Author: asomers Date: Tue Aug 13 19:27:23 2019 New Revision: 350998 URL: https://svnweb.freebsd.org/changeset/base/350998
Log: ping: use the monotonic clock to measure durations Submitted by: Ján Sučan <sucan...@gmail.com> MFC after: 2 weeks Sponsored by: Google, inc. (Google Summer of Code 2019) Differential Revision: https://reviews.freebsd.org/D21245 Modified: head/sbin/ping/ping.c Modified: head/sbin/ping/ping.c ============================================================================== --- head/sbin/ping/ping.c Tue Aug 13 19:24:17 2019 (r350997) +++ head/sbin/ping/ping.c Tue Aug 13 19:27:23 2019 (r350998) @@ -96,6 +96,7 @@ __FBSDID("$FreeBSD$"); #include <stdlib.h> #include <string.h> #include <sysexits.h> +#include <time.h> #include <unistd.h> #define INADDR_LEN ((int)sizeof(in_addr_t)) @@ -119,7 +120,7 @@ __FBSDID("$FreeBSD$"); struct tv32 { int32_t tv32_sec; - int32_t tv32_usec; + int32_t tv32_nsec; }; /* various options */ @@ -217,11 +218,10 @@ static char *pr_addr(struct in_addr); static char *pr_ntime(n_time); static void pr_icmph(struct icmp *); static void pr_iph(struct ip *); -static void pr_pack(char *, int, struct sockaddr_in *, struct timeval *); +static void pr_pack(char *, int, struct sockaddr_in *, struct timespec *); static void pr_retip(struct ip *); static void status(int); static void stopit(int); -static void tvsub(struct timeval *, const struct timeval *); static void usage(void) __dead2; int @@ -229,7 +229,7 @@ main(int argc, char *const *argv) { struct sockaddr_in from, sock_in; struct in_addr ifaddr; - struct timeval last, intvl; + struct timespec last, intvl; struct iovec iov; struct ip *ip; struct msghdr msg; @@ -247,7 +247,7 @@ main(int argc, char *const *argv) long ltmp; int almost_done, ch, df, hold, i, icmp_len, mib[4], preload; int ssend_errno, srecv_errno, tos, ttl; - char ctrl[CMSG_SPACE(sizeof(struct timeval))]; + char ctrl[CMSG_SPACE(sizeof(struct timespec))]; char hnamebuf[MAXHOSTNAMELEN], snamebuf[MAXHOSTNAMELEN]; #ifdef IP_OPTIONS char rspace[MAX_IPOPTLEN]; /* record route space */ @@ -871,19 +871,19 @@ main(int argc, char *const *argv) while (preload--) /* fire off them quickies */ pinger(); } - (void)gettimeofday(&last, NULL); + (void)clock_gettime(CLOCK_MONOTONIC, &last); if (options & F_FLOOD) { intvl.tv_sec = 0; - intvl.tv_usec = 10000; + intvl.tv_nsec = 10000000; } else { intvl.tv_sec = interval / 1000; - intvl.tv_usec = interval % 1000 * 1000; + intvl.tv_nsec = interval % 1000 * 1000000; } almost_done = 0; while (!finish_up) { - struct timeval now, timeout; + struct timespec now, timeout; fd_set rfds; int cc, n; @@ -892,24 +892,16 @@ main(int argc, char *const *argv) errx(EX_OSERR, "descriptor too large"); FD_ZERO(&rfds); FD_SET(srecv, &rfds); - (void)gettimeofday(&now, NULL); - timeout.tv_sec = last.tv_sec + intvl.tv_sec - now.tv_sec; - timeout.tv_usec = last.tv_usec + intvl.tv_usec - now.tv_usec; - while (timeout.tv_usec < 0) { - timeout.tv_usec += 1000000; - timeout.tv_sec--; - } - while (timeout.tv_usec >= 1000000) { - timeout.tv_usec -= 1000000; - timeout.tv_sec++; - } + (void)clock_gettime(CLOCK_MONOTONIC, &now); + timespecadd(&last, &intvl, &timeout); + timespecsub(&timeout, &now, &timeout); if (timeout.tv_sec < 0) - timerclear(&timeout); - n = select(srecv + 1, &rfds, NULL, NULL, &timeout); + timespecclear(&timeout); + n = pselect(srecv + 1, &rfds, NULL, NULL, &timeout, NULL); if (n < 0) continue; /* Must be EINTR. */ if (n == 1) { - struct timeval *tv = NULL; + struct timespec *tv = NULL; #ifdef SO_TIMESTAMP struct cmsghdr *cmsg = (struct cmsghdr *)&ctrl; @@ -932,7 +924,7 @@ main(int argc, char *const *argv) } #endif if (tv == NULL) { - (void)gettimeofday(&now, NULL); + (void)clock_gettime(CLOCK_MONOTONIC, &now); tv = &now; } pr_pack((char *)packet, cc, &from, tv); @@ -956,17 +948,17 @@ main(int argc, char *const *argv) if (almost_done) break; almost_done = 1; - intvl.tv_usec = 0; + intvl.tv_nsec = 0; if (nreceived) { intvl.tv_sec = 2 * tmax / 1000; if (!intvl.tv_sec) intvl.tv_sec = 1; } else { intvl.tv_sec = waittime / 1000; - intvl.tv_usec = waittime % 1000 * 1000; + intvl.tv_nsec = waittime % 1000 * 1000000; } } - (void)gettimeofday(&last, NULL); + (void)clock_gettime(CLOCK_MONOTONIC, &last); if (ntransmitted - nreceived - 1 > nmissedmax) { nmissedmax = ntransmitted - nreceived - 1; if (options & F_MISSED) @@ -1003,13 +995,13 @@ stopit(int sig __unused) * Compose and transmit an ICMP ECHO REQUEST packet. The IP packet * will be added on by the kernel. The ID field is our UNIX process ID, * and the sequence number is an ascending integer. The first TIMEVAL_LEN - * bytes of the data portion are used to hold a UNIX "timeval" struct in + * bytes of the data portion are used to hold a UNIX "timespec" struct in * host byte-order, to compute the round-trip time. */ static void pinger(void) { - struct timeval now; + struct timespec now; struct tv32 tv32; struct ip *ip; struct icmp *icp; @@ -1027,13 +1019,18 @@ pinger(void) CLR(ntransmitted % mx_dup_ck); if ((options & F_TIME) || timing) { - (void)gettimeofday(&now, NULL); - - tv32.tv32_sec = htonl(now.tv_sec); - tv32.tv32_usec = htonl(now.tv_usec); + (void)clock_gettime(CLOCK_MONOTONIC, &now); + /* + * Truncate seconds down to 32 bits in order + * to fit the timestamp within 8 bytes of the + * packet. We're only concerned with + * durations, not absolute times. + */ + tv32.tv32_sec = (uint32_t)htonl(now.tv_sec); + tv32.tv32_nsec = (uint32_t)htonl(now.tv_nsec); if (options & F_TIME) icp->icmp_otime = htonl((now.tv_sec % (24*60*60)) - * 1000 + now.tv_usec / 1000); + * 1000 + now.tv_nsec / 1000000); if (timing) bcopy((void *)&tv32, (void *)&outpack[ICMP_MINLEN + phdr_len], @@ -1079,7 +1076,7 @@ pinger(void) * program to be run without having intermingled output (or statistics!). */ static void -pr_pack(char *buf, int cc, struct sockaddr_in *from, struct timeval *tv) +pr_pack(char *buf, int cc, struct sockaddr_in *from, struct timespec *tv) { struct in_addr ina; u_char *cp, *dp; @@ -1112,7 +1109,7 @@ pr_pack(char *buf, int cc, struct sockaddr_in *from, s ++nreceived; triptime = 0.0; if (timing) { - struct timeval tv1; + struct timespec tv1; struct tv32 tv32; #ifndef icmp_data tp = &icp->icmp_ip; @@ -1126,10 +1123,10 @@ pr_pack(char *buf, int cc, struct sockaddr_in *from, s /* Copy to avoid alignment problems: */ memcpy(&tv32, tp, sizeof(tv32)); tv1.tv_sec = ntohl(tv32.tv32_sec); - tv1.tv_usec = ntohl(tv32.tv32_usec); - tvsub(tv, &tv1); + tv1.tv_nsec = ntohl(tv32.tv32_nsec); + timespecsub(tv, &tv1, tv); triptime = ((double)tv->tv_sec) * 1000.0 + - ((double)tv->tv_usec) / 1000.0; + ((double)tv->tv_nsec) / 1000000.0; tsum += triptime; tsumsq += triptime * triptime; if (triptime < tmin) @@ -1381,22 +1378,6 @@ in_cksum(u_short *addr, int len) sum += (sum >> 16); /* add carry */ answer = ~sum; /* truncate to 16 bits */ return(answer); -} - -/* - * tvsub -- - * Subtract 2 timeval structs: out = out - in. Out is assumed to - * be >= in. - */ -static void -tvsub(struct timeval *out, const struct timeval *in) -{ - - if ((out->tv_usec -= in->tv_usec) < 0) { - --out->tv_sec; - out->tv_usec += 1000000; - } - out->tv_sec -= in->tv_sec; } /* _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
