Time-HiRes-1.9719 > Time::HiRes
Time-HiRes-1.9719
Other versions:
Time-HiRes-1.55

名前

Time::HiRes - High resolution alarm, sleep, gettimeofday, interval timers

Time::HiRes - 高精度の alarm, sleep, gettimeofday, インターバル・タイマー

概要

  use Time::HiRes qw( usleep ualarm gettimeofday tv_interval nanosleep
                      clock_gettime clock_getres clock_nanosleep clock
                      stat );

  usleep ($microseconds);
  nanosleep ($nanoseconds);

  ualarm ($microseconds);
  ualarm ($microseconds, $interval_microseconds);

  $t0 = [gettimeofday];
  ($seconds, $microseconds) = gettimeofday;

  $elapsed = tv_interval ( $t0, [$seconds, $microseconds]);
  $elapsed = tv_interval ( $t0, [gettimeofday]);
  $elapsed = tv_interval ( $t0 );

  use Time::HiRes qw ( time alarm sleep );

  $now_fractions = time;
  sleep ($floating_seconds);
  alarm ($floating_seconds);
  alarm ($floating_seconds, $floating_interval);

  use Time::HiRes qw( setitimer getitimer );

  setitimer ($which, $floating_seconds, $floating_interval );
  getitimer ($which);

  use Time::HiRes qw( clock_gettime clock_getres clock_nanosleep
                      ITIMER_REAL ITIMER_VIRTUAL ITIMER_PROF ITIMER_REALPROF );

  $realtime   = clock_gettime(CLOCK_REALTIME);
  $resolution = clock_getres(CLOCK_REALTIME);

  clock_nanosleep(CLOCK_REALTIME, 1.5e9);
  clock_nanosleep(CLOCK_REALTIME, time()*1e9 + 10e9, TIMER_ABSTIME);

  my $ticktock = clock();

  use Time::HiRes qw( stat );

  my @stat = stat("file");
  my @stat = stat(FH);

説明

The Time::HiRes module implements a Perl interface to the usleep, nanosleep, ualarm, gettimeofday, and setitimer/getitimer system calls, in other words, high resolution time and timers. See the "EXAMPLES" section below and the test scripts for usage; see your system documentation for the description of the underlying nanosleep or usleep, ualarm, gettimeofday, and setitimer/getitimer calls.

Time::HiRes モジュールは usleep, nanosleep, ualarm, gettimeofday, setitimer/getitimer システムコーム、言い換えれば 高精度の時刻とタイマーへのへの Perl インターフェースを実装します。 使い方については下記の "使用例" セクションとテスト・スクリプトを ご覧ください;基になっているnanosleep あるいは usleep, ualarm, gettimeofday, そして setitimer/getitimerについては、 あなたのシステムのドキュメントをご覧ください。

If your system lacks gettimeofday() or an emulation of it you don't get gettimeofday() or the one-argument form of tv_interval(). If your system lacks all of nanosleep(), usleep(), select(), and poll, you don't get Time::HiRes::usleep(), Time::HiRes::nanosleep(), or Time::HiRes::sleep(). If your system lacks both ualarm() and setitimer() you don't get Time::HiRes::ualarm() or Time::HiRes::alarm().

あなたのシステムに gettimeofday() やそのエミュレーションがなければ、 gettimeofday() や引数一つの形での tv_interval() は使えません。 あなたのシステムに nanosleep(), usleep(), そして select(), poll の 全てがなければ、Time::HiRes::usleep(), Time::HiRes::nanosleep(), Time::HiRes::sleep() は使えません。 あなたのシステムに ualarm()setitimer() の両方がなければ Time::HiRes::ualarm()Time::HiRes::alarm() は使えません。

If you try to import an unimplemented function in the use statement it will fail at compile time.

use ステートメントのなかで実装されていない関数をインポートしようとすれば、 コンパイル時に失敗します。

If your subsecond sleeping is implemented with nanosleep() instead of usleep(), you can mix subsecond sleeping with signals since nanosleep() does not use signals. This, however, is not portable, and you should first check for the truth value of &Time::HiRes::d_nanosleep to see whether you have nanosleep, and then carefully read your nanosleep() C API documentation for any peculiarities.

あなたの 1 秒以下の sleep が usleep() ではなく nanosleep() で 実装されていれば、 nanosleep() はシグナルを使わないので、1 秒以下の sleep とシグナルを 混在させることができます。 しかしこれは移植性を欠きます。 そしてまず最初に nanosleep を持っているのか、&Time::HiRes::d_nanosleep の 値が true であるかチェックしなければなりません。 それから特有なことがないか慎重に nanosleep() C API ドキュメントを読まなければなりません。

If you are using 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.

sleep とシグナルを混在させる以外のために nanosleep を使うと、 Perl がナノ秒の正確さを要求される仕事のために使うべきツールであるか という疑問があります。

Remember that unless you are working on a hard realtime system, any clocks and timers will be imprecise, especially so if you are working in a pre-emptive multiuser system. Understand the difference between wallclock time and process time (in UNIX-like systems the sum of user and system times). Any attempt to sleep for X seconds will most probably end up sleeping more than that, but don't be surpised if you end up sleeping slightly less.

Remember that unless you are working on a hard realtime system, any clocks and timers will be imprecise, especially so if you are working in a pre-emptive multiuser system. Understand the difference between wallclock time and process time (in UNIX-like systems the sum of user and system times). Any attempt to sleep for X seconds will most probably end up sleeping more than that, but don't be surpised if you end up sleeping slightly less. (TBT)

The following functions can be imported from this module. No functions are exported by default.

このモジュールから以下の関数をインポートすることができます。 デフォルトでエクスポートされる関数はありません。

gettimeofday ()

In array context returns a two-element array with the seconds and microseconds since the epoch. In scalar context returns floating seconds like Time::HiRes::time() (see below).

配列コンテキストではエポックからの秒とマイクロ秒二つの要素の配列を返します。 スカラー・コンテキストでは、Time::HiRes::time() のように秒を 浮動小数点数で返します(下記参照)。

usleep ( $useconds )

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 usleep system call. Can also sleep for zero seconds, which often works like a thread yield. See also Time::HiRes::usleep(), Time::HiRes::sleep(), and Time::HiRes::clock_nanosleep().

指定されたマイクロ秒(100 万分の 1 秒)数、sleep します。 実際に sleep したマイクロ秒数を返します。 usleep システム・コールとは違い、1 秒以上 sleep することができます。 0 秒スリープすることもできます; しばしば スレッド委譲 (thread yield) のように働きます。 Time::HiRes::usleep(), Time::HiRes::sleep(), Time::HiRes::clock_nanosleep() もご覧ください。

Do not expect usleep() to be exact down to one microsecond.

usleep() が 1 マイクロ秒単位で正確と想定しないでください。

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. Can also sleep for zero seconds, which often works like a thread yield. See also Time::HiRes::sleep(), Time::HiRes::usleep(), and Time::HiRes::clock_nanosleep().

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. Can also sleep for zero seconds, which often works like a thread yield. See also Time::HiRes::sleep(), Time::HiRes::usleep(), and Time::HiRes::clock_nanosleep(). (TBT)

Do not expect nanosleep() to be exact down to one nanosecond. Getting even accuracy of one thousand nanoseconds is good.

Do not expect nanosleep() to be exact down to one nanosecond. Getting even accuracy of one thousand nanoseconds is good. (TBT)

ualarm ( $useconds [, $interval_useconds ] )

Issues a ualarm call; the $interval_useconds is optional and will be zero if unspecified, resulting in alarm-like behaviour.

ualarm コールを発行します; $interval_useconds はオプションで、 指定されなければ 0 になり、その結果は alarm のような動きをします。

Returns the remaining time in the alarm in microseconds, or undef if an error occurred.

Returns the remaining time in the alarm in microseconds, or undef if an error occurred. (TBT)

ualarm(0) will cancel an outstanding ualarm().

ualarm(0) will cancel an outstanding ualarm(). (TBT)

Note that the interaction between alarms and sleeps is unspecified.

アラームとスリープの相互作用は未規定であることに注意してください。

tv_interval

tv_interval ( $ref_to_gettimeofday [, $ref_to_later_gettimeofday] )

Returns the floating seconds between the two times, which should have been returned by gettimeofday(). If the second argument is omitted, then the current time is used.

二つの時刻の時間を浮動小数点の秒数を返します。 二つの時刻は gettimeofday() で返されたものでなければなりません。 2 番目の引数が省略されると、現在の時刻が使われます。

time ()

Returns a floating seconds since the epoch. This function can be imported, resulting in a nice drop-in replacement for the time provided with core Perl; see the "EXAMPLES" below.

浮動小数点でエポックからの秒数を返します。 この関数はインポートすることができます; その結果、Perl のコアで提供される 差し込み式に time を置き換えることになります; 下記の "使用例" をご覧ください。

NOTE 1: This higher resolution timer can return values either less or more than the core time(), depending on whether your platform rounds the higher resolution timer values up, down, or to the nearest second to get the core time(), but naturally the difference should be never more than half a second. See also "clock_getres", if available in your system.

注意 1: この高精度の time は、あなたのプラットホームがコアの time() を 得るために、より高精度の時刻を切り上げたり、切り捨てたり、一番近い秒に するのいずれかによって、コアの time() よりも多かったり、少なかったり することがあります。 しかし当然、その差は 0.5 秒を越えることはありえません。 システムで利用可能なら、"clock_getres" も参照してください。

NOTE 2: Since Sunday, September 9th, 2001 at 01:46:40 AM GMT, when the time() seconds since epoch rolled over to 1_000_000_000, the default floating point format of Perl and the seconds since epoch have conspired to produce an apparent bug: if you print the value of Time::HiRes::time() you seem to be getting only five decimals, not six as promised (microseconds). Not to worry, the microseconds are there (assuming your platform supports such granularity in the first place). What is going on is that the default floating point format of Perl only outputs 15 digits. In this case that means ten digits before the decimal separator and five after. To see the microseconds you can use either printf/sprintf with "%.6f", or the gettimeofday() function in list context, which will give you the seconds and microseconds as two separate values.

注意 2: 2001年9月9日 日曜日 GMTの午前 1:46:40 より、 エポックからの time() 秒は、1_000_000_000を超えています。 Perl でのデフォルトの浮動小数点のフォーマットとエポックからの秒数が あいまって明らかなバグを作り出します: Time::HiRes::time() の値を 出力すると、保証された 6 桁(マイクロ秒)ではなく 5 桁の数字しか得ることが できません。 ご心配なく。 マイクロ秒は存在します(もちろんあなたの プラットホームが、そのような粒度をサポートしているものと想定しています)。 何が起きているかといえば、Perl の浮動小数点のデフォルトのフォーマットでは 15 桁の数字しか出力しません。 この場合、小数点の前に 0 桁の数字があり、 その後ろに 5 桁あります。 マイクロ秒を見るためには "%.6f"printf/sprintf の どちらかを使うか、リスト・コンテキストで gettimeofday() を 使うことができます。 この場合には、秒とマイクロ秒の2つを別の値として与えてくれます。

sleep ( $floating_seconds )

Sleeps for the specified amount of seconds. Returns the number of seconds actually slept (a floating point value). This function can be imported, resulting in a nice drop-in replacement for the sleep provided with perl, see the "EXAMPLES" below.

指定された秒数、sleep します。 実際に sleep した秒数を(浮動小数点の値で)返します。 この関数はインポートする ことができます、その結果、Perl のコアで提供される差し込み式に sleep を 置き換えることになります;下記の "使用例" をご覧ください。

Note that the interaction between alarms and sleeps is unspecified.

アラームとスリープの相互作用は未規定であることに注意してください。

alarm ( $floating_seconds [, $interval_floating_seconds ] )

The SIGALRM signal is sent after the specified number of seconds. Implemented using setitimer() if available, ualarm() if not. The $interval_floating_seconds argument is optional and will be zero if unspecified, resulting in alarm()-like behaviour. This function can be imported, resulting in a nice drop-in replacement for the alarm provided with perl, see the "EXAMPLES" below.

指定され秒数後、SIGALRM シグナルが送られます。 setitimer() があればこれを使い、なければ ualarm() を使って 実装されています。 $interval_floating_seconds 引数は オプションで指定されないと 0 になります。 その結果、alarm() のような動きになります。 この関数はインポートすることができます。 その結果、Perl のコアで提供される差し込み式に alarm を 置き換えることになります; 下記の "使用例" をご覧ください。

Returns the remaining time in the alarm in seconds, or undef if an error occurred.

Returns the remaining time in the alarm in seconds, or undef if an error occurred. (TBT)

NOTE 1: With some combinations of operating systems and Perl releases SIGALRM restarts select(), instead of interrupting it. This means that an alarm() followed by a select() may together take the sum of the times specified for the the alarm() and the select(), not just the time of the alarm().

注意 1: オペレーティング・システムと Perl のリリースの 組み合わせによっては SIGALRM が中断させるのではなく、select() を 再開始させることもあります。 これは alarm() の後に select() をすると、alarm() に指定した 時間通りにではなく、 alarm()select() に指定された時間の合計が掛かるかも しれないことを意味します。

Note that the interaction between alarms and sleeps is unspecified.

アラームとスリープの相互作用は未規定であることに注意してください。

setitimer ( $which, $floating_seconds [, $interval_floating_seconds ] )

Start up an interval timer: after a certain time, a signal ($which) arrives, and more signals may keep arriving at certain intervals. To disable an "itimer", use $floating_seconds of zero. If the $interval_floating_seconds is set to zero (or unspecified), the timer is disabled after the next delivered signal.

インターバル・タイマーを開始させます; 一定の時間後、シグナル ($which) が届き、 ある間隔でシグナルが届き続けるかもしれません。 "itimer" を止めるには、$floating_seconds を 0 にしてください。 $interval_floating_seconds に 0 が指定されると(あるいは指定されないと)、 タイマーは次にシグナルが届いた 後に 止められます。

Use of interval timers may interfere with alarm(), sleep(), and usleep(). In standard-speak the "interaction is unspecified", which means that anything may happen: it may work, it may not.

インターバル・タイマーを使うことは alarm(), sleep()usleep() に よって邪魔されるかもしれません。 標準的には「相互作用は特定されていません」 つまりは何が起きるかわかりません: 動くかもしれませんし、 そうでないかもしれません。

In scalar context, the remaining time in the timer is returned.

スカラー・コンテキストではタイマーでの残り時間が返されます。

In list context, both the remaining time and the interval are returned.

リスト・コンテキストでは、残り時間とインターバルが返されます。

There are usually three or four interval timers (signals) available: the $which can be ITIMER_REAL, ITIMER_VIRTUAL, ITIMER_PROF, or ITIMER_REALPROF. Note that which ones are available depends: true UNIX platforms usually have the first three, but only Solaris seems to have ITIMER_REALPROF (which is used to profile multithreaded programs). Win32 unfortunately does not haveinterval timers.

通常三つあるいは四つのインターバル・タイマー(シグナル)が利用可能です: $whichITIMER_REAL, ITIMER_VIRTUAL, ITIMER_PROF, ITIMER_REALPROF にすることができます。 どれが利用できるかは以下のことに依存します: 本当の UNIX プラットホームは通常最初の三つを持っています。 しかし Solaris は ITIMER_REALPROF を持っているようです (これはマルチスレッドなプログラムをプロファイルするために使われます)。 Win32 unfortunately does not haveinterval timers. (TBT)

ITIMER_REAL results in alarm()-like behaviour. Time is counted in real time; that is, wallclock time. SIGALRM is delivered when the timer expires.

ITIMER_REAL は結果として alarm() のような動きにします。 時間は実時間; つまり壁時計の時間で計られます。 タイマーが時間切れになると SIGALRM が送られます。

ITIMER_VIRTUAL counts time in (process) virtual time; that is, only when the process is running. In multiprocessor/user/CPU systems this may be more or less than real or wallclock time. (This time is also known as the user time.) SIGVTALRM is delivered when the timer expires.

ITIMER_VIRTUAL は(プロセス)仮想の時間 で時間を計ります; つまりプロセスが実行しているときだけです。 マルチプロセッサ/ユーザ/CPU の システムではこれは実時間あるいは壁時計の時間とは多かったり、少なかったりします。 (この時間はユーザー時間(user time)とも呼ばれます。 タイマーが時間切れになると SIGVTALRM が送られます。

ITIMER_PROF counts time when either the process virtual time or when the operating system is running on behalf of the process (such as I/O). (This time is also known as the system time.) (The sum of user time and system time is known as the CPU time.) SIGPROF is delivered when the timer expires. SIGPROF can interrupt system calls.

ITIMER_PROF はプロセス仮想時間、あるいは(I/O のように)プロセスの一部として オペレーティング・システムが走っている時間を計ります。 (この時間は システム時間(system time) とも呼ばれます。) タイマーが時間切れになると、SIGPROF が送られます。 SIGPROF はシステム・コールを中断させることができます。

The semantics of interval timers for multithreaded programs are system-specific, and some systems may support additional interval timers. For example, it is unspecified which thread gets the signals. See your setitimer() documentation.

マルチスレッドなプログラムでのインターバル・タイマーの意味は システムによります。 そしてシステムによっては、さらに他の インターバル・タイマーをサポートしているかもしれません。 例えば、スレッドがどのスレッドがシグナルを受信するかは未規定です。 あなたの setitimer() のドキュメントをご覧ください。

getitimer ( $which )

Return the remaining time in the interval timer specified by $which.

$which で指定されたインターバル・タイマーでの残り時間を返します。

In scalar context, the remaining time is returned.

スカラー・コンテキストでは、残り時間が返されます。

In list context, both the remaining time and the interval are returned. The interval is always what you put in using setitimer().

リスト・コンテキストでは残り時間とインターバルの両方が返されます。 インターバルは常に、setitimer() を使ったときに入れたものです。

clock_gettime ( $which )

Return as seconds the current value of the POSIX high resolution timer specified by $which. All implementations that support POSIX high resolution timers are supposed to support at least the $which value of CLOCK_REALTIME, which is supposed to return results close to the results of 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 CLOCK_MONOTONIC, which guarantees a monotonically increasing time value (unlike time() or gettimeofday(), which can be adjusted). See your system documentation for other possibly supported values.

Return as seconds the current value of the POSIX high resolution timer specified by $which. All implementations that support POSIX high resolution timers are supposed to support at least the $which value of CLOCK_REALTIME, which is supposed to return results close to the results of 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 CLOCK_MONOTONIC, which guarantees a monotonically increasing time value (unlike time() or gettimeofday(), which can be adjusted). See your system documentation for other possibly supported values. (TBT)

clock_getres ( $which )

Return as seconds the resolution of the POSIX high resolution timer specified by $which. All implementations that support POSIX high resolution timers are supposed to support at least the $which value of CLOCK_REALTIME, see "clock_gettime".

Return as seconds the resolution of the POSIX high resolution timer specified by $which. All implementations that support POSIX high resolution timers are supposed to support at least the $which value of CLOCK_REALTIME, see "clock_gettime". (TBT)

clock_nanosleep ( $which, $nanoseconds, $flags = 0)

Sleeps for the number of nanoseconds (1e9ths of a second) specified. Returns the number of nanoseconds actually slept. The $which is the "clock id", as with clock_gettime() and clock_getres(). The flags default to zero but TIMER_ABSTIME can specified (must be exported explicitly) which means that $nanoseconds is not a time interval (as is the default) but instead an absolute time. Can sleep for more than one second. Can also sleep for zero seconds, which often works like a thread yield. See also Time::HiRes::sleep(), Time::HiRes::usleep(), and Time::HiRes::nanosleep().

Sleeps for the number of nanoseconds (1e9ths of a second) specified. Returns the number of nanoseconds actually slept. The $which is the "clock id", as with clock_gettime() and clock_getres(). The flags default to zero but TIMER_ABSTIME can specified (must be exported explicitly) which means that $nanoseconds is not a time interval (as is the default) but instead an absolute time. Can sleep for more than one second. Can also sleep for zero seconds, which often works like a thread yield. See also Time::HiRes::sleep(), Time::HiRes::usleep(), and Time::HiRes::nanosleep(). (TBT)

Do not expect clock_nanosleep() to be exact down to one nanosecond. Getting even accuracy of one thousand nanoseconds is good.

Do not expect clock_nanosleep() to be exact down to one nanosecond. Getting even accuracy of one thousand nanoseconds is good. (TBT)

clock()

Return as seconds the process time (user + system time) spent by the process since the first call to clock() (the definition is not "since the start of the process", though if you are lucky these times may be quite close to each other, depending on the system). What this means is that you probably need to store the result of your first call to clock(), and subtract that value from the following results of clock().

Return as seconds the process time (user + system time) spent by the process since the first call to clock() (the definition is not "since the start of the process", though if you are lucky these times may be quite close to each other, depending on the system). What this means is that you probably need to store the result of your first call to clock(), and subtract that value from the following results of clock(). (TBT)

The time returned also includes the process times of the terminated child processes for which wait() has been executed. This value is somewhat like the second value returned by the times() of core Perl, but not necessarily identical. Note that due to backward compatibility limitations the returned value may wrap around at about 2147 seconds or at about 36 minutes.

The time returned also includes the process times of the terminated child processes for which wait() has been executed. This value is somewhat like the second value returned by the times() of core Perl, but not necessarily identical. Note that due to backward compatibility limitations the returned value may wrap around at about 2147 seconds or at about 36 minutes. (TBT)

stat
stat FH
stat EXPR

As "stat" in perlfunc but with the access/modify/change file timestamps in subsecond resolution, if the operating system and the filesystem both support such timestamps. To override the standard stat():

As "stat" in perlfunc but with the access/modify/change file timestamps in subsecond resolution, if the operating system and the filesystem both support such timestamps. To override the standard stat(): (TBT)

    use Time::HiRes qw(stat);

Test for the value of &Time::HiRes::d_hires_stat to find out whether the operating system supports subsecond file timestamps: a value larger than zero means yes. There are unfortunately no easy ways to find out whether the filesystem supports such timestamps. UNIX filesystems often do; NTFS does; FAT doesn't (FAT timestamp granularity is two seconds).

Test for the value of &Time::HiRes::d_hires_stat to find out whether the operating system supports subsecond file timestamps: a value larger than zero means yes. There are unfortunately no easy ways to find out whether the filesystem supports such timestamps. UNIX filesystems often do; NTFS does; FAT doesn't (FAT timestamp granularity is two seconds). (TBT)

A zero return value of &Time::HiRes::d_hires_stat means that Time::HiRes::stat is a no-op passthrough for CORE::stat(), and therefore the timestamps will stay integers. The same thing will happen if the filesystem does not do subsecond timestamps, even if the &Time::HiRes::d_hires_stat is non-zero.

A zero return value of &Time::HiRes::d_hires_stat means that Time::HiRes::stat is a no-op passthrough for CORE::stat(), and therefore the timestamps will stay integers. The same thing will happen if the filesystem does not do subsecond timestamps, even if the &Time::HiRes::d_hires_stat is non-zero. (TBT)

In any case do not expect nanosecond resolution, or even a microsecond resolution. Also note that the modify/access timestamps might have different resolutions, and that they need not be synchronized, e.g. if the operations are

In any case do not expect nanosecond resolution, or even a microsecond resolution. Also note that the modify/access timestamps might have different resolutions, and that they need not be synchronized, e.g. if the operations are (TBT)

    write
    stat # t1
    read
    stat # t2

the access time stamp from t2 need not be greater-than the modify time stamp from t1: it may be equal or less.

the access time stamp from t2 need not be greater-than the modify time stamp from t1: it may be equal or less. (TBT)

  use Time::HiRes qw(usleep ualarm gettimeofday tv_interval);

  $microseconds = 750_000;
  usleep($microseconds);
  # signal alarm in 2.5s & every .1s thereafter
  ualarm(2_500_000, 100_000);
  # cancel that ualarm
  ualarm(0);
  # 2.5秒後、その後は0.1行ごとにシグナル・アラーム
  ualarm(2_500_000, 100_000);
  # この ualarm をキャンセル
  ualarm(0);
  # get seconds and microseconds since the epoch
  ($s, $usec) = gettimeofday();
  # エポックからの秒とマイクロ秒を取得
  ($s, $usec) = gettimeofday();
  # measure elapsed time 
  # (could also do by subtracting 2 gettimeofday return values)
  $t0 = [gettimeofday];
  # do bunch of stuff here
  $t1 = [gettimeofday];
  # do more stuff here
  $t0_t1 = tv_interval $t0, $t1;
  # 経過時間の計測
  # (二つの gettimeofday の戻り値を引くことによっても可能です)
  $t0 = [gettimeofday];
  # ここで何か処理の固まりを実行
  $t1 = [gettimeofday];
  # さらに処理の固まりを実行
  $t0_t1 = tv_interval $t0, $t1;

  $elapsed = tv_interval ($t0, [gettimeofday]);
  $elapsed = tv_interval ($t0); # equivalent code
  #
  # replacements for time, alarm and sleep that know about
  # floating seconds
  #
  use Time::HiRes;
  $now_fractions = Time::HiRes::time;
  Time::HiRes::sleep (2.5);
  Time::HiRes::alarm (10.6666666);
  #
  # time, alarm , sleep を浮動小数点での秒がわかる
  # もので置き換え
  #
  use Time::HiRes;
  $now_fractions = Time::HiRes::time;
  Time::HiRes::sleep (2.5);
  Time::HiRes::alarm (10.6666666);

  use Time::HiRes qw ( time alarm sleep );
  $now_fractions = time;
  sleep (2.5);
  alarm (10.6666666);
  # Arm an interval timer to go off first at 10 seconds and
  # after that every 2.5 seconds, in process virtual time
  # プロセス仮想時間で最初に 10 秒、その後は 2.5 秒ごとに
  # やってくるインターバルタイマーを装備する

  use Time::HiRes qw ( setitimer ITIMER_VIRTUAL time );

  $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);

  use Time::HiRes qw( clock_nanosleep TIMER_ABSTIME );
  clock_nanosleep(CLOCK_REALTIME, 1e6);
  clock_nanosleep(CLOCK_REALTIME, 2e9, TIMER_ABSTIME);

  use Time::HiRes qw( clock );
  my $clock0 = clock();
  ... # Do something.
  my $clock1 = clock();
  my $clockd = $clock1 - $clock0;

  use Time::HiRes qw( stat );
  my ($atime, $mtime, $ctime) = (stat("istics"))[8, 9, 10];

C API

In addition to the perl API described above, a C API is available for extension writers. The following C functions are available in the modglobal hash:

拡張を書く人には上記の perl API に加えて、C API を利用することが 利用できます。 以下の C の関数が modglobal ハッシュで利用することができます:

  name             C prototype
  ---------------  ----------------------
  Time::NVtime     double (*)()
  Time::U2time     void (*)(pTHX_ UV ret[2])
  関数名           Cプロトタイプ
  ---------------  ----------------------
  Time::NVtime     double (*)()
  Time::U2time     void (*)(pTHX_ UV ret[2])

Both functions return equivalent information (like gettimeofday) but with different representations. The names NVtime and U2time were selected mainly because they are operating system independent. (gettimeofday is Unix-centric, though some platforms like Win32 and VMS have emulations for it.)

関数は両方とも(gettimeofday のような)同じ情報を返します。 しかしその表現が違います。NVtimeU2time という名前は主に オペレーティング・システムに依存していないために選択されています。 (Win32 や VMS のようにいくつかのプラットホームではそのエミュレーションを 備えていますが、gettimeofday は Unix 中心的です。)

Here is an example of using NVtime from C:

C から NVtime を使ったときの例を以下に示します:

  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");
  myNVtime = INT2PTR(double(*)(), SvIV(*svp));
  printf("The current time is: %f\n", (*myNVtime)());

DIAGNOSTICS

useconds or interval more than ...

In ualarm() you tried to use number of microseconds or interval (also in microseconds) more than 1_000_000 and setitimer() is not available in your system to emulate that case.

In ualarm() you tried to use number of microseconds or interval (also in microseconds) more than 1_000_000 and setitimer() is not available in your system to emulate that case. (TBT)

negative time not invented yet

You tried to use a negative time argument.

引数としてマイナスの時刻を使おうとしました。

internal error: useconds < 0 (unsigned ... signed ...)

Something went horribly wrong-- the number of microseconds that cannot become negative just became negative. Maybe your compiler is broken?

何かひどい障害がおきました -- マイナスになるはずのないマイクロ秒数は マイナスになってしまいました。 コンパイラが壊れているのかも?

useconds or uinterval equal to or more than 1000000

In some platforms it is not possible to get an alarm with subsecond resolution and later than one second.

In some platforms it is not possible to get an alarm with subsecond resolution and later than one second. (TBT)

unimplemented in this platform

Some calls simply aren't available, real or emulated, on every platform.

一部の呼び出しは、実物とエミュレーションとに関わらず、全ての プラットフォームで利用可能というわけではありません。

CAVEATS

Notice that the core time() maybe rounding rather than truncating. What this means is that the core time() may be reporting the time as one second later than gettimeofday() and Time::HiRes::time().

コアの time() が切り捨てるのではなく、四捨五入するかもしれないことに 注意してください。 これはコアの time()gettimeofday()Time::HiRes::time() よりも1秒遅い時間を報告するかもしれないという ことを意味します。

Adjusting the system clock (either manually or by services like ntp) may cause problems, especially for long running programs that assume a monotonously increasing time (note that all platforms do not adjust time as gracefully as UNIX ntp does). For example in Win32 (and derived 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).

Adjusting the system clock (either manually or by services like ntp) may cause problems, especially for long running programs that assume a monotonously increasing time (note that all platforms do not adjust time as gracefully as UNIX ntp does). For example in Win32 (and derived 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). (TBT)

Some systems have APIs but not implementations: for example QNX and Haiku have the interval timer APIs but not the functionality.

Some systems have APIs but not implementations: for example QNX and Haiku have the interval timer APIs but not the functionality. (TBT)

SEE ALSO

Perl modules BSD::Resource, Time::TAI64.

Perl モジュール BSD::Resource, Time::TAI64

Your system documentation for clock, clock_gettime, clock_getres, clock_nanosleep, clock_settime, getitimer, gettimeofday, setitimer, sleep, stat, ualarm.

システムの clock, clock_gettime, clock_getres, clock_nanosleep, clock_settime, getitimer, gettimeofday, setitimer, sleep, stat, ualarm の文書。

作者

D. Wegscheid <wegscd@whirlpool.com> R. Schertler <roderick@argon.org> J. Hietaniemi <jhi@iki.fi> G. Aas <gisle@aas.no>

コピーライト & ライセンス

Copyright (c) 1996-2002 Douglas E. Wegscheid. All rights reserved.

Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008 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.