@EXPORT = qw( );
@EXPORT_OK = qw (usleep sleep ualarm alarm gettimeofday time tv_interval
- getitimer setitimer
+ getitimer setitimer nanosleep clock_gettime clock_getres
+ CLOCK_HIGHRES CLOCK_MONOTONIC CLOCK_PROCESS_CPUTIME_ID
+ CLOCK_REALTIME CLOCK_THREAD_CPUTIME_ID CLOCK_TIMEOFDAY
ITIMER_REAL ITIMER_VIRTUAL ITIMER_PROF ITIMER_REALPROF
d_usleep d_ualarm d_gettimeofday d_getitimer d_setitimer
- d_nanosleep);
+ d_nanosleep d_clock_gettime d_clock_getres);
-$VERSION = '1.65';
+$VERSION = '1.82';
$XS_VERSION = $VERSION;
$VERSION = eval $VERSION;
sub AUTOLOAD {
my $constname;
($constname = $AUTOLOAD) =~ s/.*:://;
+ # print "AUTOLOAD: constname = $constname ($AUTOLOAD)\n";
die "&Time::HiRes::constant not defined" if $constname eq 'constant';
my ($error, $val) = constant($constname);
- if ($error) { die $error; }
+ # print "AUTOLOAD: error = $error, val = $val\n";
+ if ($error) {
+ my (undef,$file,$line) = caller;
+ die "$error at $file line $line.\n";
+ }
{
no strict 'refs';
*$AUTOLOAD = sub { $val };
goto &$AUTOLOAD;
}
+sub import {
+ my $this = shift;
+ for my $i (@_) {
+ if (($i eq 'clock_getres' && !&d_clock_getres) ||
+ ($i eq 'clock_gettime' && !&d_clock_gettime) ||
+ ($i eq 'nanosleep' && !&d_nanosleep) ||
+ ($i eq 'usleep' && !&d_usleep) ||
+ ($i eq 'ualarm' && !&d_ualarm)) {
+ require Carp;
+ Carp::croak("Time::HiRes::$i(): unimplemented in this platform");
+ }
+ }
+ Time::HiRes->export_to_level(1, $this, @_);
+}
+
bootstrap Time::HiRes;
# Preloaded methods go here.
=head1 SYNOPSIS
- use Time::HiRes qw( usleep ualarm gettimeofday tv_interval );
+ use Time::HiRes qw( usleep ualarm gettimeofday tv_interval nanosleep
+ clock_gettime clock_getres );
usleep ($microseconds);
+ nanosleep ($nanoseconds);
ualarm ($microseconds);
ualarm ($microseconds, $interval_microseconds);
setitimer ($which, $floating_seconds, $floating_interval );
getitimer ($which);
+ $realtime = clock_gettime(CLOCK_REALTIME);
+ $resolution = clock_getres(CLOCK_REALTIME);
+
=head1 DESCRIPTION
The C<Time::HiRes> module implements a Perl interface to the
-C<usleep>, C<ualarm>, C<gettimeofday>, and C<setitimer>/C<getitimer>
-system calls, in other words, high resolution time and timers. See the
-L</EXAMPLES> section below and the test scripts for usage; see your
-system documentation for the description of the underlying
-C<nanosleep> or C<usleep>, C<ualarm>, C<gettimeofday>, and
-C<setitimer>/C<getitimer> calls.
+C<usleep>, C<nanosleep>, C<ualarm>, C<gettimeofday>, and
+C<setitimer>/C<getitimer> system calls, in other words, high
+resolution time and timers. See the L</EXAMPLES> section below and the
+test scripts for usage; see your system documentation for the
+description of the underlying C<nanosleep> or C<usleep>, C<ualarm>,
+C<gettimeofday>, and C<setitimer>/C<getitimer> calls.
If your system lacks C<gettimeofday()> or an emulation of it you don't
get C<gettimeofday()> or the one-argument form of C<tv_interval()>.
-If your system lacks all of C<nanosleep()>, C<usleep()>, and
-C<select()>, you don't get C<Time::HiRes::usleep()> or
-C<Time::HiRes::sleep()>. If your system lacks both C<ualarm()> and
-C<setitimer()> you don't get C<Time::HiRes::ualarm()> or
-C<Time::HiRes::alarm()>.
+If your system lacks all of C<nanosleep()>, C<usleep()>,
+C<select()>, and C<poll>, you don't get C<Time::HiRes::usleep()>,
+C<Time::HiRes::nanosleep()>, or C<Time::HiRes::sleep()>.
+If your system lacks both C<ualarm()> and C<setitimer()> you don't get
+C<Time::HiRes::ualarm()> or C<Time::HiRes::alarm()>.
If you try to import an unimplemented function in the C<use> statement
it will fail at compile time.
and you should first check for the truth value of
C<&Time::HiRes::d_nanosleep> to see whether you have nanosleep, and
then carefully read your C<nanosleep()> C API documentation for any
-peculiarities. (There is no separate interface to call
-C<nanosleep()>; just use C<Time::HiRes::sleep()> or
-C<Time::HiRes::usleep()> with small enough values.)
+peculiarities.
-Unless using C<nanosleep> for mixing sleeping with signals, give
-some thought to whether Perl is the tool you should be using for
-work requiring nanosecond accuracies.
+If you are using C<nanosleep> for something else than mixing sleeping
+with signals, give some thought to whether Perl is the tool you should
+be using for work requiring nanosecond accuracies.
The following functions can be imported from this module.
No functions are exported by default.
=item usleep ( $useconds )
-Sleeps for the number of microseconds specified. Returns the number
-of microseconds actually slept. Can sleep for more than one second,
-unlike the C<usleep> system call. See also C<Time::HiRes::sleep()> below.
+Sleeps for the number of microseconds (millionths of a second)
+specified. Returns the number of microseconds actually slept. Can
+sleep for more than one second, unlike the C<usleep> system call. See
+also C<Time::HiRes::usleep()> and C<Time::HiRes::sleep()>.
+
+Do not expect usleep() to be exact down to one microsecond.
+
+=item nanosleep ( $nanoseconds )
+
+Sleeps for the number of nanoseconds (1e9ths of a second) specified.
+Returns the number of nanoseconds actually slept (accurate only to
+microseconds, the nearest thousand of them). Can sleep for more than
+one second. See also C<Time::HiRes::sleep()> and
+C<Time::HiRes::usleep()>.
+
+Do not expect nanosleep() to be exact down to one nanosecond.
+Getting even accuracy of one thousand nanoseconds is good.
=item ualarm ( $useconds [, $interval_useconds ] )
Issues a C<ualarm> call; the C<$interval_useconds> is optional and
will be zero if unspecified, resulting in C<alarm>-like behaviour.
-Note that the interaction between alarms and sleeps are unspecified.
+Note that the interaction between alarms and sleeps is unspecified.
=item tv_interval
or more than the core C<time()>, depending on whether your platform
rounds the higher resolution timer values up, down, or to the nearest second
to get the core C<time()>, but naturally the difference should be never
-more than half a second.
+more than half a second. See also L</clock_getres>, if available
+in your system.
B<NOTE 2>: Since Sunday, September 9th, 2001 at 01:46:40 AM GMT, when
the C<time()> seconds since epoch rolled over to 1_000_000_000, the
be imported, resulting in a nice drop-in replacement for the C<sleep>
provided with perl, see the L</EXAMPLES> below.
-Note that the interaction between alarms and sleeps are unspecified.
+Note that the interaction between alarms and sleeps is unspecified.
=item alarm ( $floating_seconds [, $interval_floating_seconds ] )
take the sum of the times specified for the the C<alarm()> and the
C<select()>, not just the time of the C<alarm()>.
-Note that the interaction between alarms and sleeps are unspecified.
+Note that the interaction between alarms and sleeps is unspecified.
=item setitimer ( $which, $floating_seconds [, $interval_floating_seconds ] )
and Cygwin have only C<ITIMER_REAL>, and only Solaris seems to have
C<ITIMER_REALPROF> (which is used to profile multithreaded programs).
-C<ITIMER_REAL> results in C<alarm()>-like behavior. Time is counted in
+C<ITIMER_REAL> results in C<alarm()>-like behaviour. Time is counted in
I<real time>; that is, wallclock time. C<SIGALRM> is delivered when
the timer expires.
In list context, both the remaining time and the interval are returned.
The interval is always what you put in using C<setitimer()>.
+=item clock_gettime ( $which )
+
+Return as seconds the current value of the POSIX high resolution timer
+specified by C<$which>. All implementations that support POSIX high
+resolution timers are supposed to support at least the C<$which> value
+of C<CLOCK_REALTIME>, which is supposed to return results close to the
+results of C<gettimeofday>, or the number of seconds since 00:00:00:00
+January 1, 1970 Greenwich Mean Time (GMT). Do not assume that
+CLOCK_REALTIME is zero, it might be one, or something else.
+Another potentially useful (but not available everywhere) value is
+C<CLOCK_MONOTONIC>, which guarantees a monotonically increasing time
+value (unlike time(), which can be adjusted). See your system
+documentation for other possibly supported values.
+
+=item clock_getres ( $which )
+
+Return as seconds the resolution of the POSIX high resolution timer
+specified by C<$which>. All implementations that support POSIX high
+resolution timers are supposed to support at least the C<$which> value
+of C<CLOCK_REALTIME>, see L</clock_gettime>.
+
=back
=head1 EXAMPLES
use Time::HiRes qw(usleep ualarm gettimeofday tv_interval);
$microseconds = 750_000;
- usleep $microseconds;
+ usleep($microseconds);
# signal alarm in 2.5s & every .1s thereafter
- ualarm 2_500_000, 100_000;
+ ualarm(2_500_000, 100_000);
# get seconds and microseconds since the epoch
- ($s, $usec) = gettimeofday;
+ ($s, $usec) = gettimeofday();
# measure elapsed time
# (could also do by subtracting 2 gettimeofday return values)
$SIG{VTALRM} = sub { print time, "\n" };
setitimer(ITIMER_VIRTUAL, 10, 2.5);
+ use Time::HiRes qw( clock_gettime clock_getres CLOCK_REALTIME );
+ # Read the POSIX high resolution timer.
+ my $high = clock_getres(CLOCK_REALTIME);
+ # But how accurate we can be, really?
+ my $reso = clock_getres(CLOCK_REALTIME);
+
=head1 C API
In addition to the perl API described above, a C API is available for
name C prototype
--------------- ----------------------
Time::NVtime double (*)()
- Time::U2time void (*)(UV ret[2])
+ Time::U2time void (*)(pTHX_ UV ret[2])
Both functions return equivalent information (like C<gettimeofday>)
but with different representations. The names C<NVtime> and C<U2time>
were selected mainly because they are operating system independent.
-(C<gettimeofday> is Unix-centric, though some platforms like VMS have
-emulations for it.)
+(C<gettimeofday> is Unix-centric, though some platforms like Win32 and
+VMS have emulations for it.)
Here is an example of using C<NVtime> from C:
- double (*myNVtime)();
+ double (*myNVtime)(); /* Returns -1 on failure. */
SV **svp = hv_fetch(PL_modglobal, "Time::NVtime", 12, 0);
if (!svp) croak("Time::HiRes is required");
if (!SvIOK(*svp)) croak("Time::NVtime isn't a function pointer");
platforms like Cygwin and MinGW) the Time::HiRes::time() may temporarily
drift off from the system clock (and the original time()) by up to 0.5
seconds. Time::HiRes will notice this eventually and recalibrate.
+Note that since Time::HiRes 1.77 the clock_gettime(CLOCK_MONOTONIC)
+might help in this (in case your system supports CLOCK_MONOTONIC).
+
+=head1 SEE ALSO
+
+Perl modules L<BSD::Resource>, L<Time::TAI64>.
+
+Your system documentation for C<clock_gettime>, C<clock_settime>,
+C<gettimeofday>, C<getitimer>, C<setitimer>, C<ualarm>.
=head1 AUTHORS
Copyright (c) 1996-2002 Douglas E. Wegscheid. All rights reserved.
-Copyright (c) 2002,2003,2004 Jarkko Hietaniemi. All rights reserved.
+Copyright (c) 2002, 2003, 2004, 2005 Jarkko Hietaniemi. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
projects / p5sagit/p5-mst-13.2.git / blobdiff