X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Ftimeval.c;h=d2a4380ff068c3535780cadae6729ed6f5511390;hb=3308c696220bbfff36bf29b3e1b168449d57b3d7;hp=faf8e7bc8be277b1d3dac0b80d74822ac1f36cb3;hpb=2ba4f163d9ea84aa8b8e9d8678371a70af766b5e;p=sliver-openvswitch.git diff --git a/lib/timeval.c b/lib/timeval.c index faf8e7bc8..d2a4380ff 100644 --- a/lib/timeval.c +++ b/lib/timeval.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc. + * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014 Nicira, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -31,25 +31,40 @@ #include "fatal-signal.h" #include "hash.h" #include "hmap.h" +#include "ovs-rcu.h" #include "ovs-thread.h" #include "signals.h" +#include "seq.h" #include "unixctl.h" #include "util.h" #include "vlog.h" VLOG_DEFINE_THIS_MODULE(timeval); +#ifdef _WIN32 +typedef unsigned int clockid_t; + +#ifndef CLOCK_MONOTONIC +#define CLOCK_MONOTONIC 1 +#endif + +#ifndef CLOCK_REALTIME +#define CLOCK_REALTIME 2 +#endif + +/* Number of 100 ns intervals from January 1, 1601 till January 1, 1970. */ +static ULARGE_INTEGER unix_epoch; +#endif /* _WIN32 */ + 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. */ @@ -59,6 +74,14 @@ static struct clock wall_clock; /* CLOCK_REALTIME. */ /* 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; @@ -67,11 +90,6 @@ 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); @@ -83,8 +101,10 @@ init_clock(struct clock *c, clockid_t id) { 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 @@ -92,6 +112,16 @@ do_init_time(void) { struct timespec ts; +#ifdef _WIN32 + /* Calculate number of 100-nanosecond intervals till 01/01/1970. */ + SYSTEMTIME unix_epoch_st = { 1970, 1, 0, 1, 0, 0, 0, 0}; + FILETIME unix_epoch_ft; + + SystemTimeToFileTime(&unix_epoch_st, &unix_epoch_ft); + unix_epoch.LowPart = unix_epoch_ft.dwLowDateTime; + unix_epoch.HighPart = unix_epoch_ft.dwHighDateTime; +#endif + coverage_init(); init_clock(&monotonic_clock, (!clock_gettime(CLOCK_MONOTONIC, &ts) @@ -99,9 +129,6 @@ do_init_time(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. */ @@ -112,87 +139,31 @@ time_init(void) 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); } } @@ -268,7 +239,6 @@ time_alarm(unsigned int secs) assert_single_threaded(); time_init(); - time_refresh(); now = time_msec(); msecs = secs * 1000LL; @@ -286,29 +256,26 @@ time_alarm(unsigned int secs) * 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, - int *elapsed) +time_poll(struct pollfd *pollfds, int n_pollfds, HANDLE *handles OVS_UNUSED, + long long int timeout_when, int *elapsed) { long long int *last_wakeup = last_wakeup_get(); long long int start; - sigset_t oldsigs; - bool blocked; - int retval; + bool quiescent; + int retval = 0; time_init(); - time_refresh(); + coverage_clear(); + coverage_run(); if (*last_wakeup) { log_poll_interval(*last_wakeup); } - coverage_clear(); start = time_msec(); - blocked = false; timeout_when = MIN(timeout_when, deadline); + quiescent = ovsrcu_is_quiescent(); for (;;) { long long int now = time_msec(); @@ -322,14 +289,45 @@ time_poll(struct pollfd *pollfds, int n_pollfds, long long int timeout_when, time_left = timeout_when - now; } + if (!quiescent) { + if (!time_left) { + ovsrcu_quiesce(); + } else { + ovsrcu_quiesce_start(); + } + } + +#ifndef _WIN32 retval = poll(pollfds, n_pollfds, time_left); if (retval < 0) { retval = -errno; } +#else + if (n_pollfds > MAXIMUM_WAIT_OBJECTS) { + VLOG_ERR("Cannot handle more than maximum wait objects\n"); + } else if (n_pollfds != 0) { + retval = WaitForMultipleObjects(n_pollfds, handles, FALSE, + time_left); + } + if (retval < 0) { + /* XXX This will be replace by a win error to errno + conversion function */ + retval = -WSAGetLastError(); + retval = -EINVAL; + } +#endif + + if (!quiescent && time_left) { + ovsrcu_quiesce_end(); + } - time_refresh(); if (deadline <= time_msec()) { +#ifndef _WIN32 fatal_signal_handler(SIGALRM); +#else + VLOG_ERR("wake up from WaitForMultipleObjects after deadline"); + fatal_signal_handler(SIGTERM); +#endif if (retval < 0) { retval = 0; } @@ -339,14 +337,6 @@ time_poll(struct pollfd *pollfds, int n_pollfds, long long int timeout_when, if (retval != -EINTR) { break; } - - if (!blocked && CACHE_TIME) { - block_sigalrm(&oldsigs); - blocked = true; - } - } - if (blocked) { - unblock_sigalrm(&oldsigs); } *last_wakeup = time_msec(); refresh_rusage(); @@ -354,27 +344,6 @@ time_poll(struct pollfd *pollfds, int n_pollfds, long long int timeout_when, 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) { @@ -396,12 +365,69 @@ time_boot_msec(void) return boot_time; } +#ifdef _WIN32 +static ULARGE_INTEGER +xgetfiletime(void) +{ + ULARGE_INTEGER current_time; + FILETIME current_time_ft; + + /* Returns current time in UTC as a 64-bit value representing the number + * of 100-nanosecond intervals since January 1, 1601 . */ + GetSystemTimePreciseAsFileTime(¤t_time_ft); + current_time.LowPart = current_time_ft.dwLowDateTime; + current_time.HighPart = current_time_ft.dwHighDateTime; + + return current_time; +} + +static int +clock_gettime(clock_t id, struct timespec *ts) +{ + if (id == CLOCK_MONOTONIC) { + static LARGE_INTEGER freq; + LARGE_INTEGER count; + long long int ns; + + if (!freq.QuadPart) { + /* Number of counts per second. */ + QueryPerformanceFrequency(&freq); + } + /* Total number of counts from a starting point. */ + QueryPerformanceCounter(&count); + + /* Total nano seconds from a starting point. */ + ns = (double) count.QuadPart / freq.QuadPart * 1000000000; + + ts->tv_sec = count.QuadPart / freq.QuadPart; + ts->tv_nsec = ns % 1000000000; + } else if (id == CLOCK_REALTIME) { + ULARGE_INTEGER current_time = xgetfiletime(); + + /* Time from Epoch to now. */ + ts->tv_sec = (current_time.QuadPart - unix_epoch.QuadPart) / 10000000; + ts->tv_nsec = ((current_time.QuadPart - unix_epoch.QuadPart) % + 10000000) * 100; + } else { + return -1; + } +} +#endif /* _WIN32 */ + void xgettimeofday(struct timeval *tv) { +#ifndef _WIN32 if (gettimeofday(tv, NULL) == -1) { VLOG_FATAL("gettimeofday failed (%s)", ovs_strerror(errno)); } +#else + ULARGE_INTEGER current_time = xgetfiletime(); + + tv->tv_sec = (current_time.QuadPart - unix_epoch.QuadPart) / 10000000; + tv->tv_usec = ((current_time.QuadPart - unix_epoch.QuadPart) % + 10000000) / 10; +#endif } void @@ -414,6 +440,19 @@ xclock_gettime(clock_t id, 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) { @@ -437,14 +476,24 @@ timespec_add(struct timespec *sum, *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; @@ -568,9 +617,11 @@ timeval_stop_cb(struct unixctl_conn *conn, 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); } @@ -596,17 +647,71 @@ timeval_warp_cb(struct unixctl_conn *conn, 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); + /* give threads (eg. monitor) some chances to run */ +#ifndef _WIN32 + poll(NULL, 0, 10); +#else + Sleep(10); +#endif 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; +}