_on)) < 0)
525 error(1, errno, "setsockopt SO_TIMESTAMP");
527 const int dropmonitor_on = 1;
528 if (setsockopt(s, SOL_SOCKET, SO_RXQ_OVFL,
529 &dropmonitor_on, sizeof(dropmonitor_on)) < 0)
530 error(1, errno, "setsockopt SO_RXQ_OVFL not supported by your Linux Kernel");
534 pfd[i].events = POLLIN | POLLERR | ((opt.period_us == 0 && !opt.oneattime) ? POLLOUT : 0);
536 pfd[i].events = POLLIN;
539 set_sched_policy_and_prio(SCHED_FIFO, 40);
543 ret = send_frame(pfd[0].fd); \
544 if (ret != sizeof(struct can_frame)) { \
545 if (ret == -1 && errno == ENOBUFS && opt.period_us == 0 && !opt.oneattime) { \
547 /* Ignore this error - pfifo_fast qeuue is full */ \
549 error(1, errno, "send_frame (line %d)", __LINE__); \
562 while (!finish_flag &&
563 (opt.count == 0 || count < opt.count || msg_in_progress != 0)) {
565 get_next_timeout(&timeout);
566 //printf("ppoll"); fflush(stdout);
567 ret = ppoll(pfd, num_interfaces, &timeout, NULL);
568 //printf("=%d\n", ret);
571 if (!INTERRUPTED_SYSCALL(errno))
572 error(1, errno, "ppoll");
576 if (opt.count == 0 || count < opt.count) {
580 error(1, 0, "poll timeout");
584 if (pfd[0].revents & (POLLIN|POLLERR)) {
585 process_tx(pfd[0].fd);
587 if (pfd[0].revents & POLLOUT) {
588 if (opt.count == 0 || count < opt.count)
593 if (num_interfaces == 3 && pfd[1].revents != 0) {
594 process_on_wire_rx(pfd[1].fd);
598 i = (num_interfaces == 2) ? 1 : 2;
599 if (pfd[i].revents != 0) {
600 process_final_rx(pfd[i].fd);
603 if ((opt.count == 0 || count < opt.count) &&
611 for (i=0; i<num_interfaces; i++)
617 struct poptOption optionsTable[] = {
618 { "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" },
619 { "count", 'c', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.count, 0, "The count of messages to send, zero corresponds to infinity", "num"},
620 { "id", 'i', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.id, 0, "CAN ID of sent messages", "id"},
621 { "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"},
622 { "timeout",'t', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.timeout_ms,0, "Timeout when period is zero", "ms"},
623 { "oneattime",'o', POPT_ARG_NONE, &opt.oneattime,0, "Send the next message only when the previous was finally received"},
624 { "verbose",'v', POPT_ARG_NONE, NULL, 'v', "Send the next message only when the previous was finally received"},
625 { "file", 'f', POPT_ARG_STRING, NULL, 'f', "File where to store results", "filename"},
626 { "histogram", 'h', POPT_ARG_STRING, NULL, 'h', "Store histogram in file", "filename"},
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"},
630 { NULL, 0, 0, NULL, 0 }
633 int parse_options(int argc, const char *argv[])
636 poptContext optCon; /* context for parsing command-line options */
638 optCon = poptGetContext(NULL, argc, argv, optionsTable, 0);
639 //poptSetOtherOptionHelp(optCon, "[OPTIONS]* <port>");
641 /* Now do options processing */
642 while ((c = poptGetNextOpt(optCon)) >= 0) {
648 opt.file = fopen(poptGetOptArg(optCon), "w");
650 error(1, errno, "fopen: %s", poptGetOptArg(optCon));
653 opt.histogram = fopen(poptGetOptArg(optCon), "w");
655 error(1, errno, "fopen: %s", poptGetOptArg(optCon));
660 error(1, 0, "%s: %s\n",
661 poptBadOption(optCon, POPT_BADOPTION_NOALIAS),
664 if (num_interfaces < 2 || num_interfaces > 3)
665 error(1, 0, "-d option must be given exactly 2 or 3 times");
667 if (opt.oneattime && opt.period_us)
668 error(1, 0, "oneattime and period cannot be specified at the same time");
670 poptFreeContext(optCon);
676 int main(int argc, const char *argv[])
682 parse_options(argc, argv);
684 mlockall(MCL_CURRENT | MCL_FUTURE);
686 signal(SIGINT, term_handler);
687 signal(SIGTERM, term_handler);
689 for (i=0; i<MAX_INFOS; i++)
690 msg_infos[i].id = -1;
693 histogram_init(&histogram, 5000000, 1);
696 ret = pipe(completion_pipe);
698 error(1, errno, "pipe");
699 ret = fcntl(completion_pipe[1], F_SETFL, O_NONBLOCK);
701 error(1, errno, "pipe fcntl");
705 pthread_create(&thread, 0, measure_thread, NULL);
707 struct timespec next, now, diff;
708 clock_gettime(CLOCK_MONOTONIC, &next);
710 while (!finish_flag && (opt.count == 0 || completed < opt.count)) {
711 struct pollfd pfd[1];
712 pfd[0].fd = completion_pipe[0];
713 pfd[0].events = POLLIN;
714 ret = poll(pfd, 1, 100);
715 if (ret == -1 && !INTERRUPTED_SYSCALL(errno))
716 error(1, errno, "poll main");
717 if (ret > 0 && (pfd[0].revents & POLLIN)) {
720 ret = read(completion_pipe[0], &mi, sizeof(mi));
721 if (ret < sizeof(mi))
722 error(1, errno, "read completion returned %d", ret);
724 msg_info_print(opt.file, mi);
729 clock_gettime(CLOCK_MONOTONIC, &now);
730 if (timespec_subtract(&diff, &next, &now)) {
731 printf("\rMessage %d", count);
733 next.tv_nsec += 100000000;
734 while (next.tv_nsec >= 1000000000) {
735 next.tv_nsec -= 1000000000;
740 printf("\rMessage %d\n", count);
742 pthread_join(thread, NULL);
744 close(completion_pipe[0]);
745 close(completion_pipe[1]);
748 histogram_fprint(&histogram, opt.histogram);
749 fclose(opt.histogram);