2 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
26 #include <sys/resource.h>
30 #include "dynamic-string.h"
31 #include "fatal-signal.h"
35 #include "ovs-thread.h"
42 VLOG_DEFINE_THIS_MODULE(timeval
);
45 typedef unsigned int clockid_t
;
47 #ifndef CLOCK_MONOTONIC
48 #define CLOCK_MONOTONIC 1
51 #ifndef CLOCK_REALTIME
52 #define CLOCK_REALTIME 2
55 /* Number of 100 ns intervals from January 1, 1601 till January 1, 1970. */
56 static ULARGE_INTEGER unix_epoch
;
60 clockid_t id
; /* CLOCK_MONOTONIC or CLOCK_REALTIME. */
62 /* Features for use by unit tests. Protected by 'mutex'. */
63 struct ovs_mutex mutex
;
64 atomic_bool slow_path
; /* True if warped or stopped. */
65 struct timespec warp OVS_GUARDED
; /* Offset added for unit tests. */
66 bool stopped OVS_GUARDED
; /* Disable real-time updates if true. */
67 struct timespec cache OVS_GUARDED
; /* Last time read from kernel. */
71 static struct clock monotonic_clock
; /* CLOCK_MONOTONIC, if available. */
72 static struct clock wall_clock
; /* CLOCK_REALTIME. */
74 /* The monotonic time at which the time module was initialized. */
75 static long long int boot_time
;
77 /* True only when timeval_dummy_register() is called. */
78 static bool timewarp_enabled
;
79 /* Reference to the seq struct. Threads other than main thread can
80 * wait on timewarp_seq and be waken up when time is warped. */
81 static struct seq
*timewarp_seq
;
82 /* Last value of 'timewarp_seq'. */
83 DEFINE_STATIC_PER_THREAD_DATA(uint64_t, last_seq
, 0);
85 /* Monotonic time in milliseconds at which to die with SIGALRM (if not
87 static long long int deadline
= LLONG_MAX
;
89 /* Monotonic time, in milliseconds, at which the last call to time_poll() woke
91 DEFINE_STATIC_PER_THREAD_DATA(long long int, last_wakeup
, 0);
93 static void log_poll_interval(long long int last_wakeup
);
94 static struct rusage
*get_recent_rusage(void);
95 static void refresh_rusage(void);
96 static void timespec_add(struct timespec
*sum
,
97 const struct timespec
*a
, const struct timespec
*b
);
100 init_clock(struct clock
*c
, clockid_t id
)
102 memset(c
, 0, sizeof *c
);
104 ovs_mutex_init(&c
->mutex
);
105 atomic_init(&c
->slow_path
, false);
106 xclock_gettime(c
->id
, &c
->cache
);
107 timewarp_seq
= seq_create();
116 /* Calculate number of 100-nanosecond intervals till 01/01/1970. */
117 SYSTEMTIME unix_epoch_st
= { 1970, 1, 0, 1, 0, 0, 0, 0};
118 FILETIME unix_epoch_ft
;
120 SystemTimeToFileTime(&unix_epoch_st
, &unix_epoch_ft
);
121 unix_epoch
.LowPart
= unix_epoch_ft
.dwLowDateTime
;
122 unix_epoch
.HighPart
= unix_epoch_ft
.dwHighDateTime
;
127 init_clock(&monotonic_clock
, (!clock_gettime(CLOCK_MONOTONIC
, &ts
)
130 init_clock(&wall_clock
, CLOCK_REALTIME
);
131 boot_time
= timespec_to_msec(&monotonic_clock
.cache
);
134 /* Initializes the timetracking module, if not already initialized. */
138 static pthread_once_t once
= PTHREAD_ONCE_INIT
;
139 pthread_once(&once
, do_init_time
);
143 time_timespec__(struct clock
*c
, struct timespec
*ts
)
149 atomic_read_explicit(&c
->slow_path
, &slow_path
, memory_order_relaxed
);
151 xclock_gettime(c
->id
, ts
);
153 struct timespec warp
;
154 struct timespec cache
;
157 ovs_mutex_lock(&c
->mutex
);
158 stopped
= c
->stopped
;
161 ovs_mutex_unlock(&c
->mutex
);
164 xclock_gettime(c
->id
, &cache
);
166 timespec_add(ts
, &cache
, &warp
);
170 /* Stores a monotonic timer, accurate within TIME_UPDATE_INTERVAL ms, into
173 time_timespec(struct timespec
*ts
)
175 time_timespec__(&monotonic_clock
, ts
);
178 /* Stores the current time, accurate within TIME_UPDATE_INTERVAL ms, into
181 time_wall_timespec(struct timespec
*ts
)
183 time_timespec__(&wall_clock
, ts
);
187 time_sec__(struct clock
*c
)
191 time_timespec__(c
, &ts
);
195 /* Returns a monotonic timer, in seconds. */
199 return time_sec__(&monotonic_clock
);
202 /* Returns the current time, in seconds. */
206 return time_sec__(&wall_clock
);
210 time_msec__(struct clock
*c
)
214 time_timespec__(c
, &ts
);
215 return timespec_to_msec(&ts
);
218 /* Returns a monotonic timer, in ms (within TIME_UPDATE_INTERVAL ms). */
222 return time_msec__(&monotonic_clock
);
225 /* Returns the current time, in ms (within TIME_UPDATE_INTERVAL ms). */
229 return time_msec__(&wall_clock
);
232 /* Configures the program to die with SIGALRM 'secs' seconds from now, if
233 * 'secs' is nonzero, or disables the feature if 'secs' is zero. */
235 time_alarm(unsigned int secs
)
240 assert_single_threaded();
244 msecs
= secs
* 1000LL;
245 deadline
= now
< LLONG_MAX
- msecs
? now
+ msecs
: LLONG_MAX
;
248 /* Like poll(), except:
250 * - The timeout is specified as an absolute time, as defined by
251 * time_msec(), instead of a duration.
253 * - On error, returns a negative error code (instead of setting errno).
255 * - If interrupted by a signal, retries automatically until the original
256 * timeout is reached. (Because of this property, this function will
257 * never return -EINTR.)
259 * Stores the number of milliseconds elapsed during poll in '*elapsed'. */
261 time_poll(struct pollfd
*pollfds
, int n_pollfds
, HANDLE
*handles OVS_UNUSED
,
262 long long int timeout_when
, int *elapsed
)
264 long long int *last_wakeup
= last_wakeup_get();
273 log_poll_interval(*last_wakeup
);
277 timeout_when
= MIN(timeout_when
, deadline
);
278 quiescent
= ovsrcu_is_quiescent();
281 long long int now
= time_msec();
284 if (now
>= timeout_when
) {
286 } else if ((unsigned long long int) timeout_when
- now
> INT_MAX
) {
289 time_left
= timeout_when
- now
;
296 ovsrcu_quiesce_start();
301 retval
= poll(pollfds
, n_pollfds
, time_left
);
306 if (n_pollfds
> MAXIMUM_WAIT_OBJECTS
) {
307 VLOG_ERR("Cannot handle more than maximum wait objects\n");
308 } else if (n_pollfds
!= 0) {
309 retval
= WaitForMultipleObjects(n_pollfds
, handles
, FALSE
,
313 /* XXX This will be replace by a win error to errno
314 conversion function */
315 retval
= -WSAGetLastError();
320 if (!quiescent
&& time_left
) {
321 ovsrcu_quiesce_end();
324 if (deadline
<= time_msec()) {
326 fatal_signal_handler(SIGALRM
);
328 VLOG_ERR("wake up from WaitForMultipleObjects after deadline");
329 fatal_signal_handler(SIGTERM
);
337 if (retval
!= -EINTR
) {
341 *last_wakeup
= time_msec();
343 *elapsed
= *last_wakeup
- start
;
348 timespec_to_msec(const struct timespec
*ts
)
350 return (long long int) ts
->tv_sec
* 1000 + ts
->tv_nsec
/ (1000 * 1000);
354 timeval_to_msec(const struct timeval
*tv
)
356 return (long long int) tv
->tv_sec
* 1000 + tv
->tv_usec
/ 1000;
359 /* Returns the monotonic time at which the "time" module was initialized, in
369 static ULARGE_INTEGER
372 ULARGE_INTEGER current_time
;
373 FILETIME current_time_ft
;
375 /* Returns current time in UTC as a 64-bit value representing the number
376 * of 100-nanosecond intervals since January 1, 1601 . */
377 GetSystemTimePreciseAsFileTime(¤t_time_ft
);
378 current_time
.LowPart
= current_time_ft
.dwLowDateTime
;
379 current_time
.HighPart
= current_time_ft
.dwHighDateTime
;
385 clock_gettime(clock_t id
, struct timespec
*ts
)
387 if (id
== CLOCK_MONOTONIC
) {
388 static LARGE_INTEGER freq
;
392 if (!freq
.QuadPart
) {
393 /* Number of counts per second. */
394 QueryPerformanceFrequency(&freq
);
396 /* Total number of counts from a starting point. */
397 QueryPerformanceCounter(&count
);
399 /* Total nano seconds from a starting point. */
400 ns
= (double) count
.QuadPart
/ freq
.QuadPart
* 1000000000;
402 ts
->tv_sec
= count
.QuadPart
/ freq
.QuadPart
;
403 ts
->tv_nsec
= ns
% 1000000000;
404 } else if (id
== CLOCK_REALTIME
) {
405 ULARGE_INTEGER current_time
= xgetfiletime();
407 /* Time from Epoch to now. */
408 ts
->tv_sec
= (current_time
.QuadPart
- unix_epoch
.QuadPart
) / 10000000;
409 ts
->tv_nsec
= ((current_time
.QuadPart
- unix_epoch
.QuadPart
) %
418 xgettimeofday(struct timeval
*tv
)
421 if (gettimeofday(tv
, NULL
) == -1) {
422 VLOG_FATAL("gettimeofday failed (%s)", ovs_strerror(errno
));
425 ULARGE_INTEGER current_time
= xgetfiletime();
427 tv
->tv_sec
= (current_time
.QuadPart
- unix_epoch
.QuadPart
) / 10000000;
428 tv
->tv_usec
= ((current_time
.QuadPart
- unix_epoch
.QuadPart
) %
434 xclock_gettime(clock_t id
, struct timespec
*ts
)
436 if (clock_gettime(id
, ts
) == -1) {
437 /* It seems like a bad idea to try to use vlog here because it is
438 * likely to try to check the current time. */
439 ovs_abort(errno
, "xclock_gettime() failed");
443 /* Makes threads wait on timewarp_seq and be waken up when time is warped.
444 * This function will be no-op unless timeval_dummy_register() is called. */
448 if (timewarp_enabled
) {
449 uint64_t *last_seq
= last_seq_get();
451 *last_seq
= seq_read(timewarp_seq
);
452 seq_wait(timewarp_seq
, *last_seq
);
457 timeval_diff_msec(const struct timeval
*a
, const struct timeval
*b
)
459 return timeval_to_msec(a
) - timeval_to_msec(b
);
463 timespec_add(struct timespec
*sum
,
464 const struct timespec
*a
,
465 const struct timespec
*b
)
469 tmp
.tv_sec
= a
->tv_sec
+ b
->tv_sec
;
470 tmp
.tv_nsec
= a
->tv_nsec
+ b
->tv_nsec
;
471 if (tmp
.tv_nsec
>= 1000 * 1000 * 1000) {
472 tmp
.tv_nsec
-= 1000 * 1000 * 1000;
480 is_warped(const struct clock
*c
)
484 ovs_mutex_lock(&c
->mutex
);
485 warped
= monotonic_clock
.warp
.tv_sec
|| monotonic_clock
.warp
.tv_nsec
;
486 ovs_mutex_unlock(&c
->mutex
);
492 log_poll_interval(long long int last_wakeup
)
494 long long int interval
= time_msec() - last_wakeup
;
496 if (interval
>= 1000 && !is_warped(&monotonic_clock
)) {
497 const struct rusage
*last_rusage
= get_recent_rusage();
498 struct rusage rusage
;
500 getrusage(RUSAGE_SELF
, &rusage
);
501 VLOG_WARN("Unreasonably long %lldms poll interval"
502 " (%lldms user, %lldms system)",
504 timeval_diff_msec(&rusage
.ru_utime
,
505 &last_rusage
->ru_utime
),
506 timeval_diff_msec(&rusage
.ru_stime
,
507 &last_rusage
->ru_stime
));
508 if (rusage
.ru_minflt
> last_rusage
->ru_minflt
509 || rusage
.ru_majflt
> last_rusage
->ru_majflt
) {
510 VLOG_WARN("faults: %ld minor, %ld major",
511 rusage
.ru_minflt
- last_rusage
->ru_minflt
,
512 rusage
.ru_majflt
- last_rusage
->ru_majflt
);
514 if (rusage
.ru_inblock
> last_rusage
->ru_inblock
515 || rusage
.ru_oublock
> last_rusage
->ru_oublock
) {
516 VLOG_WARN("disk: %ld reads, %ld writes",
517 rusage
.ru_inblock
- last_rusage
->ru_inblock
,
518 rusage
.ru_oublock
- last_rusage
->ru_oublock
);
520 if (rusage
.ru_nvcsw
> last_rusage
->ru_nvcsw
521 || rusage
.ru_nivcsw
> last_rusage
->ru_nivcsw
) {
522 VLOG_WARN("context switches: %ld voluntary, %ld involuntary",
523 rusage
.ru_nvcsw
- last_rusage
->ru_nvcsw
,
524 rusage
.ru_nivcsw
- last_rusage
->ru_nivcsw
);
530 /* CPU usage tracking. */
533 long long int when
; /* Time that this sample was taken. */
534 unsigned long long int cpu
; /* Total user+system CPU usage when sampled. */
538 struct cpu_usage older
;
539 struct cpu_usage newer
;
542 struct rusage recent_rusage
;
544 DEFINE_PER_THREAD_MALLOCED_DATA(struct cpu_tracker
*, cpu_tracker_var
);
546 static struct cpu_tracker
*
547 get_cpu_tracker(void)
549 struct cpu_tracker
*t
= cpu_tracker_var_get();
551 t
= xzalloc(sizeof *t
);
552 t
->older
.when
= LLONG_MIN
;
553 t
->newer
.when
= LLONG_MIN
;
554 cpu_tracker_var_set_unsafe(t
);
559 static struct rusage
*
560 get_recent_rusage(void)
562 return &get_cpu_tracker()->recent_rusage
;
566 getrusage_thread(struct rusage
*rusage OVS_UNUSED
)
569 return getrusage(RUSAGE_THREAD
, rusage
);
579 struct cpu_tracker
*t
= get_cpu_tracker();
580 struct rusage
*recent_rusage
= &t
->recent_rusage
;
582 if (!getrusage_thread(recent_rusage
)) {
583 long long int now
= time_msec();
584 if (now
>= t
->newer
.when
+ 3 * 1000) {
587 t
->newer
.cpu
= (timeval_to_msec(&recent_rusage
->ru_utime
) +
588 timeval_to_msec(&recent_rusage
->ru_stime
));
590 if (t
->older
.when
!= LLONG_MIN
&& t
->newer
.cpu
> t
->older
.cpu
) {
591 unsigned int dividend
= t
->newer
.cpu
- t
->older
.cpu
;
592 unsigned int divisor
= (t
->newer
.when
- t
->older
.when
) / 100;
593 t
->cpu_usage
= divisor
> 0 ? dividend
/ divisor
: -1;
601 /* Returns an estimate of this process's CPU usage, as a percentage, over the
602 * past few seconds of wall-clock time. Returns -1 if no estimate is available
603 * (which will happen if the process has not been running long enough to have
604 * an estimate, and can happen for other reasons as well). */
608 return get_cpu_tracker()->cpu_usage
;
611 /* Unixctl interface. */
613 /* "time/stop" stops the monotonic time returned by e.g. time_msec() from
614 * advancing, except due to later calls to "time/warp". */
616 timeval_stop_cb(struct unixctl_conn
*conn
,
617 int argc OVS_UNUSED
, const char *argv
[] OVS_UNUSED
,
618 void *aux OVS_UNUSED
)
620 ovs_mutex_lock(&monotonic_clock
.mutex
);
621 atomic_store(&monotonic_clock
.slow_path
, true);
622 monotonic_clock
.stopped
= true;
623 xclock_gettime(monotonic_clock
.id
, &monotonic_clock
.cache
);
624 ovs_mutex_unlock(&monotonic_clock
.mutex
);
626 unixctl_command_reply(conn
, NULL
);
629 /* "time/warp MSECS" advances the current monotonic time by the specified
630 * number of milliseconds. Unless "time/stop" has also been executed, the
631 * monotonic clock continues to tick forward at the normal rate afterward.
633 * Does not affect wall clock readings. */
635 timeval_warp_cb(struct unixctl_conn
*conn
,
636 int argc OVS_UNUSED
, const char *argv
[], void *aux OVS_UNUSED
)
641 msecs
= atoi(argv
[1]);
643 unixctl_command_reply_error(conn
, "invalid MSECS");
647 ts
.tv_sec
= msecs
/ 1000;
648 ts
.tv_nsec
= (msecs
% 1000) * 1000 * 1000;
650 ovs_mutex_lock(&monotonic_clock
.mutex
);
651 atomic_store(&monotonic_clock
.slow_path
, true);
652 timespec_add(&monotonic_clock
.warp
, &monotonic_clock
.warp
, &ts
);
653 ovs_mutex_unlock(&monotonic_clock
.mutex
);
654 seq_change(timewarp_seq
);
655 /* give threads (eg. monitor) some chances to run */
661 unixctl_command_reply(conn
, "warped");
665 timeval_dummy_register(void)
667 timewarp_enabled
= true;
668 unixctl_command_register("time/stop", "", 0, 0, timeval_stop_cb
, NULL
);
669 unixctl_command_register("time/warp", "MSECS", 1, 1,
670 timeval_warp_cb
, NULL
);
675 /* strftime() with an extension for high-resolution timestamps. Any '#'s in
676 * 'format' will be replaced by subseconds, e.g. use "%S.###" to obtain results
679 strftime_msec(char *s
, size_t max
, const char *format
,
680 const struct tm_msec
*tm
)
684 n
= strftime(s
, max
, format
, &tm
->tm
);
689 sprintf(decimals
, "%03d", tm
->msec
);
690 for (p
= strchr(s
, '#'); p
; p
= strchr(p
, '#')) {
693 *p
++ = *d
? *d
++ : '0';
702 localtime_msec(long long int now
, struct tm_msec
*result
)
704 time_t now_sec
= now
/ 1000;
705 localtime_r(&now_sec
, &result
->tm
);
706 result
->msec
= now
% 1000;
711 gmtime_msec(long long int now
, struct tm_msec
*result
)
713 time_t now_sec
= now
/ 1000;
714 gmtime_r(&now_sec
, &result
->tm
);
715 result
->msec
= now
% 1000;