| File | /usr/local/lib/perl5/5.10.1/darwin-2level/Time/HiRes.pm |
| Statements Executed | 32 |
| Statement Execution Time | 481µs |
| Calls | P | F | Exclusive Time |
Inclusive Time |
Subroutine |
|---|---|---|---|---|---|
| 1 | 1 | 2 | 66µs | 66µs | Time::HiRes::bootstrap (xsub) |
| 1 | 1 | 1 | 23µs | 248µs | Time::HiRes::import |
| 1 | 1 | 1 | 21µs | 33µs | Time::HiRes::AUTOLOAD |
| 1 | 1 | 1 | 13µs | 16µs | Time::HiRes::BEGIN@3 |
| 1 | 1 | 2 | 8µs | 8µs | Time::HiRes::constant (xsub) |
| 1 | 1 | 1 | 7µs | 94µs | Time::HiRes::BEGIN@4 |
| 1 | 1 | 1 | 7µs | 18µs | Time::HiRes::BEGIN@42 |
| 1 | 1 | 2 | 4µs | 4µs | Time::HiRes::CORE:subst (opcode) |
| 1 | 1 | 1 | 1µs | 1µs | Time::HiRes::__ANON__[:43] |
| 0 | 0 | 0 | 0s | 0s | Time::HiRes::tv_interval |
| Line | State ments |
Time on line |
Calls | Time in subs |
Code |
|---|---|---|---|---|---|
| 1 | package Time::HiRes; | ||||
| 2 | |||||
| 3 | 3 | 24µs | 2 | 20µs | # spent 16µs (13+3) within Time::HiRes::BEGIN@3 which was called
# once (13µs+3µs) by SimpleDB::Client::BEGIN@51 at line 3 # spent 16µs making 1 call to Time::HiRes::BEGIN@3
# spent 3µs making 1 call to strict::import |
| 4 | 3 | 139µs | 2 | 180µs | # spent 94µs (7+86) within Time::HiRes::BEGIN@4 which was called
# once (7µs+86µs) by SimpleDB::Client::BEGIN@51 at line 4 # spent 94µs making 1 call to Time::HiRes::BEGIN@4
# spent 86µs making 1 call to vars::import |
| 5 | |||||
| 6 | 1 | 600ns | require Exporter; | ||
| 7 | 1 | 900ns | require DynaLoader; | ||
| 8 | |||||
| 9 | 1 | 13µs | @ISA = qw(Exporter DynaLoader); | ||
| 10 | |||||
| 11 | 1 | 200ns | @EXPORT = qw( ); | ||
| 12 | 1 | 6µs | @EXPORT_OK = qw (usleep sleep ualarm alarm gettimeofday time tv_interval | ||
| 13 | getitimer setitimer nanosleep clock_gettime clock_getres | ||||
| 14 | clock clock_nanosleep | ||||
| 15 | CLOCK_HIGHRES CLOCK_MONOTONIC CLOCK_PROCESS_CPUTIME_ID | ||||
| 16 | CLOCK_REALTIME CLOCK_SOFTTIME CLOCK_THREAD_CPUTIME_ID | ||||
| 17 | CLOCK_TIMEOFDAY CLOCKS_PER_SEC | ||||
| 18 | ITIMER_REAL ITIMER_VIRTUAL ITIMER_PROF ITIMER_REALPROF | ||||
| 19 | TIMER_ABSTIME | ||||
| 20 | d_usleep d_ualarm d_gettimeofday d_getitimer d_setitimer | ||||
| 21 | d_nanosleep d_clock_gettime d_clock_getres | ||||
| 22 | d_clock d_clock_nanosleep | ||||
| 23 | stat | ||||
| 24 | ); | ||||
| 25 | |||||
| 26 | 1 | 5µs | $VERSION = '1.9719'; | ||
| 27 | 1 | 200ns | $XS_VERSION = $VERSION; | ||
| 28 | 1 | 16µs | $VERSION = eval $VERSION; | ||
| 29 | |||||
| 30 | # spent 33µs (21+11) within Time::HiRes::AUTOLOAD which was called
# once (21µs+11µs) by Time::HiRes::import at line 51 | ||||
| 31 | 7 | 29µs | my $constname; | ||
| 32 | ($constname = $AUTOLOAD) =~ s/.*:://; # spent 4µs making 1 call to Time::HiRes::CORE:subst | ||||
| 33 | # print "AUTOLOAD: constname = $constname ($AUTOLOAD)\n"; | ||||
| 34 | die "&Time::HiRes::constant not defined" if $constname eq 'constant'; | ||||
| 35 | my ($error, $val) = constant($constname); # spent 8µs making 1 call to Time::HiRes::constant | ||||
| 36 | # print "AUTOLOAD: error = $error, val = $val\n"; | ||||
| 37 | if ($error) { | ||||
| 38 | my (undef,$file,$line) = caller; | ||||
| 39 | die "$error at $file line $line.\n"; | ||||
| 40 | } | ||||
| 41 | { | ||||
| 42 | 3 | 199µs | 2 | 30µs | # spent 18µs (7+11) within Time::HiRes::BEGIN@42 which was called
# once (7µs+11µs) by SimpleDB::Client::BEGIN@51 at line 42 # spent 18µs making 1 call to Time::HiRes::BEGIN@42
# spent 11µs making 1 call to strict::unimport |
| 43 | 2 | 6µs | # spent 1µs within Time::HiRes::__ANON__[/usr/local/lib/perl5/5.10.1/darwin-2level/Time/HiRes.pm:43] which was called
# once (1µs+0s) by Time::HiRes::import at line 45 | ||
| 44 | } | ||||
| 45 | goto &$AUTOLOAD; # spent 1µs making 1 call to Time::HiRes::__ANON__[Time/HiRes.pm:43] | ||||
| 46 | } | ||||
| 47 | |||||
| 48 | # spent 248µs (23+225) within Time::HiRes::import which was called
# once (23µs+225µs) by SimpleDB::Client::BEGIN@51 at line 51 of ../lib/SimpleDB/Client.pm | ||||
| 49 | 3 | 9µs | my $this = shift; | ||
| 50 | for my $i (@_) { | ||||
| 51 | 1 | 7µs | 1 | 33µs | if (($i eq 'clock_getres' && !&d_clock_getres) || # spent 33µs making 1 call to Time::HiRes::AUTOLOAD |
| 52 | ($i eq 'clock_gettime' && !&d_clock_gettime) || | ||||
| 53 | ($i eq 'clock_nanosleep' && !&d_clock_nanosleep) || | ||||
| 54 | ($i eq 'clock' && !&d_clock) || | ||||
| 55 | ($i eq 'nanosleep' && !&d_nanosleep) || | ||||
| 56 | ($i eq 'usleep' && !&d_usleep) || | ||||
| 57 | ($i eq 'ualarm' && !&d_ualarm)) { | ||||
| 58 | require Carp; | ||||
| 59 | Carp::croak("Time::HiRes::$i(): unimplemented in this platform"); | ||||
| 60 | } | ||||
| 61 | } | ||||
| 62 | Time::HiRes->export_to_level(1, $this, @_); # spent 23µs making 1 call to Exporter::export_to_level | ||||
| 63 | } | ||||
| 64 | |||||
| 65 | 1 | 6µs | 1 | 351µs | bootstrap Time::HiRes; # spent 351µs making 1 call to DynaLoader::bootstrap |
| 66 | |||||
| 67 | # Preloaded methods go here. | ||||
| 68 | |||||
| 69 | sub tv_interval { | ||||
| 70 | # probably could have been done in C | ||||
| 71 | my ($a, $b) = @_; | ||||
| 72 | $b = [gettimeofday()] unless defined($b); | ||||
| 73 | (${$b}[0] - ${$a}[0]) + ((${$b}[1] - ${$a}[1]) / 1_000_000); | ||||
| 74 | } | ||||
| 75 | |||||
| 76 | # Autoload methods go after =cut, and are processed by the autosplit program. | ||||
| 77 | |||||
| 78 | 1 | 20µs | 1; | ||
| 79 | __END__ | ||||
| 80 | |||||
| 81 | =head1 NAME | ||||
| 82 | |||||
| 83 | Time::HiRes - High resolution alarm, sleep, gettimeofday, interval timers | ||||
| 84 | |||||
| 85 | =head1 SYNOPSIS | ||||
| 86 | |||||
| 87 | use Time::HiRes qw( usleep ualarm gettimeofday tv_interval nanosleep | ||||
| 88 | clock_gettime clock_getres clock_nanosleep clock | ||||
| 89 | stat ); | ||||
| 90 | |||||
| 91 | usleep ($microseconds); | ||||
| 92 | nanosleep ($nanoseconds); | ||||
| 93 | |||||
| 94 | ualarm ($microseconds); | ||||
| 95 | ualarm ($microseconds, $interval_microseconds); | ||||
| 96 | |||||
| 97 | $t0 = [gettimeofday]; | ||||
| 98 | ($seconds, $microseconds) = gettimeofday; | ||||
| 99 | |||||
| 100 | $elapsed = tv_interval ( $t0, [$seconds, $microseconds]); | ||||
| 101 | $elapsed = tv_interval ( $t0, [gettimeofday]); | ||||
| 102 | $elapsed = tv_interval ( $t0 ); | ||||
| 103 | |||||
| 104 | use Time::HiRes qw ( time alarm sleep ); | ||||
| 105 | |||||
| 106 | $now_fractions = time; | ||||
| 107 | sleep ($floating_seconds); | ||||
| 108 | alarm ($floating_seconds); | ||||
| 109 | alarm ($floating_seconds, $floating_interval); | ||||
| 110 | |||||
| 111 | use Time::HiRes qw( setitimer getitimer ); | ||||
| 112 | |||||
| 113 | setitimer ($which, $floating_seconds, $floating_interval ); | ||||
| 114 | getitimer ($which); | ||||
| 115 | |||||
| 116 | use Time::HiRes qw( clock_gettime clock_getres clock_nanosleep | ||||
| 117 | ITIMER_REAL ITIMER_VIRTUAL ITIMER_PROF ITIMER_REALPROF ); | ||||
| 118 | |||||
| 119 | $realtime = clock_gettime(CLOCK_REALTIME); | ||||
| 120 | $resolution = clock_getres(CLOCK_REALTIME); | ||||
| 121 | |||||
| 122 | clock_nanosleep(CLOCK_REALTIME, 1.5e9); | ||||
| 123 | clock_nanosleep(CLOCK_REALTIME, time()*1e9 + 10e9, TIMER_ABSTIME); | ||||
| 124 | |||||
| 125 | my $ticktock = clock(); | ||||
| 126 | |||||
| 127 | use Time::HiRes qw( stat ); | ||||
| 128 | |||||
| 129 | my @stat = stat("file"); | ||||
| 130 | my @stat = stat(FH); | ||||
| 131 | |||||
| 132 | =head1 DESCRIPTION | ||||
| 133 | |||||
| 134 | The C<Time::HiRes> module implements a Perl interface to the | ||||
| 135 | C<usleep>, C<nanosleep>, C<ualarm>, C<gettimeofday>, and | ||||
| 136 | C<setitimer>/C<getitimer> system calls, in other words, high | ||||
| 137 | resolution time and timers. See the L</EXAMPLES> section below and the | ||||
| 138 | test scripts for usage; see your system documentation for the | ||||
| 139 | description of the underlying C<nanosleep> or C<usleep>, C<ualarm>, | ||||
| 140 | C<gettimeofday>, and C<setitimer>/C<getitimer> calls. | ||||
| 141 | |||||
| 142 | If your system lacks C<gettimeofday()> or an emulation of it you don't | ||||
| 143 | get C<gettimeofday()> or the one-argument form of C<tv_interval()>. | ||||
| 144 | If your system lacks all of C<nanosleep()>, C<usleep()>, | ||||
| 145 | C<select()>, and C<poll>, you don't get C<Time::HiRes::usleep()>, | ||||
| 146 | C<Time::HiRes::nanosleep()>, or C<Time::HiRes::sleep()>. | ||||
| 147 | If your system lacks both C<ualarm()> and C<setitimer()> you don't get | ||||
| 148 | C<Time::HiRes::ualarm()> or C<Time::HiRes::alarm()>. | ||||
| 149 | |||||
| 150 | If you try to import an unimplemented function in the C<use> statement | ||||
| 151 | it will fail at compile time. | ||||
| 152 | |||||
| 153 | If your subsecond sleeping is implemented with C<nanosleep()> instead | ||||
| 154 | of C<usleep()>, you can mix subsecond sleeping with signals since | ||||
| 155 | C<nanosleep()> does not use signals. This, however, is not portable, | ||||
| 156 | and you should first check for the truth value of | ||||
| 157 | C<&Time::HiRes::d_nanosleep> to see whether you have nanosleep, and | ||||
| 158 | then carefully read your C<nanosleep()> C API documentation for any | ||||
| 159 | peculiarities. | ||||
| 160 | |||||
| 161 | If you are using C<nanosleep> for something else than mixing sleeping | ||||
| 162 | with signals, give some thought to whether Perl is the tool you should | ||||
| 163 | be using for work requiring nanosecond accuracies. | ||||
| 164 | |||||
| 165 | Remember that unless you are working on a I<hard realtime> system, | ||||
| 166 | any clocks and timers will be imprecise, especially so if you are working | ||||
| 167 | in a pre-emptive multiuser system. Understand the difference between | ||||
| 168 | I<wallclock time> and process time (in UNIX-like systems the sum of | ||||
| 169 | I<user> and I<system> times). Any attempt to sleep for X seconds will | ||||
| 170 | most probably end up sleeping B<more> than that, but don't be surpised | ||||
| 171 | if you end up sleeping slightly B<less>. | ||||
| 172 | |||||
| 173 | The following functions can be imported from this module. | ||||
| 174 | No functions are exported by default. | ||||
| 175 | |||||
| 176 | =over 4 | ||||
| 177 | |||||
| 178 | =item gettimeofday () | ||||
| 179 | |||||
| 180 | In array context returns a two-element array with the seconds and | ||||
| 181 | microseconds since the epoch. In scalar context returns floating | ||||
| 182 | seconds like C<Time::HiRes::time()> (see below). | ||||
| 183 | |||||
| 184 | =item usleep ( $useconds ) | ||||
| 185 | |||||
| 186 | Sleeps for the number of microseconds (millionths of a second) | ||||
| 187 | specified. Returns the number of microseconds actually slept. | ||||
| 188 | Can sleep for more than one second, unlike the C<usleep> system call. | ||||
| 189 | Can also sleep for zero seconds, which often works like a I<thread yield>. | ||||
| 190 | See also C<Time::HiRes::usleep()>, C<Time::HiRes::sleep()>, and | ||||
| 191 | C<Time::HiRes::clock_nanosleep()>. | ||||
| 192 | |||||
| 193 | Do not expect usleep() to be exact down to one microsecond. | ||||
| 194 | |||||
| 195 | =item nanosleep ( $nanoseconds ) | ||||
| 196 | |||||
| 197 | Sleeps for the number of nanoseconds (1e9ths of a second) specified. | ||||
| 198 | Returns the number of nanoseconds actually slept (accurate only to | ||||
| 199 | microseconds, the nearest thousand of them). Can sleep for more than | ||||
| 200 | one second. Can also sleep for zero seconds, which often works like | ||||
| 201 | a I<thread yield>. See also C<Time::HiRes::sleep()>, | ||||
| 202 | C<Time::HiRes::usleep()>, and C<Time::HiRes::clock_nanosleep()>. | ||||
| 203 | |||||
| 204 | Do not expect nanosleep() to be exact down to one nanosecond. | ||||
| 205 | Getting even accuracy of one thousand nanoseconds is good. | ||||
| 206 | |||||
| 207 | =item ualarm ( $useconds [, $interval_useconds ] ) | ||||
| 208 | |||||
| 209 | Issues a C<ualarm> call; the C<$interval_useconds> is optional and | ||||
| 210 | will be zero if unspecified, resulting in C<alarm>-like behaviour. | ||||
| 211 | |||||
| 212 | Returns the remaining time in the alarm in microseconds, or C<undef> | ||||
| 213 | if an error occurred. | ||||
| 214 | |||||
| 215 | ualarm(0) will cancel an outstanding ualarm(). | ||||
| 216 | |||||
| 217 | Note that the interaction between alarms and sleeps is unspecified. | ||||
| 218 | |||||
| 219 | =item tv_interval | ||||
| 220 | |||||
| 221 | tv_interval ( $ref_to_gettimeofday [, $ref_to_later_gettimeofday] ) | ||||
| 222 | |||||
| 223 | Returns the floating seconds between the two times, which should have | ||||
| 224 | been returned by C<gettimeofday()>. If the second argument is omitted, | ||||
| 225 | then the current time is used. | ||||
| 226 | |||||
| 227 | =item time () | ||||
| 228 | |||||
| 229 | Returns a floating seconds since the epoch. This function can be | ||||
| 230 | imported, resulting in a nice drop-in replacement for the C<time> | ||||
| 231 | provided with core Perl; see the L</EXAMPLES> below. | ||||
| 232 | |||||
| 233 | B<NOTE 1>: This higher resolution timer can return values either less | ||||
| 234 | or more than the core C<time()>, depending on whether your platform | ||||
| 235 | rounds the higher resolution timer values up, down, or to the nearest second | ||||
| 236 | to get the core C<time()>, but naturally the difference should be never | ||||
| 237 | more than half a second. See also L</clock_getres>, if available | ||||
| 238 | in your system. | ||||
| 239 | |||||
| 240 | B<NOTE 2>: Since Sunday, September 9th, 2001 at 01:46:40 AM GMT, when | ||||
| 241 | the C<time()> seconds since epoch rolled over to 1_000_000_000, the | ||||
| 242 | default floating point format of Perl and the seconds since epoch have | ||||
| 243 | conspired to produce an apparent bug: if you print the value of | ||||
| 244 | C<Time::HiRes::time()> you seem to be getting only five decimals, not | ||||
| 245 | six as promised (microseconds). Not to worry, the microseconds are | ||||
| 246 | there (assuming your platform supports such granularity in the first | ||||
| 247 | place). What is going on is that the default floating point format of | ||||
| 248 | Perl only outputs 15 digits. In this case that means ten digits | ||||
| 249 | before the decimal separator and five after. To see the microseconds | ||||
| 250 | you can use either C<printf>/C<sprintf> with C<"%.6f">, or the | ||||
| 251 | C<gettimeofday()> function in list context, which will give you the | ||||
| 252 | seconds and microseconds as two separate values. | ||||
| 253 | |||||
| 254 | =item sleep ( $floating_seconds ) | ||||
| 255 | |||||
| 256 | Sleeps for the specified amount of seconds. Returns the number of | ||||
| 257 | seconds actually slept (a floating point value). This function can | ||||
| 258 | be imported, resulting in a nice drop-in replacement for the C<sleep> | ||||
| 259 | provided with perl, see the L</EXAMPLES> below. | ||||
| 260 | |||||
| 261 | Note that the interaction between alarms and sleeps is unspecified. | ||||
| 262 | |||||
| 263 | =item alarm ( $floating_seconds [, $interval_floating_seconds ] ) | ||||
| 264 | |||||
| 265 | The C<SIGALRM> signal is sent after the specified number of seconds. | ||||
| 266 | Implemented using C<setitimer()> if available, C<ualarm()> if not. | ||||
| 267 | The C<$interval_floating_seconds> argument is optional and will be | ||||
| 268 | zero if unspecified, resulting in C<alarm()>-like behaviour. This | ||||
| 269 | function can be imported, resulting in a nice drop-in replacement for | ||||
| 270 | the C<alarm> provided with perl, see the L</EXAMPLES> below. | ||||
| 271 | |||||
| 272 | Returns the remaining time in the alarm in seconds, or C<undef> | ||||
| 273 | if an error occurred. | ||||
| 274 | |||||
| 275 | B<NOTE 1>: With some combinations of operating systems and Perl | ||||
| 276 | releases C<SIGALRM> restarts C<select()>, instead of interrupting it. | ||||
| 277 | This means that an C<alarm()> followed by a C<select()> may together | ||||
| 278 | take the sum of the times specified for the the C<alarm()> and the | ||||
| 279 | C<select()>, not just the time of the C<alarm()>. | ||||
| 280 | |||||
| 281 | Note that the interaction between alarms and sleeps is unspecified. | ||||
| 282 | |||||
| 283 | =item setitimer ( $which, $floating_seconds [, $interval_floating_seconds ] ) | ||||
| 284 | |||||
| 285 | Start up an interval timer: after a certain time, a signal ($which) arrives, | ||||
| 286 | and more signals may keep arriving at certain intervals. To disable | ||||
| 287 | an "itimer", use C<$floating_seconds> of zero. If the | ||||
| 288 | C<$interval_floating_seconds> is set to zero (or unspecified), the | ||||
| 289 | timer is disabled B<after> the next delivered signal. | ||||
| 290 | |||||
| 291 | Use of interval timers may interfere with C<alarm()>, C<sleep()>, | ||||
| 292 | and C<usleep()>. In standard-speak the "interaction is unspecified", | ||||
| 293 | which means that I<anything> may happen: it may work, it may not. | ||||
| 294 | |||||
| 295 | In scalar context, the remaining time in the timer is returned. | ||||
| 296 | |||||
| 297 | In list context, both the remaining time and the interval are returned. | ||||
| 298 | |||||
| 299 | There are usually three or four interval timers (signals) available: the | ||||
| 300 | C<$which> can be C<ITIMER_REAL>, C<ITIMER_VIRTUAL>, C<ITIMER_PROF>, or | ||||
| 301 | C<ITIMER_REALPROF>. Note that which ones are available depends: true | ||||
| 302 | UNIX platforms usually have the first three, but only Solaris seems to | ||||
| 303 | have C<ITIMER_REALPROF> (which is used to profile multithreaded programs). | ||||
| 304 | Win32 unfortunately does not haveinterval timers. | ||||
| 305 | |||||
| 306 | C<ITIMER_REAL> results in C<alarm()>-like behaviour. Time is counted in | ||||
| 307 | I<real time>; that is, wallclock time. C<SIGALRM> is delivered when | ||||
| 308 | the timer expires. | ||||
| 309 | |||||
| 310 | C<ITIMER_VIRTUAL> counts time in (process) I<virtual time>; that is, | ||||
| 311 | only when the process is running. In multiprocessor/user/CPU systems | ||||
| 312 | this may be more or less than real or wallclock time. (This time is | ||||
| 313 | also known as the I<user time>.) C<SIGVTALRM> is delivered when the | ||||
| 314 | timer expires. | ||||
| 315 | |||||
| 316 | C<ITIMER_PROF> counts time when either the process virtual time or when | ||||
| 317 | the operating system is running on behalf of the process (such as I/O). | ||||
| 318 | (This time is also known as the I<system time>.) (The sum of user | ||||
| 319 | time and system time is known as the I<CPU time>.) C<SIGPROF> is | ||||
| 320 | delivered when the timer expires. C<SIGPROF> can interrupt system calls. | ||||
| 321 | |||||
| 322 | The semantics of interval timers for multithreaded programs are | ||||
| 323 | system-specific, and some systems may support additional interval | ||||
| 324 | timers. For example, it is unspecified which thread gets the signals. | ||||
| 325 | See your C<setitimer()> documentation. | ||||
| 326 | |||||
| 327 | =item getitimer ( $which ) | ||||
| 328 | |||||
| 329 | Return the remaining time in the interval timer specified by C<$which>. | ||||
| 330 | |||||
| 331 | In scalar context, the remaining time is returned. | ||||
| 332 | |||||
| 333 | In list context, both the remaining time and the interval are returned. | ||||
| 334 | The interval is always what you put in using C<setitimer()>. | ||||
| 335 | |||||
| 336 | =item clock_gettime ( $which ) | ||||
| 337 | |||||
| 338 | Return as seconds the current value of the POSIX high resolution timer | ||||
| 339 | specified by C<$which>. All implementations that support POSIX high | ||||
| 340 | resolution timers are supposed to support at least the C<$which> value | ||||
| 341 | of C<CLOCK_REALTIME>, which is supposed to return results close to the | ||||
| 342 | results of C<gettimeofday>, or the number of seconds since 00:00:00:00 | ||||
| 343 | January 1, 1970 Greenwich Mean Time (GMT). Do not assume that | ||||
| 344 | CLOCK_REALTIME is zero, it might be one, or something else. | ||||
| 345 | Another potentially useful (but not available everywhere) value is | ||||
| 346 | C<CLOCK_MONOTONIC>, which guarantees a monotonically increasing time | ||||
| 347 | value (unlike time() or gettimeofday(), which can be adjusted). | ||||
| 348 | See your system documentation for other possibly supported values. | ||||
| 349 | |||||
| 350 | =item clock_getres ( $which ) | ||||
| 351 | |||||
| 352 | Return as seconds the resolution of the POSIX high resolution timer | ||||
| 353 | specified by C<$which>. All implementations that support POSIX high | ||||
| 354 | resolution timers are supposed to support at least the C<$which> value | ||||
| 355 | of C<CLOCK_REALTIME>, see L</clock_gettime>. | ||||
| 356 | |||||
| 357 | =item clock_nanosleep ( $which, $nanoseconds, $flags = 0) | ||||
| 358 | |||||
| 359 | Sleeps for the number of nanoseconds (1e9ths of a second) specified. | ||||
| 360 | Returns the number of nanoseconds actually slept. The $which is the | ||||
| 361 | "clock id", as with clock_gettime() and clock_getres(). The flags | ||||
| 362 | default to zero but C<TIMER_ABSTIME> can specified (must be exported | ||||
| 363 | explicitly) which means that C<$nanoseconds> is not a time interval | ||||
| 364 | (as is the default) but instead an absolute time. Can sleep for more | ||||
| 365 | than one second. Can also sleep for zero seconds, which often works | ||||
| 366 | like a I<thread yield>. See also C<Time::HiRes::sleep()>, | ||||
| 367 | C<Time::HiRes::usleep()>, and C<Time::HiRes::nanosleep()>. | ||||
| 368 | |||||
| 369 | Do not expect clock_nanosleep() to be exact down to one nanosecond. | ||||
| 370 | Getting even accuracy of one thousand nanoseconds is good. | ||||
| 371 | |||||
| 372 | =item clock() | ||||
| 373 | |||||
| 374 | Return as seconds the I<process time> (user + system time) spent by | ||||
| 375 | the process since the first call to clock() (the definition is B<not> | ||||
| 376 | "since the start of the process", though if you are lucky these times | ||||
| 377 | may be quite close to each other, depending on the system). What this | ||||
| 378 | means is that you probably need to store the result of your first call | ||||
| 379 | to clock(), and subtract that value from the following results of clock(). | ||||
| 380 | |||||
| 381 | The time returned also includes the process times of the terminated | ||||
| 382 | child processes for which wait() has been executed. This value is | ||||
| 383 | somewhat like the second value returned by the times() of core Perl, | ||||
| 384 | but not necessarily identical. Note that due to backward | ||||
| 385 | compatibility limitations the returned value may wrap around at about | ||||
| 386 | 2147 seconds or at about 36 minutes. | ||||
| 387 | |||||
| 388 | =item stat | ||||
| 389 | |||||
| 390 | =item stat FH | ||||
| 391 | |||||
| 392 | =item stat EXPR | ||||
| 393 | |||||
| 394 | As L<perlfunc/stat> but with the access/modify/change file timestamps | ||||
| 395 | in subsecond resolution, if the operating system and the filesystem | ||||
| 396 | both support such timestamps. To override the standard stat(): | ||||
| 397 | |||||
| 398 | use Time::HiRes qw(stat); | ||||
| 399 | |||||
| 400 | Test for the value of &Time::HiRes::d_hires_stat to find out whether | ||||
| 401 | the operating system supports subsecond file timestamps: a value | ||||
| 402 | larger than zero means yes. There are unfortunately no easy | ||||
| 403 | ways to find out whether the filesystem supports such timestamps. | ||||
| 404 | UNIX filesystems often do; NTFS does; FAT doesn't (FAT timestamp | ||||
| 405 | granularity is B<two> seconds). | ||||
| 406 | |||||
| 407 | A zero return value of &Time::HiRes::d_hires_stat means that | ||||
| 408 | Time::HiRes::stat is a no-op passthrough for CORE::stat(), | ||||
| 409 | and therefore the timestamps will stay integers. The same | ||||
| 410 | thing will happen if the filesystem does not do subsecond timestamps, | ||||
| 411 | even if the &Time::HiRes::d_hires_stat is non-zero. | ||||
| 412 | |||||
| 413 | In any case do not expect nanosecond resolution, or even a microsecond | ||||
| 414 | resolution. Also note that the modify/access timestamps might have | ||||
| 415 | different resolutions, and that they need not be synchronized, e.g. | ||||
| 416 | if the operations are | ||||
| 417 | |||||
| 418 | write | ||||
| 419 | stat # t1 | ||||
| 420 | read | ||||
| 421 | stat # t2 | ||||
| 422 | |||||
| 423 | the access time stamp from t2 need not be greater-than the modify | ||||
| 424 | time stamp from t1: it may be equal or I<less>. | ||||
| 425 | |||||
| 426 | =back | ||||
| 427 | |||||
| 428 | =head1 EXAMPLES | ||||
| 429 | |||||
| 430 | use Time::HiRes qw(usleep ualarm gettimeofday tv_interval); | ||||
| 431 | |||||
| 432 | $microseconds = 750_000; | ||||
| 433 | usleep($microseconds); | ||||
| 434 | |||||
| 435 | # signal alarm in 2.5s & every .1s thereafter | ||||
| 436 | ualarm(2_500_000, 100_000); | ||||
| 437 | # cancel that ualarm | ||||
| 438 | ualarm(0); | ||||
| 439 | |||||
| 440 | # get seconds and microseconds since the epoch | ||||
| 441 | ($s, $usec) = gettimeofday(); | ||||
| 442 | |||||
| 443 | # measure elapsed time | ||||
| 444 | # (could also do by subtracting 2 gettimeofday return values) | ||||
| 445 | $t0 = [gettimeofday]; | ||||
| 446 | # do bunch of stuff here | ||||
| 447 | $t1 = [gettimeofday]; | ||||
| 448 | # do more stuff here | ||||
| 449 | $t0_t1 = tv_interval $t0, $t1; | ||||
| 450 | |||||
| 451 | $elapsed = tv_interval ($t0, [gettimeofday]); | ||||
| 452 | $elapsed = tv_interval ($t0); # equivalent code | ||||
| 453 | |||||
| 454 | # | ||||
| 455 | # replacements for time, alarm and sleep that know about | ||||
| 456 | # floating seconds | ||||
| 457 | # | ||||
| 458 | use Time::HiRes; | ||||
| 459 | $now_fractions = Time::HiRes::time; | ||||
| 460 | Time::HiRes::sleep (2.5); | ||||
| 461 | Time::HiRes::alarm (10.6666666); | ||||
| 462 | |||||
| 463 | use Time::HiRes qw ( time alarm sleep ); | ||||
| 464 | $now_fractions = time; | ||||
| 465 | sleep (2.5); | ||||
| 466 | alarm (10.6666666); | ||||
| 467 | |||||
| 468 | # Arm an interval timer to go off first at 10 seconds and | ||||
| 469 | # after that every 2.5 seconds, in process virtual time | ||||
| 470 | |||||
| 471 | use Time::HiRes qw ( setitimer ITIMER_VIRTUAL time ); | ||||
| 472 | |||||
| 473 | $SIG{VTALRM} = sub { print time, "\n" }; | ||||
| 474 | setitimer(ITIMER_VIRTUAL, 10, 2.5); | ||||
| 475 | |||||
| 476 | use Time::HiRes qw( clock_gettime clock_getres CLOCK_REALTIME ); | ||||
| 477 | # Read the POSIX high resolution timer. | ||||
| 478 | my $high = clock_getres(CLOCK_REALTIME); | ||||
| 479 | # But how accurate we can be, really? | ||||
| 480 | my $reso = clock_getres(CLOCK_REALTIME); | ||||
| 481 | |||||
| 482 | use Time::HiRes qw( clock_nanosleep TIMER_ABSTIME ); | ||||
| 483 | clock_nanosleep(CLOCK_REALTIME, 1e6); | ||||
| 484 | clock_nanosleep(CLOCK_REALTIME, 2e9, TIMER_ABSTIME); | ||||
| 485 | |||||
| 486 | use Time::HiRes qw( clock ); | ||||
| 487 | my $clock0 = clock(); | ||||
| 488 | ... # Do something. | ||||
| 489 | my $clock1 = clock(); | ||||
| 490 | my $clockd = $clock1 - $clock0; | ||||
| 491 | |||||
| 492 | use Time::HiRes qw( stat ); | ||||
| 493 | my ($atime, $mtime, $ctime) = (stat("istics"))[8, 9, 10]; | ||||
| 494 | |||||
| 495 | =head1 C API | ||||
| 496 | |||||
| 497 | In addition to the perl API described above, a C API is available for | ||||
| 498 | extension writers. The following C functions are available in the | ||||
| 499 | modglobal hash: | ||||
| 500 | |||||
| 501 | name C prototype | ||||
| 502 | --------------- ---------------------- | ||||
| 503 | Time::NVtime double (*)() | ||||
| 504 | Time::U2time void (*)(pTHX_ UV ret[2]) | ||||
| 505 | |||||
| 506 | Both functions return equivalent information (like C<gettimeofday>) | ||||
| 507 | but with different representations. The names C<NVtime> and C<U2time> | ||||
| 508 | were selected mainly because they are operating system independent. | ||||
| 509 | (C<gettimeofday> is Unix-centric, though some platforms like Win32 and | ||||
| 510 | VMS have emulations for it.) | ||||
| 511 | |||||
| 512 | Here is an example of using C<NVtime> from C: | ||||
| 513 | |||||
| 514 | double (*myNVtime)(); /* Returns -1 on failure. */ | ||||
| 515 | SV **svp = hv_fetch(PL_modglobal, "Time::NVtime", 12, 0); | ||||
| 516 | if (!svp) croak("Time::HiRes is required"); | ||||
| 517 | if (!SvIOK(*svp)) croak("Time::NVtime isn't a function pointer"); | ||||
| 518 | myNVtime = INT2PTR(double(*)(), SvIV(*svp)); | ||||
| 519 | printf("The current time is: %f\n", (*myNVtime)()); | ||||
| 520 | |||||
| 521 | =head1 DIAGNOSTICS | ||||
| 522 | |||||
| 523 | =head2 useconds or interval more than ... | ||||
| 524 | |||||
| 525 | In ualarm() you tried to use number of microseconds or interval (also | ||||
| 526 | in microseconds) more than 1_000_000 and setitimer() is not available | ||||
| 527 | in your system to emulate that case. | ||||
| 528 | |||||
| 529 | =head2 negative time not invented yet | ||||
| 530 | |||||
| 531 | You tried to use a negative time argument. | ||||
| 532 | |||||
| 533 | =head2 internal error: useconds < 0 (unsigned ... signed ...) | ||||
| 534 | |||||
| 535 | Something went horribly wrong-- the number of microseconds that cannot | ||||
| 536 | become negative just became negative. Maybe your compiler is broken? | ||||
| 537 | |||||
| 538 | =head2 useconds or uinterval equal to or more than 1000000 | ||||
| 539 | |||||
| 540 | In some platforms it is not possible to get an alarm with subsecond | ||||
| 541 | resolution and later than one second. | ||||
| 542 | |||||
| 543 | =head2 unimplemented in this platform | ||||
| 544 | |||||
| 545 | Some calls simply aren't available, real or emulated, on every platform. | ||||
| 546 | |||||
| 547 | =head1 CAVEATS | ||||
| 548 | |||||
| 549 | Notice that the core C<time()> maybe rounding rather than truncating. | ||||
| 550 | What this means is that the core C<time()> may be reporting the time | ||||
| 551 | as one second later than C<gettimeofday()> and C<Time::HiRes::time()>. | ||||
| 552 | |||||
| 553 | Adjusting the system clock (either manually or by services like ntp) | ||||
| 554 | may cause problems, especially for long running programs that assume | ||||
| 555 | a monotonously increasing time (note that all platforms do not adjust | ||||
| 556 | time as gracefully as UNIX ntp does). For example in Win32 (and derived | ||||
| 557 | platforms like Cygwin and MinGW) the Time::HiRes::time() may temporarily | ||||
| 558 | drift off from the system clock (and the original time()) by up to 0.5 | ||||
| 559 | seconds. Time::HiRes will notice this eventually and recalibrate. | ||||
| 560 | Note that since Time::HiRes 1.77 the clock_gettime(CLOCK_MONOTONIC) | ||||
| 561 | might help in this (in case your system supports CLOCK_MONOTONIC). | ||||
| 562 | |||||
| 563 | Some systems have APIs but not implementations: for example QNX and Haiku | ||||
| 564 | have the interval timer APIs but not the functionality. | ||||
| 565 | |||||
| 566 | =head1 SEE ALSO | ||||
| 567 | |||||
| 568 | Perl modules L<BSD::Resource>, L<Time::TAI64>. | ||||
| 569 | |||||
| 570 | Your system documentation for C<clock>, C<clock_gettime>, | ||||
| 571 | C<clock_getres>, C<clock_nanosleep>, C<clock_settime>, C<getitimer>, | ||||
| 572 | C<gettimeofday>, C<setitimer>, C<sleep>, C<stat>, C<ualarm>. | ||||
| 573 | |||||
| 574 | =head1 AUTHORS | ||||
| 575 | |||||
| 576 | D. Wegscheid <wegscd@whirlpool.com> | ||||
| 577 | R. Schertler <roderick@argon.org> | ||||
| 578 | J. Hietaniemi <jhi@iki.fi> | ||||
| 579 | G. Aas <gisle@aas.no> | ||||
| 580 | |||||
| 581 | =head1 COPYRIGHT AND LICENSE | ||||
| 582 | |||||
| 583 | Copyright (c) 1996-2002 Douglas E. Wegscheid. All rights reserved. | ||||
| 584 | |||||
| 585 | Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008 Jarkko Hietaniemi. | ||||
| 586 | All rights reserved. | ||||
| 587 | |||||
| 588 | This program is free software; you can redistribute it and/or modify | ||||
| 589 | it under the same terms as Perl itself. | ||||
| 590 | |||||
| 591 | =cut | ||||
# spent 4µs within Time::HiRes::CORE:subst which was called
# once (4µs+0s) by Time::HiRes::AUTOLOAD at line 32 of Time/HiRes.pm | |||||
# spent 66µs within Time::HiRes::bootstrap which was called
# once (66µs+0s) by DynaLoader::bootstrap at line 227 of DynaLoader.pm | |||||
# spent 8µs within Time::HiRes::constant which was called
# once (8µs+0s) by Time::HiRes::AUTOLOAD at line 35 of Time/HiRes.pm |