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 = {
75 int num_interfaces = 0;
76 int count = 0; /* Number of sent messages */
77 int completion_pipe[2];
82 struct timespec ts_sent, ts_sent_kern;
83 struct timespec ts_rx_onwire, ts_rx_onwire_kern;
84 struct timespec ts_rx_final, ts_rx_final_kern;
85 struct can_frame sent, received;
88 #define MAX_INFOS 10000
89 struct msg_info msg_infos[MAX_INFOS];
91 struct histogram histogram;
93 void sprint_canframe(char *buf , struct can_frame *cf, int sep) {
94 /* documentation see lib.h */
97 int dlc = (cf->can_dlc > 8)? 8 : cf->can_dlc;
99 if (cf->can_id & CAN_ERR_FLAG) {
100 sprintf(buf, "%08X#", cf->can_id & (CAN_ERR_MASK|CAN_ERR_FLAG));
102 } else if (cf->can_id & CAN_EFF_FLAG) {
103 sprintf(buf, "%08X#", cf->can_id & CAN_EFF_MASK);
106 sprintf(buf, "%03X#", cf->can_id & CAN_SFF_MASK);
110 if (cf->can_id & CAN_RTR_FLAG) /* there are no ERR frames with RTR */
111 sprintf(buf+offset, "R");
113 for (i = 0; i < dlc; i++) {
114 sprintf(buf+offset, "%02X", cf->data[i]);
116 if (sep && (i+1 < dlc))
117 sprintf(buf+offset++, ".");
121 static inline struct msg_info *frame2info(struct can_frame *frame)
124 if (frame->can_dlc >= 2) {
125 memcpy(&idx, frame->data, sizeof(idx));
126 if (idx >= MAX_INFOS)
127 error(1, 0, "%s idx too high", __FUNCTION__);
130 error(1, 0, "%s error", __FUNCTION__);
132 return &msg_infos[idx];
135 static inline char *tstamp_str(const void *ctx, struct timespec *tstamp)
137 return talloc_asprintf(ctx, "%ld.%06ld",
138 tstamp->tv_sec, tstamp->tv_nsec/1000);
141 void msg_info_print(FILE *f, struct msg_info *mi)
143 struct timespec diff;
144 void *local = talloc_new (NULL);
146 char sent[64], received[64];
148 sprint_canframe(sent, &mi->sent, true);
149 sprint_canframe(received, &mi->received, true);
151 #define S(ts) tstamp_str(local, &ts)
152 #define DIFF(a, b) (timespec_subtract(&diff, &b, &a), S(diff))
154 if (num_interfaces == 2)
155 fprintf(f, "%ld: %s %s -> %s (%s) %s = %s (%s)\n",
156 num, S(mi->ts_sent), sent, S(mi->ts_rx_final_kern), S(mi->ts_rx_final), received,
157 DIFF(mi->ts_sent, mi->ts_rx_final_kern),
158 DIFF(mi->ts_sent, mi->ts_rx_final));
160 fprintf(f, "%ld: %s %s -> %s (%s) -> %s (%s) %s = %s (%s), %s (%s)\n",
161 num, S(mi->ts_sent), sent,
162 S(mi->ts_rx_onwire_kern), S(mi->ts_rx_onwire),
163 S(mi->ts_rx_final_kern), S(mi->ts_rx_final), received,
164 DIFF(mi->ts_sent, mi->ts_rx_onwire_kern),
165 DIFF(mi->ts_sent, mi->ts_rx_onwire),
166 DIFF(mi->ts_rx_onwire_kern, mi->ts_rx_final_kern),
167 DIFF(mi->ts_rx_onwire, mi->ts_rx_final));
174 int msg_info_store(FILE *f, struct msg_info *mi)
176 struct timespec diff;
177 void *local = talloc_new (NULL);
180 #define S(ts) tstamp_str(local, &ts)
181 #define DIFF(a, b) (timespec_subtract(&diff, &b, &a), S(diff))
183 if (num_interfaces == 2)
184 fprintf(f, "%ld %d %d %s\n",
185 num, mi->id, mi->length,
186 DIFF(mi->ts_sent, mi->ts_rx_final_kern));
188 fprintf(f, "%ld %d %d %s\n",
189 num, mi->id, mi->length,
190 DIFF(mi->ts_rx_onwire_kern, mi->ts_rx_final_kern));
197 /* Subtract the `struct timespec' values X and Y, storing the result in
198 RESULT. Return 1 if the difference is negative, otherwise 0. */
200 int timespec_subtract (struct timespec *result, struct timespec *x, struct timespec *yy)
202 struct timespec ylocal = *yy, *y = &ylocal;
203 /* Perform the carry for the later subtraction by updating Y. */
204 if (x->tv_nsec < y->tv_nsec) {
205 int nsec = (y->tv_nsec - x->tv_nsec) / 1000000000 + 1;
206 y->tv_nsec -= 1000000000 * nsec;
209 if (x->tv_nsec - y->tv_nsec > 1000000000) {
210 int nsec = (x->tv_nsec - y->tv_nsec) / 1000000000;
211 y->tv_nsec += 1000000000 * nsec;
215 /* Compute the time remaining to wait.
216 `tv_nsec' is certainly positive. */
217 result->tv_sec = x->tv_sec - y->tv_sec;
218 result->tv_nsec = x->tv_nsec - y->tv_nsec;
220 /* Return 1 if result is negative. */
221 return x->tv_sec < y->tv_sec;
224 void dbg_print_timespec(char *msg, struct timespec *tv)
227 printf("%s sec=%ld nsec=%ld\n", msg, tv->tv_sec, tv->tv_nsec);
230 static inline unsigned get_msg_latency_us(struct msg_info *mi)
232 struct timespec diff;
233 if (num_interfaces == 3)
235 timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_rx_onwire_kern);
237 timespec_subtract(&diff, &mi->ts_rx_final, &mi->ts_rx_onwire);
240 timespec_subtract(&diff, &mi->ts_rx_final, &mi->ts_sent);
242 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 int send_frame(int socket)
321 struct can_frame frame;
324 static int curr_msg = -1;
330 while (msg_infos[i].id != -1 && i != curr_msg) {
336 error(1, 0, "Msg info table is full! Probably, many packets were lost.");
340 frame.can_id = opt.id;
342 error(1, 0, "Length < 2 is not yet supported");
343 frame.can_dlc = opt.length;
345 memcpy(frame.data, &idx, sizeof(idx));
346 mi = frame2info(&frame);
348 mi->id = frame.can_id;
349 mi->length = frame.can_dlc;
350 get_tstamp(&mi->ts_sent);
354 write(trace_fd, "1", 1);
355 ret = write(socket, &frame, sizeof(frame));
356 if (marker_fd >= 0) {
358 sprintf(marker, "write returned %d\n", ret);
359 write(marker_fd, marker, strlen(marker));
362 write(trace_fd, "0", 1);
366 void msg_info_free(struct msg_info *mi)
371 static inline void get_next_timeout(struct timespec *timeout)
374 static struct timespec last = {-1, 0 };
376 clock_gettime(CLOCK_MONOTONIC, &now);
378 if (last.tv_sec == -1)
380 if (opt.period_us != 0) {
381 last.tv_sec += opt.period_us/1000000;
382 last.tv_nsec += (opt.period_us%1000000)*1000;
383 while (last.tv_nsec >= 1000000000) {
384 last.tv_nsec -= 1000000000;
387 timespec_subtract(timeout, &last, &now);
388 } else if (opt.timeout_ms != 0) {
389 timeout->tv_sec = opt.timeout_ms/1000;
390 timeout->tv_nsec = (opt.timeout_ms%1000)*1000000;
392 error(1, 0, "Timeout and period cannot be both zero");
395 void receive(int s, struct can_frame *frame, struct timespec *ts_kern, struct timespec *ts_user)
397 char ctrlmsg[CMSG_SPACE(sizeof(struct timeval)) + CMSG_SPACE(sizeof(__u32))];
400 struct cmsghdr *cmsg;
401 struct sockaddr_can addr;
403 static uint64_t dropcnt = 0;
405 iov.iov_base = frame;
406 msg.msg_name = &addr;
409 msg.msg_control = &ctrlmsg;
411 /* these settings may be modified by recvmsg() */
412 iov.iov_len = sizeof(*frame);
413 msg.msg_namelen = sizeof(addr);
414 msg.msg_controllen = sizeof(ctrlmsg);
417 nbytes = recvmsg(s, &msg, 0);
419 error(1, errno, "recvmsg");
421 if (nbytes < sizeof(struct can_frame))
422 error(1, 0, "recvmsg: incomplete CAN frame\n");
425 MEMSET_ZERO(*ts_kern);
426 for (cmsg = CMSG_FIRSTHDR(&msg);
427 cmsg && (cmsg->cmsg_level == SOL_SOCKET);
428 cmsg = CMSG_NXTHDR(&msg,cmsg)) {
429 if (cmsg->cmsg_type == SO_TIMESTAMPNS)
430 *ts_kern = *(struct timespec *)CMSG_DATA(cmsg);
431 else if (cmsg->cmsg_type == SO_RXQ_OVFL)
432 dropcnt += *(__u32 *)CMSG_DATA(cmsg);
437 void process_tx(int s)
439 error(1, 0, "%s: not implemented", __FUNCTION__);
442 void process_on_wire_rx(int s)
444 struct timespec ts_kern, ts_user, ts_diff;
445 struct can_frame frame;
447 receive(s, &frame, &ts_kern, &ts_user);
448 mi = frame2info(&frame);
449 mi->ts_rx_onwire_kern = ts_kern;
450 mi->ts_rx_onwire = ts_user;
454 void process_final_rx(int s)
456 struct timespec ts_kern, ts_user, ts_diff;
457 struct can_frame frame;
461 receive(s, &frame, &ts_kern, &ts_user);
462 mi = frame2info(&frame);
463 mi->ts_rx_final_kern = ts_kern;
464 mi->ts_rx_final = ts_user;
465 mi->received = frame;
468 histogram_add(&histogram, get_msg_latency_us(mi));
470 ret = write(completion_pipe[1], &mi, sizeof(mi));
472 error(1, errno, "completion_pipe write");
475 void *measure_thread(void *arg)
478 struct pollfd pfd[3];
479 struct timespec timeout;
480 struct sockaddr_can addr;
482 unsigned msg_in_progress = 0;
486 for (i=0; i<num_interfaces; i++) {
487 if ((s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0)
488 error(1, errno, "socket");
490 addr.can_family = AF_CAN;
491 addr.can_ifindex = sock_get_if_index(s, opt.interface[i]);
493 if (i == 0) { /* TX socket */
494 /* disable default receive filter on this RAW socket */
495 /* This is obsolete as we do not read from the socket at all, but for */
496 /* this reason we can remove the receive list in the Kernel to save a */
497 /* little (really a very little!) CPU usage. */
498 if (setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0) == -1)
499 error(1, errno, "SOL_CAN_RAW");
502 if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0)
503 error(1, errno, "bind");
505 const int timestamp_on = 1;
506 if (setsockopt(s, SOL_SOCKET, SO_TIMESTAMPNS,
507 ×tamp_on, sizeof(timestamp_on)) < 0)
508 error(1, errno, "setsockopt SO_TIMESTAMP");
510 const int dropmonitor_on = 1;
511 if (setsockopt(s, SOL_SOCKET, SO_RXQ_OVFL,
512 &dropmonitor_on, sizeof(dropmonitor_on)) < 0)
513 error(1, errno, "setsockopt SO_RXQ_OVFL not supported by your Linux Kernel");
517 pfd[i].events = POLLIN | POLLERR | ((opt.period_us == 0 && !opt.oneattime) ? POLLOUT : 0);
519 pfd[i].events = POLLIN;
522 set_sched_policy_and_prio(SCHED_FIFO, 99);
526 ret = send_frame(pfd[0].fd); \
527 if (ret != sizeof(struct can_frame)) \
528 error(1, errno, "send_frame (line %d)", __LINE__); \
538 while (!finish_flag &&
539 (opt.count == 0 || count < opt.count || msg_in_progress != 0)) {
541 get_next_timeout(&timeout);
542 //printf("ppoll"); fflush(stdout);
543 ret = ppoll(pfd, num_interfaces, &timeout, NULL);
544 //printf("=%d\n", ret);
547 if (!INTERRUPTED_SYSCALL(errno))
548 error(1, errno, "ppoll");
552 if (opt.count == 0 || count < opt.count) {
556 error(1, 0, "poll timeout");
560 if (pfd[0].revents & (POLLIN|POLLERR)) {
561 process_tx(pfd[0].fd);
563 if (pfd[0].revents & POLLOUT) {
564 if (opt.count == 0 || count < opt.count)
569 if (num_interfaces == 3 && pfd[1].revents != 0) {
570 process_on_wire_rx(pfd[1].fd);
574 i = (num_interfaces == 2) ? 1 : 2;
575 if (pfd[i].revents != 0) {
576 process_final_rx(pfd[i].fd);
579 if ((opt.count == 0 || count < opt.count) &&
587 for (i=0; i<num_interfaces; i++)
593 struct poptOption optionsTable[] = {
594 { "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" },
595 { "count", 'c', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.count, 0, "The count of messages to send, zero corresponds to infinity", "num"},
596 { "id", 'i', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.id, 0, "CAN ID of sent messages", "id"},
597 { "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"},
598 { "timeout",'t', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.timeout_ms,0, "Timeout when period is zero", "ms"},
599 { "oneattime",'o', POPT_ARG_NONE, &opt.oneattime,0, "Send the next message only when the previous was finally received"},
600 { "verbose",'v', POPT_ARG_NONE, NULL, 'v', "Send the next message only when the previous was finally received"},
601 { "file", 'f', POPT_ARG_STRING, NULL, 'f', "File where to store results", "filename"},
602 { "histogram", 'h', POPT_ARG_STRING, NULL, 'h', "Store histogram in file", "filename"},
603 { "length", 'l', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.length, 0, "The length of generated messages", "bytes"},
604 { "userhist", 'u', POPT_ARG_NONE, &opt.userhist, 0, "Generate histogram from userspace timestamps"},
606 { NULL, 0, 0, NULL, 0 }
609 int parse_options(int argc, const char *argv[])
612 poptContext optCon; /* context for parsing command-line options */
614 optCon = poptGetContext(NULL, argc, argv, optionsTable, 0);
615 //poptSetOtherOptionHelp(optCon, "[OPTIONS]* <port>");
617 /* Now do options processing */
618 while ((c = poptGetNextOpt(optCon)) >= 0) {
624 opt.file = fopen(poptGetOptArg(optCon), "w");
626 error(1, errno, "fopen: %s", poptGetOptArg(optCon));
629 opt.histogram = fopen(poptGetOptArg(optCon), "w");
631 error(1, errno, "fopen: %s", poptGetOptArg(optCon));
636 error(1, 0, "%s: %s\n",
637 poptBadOption(optCon, POPT_BADOPTION_NOALIAS),
640 if (num_interfaces < 2 || num_interfaces > 3)
641 error(1, 0, "-d option must be given exactly 2 or 3 times");
643 if (opt.oneattime && opt.period_us)
644 error(1, 0, "oneattime and period cannot be specified at the same time");
646 poptFreeContext(optCon);
652 int main(int argc, const char *argv[])
658 parse_options(argc, argv);
660 mlockall(MCL_CURRENT | MCL_FUTURE);
662 signal(SIGINT, term_handler);
663 signal(SIGTERM, term_handler);
665 for (i=0; i<MAX_INFOS; i++)
666 msg_infos[i].id = -1;
669 histogram_init(&histogram, 5000000, 1);
672 ret = pipe(completion_pipe);
674 error(1, errno, "pipe");
675 ret = fcntl(completion_pipe[1], F_SETFL, O_NONBLOCK);
677 error(1, errno, "pipe fcntl");
681 pthread_create(&thread, 0, measure_thread, NULL);
683 struct timespec next, now, diff;
684 clock_gettime(CLOCK_MONOTONIC, &next);
686 while (!finish_flag && (opt.count == 0 || completed < opt.count)) {
687 struct pollfd pfd[1];
688 pfd[0].fd = completion_pipe[0];
689 pfd[0].events = POLLIN;
690 ret = poll(pfd, 1, 100);
691 if (ret == -1 && !INTERRUPTED_SYSCALL(errno))
692 error(1, errno, "poll main");
693 if (ret > 0 && (pfd[0].revents & POLLIN)) {
696 ret = read(completion_pipe[0], &mi, sizeof(mi));
697 if (ret < sizeof(mi))
698 error(1, errno, "read completion returned %d", ret);
700 msg_info_print(opt.file, mi);
705 clock_gettime(CLOCK_MONOTONIC, &now);
706 if (timespec_subtract(&diff, &next, &now)) {
707 printf("\rMessage %d", count);
709 next.tv_nsec += 100000000;
710 while (next.tv_nsec >= 1000000000) {
711 next.tv_nsec -= 1000000000;
716 printf("\rMessage %d\n", count);
718 pthread_join(thread, NULL);
720 close(completion_pipe[0]);
721 close(completion_pipe[1]);
724 histogram_fprint(&histogram, opt.histogram);
725 fclose(opt.histogram);