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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.292 by root, Tue Aug 14 09:29:50 2018 UTC vs.
Revision 1.317 by root, Sun Sep 25 16:30:50 2022 UTC

171use common::sense; 171use common::sense;
172 172
173use base 'Exporter'; 173use base 'Exporter';
174 174
175BEGIN { 175BEGIN {
176 our $VERSION = 4.53; 176 our $VERSION = 4.79;
177 177
178 our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close 178 our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close
179 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx 179 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
180 aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl 180 aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl
181 aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range 181 aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range
192 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 192 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
193 min_parallel max_parallel max_idle idle_timeout 193 min_parallel max_parallel max_idle idle_timeout
194 nreqs nready npending nthreads 194 nreqs nready npending nthreads
195 max_poll_time max_poll_reqs 195 max_poll_time max_poll_reqs
196 sendfile fadvise madvise 196 sendfile fadvise madvise
197 mmap munmap mremap munlock munlockall); 197 mmap munmap mremap munlock munlockall
198
199 accept4 tee splice pipe2 pipesize
200 fexecve mount umount memfd_create eventfd
201 timerfd_create timerfd_settime timerfd_gettime
202 pidfd_open pidfd_send_signal pidfd_getfd);
198 203
199 push @AIO_REQ, qw(aio_busy); # not exported 204 push @AIO_REQ, qw(aio_busy); # not exported
200 205
201 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 206 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
202 207
278 IO::AIO::idle_timeout $seconds 283 IO::AIO::idle_timeout $seconds
279 IO::AIO::max_outstanding $maxreqs 284 IO::AIO::max_outstanding $maxreqs
280 IO::AIO::nreqs 285 IO::AIO::nreqs
281 IO::AIO::nready 286 IO::AIO::nready
282 IO::AIO::npending 287 IO::AIO::npending
288 IO::AIO::reinit
289
283 $nfd = IO::AIO::get_fdlimit [EXPERIMENTAL] 290 $nfd = IO::AIO::get_fdlimit
284 IO::AIO::min_fdlimit $nfd [EXPERIMENTAL] 291 IO::AIO::min_fdlimit $nfd
285 292
286 IO::AIO::sendfile $ofh, $ifh, $offset, $count 293 IO::AIO::sendfile $ofh, $ifh, $offset, $count
287 IO::AIO::fadvise $fh, $offset, $len, $advice 294 IO::AIO::fadvise $fh, $offset, $len, $advice
295 IO::AIO::fexecve $fh, $argv, $envp
296
288 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] 297 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
289 IO::AIO::munmap $scalar 298 IO::AIO::munmap $scalar
290 IO::AIO::mremap $scalar, $new_length, $flags[, $new_address] 299 IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
291 IO::AIO::madvise $scalar, $offset, $length, $advice 300 IO::AIO::madvise $scalar, $offset, $length, $advice
292 IO::AIO::mprotect $scalar, $offset, $length, $protect 301 IO::AIO::mprotect $scalar, $offset, $length, $protect
293 IO::AIO::munlock $scalar, $offset = 0, $length = undef 302 IO::AIO::munlock $scalar, $offset = 0, $length = undef
294 IO::AIO::munlockall 303 IO::AIO::munlockall
304
305 # stat extensions
306 $counter = IO::AIO::st_gen
307 $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
308 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
309 $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
310 $seconds = IO::AIO::st_btimesec
311 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
312
313 # very much unportable syscalls
314 IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_len, $flags
315 IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
316 IO::AIO::tee $r_fh, $w_fh, $length, $flags
317
318 $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
319 ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
320
321 $fh = IO::AIO::eventfd [$initval, [$flags]]
322 $fh = IO::AIO::memfd_create $pathname[, $flags]
323
324 $fh = IO::AIO::timerfd_create $clockid[, $flags]
325 ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
326 ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
327
328 $fh = IO::AIO::pidfd_open $pid[, $flags]
329 $status = IO::AIO::pidfd_send_signal $pidfh, $signal[, $siginfo[, $flags]]
330 $fh = IO::AIO::pidfd_getfd $pidfh, $targetfd[, $flags]
331
332 $retval = IO::AIO::mount $special, $path, $fstype, $flags = 0, $data = undef
333 $retval = IO::AIO::umount $path, $flags = 0
295 334
296=head2 API NOTES 335=head2 API NOTES
297 336
298All the C<aio_*> calls are more or less thin wrappers around the syscall 337All the C<aio_*> calls are more or less thin wrappers around the syscall
299with the same name (sans C<aio_>). The arguments are similar or identical, 338with the same name (sans C<aio_>). The arguments are similar or identical,
541 580
542=item aio_stat $fh_or_path, $callback->($status) 581=item aio_stat $fh_or_path, $callback->($status)
543 582
544=item aio_lstat $fh, $callback->($status) 583=item aio_lstat $fh, $callback->($status)
545 584
546Works like perl's C<stat> or C<lstat> in void context. The callback will 585Works almost exactly like perl's C<stat> or C<lstat> in void context. The
547be called after the stat and the results will be available using C<stat _> 586callback will be called after the stat and the results will be available
548or C<-s _> etc... 587using C<stat _> or C<-s _> and other tests (with the exception of C<-B>
588and C<-T>).
549 589
550The pathname passed to C<aio_stat> must be absolute. See API NOTES, above, 590The pathname passed to C<aio_stat> must be absolute. See API NOTES, above,
551for an explanation. 591for an explanation.
552 592
553Currently, the stats are always 64-bit-stats, i.e. instead of returning an 593Currently, the stats are always 64-bit-stats, i.e. instead of returning an
622 662
623Works like perl's C<utime> function (including the special case of $atime 663Works like perl's C<utime> function (including the special case of $atime
624and $mtime being undef). Fractional times are supported if the underlying 664and $mtime being undef). Fractional times are supported if the underlying
625syscalls support them. 665syscalls support them.
626 666
627When called with a pathname, uses utimes(2) if available, otherwise 667When called with a pathname, uses utimensat(2) or utimes(2) if available,
628utime(2). If called on a file descriptor, uses futimes(2) if available, 668otherwise utime(2). If called on a file descriptor, uses futimens(2)
629otherwise returns ENOSYS, so this is not portable. 669or futimes(2) if available, otherwise returns ENOSYS, so this is not
670portable.
630 671
631Examples: 672Examples:
632 673
633 # set atime and mtime to current time (basically touch(1)): 674 # set atime and mtime to current time (basically touch(1)):
634 aio_utime "path", undef, undef; 675 aio_utime "path", undef, undef;
1107 aioreq_pri $pri; 1148 aioreq_pri $pri;
1108 add $grp aio_stat $wd, sub { 1149 add $grp aio_stat $wd, sub {
1109 return $grp->result () if $_[0]; 1150 return $grp->result () if $_[0];
1110 my $now = time; 1151 my $now = time;
1111 my $hash1 = join ":", (stat _)[0,1,3,7,9]; 1152 my $hash1 = join ":", (stat _)[0,1,3,7,9];
1153 my $rdxflags = READDIR_DIRS_FIRST;
1154
1155 if ((stat _)[3] < 2) {
1156 # at least one non-POSIX filesystem exists
1157 # that returns useful DT_type values: btrfs,
1158 # so optimise for this here by requesting dents
1159 $rdxflags |= READDIR_DENTS;
1160 }
1112 1161
1113 # read the directory entries 1162 # read the directory entries
1114 aioreq_pri $pri; 1163 aioreq_pri $pri;
1115 add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub { 1164 add $grp aio_readdirx $wd, $rdxflags, sub {
1116 my $entries = shift 1165 my ($entries, $flags) = @_
1117 or return $grp->result (); 1166 or return $grp->result ();
1167
1168 if ($rdxflags & READDIR_DENTS) {
1169 # if we requested type values, see if we can use them directly.
1170
1171 # if there were any DT_UNKNOWN entries then we assume we
1172 # don't know. alternatively, we could assume that if we get
1173 # one DT_DIR, then all directories are indeed marked with
1174 # DT_DIR, but this seems not required for btrfs, and this
1175 # is basically the "btrfs can't get it's act together" code
1176 # branch.
1177 unless ($flags & READDIR_FOUND_UNKNOWN) {
1178 # now we have valid DT_ information for all entries,
1179 # so use it as an optimisation without further stat's.
1180 # they must also all be at the beginning of @$entries
1181 # by now.
1182
1183 my $dirs;
1184
1185 if (@$entries) {
1186 for (0 .. $#$entries) {
1187 if ($entries->[$_][1] != DT_DIR) {
1188 # splice out directories
1189 $dirs = [splice @$entries, 0, $_];
1190 last;
1191 }
1192 }
1193
1194 # if we didn't find any non-dir, then all entries are dirs
1195 unless ($dirs) {
1196 ($dirs, $entries) = ($entries, []);
1197 }
1198 } else {
1199 # directory is empty, so there are no sbdirs
1200 $dirs = [];
1201 }
1202
1203 # either splice'd the directories out or the dir was empty.
1204 # convert dents to filenames
1205 $_ = $_->[0] for @$dirs;
1206 $_ = $_->[0] for @$entries;
1207
1208 return $grp->result ($dirs, $entries);
1209 }
1210
1211 # cannot use, so return to our old ways
1212 # by pretending we only scanned for names.
1213 $_ = $_->[0] for @$entries;
1214 }
1118 1215
1119 # stat the dir another time 1216 # stat the dir another time
1120 aioreq_pri $pri; 1217 aioreq_pri $pri;
1121 add $grp aio_stat $wd, sub { 1218 add $grp aio_stat $wd, sub {
1122 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 1219 my $hash2 = join ":", (stat _)[0,1,3,7,9];
1228So in general, you should only use these calls for things that do 1325So in general, you should only use these calls for things that do
1229(filesystem) I/O, not for things that wait for other events (network, 1326(filesystem) I/O, not for things that wait for other events (network,
1230other processes), although if you are careful and know what you are doing, 1327other processes), although if you are careful and know what you are doing,
1231you still can. 1328you still can.
1232 1329
1233The following constants are available (missing ones are, as usual C<0>): 1330The following constants are available and can be used for normal C<ioctl>
1331and C<fcntl> as well (missing ones are, as usual C<0>):
1234 1332
1235C<F_DUPFD_CLOEXEC>, 1333C<F_DUPFD_CLOEXEC>,
1236 1334
1237C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>, 1335C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
1238 1336
1239C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>. 1337C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
1338
1339C<F_ADD_SEALS>, C<F_GET_SEALS>, C<F_SEAL_SEAL>, C<F_SEAL_SHRINK>, C<F_SEAL_GROW> and
1340C<F_SEAL_WRITE>.
1240 1341
1241C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>, 1342C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
1242C<FS_IOC_FIEMAP>. 1343C<FS_IOC_FIEMAP>.
1243 1344
1244C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>, 1345C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
1252 1353
1253C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>, 1354C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>,
1254C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>, 1355C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>,
1255C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>, 1356C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>,
1256C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>, 1357C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>,
1358
1359C<BLKROSET>, C<BLKROGET>, C<BLKRRPART>, C<BLKGETSIZE>, C<BLKFLSBUF>, C<BLKRASET>,
1360C<BLKRAGET>, C<BLKFRASET>, C<BLKFRAGET>, C<BLKSECTSET>, C<BLKSECTGET>, C<BLKSSZGET>,
1361C<BLKBSZGET>, C<BLKBSZSET>, C<BLKGETSIZE64>,
1362
1257 1363
1258=item aio_sync $callback->($status) 1364=item aio_sync $callback->($status)
1259 1365
1260Asynchronously call sync and call the callback when finished. 1366Asynchronously call sync and call the callback when finished.
1261 1367
1383 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; 1489 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1384 aio_mlock $data; # mlock in background 1490 aio_mlock $data; # mlock in background
1385 1491
1386=item aio_mlockall $flags, $callback->($status) 1492=item aio_mlockall $flags, $callback->($status)
1387 1493
1388Calls the C<mlockall> function with the given C<$flags> (a combination of 1494Calls the C<mlockall> function with the given C<$flags> (a
1389C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>). 1495combination of C<IO::AIO::MCL_CURRENT>, C<IO::AIO::MCL_FUTURE> and
1496C<IO::AIO::MCL_ONFAULT>).
1390 1497
1391On systems that do not implement C<mlockall>, this function returns C<-1> 1498On systems that do not implement C<mlockall>, this function returns C<-1>
1392and sets errno to C<ENOSYS>. 1499and sets errno to C<ENOSYS>. Similarly, flag combinations not supported
1500by the system result in a return value of C<-1> with errno being set to
1501C<EINVAL>.
1393 1502
1394Note that the corresponding C<munlockall> is synchronous and is 1503Note that the corresponding C<munlockall> is synchronous and is
1395documented under L<MISCELLANEOUS FUNCTIONS>. 1504documented under L<MISCELLANEOUS FUNCTIONS>.
1396 1505
1397Example: asynchronously lock all current and future pages into memory. 1506Example: asynchronously lock all current and future pages into memory.
1591C<aio_wd> callback, as future requests using the value will fail in the 1700C<aio_wd> callback, as future requests using the value will fail in the
1592expected way. 1701expected way.
1593 1702
1594=item IO::AIO::CWD 1703=item IO::AIO::CWD
1595 1704
1596This is a compiletime constant (object) that represents the process 1705This is a compile time constant (object) that represents the process
1597current working directory. 1706current working directory.
1598 1707
1599Specifying this object as working directory object for a pathname is as if 1708Specifying this object as working directory object for a pathname is as if
1600the pathname would be specified directly, without a directory object. For 1709the pathname would be specified directly, without a directory object. For
1601example, these calls are functionally identical: 1710example, these calls are functionally identical:
1782The default value for the limit is C<0>, but note that setting a feeder 1891The default value for the limit is C<0>, but note that setting a feeder
1783automatically bumps it up to C<2>. 1892automatically bumps it up to C<2>.
1784 1893
1785=back 1894=back
1786 1895
1896
1787=head2 SUPPORT FUNCTIONS 1897=head2 SUPPORT FUNCTIONS
1788 1898
1789=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1899=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1790 1900
1791=over 4 1901=over 4
1856Strictly equivalent to: 1966Strictly equivalent to:
1857 1967
1858 IO::AIO::poll_wait, IO::AIO::poll_cb 1968 IO::AIO::poll_wait, IO::AIO::poll_cb
1859 while IO::AIO::nreqs; 1969 while IO::AIO::nreqs;
1860 1970
1971This function can be useful at program aborts, to make sure outstanding
1972I/O has been done (C<IO::AIO> uses an C<END> block which already calls
1973this function on normal exits), or when you are merely using C<IO::AIO>
1974for its more advanced functions, rather than for async I/O, e.g.:
1975
1976 my ($dirs, $nondirs);
1977 IO::AIO::aio_scandir "/tmp", 0, sub { ($dirs, $nondirs) = @_ };
1978 IO::AIO::flush;
1979 # $dirs, $nondirs are now set
1980
1861=item IO::AIO::max_poll_reqs $nreqs 1981=item IO::AIO::max_poll_reqs $nreqs
1862 1982
1863=item IO::AIO::max_poll_time $seconds 1983=item IO::AIO::max_poll_time $seconds
1864 1984
1865These set the maximum number of requests (default C<0>, meaning infinity) 1985These set the maximum number of requests (default C<0>, meaning infinity)
1891 poll => 'r', nice => 1, 2011 poll => 'r', nice => 1,
1892 cb => &IO::AIO::poll_cb); 2012 cb => &IO::AIO::poll_cb);
1893 2013
1894=back 2014=back
1895 2015
2016
1896=head3 CONTROLLING THE NUMBER OF THREADS 2017=head3 CONTROLLING THE NUMBER OF THREADS
1897 2018
1898=over 2019=over
1899 2020
1900=item IO::AIO::min_parallel $nthreads 2021=item IO::AIO::min_parallel $nthreads
1961longer exceeded. 2082longer exceeded.
1962 2083
1963In other words, this setting does not enforce a queue limit, but can be 2084In other words, this setting does not enforce a queue limit, but can be
1964used to make poll functions block if the limit is exceeded. 2085used to make poll functions block if the limit is exceeded.
1965 2086
1966This is a very bad function to use in interactive programs because it 2087This is a bad function to use in interactive programs because it blocks,
1967blocks, and a bad way to reduce concurrency because it is inexact: Better 2088and a bad way to reduce concurrency because it is inexact. If you need to
2089issue many requests without being able to call a poll function on demand,
1968use an C<aio_group> together with a feed callback. 2090it is better to use an C<aio_group> together with a feed callback.
1969 2091
1970Its main use is in scripts without an event loop - when you want to stat 2092Its main use is in scripts without an event loop - when you want to stat a
1971a lot of files, you can write something like this: 2093lot of files, you can write something like this:
1972 2094
1973 IO::AIO::max_outstanding 32; 2095 IO::AIO::max_outstanding 32;
1974 2096
1975 for my $path (...) { 2097 for my $path (...) {
1976 aio_stat $path , ...; 2098 aio_stat $path , ...;
1977 IO::AIO::poll_cb; 2099 IO::AIO::poll_cb;
1978 } 2100 }
1979 2101
1980 IO::AIO::flush; 2102 IO::AIO::flush;
1981 2103
1982The call to C<poll_cb> inside the loop will normally return instantly, but 2104The call to C<poll_cb> inside the loop will normally return instantly,
1983as soon as more thna C<32> reqeusts are in-flight, it will block until 2105allowing the loop to progress, but as soon as more than C<32> requests
1984some requests have been handled. This keeps the loop from pushing a large 2106are in-flight, it will block until some requests have been handled. This
1985number of C<aio_stat> requests onto the queue. 2107keeps the loop from pushing a large number of C<aio_stat> requests onto
2108the queue (which, with many paths to stat, can use up a lot of memory).
1986 2109
1987The default value for C<max_outstanding> is very large, so there is no 2110The default value for C<max_outstanding> is very large, so there is no
1988practical limit on the number of outstanding requests. 2111practical limit on the number of outstanding requests.
1989 2112
1990=back 2113=back
1991 2114
2115
1992=head3 STATISTICAL INFORMATION 2116=head3 STATISTICAL INFORMATION
1993 2117
1994=over 2118=over
1995 2119
1996=item IO::AIO::nreqs 2120=item IO::AIO::nreqs
2012 2136
2013Returns the number of requests currently in the pending state (executed, 2137Returns the number of requests currently in the pending state (executed,
2014but not yet processed by poll_cb). 2138but not yet processed by poll_cb).
2015 2139
2016=back 2140=back
2141
2017 2142
2018=head3 SUBSECOND STAT TIME ACCESS 2143=head3 SUBSECOND STAT TIME ACCESS
2019 2144
2020Both C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> functions can 2145Both C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> functions can
2021generally find access/modification and change times with subsecond time 2146generally find access/modification and change times with subsecond time
2037not supported or could not be detected, a fractional part of C<0> is 2162not supported or could not be detected, a fractional part of C<0> is
2038returned, so it is always safe to call these functions. 2163returned, so it is always safe to call these functions.
2039 2164
2040=over 4 2165=over 4
2041 2166
2042=item $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime 2167=item $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
2043 2168
2044Return the access, modication or change time, respectively, including 2169Return the access, modication, change or birth time, respectively,
2045fractional part. Due to the limited precision of floating point, the 2170including fractional part. Due to the limited precision of floating point,
2046accuracy on most platforms is only a bit better than milliseconds for 2171the accuracy on most platforms is only a bit better than milliseconds
2047times around now - see the I<nsec> function family, below, for full 2172for times around now - see the I<nsec> function family, below, for full
2048accuracy. 2173accuracy.
2049 2174
2175File birth time is only available when the OS and perl support it (on
2176FreeBSD and NetBSD at the time of this writing, although support is
2177adaptive, so if your OS/perl gains support, IO::AIO can take advantage of
2178it). On systems where it isn't available, C<0> is currently returned, but
2179this might change to C<undef> in a future version.
2180
2050=item ($atime, $mtime, $ctime, ...) = IO::AIO::st_xtime 2181=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
2051 2182
2052Returns access, modification and change time all in one go, and maybe more 2183Returns access, modification, change and birth time all in one go, and
2053times in the future version. 2184maybe more times in the future version.
2054 2185
2055=item $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec 2186=item $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
2056 2187
2057Return the fractional access, modifcation or change time, in nanoseconds, 2188Return the fractional access, modifcation, change or birth time, in nanoseconds,
2058as an integer in the range C<0> to C<999999999>. 2189as an integer in the range C<0> to C<999999999>.
2059 2190
2191Note that no accessors are provided for access, modification and
2192change times - you need to get those from C<stat _> if required (C<int
2193IO::AIO::st_atime> and so on will I<not> generally give you the correct
2194value).
2195
2196=item $seconds = IO::AIO::st_btimesec
2197
2198The (integral) seconds part of the file birth time, if available.
2199
2060=item ($atime, $mtime, $ctime, ...) = IO::AIO::st_xtimensec 2200=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
2061 2201
2062Like the functions above, but returns all three times in one go (and maybe 2202Like the functions above, but returns all four times in one go (and maybe
2063more in future versions). 2203more in future versions).
2204
2205=item $counter = IO::AIO::st_gen
2206
2207Returns the generation counter (in practice this is just a random number)
2208of the file. This is only available on platforms which have this member in
2209their C<struct stat> (most BSDs at the time of this writing) and generally
2210only to the root usert. If unsupported, C<0> is returned, but this might
2211change to C<undef> in a future version.
2064 2212
2065=back 2213=back
2066 2214
2067Example: print the high resolution modification time of F</etc>, using 2215Example: print the high resolution modification time of F</etc>, using
2068C<stat>, and C<IO::AIO::aio_stat>. 2216C<stat>, and C<IO::AIO::aio_stat>.
2082 2230
2083Output of the awbove on my system, showing reduced and full accuracy: 2231Output of the awbove on my system, showing reduced and full accuracy:
2084 2232
2085 stat(/etc) mtime: 1534043702.020808 2233 stat(/etc) mtime: 1534043702.020808
2086 aio_stat(/etc) mtime: 1534043702.020807792 2234 aio_stat(/etc) mtime: 1534043702.020807792
2235
2087 2236
2088=head3 MISCELLANEOUS FUNCTIONS 2237=head3 MISCELLANEOUS FUNCTIONS
2089 2238
2090IO::AIO implements some functions that are useful when you want to use 2239IO::AIO implements some functions that are useful when you want to use
2091some "Advanced I/O" function not available to in Perl, without going the 2240some "Advanced I/O" function not available to in Perl, without going the
2092"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*> 2241"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
2093counterpart. 2242counterpart.
2094 2243
2095=over 4 2244=over 4
2096 2245
2246=item $retval = IO::AIO::fexecve $fh, $argv, $envp
2247
2248A more-or-less direct equivalent to the POSIX C<fexecve> functions, which
2249allows you to specify the program to be executed via a file descriptor (or
2250handle). Returns C<-1> and sets errno to C<ENOSYS> if not available.
2251
2252=item $retval = IO::AIO::mount $special, $path, $fstype, $flags = 0, $data = undef
2253
2254Calls the GNU/Linux mount syscall with the given arguments. All except
2255C<$flags> are strings, and if C<$data> is C<undef>, a C<NULL> will be
2256passed.
2257
2258The following values for C<$flags> are available:
2259
2260C<IO::AIO::MS_RDONLY>, C<IO::AIO::MS_NOSUID>, C<IO::AIO::MS_NODEV>, C<IO::AIO::MS_NOEXEC>, C<IO::AIO::MS_SYNCHRONOUS>,
2261C<IO::AIO::MS_REMOUNT>, C<IO::AIO::MS_MANDLOCK>, C<IO::AIO::MS_DIRSYNC>, C<IO::AIO::MS_NOATIME>,
2262C<IO::AIO::MS_NODIRATIME>, C<IO::AIO::MS_BIND>, C<IO::AIO::MS_MOVE>, C<IO::AIO::MS_REC>, C<IO::AIO::MS_SILENT>,
2263C<IO::AIO::MS_POSIXACL>, C<IO::AIO::MS_UNBINDABLE>, C<IO::AIO::MS_PRIVATE>, C<IO::AIO::MS_SLAVE>, C<IO::AIO::MS_SHARED>,
2264C<IO::AIO::MS_RELATIME>, C<IO::AIO::MS_KERNMOUNT>, C<IO::AIO::MS_I_VERSION>, C<IO::AIO::MS_STRICTATIME>,
2265C<IO::AIO::MS_LAZYTIME>, C<IO::AIO::MS_ACTIVE>, C<IO::AIO::MS_NOUSER>, C<IO::AIO::MS_RMT_MASK>, C<IO::AIO::MS_MGC_VAL> and
2266C<IO::AIO::MS_MGC_MSK>.
2267
2268=item $retval = IO::AIO::umount $path, $flags = 0
2269
2270Invokes the GNU/Linux C<umount> or C<umount2> syscalls. Always calls
2271C<umount> if C<$flags> is C<0>, otherwqise always tries to call
2272C<umount2>.
2273
2274The following C<$flags> are available:
2275
2276C<IO::AIO::MNT_FORCE>, C<IO::AIO::MNT_DETACH>, C<IO::AIO::MNT_EXPIRE> and C<IO::AIO::UMOUNT_NOFOLLOW>.
2277
2097=item $numfd = IO::AIO::get_fdlimit 2278=item $numfd = IO::AIO::get_fdlimit
2098
2099This function is I<EXPERIMENTAL> and subject to change.
2100 2279
2101Tries to find the current file descriptor limit and returns it, or 2280Tries to find the current file descriptor limit and returns it, or
2102C<undef> and sets C<$!> in case of an error. The limit is one larger than 2281C<undef> and sets C<$!> in case of an error. The limit is one larger than
2103the highest valid file descriptor number. 2282the highest valid file descriptor number.
2104 2283
2105=item IO::AIO::min_fdlimit [$numfd] 2284=item IO::AIO::min_fdlimit [$numfd]
2106
2107This function is I<EXPERIMENTAL> and subject to change.
2108 2285
2109Try to increase the current file descriptor limit(s) to at least C<$numfd> 2286Try to increase the current file descriptor limit(s) to at least C<$numfd>
2110by changing the soft or hard file descriptor resource limit. If C<$numfd> 2287by changing the soft or hard file descriptor resource limit. If C<$numfd>
2111is missing, it will try to set a very high limit, although this is not 2288is missing, it will try to set a very high limit, although this is not
2112recommended when you know the actual minimum that you require. 2289recommended when you know the actual minimum that you require.
2207C<IO::AIO::MAP_POPULATE>, 2384C<IO::AIO::MAP_POPULATE>,
2208C<IO::AIO::MAP_NONBLOCK>, 2385C<IO::AIO::MAP_NONBLOCK>,
2209C<IO::AIO::MAP_FIXED>, 2386C<IO::AIO::MAP_FIXED>,
2210C<IO::AIO::MAP_GROWSDOWN>, 2387C<IO::AIO::MAP_GROWSDOWN>,
2211C<IO::AIO::MAP_32BIT>, 2388C<IO::AIO::MAP_32BIT>,
2212C<IO::AIO::MAP_HUGETLB> or 2389C<IO::AIO::MAP_HUGETLB>,
2213C<IO::AIO::MAP_STACK>. 2390C<IO::AIO::MAP_STACK>,
2391C<IO::AIO::MAP_FIXED_NOREPLACE>,
2392C<IO::AIO::MAP_SHARED_VALIDATE>,
2393C<IO::AIO::MAP_SYNC> or
2394C<IO::AIO::MAP_UNINITIALIZED>.
2214 2395
2215If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. 2396If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
2216 2397
2217C<$offset> is the offset from the start of the file - it generally must be 2398C<$offset> is the offset from the start of the file - it generally must be
2218a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. 2399a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
2255implemented, but not supported and might go away in a future version. 2436implemented, but not supported and might go away in a future version.
2256 2437
2257On systems where this call is not supported or is not emulated, this call 2438On systems where this call is not supported or is not emulated, this call
2258returns falls and sets C<$!> to C<ENOSYS>. 2439returns falls and sets C<$!> to C<ENOSYS>.
2259 2440
2441=item IO::AIO::mlockall $flags
2442
2443Calls the C<eio_mlockall_sync> function, which is like C<aio_mlockall>,
2444but is blocking.
2445
2260=item IO::AIO::munlock $scalar, $offset = 0, $length = undef 2446=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
2261 2447
2262Calls the C<munlock> function, undoing the effects of a previous 2448Calls the C<munlock> function, undoing the effects of a previous
2263C<aio_mlock> call (see its description for details). 2449C<aio_mlock> call (see its description for details).
2264 2450
2266 2452
2267Calls the C<munlockall> function. 2453Calls the C<munlockall> function.
2268 2454
2269On systems that do not implement C<munlockall>, this function returns 2455On systems that do not implement C<munlockall>, this function returns
2270ENOSYS, otherwise the return value of C<munlockall>. 2456ENOSYS, otherwise the return value of C<munlockall>.
2457
2458=item $fh = IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_maxlen, $flags
2459
2460Uses the GNU/Linux C<accept4(2)> syscall, if available, to accept a socket
2461and return the new file handle on success, or sets C<$!> and returns
2462C<undef> on error.
2463
2464The remote name of the new socket will be stored in C<$sockaddr>, which
2465will be extended to allow for at least C<$sockaddr_maxlen> octets. If the
2466socket name does not fit into C<$sockaddr_maxlen> octets, this is signaled
2467by returning a longer string in C<$sockaddr>, which might or might not be
2468truncated.
2469
2470To accept name-less sockets, use C<undef> for C<$sockaddr> and C<0> for
2471C<$sockaddr_maxlen>.
2472
2473The main reasons to use this syscall rather than portable C<accept(2)>
2474are that you can specify C<SOCK_NONBLOCK> and/or C<SOCK_CLOEXEC>
2475flags and you can accept name-less sockets by specifying C<0> for
2476C<$sockaddr_maxlen>, which is sadly not possible with perl's interface to
2477C<accept>.
2271 2478
2272=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags 2479=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
2273 2480
2274Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or 2481Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
2275C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they 2482C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
2319Example: create a pipe race-free w.r.t. threads and fork: 2526Example: create a pipe race-free w.r.t. threads and fork:
2320 2527
2321 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC 2528 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
2322 or die "pipe2: $!\n"; 2529 or die "pipe2: $!\n";
2323 2530
2531=item $fh = IO::AIO::memfd_create $pathname[, $flags]
2532
2533This is a direct interface to the Linux L<memfd_create(2)> system
2534call. The (unhelpful) default for C<$flags> is C<0>, but your default
2535should be C<IO::AIO::MFD_CLOEXEC>.
2536
2537On success, the new memfd filehandle is returned, otherwise returns
2538C<undef>. If the memfd_create syscall is missing, fails with C<ENOSYS>.
2539
2540Please refer to L<memfd_create(2)> for more info on this call.
2541
2542The following C<$flags> values are available: C<IO::AIO::MFD_CLOEXEC>,
2543C<IO::AIO::MFD_ALLOW_SEALING>, C<IO::AIO::MFD_HUGETLB>,
2544C<IO::AIO::MFD_HUGETLB_2MB> and C<IO::AIO::MFD_HUGETLB_1GB>.
2545
2546Example: create a new memfd.
2547
2548 my $fh = IO::AIO::memfd_create "somenameforprocfd", IO::AIO::MFD_CLOEXEC
2549 or die "memfd_create: $!\n";
2550
2551=item $fh = IO::AIO::pidfd_open $pid[, $flags]
2552
2553This is an interface to the Linux L<pidfd_open(2)> system call. The
2554default for C<$flags> is C<0>.
2555
2556On success, a new pidfd filehandle is returned (that is already set to
2557close-on-exec), otherwise returns C<undef>. If the syscall is missing,
2558fails with C<ENOSYS>.
2559
2560Example: open pid 6341 as pidfd.
2561
2562 my $fh = IO::AIO::pidfd_open 6341
2563 or die "pidfd_open: $!\n";
2564
2565=item $status = IO::AIO::pidfd_send_signal $pidfh, $signal[, $siginfo[, $flags]]
2566
2567This is an interface to the Linux L<pidfd_send_signal> system call. The
2568default for C<$siginfo> is C<undef> and the default for C<$flags> is C<0>.
2569
2570Returns the system call status. If the syscall is missing, fails with
2571C<ENOSYS>.
2572
2573When specified, C<$siginfo> must be a reference to a hash with one or more
2574of the following members:
2575
2576=over
2577
2578=item code - the C<si_code> member
2579
2580=item pid - the C<si_pid> member
2581
2582=item uid - the C<si_uid> member
2583
2584=item value_int - the C<si_value.sival_int> member
2585
2586=item value_ptr - the C<si_value.sival_ptr> member, specified as an integer
2587
2588=back
2589
2590Example: send a SIGKILL to the specified process.
2591
2592 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, undef
2593 and die "pidfd_send_signal: $!\n";
2594
2595Example: send a SIGKILL to the specified process with extra data.
2596
2597 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, { code => -1, value_int => 7 }
2598 and die "pidfd_send_signal: $!\n";
2599
2600=item $fh = IO::AIO::pidfd_getfd $pidfh, $targetfd[, $flags]
2601
2602This is an interface to the Linux L<pidfd_getfd> system call. The default
2603for C<$flags> is C<0>.
2604
2605On success, returns a dup'ed copy of the target file descriptor (specified
2606as an integer) returned (that is already set to close-on-exec), otherwise
2607returns C<undef>. If the syscall is missing, fails with C<ENOSYS>.
2608
2609Example: get a copy of standard error of another process and print soemthing to it.
2610
2611 my $errfh = IO::AIO::pidfd_getfd $pidfh, 2
2612 or die "pidfd_getfd: $!\n";
2613 print $errfh "stderr\n";
2614
2324=item $fh = IO::AIO::eventfd [$initval, [$flags]] 2615=item $fh = IO::AIO::eventfd [$initval, [$flags]]
2325 2616
2326This is a direct interface to the Linux L<eventfd(2)> system call. The 2617This is a direct interface to the Linux L<eventfd(2)> system call. The
2327(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both. 2618(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
2328 2619
2334The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>, 2625The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
2335C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30). 2626C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
2336 2627
2337Example: create a new eventfd filehandle: 2628Example: create a new eventfd filehandle:
2338 2629
2339 $fh = IO::AIO::eventfd 0, IO::AIO::O_CLOEXEC 2630 $fh = IO::AIO::eventfd 0, IO::AIO::EFD_CLOEXEC
2340 or die "eventfd: $!\n"; 2631 or die "eventfd: $!\n";
2341 2632
2342=item $fh = IO::AIO::timerfd_create $clockid[, $flags] 2633=item $fh = IO::AIO::timerfd_create $clockid[, $flags]
2343 2634
2344This is a direct interface to the Linux L<timerfd_create(2)> system call. The 2635This is a direct interface to the Linux L<timerfd_create(2)> system
2345(unhelpful) default for C<$flags> is C<0>. 2636call. The (unhelpful) default for C<$flags> is C<0>, but your default
2637should be C<IO::AIO::TFD_CLOEXEC>.
2346 2638
2347On success, the new timerfd filehandle is returned, otherwise returns 2639On success, the new timerfd filehandle is returned, otherwise returns
2348C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>. 2640C<undef>. If the timerfd_create syscall is missing, fails with C<ENOSYS>.
2349 2641
2350Please refer to L<timerfd_create(2)> for more info on this call. 2642Please refer to L<timerfd_create(2)> for more info on this call.
2351 2643
2352The following C<$clockid> values are 2644The following C<$clockid> values are
2353available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC> 2645available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
2519known issue, rather than a bug. 2811known issue, rather than a bug.
2520 2812
2521=head1 SEE ALSO 2813=head1 SEE ALSO
2522 2814
2523L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a 2815L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
2524more natural syntax. 2816more natural syntax and L<IO::FDPass> for file descriptor passing.
2525 2817
2526=head1 AUTHOR 2818=head1 AUTHOR
2527 2819
2528 Marc Lehmann <schmorp@schmorp.de> 2820 Marc Lehmann <schmorp@schmorp.de>
2529 http://home.schmorp.de/ 2821 http://home.schmorp.de/

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