1 /**************************************************************************/
2 /* CAN latency tester */
3 /* Copyright (C) 2010 Michal Sojka, DCE FEE CTU Prague */
5 /**************************************************************************/
14 #include <semaphore.h>
21 #include <sys/ioctl.h>
23 #include <sys/types.h>
24 //#include <ul_list.h>
28 #include <sys/socket.h>
29 #include <linux/can.h>
30 #include <linux/can/raw.h>
35 #include "histogram.h"
38 #define dbg(level, fmt, arg...) do {} while (0)
40 #define dbg(level, fmt, arg...) do { if (level <= DEBUG) { printf("candping: " fmt, ## arg); } } while (0)
43 #define INTERRUPTED_SYSCALL(errno) (errno == EINTR || errno == ERESTART)
45 #define MEMSET_ZERO(obj) memset(&(obj), 0, sizeof(obj))
47 /* Global variables */
48 volatile sig_atomic_t finish_flag = 0; /* Threads should terminate. */
49 sem_t finish_sem; /* Thread signals a termination */
51 /* Command line options */
68 int num_interfaces = 0;
73 struct timespec ts_sent, ts_sent_kern;
74 struct timespec ts_rx_onwire, ts_rx_onwire_kern;
75 struct timespec ts_rx_final, ts_rx_final_kern;
78 #define MAX_INFOS 10000
79 struct msg_info msg_infos[MAX_INFOS];
80 uint16_t curr_msg = 0;
82 struct histogram histogram;
84 static inline struct msg_info *frame2info(struct can_frame *frame)
87 if (frame->can_dlc == 2) {
88 memcpy(&idx, frame->data, sizeof(idx));
90 error(1, 0, "%s idx too high", __FUNCTION__);
92 error(1, 0, "%s error", __FUNCTION__);
93 return &msg_infos[idx];
96 static inline char *tstamp_str(const void *ctx, struct timespec *tstamp)
98 return talloc_asprintf(ctx, "%ld.%06ld",
99 tstamp->tv_sec, tstamp->tv_nsec/1000);
102 void print_msg_info(struct msg_info *mi)
104 struct timespec diff;
105 void *local = talloc_new (NULL);
107 #define S(ts) tstamp_str(local, &ts)
108 #define DIFF(a, b) (timespec_subtract(&diff, &b, &a), S(diff))
110 if (num_interfaces == 2)
111 printf("%s -> %s (%s) = %s (%s)\n",
112 S(mi->ts_sent), S(mi->ts_rx_final_kern), S(mi->ts_rx_final),
113 DIFF(mi->ts_sent, mi->ts_rx_onwire_kern),
114 DIFF(mi->ts_sent, mi->ts_rx_onwire));
116 printf("%s -> %s (%s) -> %s (%s) = %s (%s), %s (%s)\n",
118 S(mi->ts_rx_onwire_kern), S(mi->ts_rx_onwire),
119 S(mi->ts_rx_final_kern), S(mi->ts_rx_final),
120 DIFF(mi->ts_sent, mi->ts_rx_onwire_kern),
121 DIFF(mi->ts_sent, mi->ts_rx_onwire),
122 DIFF(mi->ts_rx_onwire_kern, mi->ts_rx_final_kern),
123 DIFF(mi->ts_rx_onwire, mi->ts_rx_final));
130 /* Subtract the `struct timespec' values X and Y, storing the result in
131 RESULT. Return 1 if the difference is negative, otherwise 0. */
133 int timespec_subtract (struct timespec *result, struct timespec *x, struct timespec *yy)
135 struct timespec ylocal = *yy, *y = &ylocal;
136 /* Perform the carry for the later subtraction by updating Y. */
137 if (x->tv_nsec < y->tv_nsec) {
138 int nsec = (y->tv_nsec - x->tv_nsec) / 1000000000 + 1;
139 y->tv_nsec -= 1000000000 * nsec;
142 if (x->tv_nsec - y->tv_nsec > 1000000000) {
143 int nsec = (x->tv_nsec - y->tv_nsec) / 1000000000;
144 y->tv_nsec += 1000000000 * nsec;
148 /* Compute the time remaining to wait.
149 `tv_nsec' is certainly positive. */
150 result->tv_sec = x->tv_sec - y->tv_sec;
151 result->tv_nsec = x->tv_nsec - y->tv_nsec;
153 /* Return 1 if result is negative. */
154 return x->tv_sec < y->tv_sec;
157 void dbg_print_timespec(char *msg, struct timespec *tv)
160 printf("%s sec=%ld nsec=%ld\n", msg, tv->tv_sec, tv->tv_nsec);
163 static inline unsigned get_msg_latency_us(struct msg_info *mi)
165 struct timespec diff;
166 timespec_subtract(&diff, &mi->ts_rx_final_kern, &mi->ts_rx_onwire_kern);
167 return diff.tv_sec * 1000000 + diff.tv_nsec/1000;
170 void set_sched_policy_and_prio(int policy, int rtprio)
172 struct sched_param scheduling_parameters;
173 int maxprio=sched_get_priority_max(policy);
174 int minprio=sched_get_priority_min(policy);
176 if((rtprio < minprio) || (rtprio > maxprio))
177 error(1, 0, "The priority for requested policy is out of <%d, %d> range\n",
180 scheduling_parameters.sched_priority = rtprio;
182 if (0 != pthread_setschedparam(pthread_self(), policy, &scheduling_parameters))
183 error(1, errno, "pthread_setschedparam error");
186 void term_handler(int signum)
191 static inline int sock_get_if_index(int s, const char *if_name)
196 strcpy(ifr.ifr_name, if_name);
197 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0)
198 error(1, errno, "SIOCGIFINDEX '%s'", if_name);
199 return ifr.ifr_ifindex;
202 static inline get_tstamp(struct timespec *ts)
204 clock_gettime(CLOCK_REALTIME, ts);
207 int send_frame(int socket)
209 struct can_frame frame;
213 frame.can_id = opt.id;
215 memcpy(frame.data, &curr_msg, sizeof(curr_msg));
216 mi = frame2info(&frame);
218 get_tstamp(&mi->ts_sent);
219 ret = write(socket, &frame, sizeof(frame));
223 static inline void get_next_timeout(struct timespec *timeout)
226 static struct timespec last = {-1, 0 };
228 clock_gettime(CLOCK_MONOTONIC, &now);
230 if (last.tv_sec == -1)
232 if (opt.period_us != 0) {
233 last.tv_sec += opt.period_us/1000000;
234 last.tv_nsec += (opt.period_us%1000000)*1000;
235 while (last.tv_nsec >= 1000000000) {
236 last.tv_nsec -= 1000000000;
239 timespec_subtract(timeout, &last, &now);
240 } else if (opt.timeout_ms != 0) {
241 timeout->tv_sec = opt.timeout_ms/1000;
242 timeout->tv_nsec = (opt.timeout_ms%1000)*1000000;
244 error(1, 0, "Timeout and period cannot be both zero");
247 void receive(int s, struct can_frame *frame, struct timespec *ts_kern, struct timespec *ts_user)
249 char ctrlmsg[CMSG_SPACE(sizeof(struct timeval)) + CMSG_SPACE(sizeof(__u32))];
252 struct cmsghdr *cmsg;
253 struct sockaddr_can addr;
255 static uint64_t dropcnt = 0;
257 iov.iov_base = frame;
258 msg.msg_name = &addr;
261 msg.msg_control = &ctrlmsg;
263 /* these settings may be modified by recvmsg() */
264 iov.iov_len = sizeof(*frame);
265 msg.msg_namelen = sizeof(addr);
266 msg.msg_controllen = sizeof(ctrlmsg);
269 nbytes = recvmsg(s, &msg, 0);
271 error(1, errno, "recvmsg");
273 if (nbytes < sizeof(struct can_frame))
274 error(1, 0, "recvmsg: incomplete CAN frame\n");
277 MEMSET_ZERO(*ts_kern);
278 for (cmsg = CMSG_FIRSTHDR(&msg);
279 cmsg && (cmsg->cmsg_level == SOL_SOCKET);
280 cmsg = CMSG_NXTHDR(&msg,cmsg)) {
281 if (cmsg->cmsg_type == SO_TIMESTAMPNS)
282 *ts_kern = *(struct timespec *)CMSG_DATA(cmsg);
283 else if (cmsg->cmsg_type == SO_RXQ_OVFL)
284 dropcnt += *(__u32 *)CMSG_DATA(cmsg);
289 void process_tx(int s)
291 error(1, 0, "%s: not implemented", __FUNCTION__);
294 void process_on_wire_rx(int s)
296 struct timespec ts_kern, ts_user, ts_diff;
297 struct can_frame frame;
299 receive(s, &frame, &ts_kern, &ts_user);
300 mi = frame2info(&frame);
301 mi->ts_rx_onwire_kern = ts_kern;
302 mi->ts_rx_onwire = ts_user;
306 void process_final_rx(int s)
308 struct timespec ts_kern, ts_user, ts_diff;
309 struct can_frame frame;
311 receive(s, &frame, &ts_kern, &ts_user);
312 mi = frame2info(&frame);
313 mi->ts_rx_final_kern = ts_kern;
314 mi->ts_rx_final = ts_user;
316 if (opt.histogram_fn)
317 histogram_add(&histogram, get_msg_latency_us(mi));
323 void *measure_thread(void *arg)
326 struct pollfd pfd[3];
327 struct timespec timeout;
328 struct sockaddr_can addr;
331 unsigned msg_in_progress = 0;
335 for (i=0; i<num_interfaces; i++) {
336 if ((s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0)
337 error(1, errno, "socket");
339 addr.can_family = AF_CAN;
340 addr.can_ifindex = sock_get_if_index(s, opt.interface[i]);
342 if (i == 0) { /* TX socket */
343 /* disable default receive filter on this RAW socket */
344 /* This is obsolete as we do not read from the socket at all, but for */
345 /* this reason we can remove the receive list in the Kernel to save a */
346 /* little (really a very little!) CPU usage. */
347 if (setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0) == -1)
348 error(1, errno, "SOL_CAN_RAW");
351 if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0)
352 error(1, errno, "bind");
354 const int timestamp_on = 1;
355 if (setsockopt(s, SOL_SOCKET, SO_TIMESTAMPNS,
356 ×tamp_on, sizeof(timestamp_on)) < 0)
357 error(1, errno, "setsockopt SO_TIMESTAMP");
359 // const int dropmonitor_on = 1;
360 // if (setsockopt(s, SOL_SOCKET, SO_RXQ_OVFL,
361 // &dropmonitor_on, sizeof(dropmonitor_on)) < 0)
362 // error(1, errno, "setsockopt SO_RXQ_OVFL not supported by your Linux Kernel");
366 pfd[i].events = POLLIN | POLLERR | ((opt.period_us == 0 && !opt.oneattime) ? POLLOUT : 0);
368 pfd[i].events = POLLIN;
371 set_sched_policy_and_prio(SCHED_FIFO, 99);
374 do { printf("send\n"); \
375 ret = send_frame(pfd[0].fd); \
376 if (ret != sizeof(struct can_frame)) \
377 error(1, errno, "send_frame"); \
386 while (!finish_flag &&
387 (opt.count == 0 || count < opt.count || msg_in_progress != 0)) {
389 get_next_timeout(&timeout);
392 ret = ppoll(pfd, num_interfaces, &timeout, NULL);
393 printf("=%d\n", ret);
396 if (!INTERRUPTED_SYSCALL(errno))
397 error(1, errno, "ppoll");
401 if (opt.count == 0 || count++ < opt.count) {
404 error(1, 0, "poll timeout");
409 if (pfd[0].revents & (POLLIN|POLLERR)) {
410 process_tx(pfd[0].fd);
412 if (pfd[0].revents & POLLOUT) {
413 if (opt.count == 0 || count++ < opt.count)
418 if (num_interfaces == 3 && pfd[1].revents != 0) {
419 process_on_wire_rx(pfd[1].fd);
423 i = (num_interfaces == 2) ? 1 : 2;
424 if (pfd[i].revents != 0) {
425 process_final_rx(pfd[i].fd);
428 if ((opt.count == 0 || count++ < opt.count) &&
436 for (i=0; i<num_interfaces; i++)
442 struct poptOption optionsTable[] = {
443 { "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" },
444 { "count", 'c', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.count, 0, "The count of messages to send, zero corresponds to infinity", "num"},
445 { "id", 'i', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.id, 0, "CAN ID of sent messages", "id"},
446 { "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"},
447 { "timeout",'t', POPT_ARG_INT|POPT_ARGFLAG_SHOW_DEFAULT, &opt.timeout_ms,0, "Timeout when period is zero", "ms"},
448 { "oneattime",'o', POPT_ARG_NONE, &opt.oneattime,0, "Send the next message only when the previous was finally received"},
449 { "verbose",'v', POPT_ARG_NONE, NULL, 'v', "Send the next message only when the previous was finally received"},
450 { "file", 'f', POPT_ARG_STRING, &opt.file, 0, "File where to store results", "filename"},
451 { "histogram", 'h', POPT_ARG_STRING, &opt.histogram_fn, 0, "Store histogram in file", "filename"},
453 { NULL, 0, 0, NULL, 0 }
456 int parse_options(int argc, const char *argv[])
459 poptContext optCon; /* context for parsing command-line options */
461 optCon = poptGetContext(NULL, argc, argv, optionsTable, 0);
462 //poptSetOtherOptionHelp(optCon, "[OPTIONS]* <port>");
464 /* Now do options processing */
465 while ((c = poptGetNextOpt(optCon)) >= 0) {
473 error(1, 0, "%s: %s\n",
474 poptBadOption(optCon, POPT_BADOPTION_NOALIAS),
477 if (num_interfaces < 2 || num_interfaces > 3)
478 error(1, 0, "-d option must be given exactly 2 or 3 times");
480 if (opt.oneattime && opt.period_us)
481 error(1, 0, "oneattime and period cannot be specified at the same time");
483 poptFreeContext(optCon);
489 int main(int argc, const char *argv[])
496 parse_options(argc, argv);
498 mlockall(MCL_CURRENT | MCL_FUTURE);
500 signal(SIGINT, term_handler);
501 signal(SIGTERM, term_handler);
503 if (opt.histogram_fn) {
504 histogram_init(&histogram, 1000000, 5);
505 fhist = fopen(opt.histogram_fn, "w");
507 error(1, errno, "open %s", opt.histogram_fn);
511 pthread_create(&thread, 0, measure_thread, NULL);
513 /* while (!finish_flag) { */
517 pthread_join(thread, NULL);
519 if (opt.histogram_fn) {
520 histogram_fprint(&histogram, fhist);