/*
- * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* to CLOCK_REALTIME. */
static clockid_t monotonic_clock;
-/* Has a timer tick occurred?
+/* Has a timer tick occurred? Only relevant if CACHE_TIME is true.
*
* We initialize these to true to force time_init() to get called on the first
* call to time_msec() or another function that queries the current time. */
static struct timespec wall_time;
static struct timespec monotonic_time;
-/* Fixed monotonic time offset, for use by unit tests. */
-static struct timespec warp_offset;
+/* The monotonic time at which the time module was initialized. */
+static long long int boot_time;
-/* Time at which to die with SIGALRM (if not TIME_MIN). */
-static time_t deadline = TIME_MIN;
+/* features for use by unit tests. */
+static struct timespec warp_offset; /* Offset added to monotonic_time. */
+static bool time_stopped; /* Disables real-time updates, if true. */
+
+/* Time in milliseconds at which to die with SIGALRM (if not LLONG_MAX). */
+static long long int deadline = LLONG_MAX;
static void set_up_timer(void);
static void set_up_signal(int flags);
static void sigalrm_handler(int);
static void refresh_wall_if_ticked(void);
static void refresh_monotonic_if_ticked(void);
-static time_t time_add(time_t, time_t);
static void block_sigalrm(sigset_t *);
static void unblock_sigalrm(const sigset_t *);
static void log_poll_interval(long long int last_wakeup);
static void timespec_add(struct timespec *sum,
const struct timespec *a, const struct timespec *b);
-/* Initializes the timetracking module.
- *
- * It is not necessary to call this function directly, because other time
- * functions will call it automatically, but it doesn't hurt. */
+/* Initializes the timetracking module, if not already initialized. */
static void
time_init(void)
{
set_up_signal(SA_RESTART);
set_up_timer();
+
+ boot_time = time_msec();
}
static void
static timer_t timer_id; /* "static" to avoid apparent memory leak. */
struct itimerspec itimer;
+ if (!CACHE_TIME) {
+ return;
+ }
+
if (timer_create(monotonic_clock, NULL, &timer_id)) {
VLOG_FATAL("timer_create failed (%s)", strerror(errno));
}
{
time_init();
- if (monotonic_clock == CLOCK_MONOTONIC) {
- clock_gettime(monotonic_clock, &monotonic_time);
- } else {
- refresh_wall_if_ticked();
- monotonic_time = wall_time;
- }
- timespec_add(&monotonic_time, &monotonic_time, &warp_offset);
+ if (!time_stopped) {
+ if (monotonic_clock == CLOCK_MONOTONIC) {
+ clock_gettime(monotonic_clock, &monotonic_time);
+ } else {
+ refresh_wall_if_ticked();
+ monotonic_time = wall_time;
+ }
+ timespec_add(&monotonic_time, &monotonic_time, &warp_offset);
- monotonic_tick = false;
+ monotonic_tick = false;
+ }
}
/* Forces a refresh of the current time from the kernel. It is not usually
* necessary to call this function, since the time will be refreshed
- * automatically at least every TIME_UPDATE_INTERVAL milliseconds. */
+ * automatically at least every TIME_UPDATE_INTERVAL milliseconds. If
+ * CACHE_TIME is false, we will always refresh the current time so this
+ * function has no effect. */
void
time_refresh(void)
{
return monotonic_time.tv_sec;
}
-/* Same as time_now() except does not write to static variables, for use in
- * signal handlers. */
-static time_t
-time_now_sig(void)
-{
- struct timespec cur_time;
-
- clock_gettime(monotonic_clock, &cur_time);
- return cur_time.tv_sec;
-}
-
/* Returns the current time, in seconds. */
time_t
time_wall(void)
void
time_alarm(unsigned int secs)
{
+ long long int now;
+ long long int msecs;
+
sigset_t oldsigs;
time_init();
+ time_refresh();
+
+ now = time_msec();
+ msecs = secs * 1000;
+
block_sigalrm(&oldsigs);
- deadline = secs ? time_add(time_now(), secs) : TIME_MIN;
+ deadline = now < LLONG_MAX - msecs ? now + msecs : LLONG_MAX;
unblock_sigalrm(&oldsigs);
}
coverage_clear();
start = time_msec();
blocked = false;
+
+ timeout_when = MIN(timeout_when, deadline);
+
for (;;) {
long long int now = time_msec();
int time_left;
if (retval < 0) {
retval = -errno;
}
+
time_refresh();
+ if (deadline <= time_msec()) {
+ fatal_signal_handler(SIGALRM);
+ if (retval < 0) {
+ retval = 0;
+ }
+ break;
+ }
+
if (retval != -EINTR) {
break;
}
- if (!blocked && deadline == TIME_MIN) {
+ if (!blocked && !CACHE_TIME) {
block_sigalrm(&oldsigs);
blocked = true;
}
return retval;
}
-/* Returns the sum of 'a' and 'b', with saturation on overflow or underflow. */
-static time_t
-time_add(time_t a, time_t b)
-{
- return (a >= 0
- ? (b > TIME_MAX - a ? TIME_MAX : a + b)
- : (b < TIME_MIN - a ? TIME_MIN : a + b));
-}
-
static void
-sigalrm_handler(int sig_nr)
+sigalrm_handler(int sig_nr OVS_UNUSED)
{
wall_tick = true;
monotonic_tick = true;
- if (deadline != TIME_MIN && time_now_sig() > deadline) {
- fatal_signal_handler(sig_nr);
- }
}
static void
refresh_wall_if_ticked(void)
{
- if (wall_tick) {
+ if (!CACHE_TIME || wall_tick) {
refresh_wall();
}
}
static void
refresh_monotonic_if_ticked(void)
{
- if (monotonic_tick) {
+ if (!CACHE_TIME || monotonic_tick) {
refresh_monotonic();
}
}
return (long long int) tv->tv_sec * 1000 + tv->tv_usec / 1000;
}
+/* Returns the monotonic time at which the "time" module was initialized, in
+ * milliseconds(). */
+long long int
+time_boot_msec(void)
+{
+ time_init();
+ return boot_time;
+}
+
void
xgettimeofday(struct timeval *tv)
{
/* Warn if we took too much time between polls: at least 50 ms and at least
* 8X the mean interval. */
if (n_samples > 10 && interval > mean_interval * 8 && interval > 50 * 16) {
- const struct rusage *last_rusage = get_recent_rusage();
- struct rusage rusage;
-
- getrusage(RUSAGE_SELF, &rusage);
- VLOG_WARN("%lld ms poll interval (%lld ms user, %lld ms system) "
- "is over %u times the weighted mean interval %u ms "
- "(%u samples)",
- now - last_wakeup,
- timeval_diff_msec(&rusage.ru_utime, &last_rusage->ru_utime),
- timeval_diff_msec(&rusage.ru_stime, &last_rusage->ru_stime),
- interval / mean_interval,
- (mean_interval + 8) / 16, n_samples);
- if (rusage.ru_minflt > last_rusage->ru_minflt
- || rusage.ru_majflt > last_rusage->ru_majflt) {
- VLOG_WARN("faults: %ld minor, %ld major",
- rusage.ru_minflt - last_rusage->ru_minflt,
- rusage.ru_majflt - last_rusage->ru_majflt);
+ static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 3);
+
+ if (!VLOG_DROP_WARN(&rl)) {
+ const struct rusage *last_rusage = get_recent_rusage();
+ struct rusage rusage;
+
+ getrusage(RUSAGE_SELF, &rusage);
+ VLOG_WARN("%lld ms poll interval (%lld ms user, %lld ms system) "
+ "is over %u times the weighted mean interval %u ms "
+ "(%u samples)",
+ now - last_wakeup,
+ timeval_diff_msec(&rusage.ru_utime,
+ &last_rusage->ru_utime),
+ timeval_diff_msec(&rusage.ru_stime,
+ &last_rusage->ru_stime),
+ interval / mean_interval,
+ (mean_interval + 8) / 16, n_samples);
+ if (rusage.ru_minflt > last_rusage->ru_minflt
+ || rusage.ru_majflt > last_rusage->ru_majflt) {
+ VLOG_WARN("faults: %ld minor, %ld major",
+ rusage.ru_minflt - last_rusage->ru_minflt,
+ rusage.ru_majflt - last_rusage->ru_majflt);
+ }
+ if (rusage.ru_inblock > last_rusage->ru_inblock
+ || rusage.ru_oublock > last_rusage->ru_oublock) {
+ VLOG_WARN("disk: %ld reads, %ld writes",
+ rusage.ru_inblock - last_rusage->ru_inblock,
+ rusage.ru_oublock - last_rusage->ru_oublock);
+ }
+ if (rusage.ru_nvcsw > last_rusage->ru_nvcsw
+ || rusage.ru_nivcsw > last_rusage->ru_nivcsw) {
+ VLOG_WARN("context switches: %ld voluntary, %ld involuntary",
+ rusage.ru_nvcsw - last_rusage->ru_nvcsw,
+ rusage.ru_nivcsw - last_rusage->ru_nivcsw);
+ }
}
- if (rusage.ru_inblock > last_rusage->ru_inblock
- || rusage.ru_oublock > last_rusage->ru_oublock) {
- VLOG_WARN("disk: %ld reads, %ld writes",
- rusage.ru_inblock - last_rusage->ru_inblock,
- rusage.ru_oublock - last_rusage->ru_oublock);
- }
- if (rusage.ru_nvcsw > last_rusage->ru_nvcsw
- || rusage.ru_nivcsw > last_rusage->ru_nivcsw) {
- VLOG_WARN("context switches: %ld voluntary, %ld involuntary",
- rusage.ru_nvcsw - last_rusage->ru_nvcsw,
- rusage.ru_nivcsw - last_rusage->ru_nivcsw);
- }
-
- /* Care should be taken in the value chosen for logging. Depending
- * on the configuration, syslog can write changes synchronously,
- * which can cause the coverage messages to take longer to log
- * than the processing delay that triggered it. */
- coverage_log(VLL_INFO, true);
+ coverage_log();
}
/* Update exponentially weighted moving average. With these parameters, a
\f
/* Unixctl interface. */
+/* "time/stop" stops the monotonic time returned by e.g. time_msec() from
+ * advancing, except due to later calls to "time/warp". */
+static void
+timeval_stop_cb(struct unixctl_conn *conn,
+ int argc OVS_UNUSED, const char *argv[] OVS_UNUSED,
+ void *aux OVS_UNUSED)
+{
+ time_stopped = true;
+ unixctl_command_reply(conn, NULL);
+}
+
+/* "time/warp MSECS" advances the current monotonic time by the specified
+ * number of milliseconds. Unless "time/stop" has also been executed, the
+ * monotonic clock continues to tick forward at the normal rate afterward.
+ *
+ * Does not affect wall clock readings. */
static void
timeval_warp_cb(struct unixctl_conn *conn,
int argc OVS_UNUSED, const char *argv[], void *aux OVS_UNUSED)
msecs = atoi(argv[1]);
if (msecs <= 0) {
- unixctl_command_reply(conn, 501, "invalid MSECS");
+ unixctl_command_reply_error(conn, "invalid MSECS");
return;
}
ts.tv_sec = msecs / 1000;
ts.tv_nsec = (msecs % 1000) * 1000 * 1000;
timespec_add(&warp_offset, &warp_offset, &ts);
- unixctl_command_reply(conn, 200, "warped");
+ timespec_add(&monotonic_time, &monotonic_time, &ts);
+ unixctl_command_reply(conn, "warped");
}
void
timeval_dummy_register(void)
{
+ unixctl_command_register("time/stop", "", 0, 0, timeval_stop_cb, NULL);
unixctl_command_register("time/warp", "MSECS", 1, 1,
timeval_warp_cb, NULL);
}
projects / openvswitch / blobdiff