/* Portable timers.
- Copyright (C) 2005 Free Software Foundation, Inc.
+ Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software
+ Foundation, Inc.
This file is part of GNU Wget.
GNU Wget is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2 of the License, or
+the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
GNU Wget is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
-along with Wget; if not, write to the Free Software
-Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-
-In addition, as a special exception, the Free Software Foundation
-gives permission to link the code of its release of Wget with the
-OpenSSL project's "OpenSSL" library (or with modified versions of it
-that use the same license as the "OpenSSL" library), and distribute
-the linked executables. You must obey the GNU General Public License
-in all respects for all of the code used other than "OpenSSL". If you
-modify this file, you may extend this exception to your version of the
-file, but you are not obligated to do so. If you do not wish to do
-so, delete this exception statement from your version. */
+along with Wget. If not, see <http://www.gnu.org/licenses/>.
+
+Additional permission under GNU GPL version 3 section 7
+
+If you modify this program, or any covered work, by linking or
+combining it with the OpenSSL project's OpenSSL library (or a
+modified version of that library), containing parts covered by the
+terms of the OpenSSL or SSLeay licenses, the Free Software Foundation
+grants you additional permission to convey the resulting work.
+Corresponding Source for a non-source form of such a combination
+shall include the source code for the parts of OpenSSL used as well
+as that of the covered work. */
/* This file implements "portable timers" (ptimers), objects that
measure elapsed time using the primitives most appropriate for the
ptimer_new -- creates a timer.
ptimer_reset -- resets the timer's elapsed time to zero.
ptimer_measure -- measure and return the time elapsed since
- creation or last reset.
+ creation or last reset.
ptimer_read -- reads the last measured elapsed value.
ptimer_destroy -- destroy the timer.
ptimer_granularity -- returns the approximate granularity of the timers.
- Timers operate in milliseconds, but return floating point values
- that can be more precise. For example, to measure the time it
- takes to run a loop, you can use something like:
+ Timers measure time in seconds, returning the timings as floating
+ point numbers, so they can carry as much precision as the
+ underlying system timer supports. For example, to measure the time
+ it takes to run a loop, you can use something like:
ptimer *tmr = ptimer_new ();
while (...)
... loop ...
- double msecs = ptimer_measure ();
- printf ("The loop took %.2f ms\n", msecs); */
+ double secs = ptimer_measure ();
+ printf ("The loop took %.2fs\n", secs); */
-#include <config.h>
+#include "wget.h"
#include <stdio.h>
#include <stdlib.h>
-#ifdef HAVE_STRING_H
-# include <string.h>
-#else /* not HAVE_STRING_H */
-# include <strings.h>
-#endif /* not HAVE_STRING_H */
-#include <sys/types.h>
+#include <string.h>
#include <errno.h>
-#ifdef HAVE_UNISTD_H
-# include <unistd.h>
+#include <unistd.h>
+#include <time.h>
+#include <sys/time.h>
+
+/* Cygwin currently (as of 2005-04-08, Cygwin 1.5.14) lacks clock_getres,
+ but still defines _POSIX_TIMERS! Because of that we simply use the
+ Windows timers under Cygwin. */
+#ifdef __CYGWIN__
+# include <windows.h>
#endif
-#include <assert.h>
-#include "wget.h"
+#include "utils.h"
#include "ptimer.h"
-#ifndef errno
-extern int errno;
-#endif
-
-/* Depending on the OS and availability of gettimeofday(), one and
- only one of PTIMER_WINDOWS, PTIMER_GETTIMEOFDAY, or PTIMER_TIME will
- be defined.
-
- Virtually all modern Unix systems will define PTIMER_GETTIMEOFDAY;
- Windows will use PTIMER_WINDOWS. PTIMER_TIME is a catch-all method
- for non-Windows systems without gettimeofday, such as DOS or really
- old Unix-like systems. */
+/* Depending on the OS, one and only one of PTIMER_POSIX,
+ PTIMER_GETTIMEOFDAY, or PTIMER_WINDOWS will be defined. */
#undef PTIMER_POSIX
#undef PTIMER_GETTIMEOFDAY
-#undef PTIMER_TIME
#undef PTIMER_WINDOWS
-#ifdef WINDOWS
-# define PTIMER_WINDOWS /* use Windows timers */
+#if defined(WINDOWS) || defined(__CYGWIN__)
+# define PTIMER_WINDOWS /* use Windows timers */
+#elif _POSIX_TIMERS - 0 > 0
+# define PTIMER_POSIX /* use POSIX timers (clock_gettime) */
#else
-# if _POSIX_TIMERS > 0
-# define PTIMER_POSIX /* use POSIX timers (clock_gettime) */
-# else
-# ifdef HAVE_GETTIMEOFDAY
-# define PTIMER_GETTIMEOFDAY /* use gettimeofday */
-# else
-# define PTIMER_TIME
-# endif
-# endif
+# define PTIMER_GETTIMEOFDAY /* use gettimeofday */
#endif
-/* The type ptimer_system_time holds system time. */
-
#ifdef PTIMER_POSIX
+/* Elapsed time measurement using POSIX timers: system time is held in
+ struct timespec, time is retrieved using clock_gettime, and
+ resolution using clock_getres.
+
+ This method is used on Unix systems that implement POSIX
+ timers. */
+
typedef struct timespec ptimer_system_time;
+
+#define IMPL_init posix_init
+#define IMPL_measure posix_measure
+#define IMPL_diff posix_diff
+#define IMPL_resolution posix_resolution
+
+/* clock_id to use for POSIX clocks. This tries to use
+ CLOCK_MONOTONIC where available, CLOCK_REALTIME otherwise. */
+static int posix_clock_id;
+
+/* Resolution of the clock, initialized in posix_init. */
+static double posix_clock_resolution;
+
+/* Decide which clock_id to use. */
+
+static void
+posix_init (void)
+{
+ /* List of clocks we want to support: some systems support monotonic
+ clocks, Solaris has "high resolution" clock (sometimes
+ unavailable except to superuser), and all should support the
+ real-time clock. */
+#define NO_SYSCONF_CHECK -1
+ static const struct {
+ int id;
+ int sysconf_name;
+ } clocks[] = {
+#if defined(_POSIX_MONOTONIC_CLOCK) && _POSIX_MONOTONIC_CLOCK - 0 >= 0
+ { CLOCK_MONOTONIC, _SC_MONOTONIC_CLOCK },
#endif
+#ifdef CLOCK_HIGHRES
+ { CLOCK_HIGHRES, NO_SYSCONF_CHECK },
+#endif
+ { CLOCK_REALTIME, NO_SYSCONF_CHECK },
+ };
+ size_t i;
+
+ /* Determine the clock we can use. For a clock to be usable, it
+ must be confirmed with sysconf (where applicable) and with
+ clock_getres. If no clock is found, CLOCK_REALTIME is used. */
+
+ for (i = 0; i < countof (clocks); i++)
+ {
+ struct timespec r;
+ if (clocks[i].sysconf_name != NO_SYSCONF_CHECK)
+ if (sysconf (clocks[i].sysconf_name) < 0)
+ continue; /* sysconf claims this clock is unavailable */
+ if (clock_getres (clocks[i].id, &r) < 0)
+ continue; /* clock_getres doesn't work for this clock */
+ posix_clock_id = clocks[i].id;
+ posix_clock_resolution = (double) r.tv_sec + r.tv_nsec / 1e9;
+ /* Guard against nonsense returned by a broken clock_getres. */
+ if (posix_clock_resolution == 0)
+ posix_clock_resolution = 1e-3;
+ break;
+ }
+ if (i == countof (clocks))
+ {
+ /* If no clock was found, it means that clock_getres failed for
+ the realtime clock. */
+ logprintf (LOG_NOTQUIET, _("Cannot get REALTIME clock frequency: %s\n"),
+ strerror (errno));
+ /* Use CLOCK_REALTIME, but invent a plausible resolution. */
+ posix_clock_id = CLOCK_REALTIME;
+ posix_clock_resolution = 1e-3;
+ }
+}
+
+static inline void
+posix_measure (ptimer_system_time *pst)
+{
+ clock_gettime (posix_clock_id, pst);
+}
+
+static inline double
+posix_diff (ptimer_system_time *pst1, ptimer_system_time *pst2)
+{
+ return ((pst1->tv_sec - pst2->tv_sec)
+ + (pst1->tv_nsec - pst2->tv_nsec) / 1e9);
+}
+
+static inline double
+posix_resolution (void)
+{
+ return posix_clock_resolution;
+}
+#endif /* PTIMER_POSIX */
#ifdef PTIMER_GETTIMEOFDAY
+/* Elapsed time measurement using gettimeofday: system time is held in
+ struct timeval, retrieved using gettimeofday, and resolution is
+ unknown.
+
+ This method is used Unix systems without POSIX timers. */
+
typedef struct timeval ptimer_system_time;
-#endif
-#ifdef PTIMER_TIME
-typedef time_t ptimer_system_time;
-#endif
+#define IMPL_measure gettimeofday_measure
+#define IMPL_diff gettimeofday_diff
+#define IMPL_resolution gettimeofday_resolution
+
+static inline void
+gettimeofday_measure (ptimer_system_time *pst)
+{
+ gettimeofday (pst, NULL);
+}
+
+static inline double
+gettimeofday_diff (ptimer_system_time *pst1, ptimer_system_time *pst2)
+{
+ return ((pst1->tv_sec - pst2->tv_sec)
+ + (pst1->tv_usec - pst2->tv_usec) / 1e6);
+}
+
+static inline double
+gettimeofday_resolution (void)
+{
+ /* Granularity of gettimeofday varies wildly between architectures.
+ However, it appears that on modern machines it tends to be better
+ than 1ms. Assume 100 usecs. */
+ return 0.1;
+}
+#endif /* PTIMER_GETTIMEOFDAY */
#ifdef PTIMER_WINDOWS
+/* Elapsed time measurement on Windows: where high-resolution timers
+ are available, time is stored in a LARGE_INTEGER and retrieved
+ using QueryPerformanceCounter. Otherwise, it is stored in a DWORD
+ and retrieved using GetTickCount.
+
+ This method is used on Windows. */
+
typedef union {
DWORD lores; /* In case GetTickCount is used */
LARGE_INTEGER hires; /* In case high-resolution timer is used */
} ptimer_system_time;
-#endif
-
-struct ptimer {
- /* Whether the start time has been set. */
- int initialized;
- /* The starting point in time which, subtracted from the current
- time, yields elapsed time. */
- ptimer_system_time start;
-
- /* The most recent elapsed time, calculated by ptimer_measure().
- Measured in milliseconds. */
- double elapsed_last;
+#define IMPL_init windows_init
+#define IMPL_measure windows_measure
+#define IMPL_diff windows_diff
+#define IMPL_resolution windows_resolution
- /* Approximately, the time elapsed between the true start of the
- measurement and the time represented by START. */
- double elapsed_pre_start;
-};
-
-#ifdef PTIMER_WINDOWS
/* Whether high-resolution timers are used. Set by ptimer_initialize_once
- the first time ptimer_allocate is called. */
-static int windows_hires_timers;
+ the first time ptimer_new is called. */
+static bool windows_hires_timers;
/* Frequency of high-resolution timers -- number of updates per
- millisecond. Calculated the first time ptimer_allocate is called
- provided that high-resolution timers are available. */
-static double windows_hires_msfreq;
-
-/* The first time a timer is created, determine whether to use
- high-resolution timers. */
+ second. Calculated the first time ptimer_new is called provided
+ that high-resolution timers are available. */
+static double windows_hires_freq;
static void
-ptimer_init (void)
+windows_init (void)
{
LARGE_INTEGER freq;
freq.QuadPart = 0;
QueryPerformanceFrequency (&freq);
if (freq.QuadPart != 0)
{
- windows_hires_timers = 1;
- windows_hires_msfreq = (double) freq.QuadPart / 1000.0;
+ windows_hires_timers = true;
+ windows_hires_freq = (double) freq.QuadPart;
}
}
-#define PTIMER_INIT_DEFINED
-#endif /* PTIMER_WINDOWS */
-#ifdef PTIMER_POSIX
-
-/* clock_id to use for POSIX clocks. This tries to use
- CLOCK_MONOTONIC where available, CLOCK_REALTIME otherwise. */
-static int posix_clock_id;
-
-/* Resolution of the clock, in milliseconds. */
-static double posix_resolution;
-
-/* Check whether the monotonic clock is available, and retrieve POSIX
- timer resolution. */
-
-static void
-ptimer_init (void)
+static inline void
+windows_measure (ptimer_system_time *pst)
{
- struct timespec res;
-
-#if _POSIX_MONOTONIC_CLOCK > 0
- if (sysconf (_SC_MONOTONIC_CLOCK) > 0)
- posix_clock_id = CLOCK_MONOTONIC;
+ if (windows_hires_timers)
+ QueryPerformanceCounter (&pst->hires);
else
-#endif
- posix_clock_id = CLOCK_REALTIME;
-
- if (clock_getres (posix_clock_id, &res) < 0)
- {
- logprintf (LOG_NOTQUIET, _("Cannot read clock resolution: %s\n"),
- strerror (errno));
- /* Assume 1 ms resolution */
- res.tv_sec = 0;
- res.tv_nsec = 1000000;
- }
-
- posix_resolution = res.tv_sec * 1000.0 + res.tv_nsec / 1000000.0;
- /* Guard against clock_getres reporting 0 resolution; after all, it
- can be used for division. */
- if (posix_resolution == 0)
- posix_resolution = 1;
+ /* Where hires counters are not available, use GetTickCount rather
+ GetSystemTime, because it is unaffected by clock skew and
+ simpler to use. Note that overflows don't affect us because we
+ never use absolute values of the ticker, only the
+ differences. */
+ pst->lores = GetTickCount ();
}
-#define PTIMER_INIT_DEFINED
-#endif
-/* Allocate a timer. Calling ptimer_read on the timer will return
- zero. It is not legal to call ptimer_measure with a freshly
- allocated timer -- use ptimer_reset first. */
+static inline double
+windows_diff (ptimer_system_time *pst1, ptimer_system_time *pst2)
+{
+ if (windows_hires_timers)
+ return (pst1->hires.QuadPart - pst2->hires.QuadPart) / windows_hires_freq;
+ else
+ return pst1->lores - pst2->lores;
+}
-struct ptimer *
-ptimer_allocate (void)
+static double
+windows_resolution (void)
{
- struct ptimer *wt;
+ if (windows_hires_timers)
+ return 1.0 / windows_hires_freq;
+ else
+ return 10; /* according to MSDN */
+}
+#endif /* PTIMER_WINDOWS */
+\f
+/* The code below this point is independent of timer implementation. */
-#ifdef PTIMER_INIT_DEFINED
- static int init_done;
- if (!init_done)
- {
- init_done = 1;
- ptimer_init ();
- }
-#endif
+struct ptimer {
+ /* The starting point in time which, subtracted from the current
+ time, yields elapsed time. */
+ ptimer_system_time start;
- wt = xnew0 (struct ptimer);
- return wt;
-}
+ /* The most recent elapsed time, calculated by ptimer_measure(). */
+ double elapsed_last;
+
+ /* Approximately, the time elapsed between the true start of the
+ measurement and the time represented by START. This is used for
+ adjustment when clock skew is detected. */
+ double elapsed_pre_start;
+};
/* Allocate a new timer and reset it. Return the new timer. */
struct ptimer *
ptimer_new (void)
{
- struct ptimer *wt = ptimer_allocate ();
- ptimer_reset (wt);
- return wt;
+ struct ptimer *pt = xnew0 (struct ptimer);
+#ifdef IMPL_init
+ static bool init_done;
+ if (!init_done)
+ {
+ init_done = true;
+ IMPL_init ();
+ }
+#endif
+ ptimer_reset (pt);
+ return pt;
}
/* Free the resources associated with the timer. Its further use is
prohibited. */
void
-ptimer_destroy (struct ptimer *wt)
+ptimer_destroy (struct ptimer *pt)
{
- xfree (wt);
-}
-
-/* Store system time to PST. */
-
-static void
-ptimer_sys_set (ptimer_system_time *pst)
-{
-#ifdef PTIMER_POSIX
- clock_gettime (posix_clock_id, pst);
-#endif
-
-#ifdef PTIMER_GETTIMEOFDAY
- gettimeofday (pst, NULL);
-#endif
-
-#ifdef PTIMER_TIME
- time (pst);
-#endif
-
-#ifdef PTIMER_WINDOWS
- if (windows_hires_timers)
- {
- QueryPerformanceCounter (&pst->hires);
- }
- else
- {
- /* Where hires counters are not available, use GetTickCount rather
- GetSystemTime, because it is unaffected by clock skew and simpler
- to use. Note that overflows don't affect us because we never use
- absolute values of the ticker, only the differences. */
- pst->lores = GetTickCount ();
- }
-#endif
+ xfree (pt);
}
-/* Reset timer WT. This establishes the starting point from which
- ptimer_read() will return the number of elapsed milliseconds.
- It is allowed to reset a previously used timer. */
+/* Reset timer PT. This establishes the starting point from which
+ ptimer_measure() will return the elapsed time in seconds. It is
+ allowed to reset a previously used timer. */
void
-ptimer_reset (struct ptimer *wt)
+ptimer_reset (struct ptimer *pt)
{
/* Set the start time to the current time. */
- ptimer_sys_set (&wt->start);
- wt->elapsed_last = 0;
- wt->elapsed_pre_start = 0;
- wt->initialized = 1;
+ IMPL_measure (&pt->start);
+ pt->elapsed_last = 0;
+ pt->elapsed_pre_start = 0;
}
-static double
-ptimer_diff (ptimer_system_time *pst1, ptimer_system_time *pst2)
-{
-#ifdef PTIMER_POSIX
- return ((pst1->tv_sec - pst2->tv_sec) * 1000.0
- + (pst1->tv_nsec - pst2->tv_nsec) / 1000000.0);
-#endif
-
-#ifdef PTIMER_GETTIMEOFDAY
- return ((pst1->tv_sec - pst2->tv_sec) * 1000.0
- + (pst1->tv_usec - pst2->tv_usec) / 1000.0);
-#endif
-
-#ifdef PTIMER_TIME
- return 1000 * (*pst1 - *pst2);
-#endif
-
-#ifdef WINDOWS
- if (using_hires_timers)
- return (pst1->hires.QuadPart - pst2->hires.QuadPart) / windows_hires_msfreq;
- else
- return pst1->lores - pst2->lores;
-#endif
-}
-
-/* Measure the elapsed time since timer creation/reset and return it
- to the caller. The value remains stored for further reads by
- ptimer_read.
-
- This function causes the timer to call gettimeofday (or time(),
- etc.) to update its idea of current time. To get the elapsed
- interval in milliseconds, use ptimer_read.
+/* Measure the elapsed time since timer creation/reset. This causes
+ the timer to internally call clock_gettime (or gettimeofday, etc.)
+ to update its idea of current time. The time is returned, but is
+ also stored for later access through ptimer_read().
This function handles clock skew, i.e. time that moves backwards is
ignored. */
double
-ptimer_measure (struct ptimer *wt)
+ptimer_measure (struct ptimer *pt)
{
ptimer_system_time now;
double elapsed;
- assert (wt->initialized != 0);
-
- ptimer_sys_set (&now);
- elapsed = wt->elapsed_pre_start + ptimer_diff (&now, &wt->start);
+ IMPL_measure (&now);
+ elapsed = pt->elapsed_pre_start + IMPL_diff (&now, &pt->start);
/* Ideally we'd just return the difference between NOW and
- wt->start. However, the system timer can be set back, and we
+ pt->start. However, the system timer can be set back, and we
could return a value smaller than when we were last called, even
a negative value. Both of these would confuse the callers, which
expect us to return monotonically nondecreasing values.
Therefore: if ELAPSED is smaller than its previous known value,
- we reset wt->start to the current time and effectively start
+ we reset pt->start to the current time and effectively start
measuring from this point. But since we don't want the elapsed
value to start from zero, we set elapsed_pre_start to the last
elapsed time and increment all future calculations by that
amount.
- This cannot happen with Windows and CLOCK_MONOTONIC timers, but
- the check is not expensive. */
+ This cannot happen with Windows and POSIX monotonic/highres
+ timers, but the check is not expensive. */
- if (elapsed < wt->elapsed_last)
+ if (elapsed < pt->elapsed_last)
{
- wt->start = now;
- wt->elapsed_pre_start = wt->elapsed_last;
- elapsed = wt->elapsed_last;
+ pt->start = now;
+ pt->elapsed_pre_start = pt->elapsed_last;
+ elapsed = pt->elapsed_last;
}
- wt->elapsed_last = elapsed;
+ pt->elapsed_last = elapsed;
return elapsed;
}
-/* Return the elapsed time in milliseconds between the last call to
- ptimer_reset and the last call to ptimer_update. */
+/* Return the most recent elapsed time measured with ptimer_measure.
+ If ptimer_measure has not yet been called since the timer was
+ created or reset, this returns 0. */
double
-ptimer_read (const struct ptimer *wt)
+ptimer_read (const struct ptimer *pt)
{
- return wt->elapsed_last;
+ return pt->elapsed_last;
}
-/* Return the assessed granularity of the timer implementation, in
- milliseconds. This is used by code that tries to substitute a
- better value for timers that have returned zero. */
+/* Return the assessed resolution of the timer implementation, in
+ seconds. This is used by code that tries to substitute a better
+ value for timers that have returned zero. */
double
-ptimer_granularity (void)
+ptimer_resolution (void)
{
-#ifdef PTIMER_POSIX
- /* POSIX timers give us a way to measure granularity. */
- assert (posix_resolution != 0);
- return posix_resolution;
-#endif
-
-#ifdef PTIMER_GETTIMEOFDAY
- /* Granularity of gettimeofday varies wildly between architectures.
- However, it appears that on modern machines it tends to be better
- than 1ms. Assume 100 usecs. */
- return 0.1;
-#endif
-
-#ifdef PTIMER_TIME
- return 1000;
-#endif
-
-#ifdef PTIMER_WINDOWS
- if (windows_hires_timers)
- return 1.0 / windows_hires_msfreq;
- else
- return 10; /* according to MSDN */
-#endif
+ return IMPL_resolution ();
}
projects / wget / blobdiff