#include "hmap.h"
#include "ovs-thread.h"
#include "signals.h"
+#include "seq.h"
#include "unixctl.h"
#include "util.h"
#include "vlog.h"
struct clock {
clockid_t id; /* CLOCK_MONOTONIC or CLOCK_REALTIME. */
- struct ovs_rwlock rwlock; /* Mutual exclusion for 'cache'. */
- /* Features for use by unit tests. Protected by 'rwlock'. */
- struct timespec warp; /* Offset added for unit tests. */
- bool stopped; /* Disables real-time updates if true. */
-
- /* Relevant only if CACHE_TIME is true. */
- volatile sig_atomic_t tick; /* Has the timer ticked? Set by signal. */
- struct timespec cache; /* Last time read from kernel. */
+ /* Features for use by unit tests. Protected by 'mutex'. */
+ struct ovs_mutex mutex;
+ atomic_bool slow_path; /* True if warped or stopped. */
+ struct timespec warp OVS_GUARDED; /* Offset added for unit tests. */
+ bool stopped OVS_GUARDED; /* Disable real-time updates if true. */
+ struct timespec cache OVS_GUARDED; /* Last time read from kernel. */
};
/* Our clocks. */
/* The monotonic time at which the time module was initialized. */
static long long int boot_time;
+/* True only when timeval_dummy_register() is called. */
+static bool timewarp_enabled;
+/* Reference to the seq struct. Threads other than main thread can
+ * wait on timewarp_seq and be waken up when time is warped. */
+static struct seq *timewarp_seq;
+/* Last value of 'timewarp_seq'. */
+DEFINE_STATIC_PER_THREAD_DATA(uint64_t, last_seq, 0);
+
/* Monotonic time in milliseconds at which to die with SIGALRM (if not
* LLONG_MAX). */
static long long int deadline = LLONG_MAX;
* up. */
DEFINE_STATIC_PER_THREAD_DATA(long long int, last_wakeup, 0);
-static void set_up_timer(void);
-static void set_up_signal(int flags);
-static void sigalrm_handler(int);
-static void block_sigalrm(sigset_t *);
-static void unblock_sigalrm(const sigset_t *);
static void log_poll_interval(long long int last_wakeup);
static struct rusage *get_recent_rusage(void);
static void refresh_rusage(void);
{
memset(c, 0, sizeof *c);
c->id = id;
- ovs_rwlock_init(&c->rwlock);
+ ovs_mutex_init(&c->mutex);
+ atomic_init(&c->slow_path, false);
xclock_gettime(c->id, &c->cache);
+ timewarp_seq = seq_create();
}
static void
: CLOCK_REALTIME));
init_clock(&wall_clock, CLOCK_REALTIME);
boot_time = timespec_to_msec(&monotonic_clock.cache);
-
- set_up_signal(SA_RESTART);
- set_up_timer();
}
/* Initializes the timetracking module, if not already initialized. */
pthread_once(&once, do_init_time);
}
-static void
-set_up_signal(int flags)
-{
- struct sigaction sa;
-
- memset(&sa, 0, sizeof sa);
- sa.sa_handler = sigalrm_handler;
- sigemptyset(&sa.sa_mask);
- sa.sa_flags = flags;
- xsigaction(SIGALRM, &sa, NULL);
-}
-
-static void
-set_up_timer(void)
-{
- static timer_t timer_id; /* "static" to avoid apparent memory leak. */
- struct itimerspec itimer;
-
- if (!CACHE_TIME) {
- return;
- }
-
- if (timer_create(monotonic_clock.id, NULL, &timer_id)) {
- VLOG_FATAL("timer_create failed (%s)", ovs_strerror(errno));
- }
-
- itimer.it_interval.tv_sec = 0;
- itimer.it_interval.tv_nsec = TIME_UPDATE_INTERVAL * 1000 * 1000;
- itimer.it_value = itimer.it_interval;
-
- if (timer_settime(timer_id, 0, &itimer, NULL)) {
- VLOG_FATAL("timer_settime failed (%s)", ovs_strerror(errno));
- }
-}
-
-/* Set up the interval timer, to ensure that time advances even without calling
- * time_refresh().
- *
- * A child created with fork() does not inherit the parent's interval timer, so
- * this function needs to be called from the child after fork(). */
-void
-time_postfork(void)
-{
- assert_single_threaded();
- time_init();
- set_up_timer();
-}
-
-/* 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. If
- * CACHE_TIME is false, we will always refresh the current time so this
- * function has no effect. */
-void
-time_refresh(void)
-{
- monotonic_clock.tick = wall_clock.tick = true;
-}
-
static void
time_timespec__(struct clock *c, struct timespec *ts)
{
+ bool slow_path;
+
time_init();
- for (;;) {
- /* Use the cached time by preference, but fall through if there's been
- * a clock tick. */
- ovs_rwlock_rdlock(&c->rwlock);
- if (c->stopped || !c->tick) {
- timespec_add(ts, &c->cache, &c->warp);
- ovs_rwlock_unlock(&c->rwlock);
- return;
- }
- ovs_rwlock_unlock(&c->rwlock);
- /* Refresh the cache. */
- ovs_rwlock_wrlock(&c->rwlock);
- if (c->tick) {
- c->tick = false;
- xclock_gettime(c->id, &c->cache);
+ atomic_read_explicit(&c->slow_path, &slow_path, memory_order_relaxed);
+ if (!slow_path) {
+ xclock_gettime(c->id, ts);
+ } else {
+ struct timespec warp;
+ struct timespec cache;
+ bool stopped;
+
+ ovs_mutex_lock(&c->mutex);
+ stopped = c->stopped;
+ warp = c->warp;
+ cache = c->cache;
+ ovs_mutex_unlock(&c->mutex);
+
+ if (!stopped) {
+ xclock_gettime(c->id, &cache);
}
- ovs_rwlock_unlock(&c->rwlock);
+ timespec_add(ts, &cache, &warp);
}
}
assert_single_threaded();
time_init();
- time_refresh();
now = time_msec();
msecs = secs * 1000LL;
* timeout is reached. (Because of this property, this function will
* never return -EINTR.)
*
- * - As a side effect, refreshes the current time (like time_refresh()).
- *
* Stores the number of milliseconds elapsed during poll in '*elapsed'. */
int
time_poll(struct pollfd *pollfds, int n_pollfds, long long int timeout_when,
{
long long int *last_wakeup = last_wakeup_get();
long long int start;
- sigset_t oldsigs;
- bool blocked;
int retval;
time_init();
- time_refresh();
if (*last_wakeup) {
log_poll_interval(*last_wakeup);
}
coverage_clear();
+ coverage_run();
start = time_msec();
- blocked = false;
timeout_when = MIN(timeout_when, deadline);
retval = -errno;
}
- time_refresh();
if (deadline <= time_msec()) {
fatal_signal_handler(SIGALRM);
if (retval < 0) {
if (retval != -EINTR) {
break;
}
-
- if (!blocked && CACHE_TIME) {
- block_sigalrm(&oldsigs);
- blocked = true;
- }
- }
- if (blocked) {
- unblock_sigalrm(&oldsigs);
}
*last_wakeup = time_msec();
refresh_rusage();
return retval;
}
-static void
-sigalrm_handler(int sig_nr OVS_UNUSED)
-{
- monotonic_clock.tick = wall_clock.tick = true;
-}
-
-static void
-block_sigalrm(sigset_t *oldsigs)
-{
- sigset_t sigalrm;
- sigemptyset(&sigalrm);
- sigaddset(&sigalrm, SIGALRM);
- xpthread_sigmask(SIG_BLOCK, &sigalrm, oldsigs);
-}
-
-static void
-unblock_sigalrm(const sigset_t *oldsigs)
-{
- xpthread_sigmask(SIG_SETMASK, oldsigs, NULL);
-}
-
long long int
timespec_to_msec(const struct timespec *ts)
{
}
}
+/* Makes threads wait on timewarp_seq and be waken up when time is warped.
+ * This function will be no-op unless timeval_dummy_register() is called. */
+void
+timewarp_wait(void)
+{
+ if (timewarp_enabled) {
+ uint64_t *last_seq = last_seq_get();
+
+ *last_seq = seq_read(timewarp_seq);
+ seq_wait(timewarp_seq, *last_seq);
+ }
+}
+
static long long int
timeval_diff_msec(const struct timeval *a, const struct timeval *b)
{
*sum = tmp;
}
+static bool
+is_warped(const struct clock *c)
+{
+ bool warped;
+
+ ovs_mutex_lock(&c->mutex);
+ warped = monotonic_clock.warp.tv_sec || monotonic_clock.warp.tv_nsec;
+ ovs_mutex_unlock(&c->mutex);
+
+ return warped;
+}
+
static void
log_poll_interval(long long int last_wakeup)
{
long long int interval = time_msec() - last_wakeup;
- if (interval >= 1000
- && !monotonic_clock.warp.tv_sec
- && !monotonic_clock.warp.tv_nsec) {
+ if (interval >= 1000 && !is_warped(&monotonic_clock)) {
const struct rusage *last_rusage = get_recent_rusage();
struct rusage rusage;
int argc OVS_UNUSED, const char *argv[] OVS_UNUSED,
void *aux OVS_UNUSED)
{
- ovs_rwlock_wrlock(&monotonic_clock.rwlock);
+ ovs_mutex_lock(&monotonic_clock.mutex);
+ atomic_store(&monotonic_clock.slow_path, true);
monotonic_clock.stopped = true;
- ovs_rwlock_unlock(&monotonic_clock.rwlock);
+ xclock_gettime(monotonic_clock.id, &monotonic_clock.cache);
+ ovs_mutex_unlock(&monotonic_clock.mutex);
unixctl_command_reply(conn, NULL);
}
ts.tv_sec = msecs / 1000;
ts.tv_nsec = (msecs % 1000) * 1000 * 1000;
- ovs_rwlock_wrlock(&monotonic_clock.rwlock);
+ ovs_mutex_lock(&monotonic_clock.mutex);
+ atomic_store(&monotonic_clock.slow_path, true);
timespec_add(&monotonic_clock.warp, &monotonic_clock.warp, &ts);
- ovs_rwlock_unlock(&monotonic_clock.rwlock);
-
+ ovs_mutex_unlock(&monotonic_clock.mutex);
+ seq_change(timewarp_seq);
unixctl_command_reply(conn, "warped");
}
void
timeval_dummy_register(void)
{
+ timewarp_enabled = true;
unixctl_command_register("time/stop", "", 0, 0, timeval_stop_cb, NULL);
unixctl_command_register("time/warp", "MSECS", 1, 1,
timeval_warp_cb, NULL);
}
+
+
+
+/* strftime() with an extension for high-resolution timestamps. Any '#'s in
+ * 'format' will be replaced by subseconds, e.g. use "%S.###" to obtain results
+ * like "01.123". */
+size_t
+strftime_msec(char *s, size_t max, const char *format,
+ const struct tm_msec *tm)
+{
+ size_t n;
+
+ n = strftime(s, max, format, &tm->tm);
+ if (n) {
+ char decimals[4];
+ char *p;
+
+ sprintf(decimals, "%03d", tm->msec);
+ for (p = strchr(s, '#'); p; p = strchr(p, '#')) {
+ char *d = decimals;
+ while (*p == '#') {
+ *p++ = *d ? *d++ : '0';
+ }
+ }
+ }
+
+ return n;
+}
+
+struct tm_msec *
+localtime_msec(long long int now, struct tm_msec *result)
+{
+ time_t now_sec = now / 1000;
+ localtime_r(&now_sec, &result->tm);
+ result->msec = now % 1000;
+ return result;
+}
+
+struct tm_msec *
+gmtime_msec(long long int now, struct tm_msec *result)
+{
+ time_t now_sec = now / 1000;
+ gmtime_r(&now_sec, &result->tm);
+ result->msec = now % 1000;
+ return result;
+}
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