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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 1.314 by root, Sat Apr 9 19:34:05 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 = 4.76;
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
278 IO::AIO::idle_timeout $seconds 278 IO::AIO::idle_timeout $seconds
279 IO::AIO::max_outstanding $maxreqs 279 IO::AIO::max_outstanding $maxreqs
280 IO::AIO::nreqs 280 IO::AIO::nreqs
281 IO::AIO::nready 281 IO::AIO::nready
282 IO::AIO::npending 282 IO::AIO::npending
283 IO::AIO::reinit
284
283 $nfd = IO::AIO::get_fdlimit [EXPERIMENTAL] 285 $nfd = IO::AIO::get_fdlimit
284 IO::AIO::min_fdlimit $nfd [EXPERIMENTAL] 286 IO::AIO::min_fdlimit $nfd
285 287
286 IO::AIO::sendfile $ofh, $ifh, $offset, $count 288 IO::AIO::sendfile $ofh, $ifh, $offset, $count
287 IO::AIO::fadvise $fh, $offset, $len, $advice 289 IO::AIO::fadvise $fh, $offset, $len, $advice
290
288 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] 291 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
289 IO::AIO::munmap $scalar 292 IO::AIO::munmap $scalar
290 IO::AIO::mremap $scalar, $new_length, $flags[, $new_address] 293 IO::AIO::mremap $scalar, $new_length, $flags[, $new_address]
291 IO::AIO::madvise $scalar, $offset, $length, $advice 294 IO::AIO::madvise $scalar, $offset, $length, $advice
292 IO::AIO::mprotect $scalar, $offset, $length, $protect 295 IO::AIO::mprotect $scalar, $offset, $length, $protect
293 IO::AIO::munlock $scalar, $offset = 0, $length = undef 296 IO::AIO::munlock $scalar, $offset = 0, $length = undef
294 IO::AIO::munlockall 297 IO::AIO::munlockall
298
299 # stat extensions
300 $counter = IO::AIO::st_gen
301 $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
302 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
303 $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
304 $seconds = IO::AIO::st_btimesec
305 ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
306
307 # very much unportable syscalls
308 IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_len, $flags
309 IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
310 IO::AIO::tee $r_fh, $w_fh, $length, $flags
311 $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
312 ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
313 $fh = IO::AIO::memfd_create $pathname[, $flags]
314 $fh = IO::AIO::eventfd [$initval, [$flags]]
315 $fh = IO::AIO::timerfd_create $clockid[, $flags]
316 ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
317 ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
295 318
296=head2 API NOTES 319=head2 API NOTES
297 320
298All the C<aio_*> calls are more or less thin wrappers around the syscall 321All 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, 322with the same name (sans C<aio_>). The arguments are similar or identical,
541 564
542=item aio_stat $fh_or_path, $callback->($status) 565=item aio_stat $fh_or_path, $callback->($status)
543 566
544=item aio_lstat $fh, $callback->($status) 567=item aio_lstat $fh, $callback->($status)
545 568
546Works like perl's C<stat> or C<lstat> in void context. The callback will 569Works 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 _> 570callback will be called after the stat and the results will be available
548or C<-s _> etc... 571using C<stat _> or C<-s _> and other tests (with the exception of C<-B>
572and C<-T>).
549 573
550The pathname passed to C<aio_stat> must be absolute. See API NOTES, above, 574The pathname passed to C<aio_stat> must be absolute. See API NOTES, above,
551for an explanation. 575for an explanation.
552 576
553Currently, the stats are always 64-bit-stats, i.e. instead of returning an 577Currently, the stats are always 64-bit-stats, i.e. instead of returning an
622 646
623Works like perl's C<utime> function (including the special case of $atime 647Works like perl's C<utime> function (including the special case of $atime
624and $mtime being undef). Fractional times are supported if the underlying 648and $mtime being undef). Fractional times are supported if the underlying
625syscalls support them. 649syscalls support them.
626 650
627When called with a pathname, uses utimes(2) if available, otherwise 651When 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, 652otherwise utime(2). If called on a file descriptor, uses futimens(2)
629otherwise returns ENOSYS, so this is not portable. 653or futimes(2) if available, otherwise returns ENOSYS, so this is not
654portable.
630 655
631Examples: 656Examples:
632 657
633 # set atime and mtime to current time (basically touch(1)): 658 # set atime and mtime to current time (basically touch(1)):
634 aio_utime "path", undef, undef; 659 aio_utime "path", undef, undef;
1107 aioreq_pri $pri; 1132 aioreq_pri $pri;
1108 add $grp aio_stat $wd, sub { 1133 add $grp aio_stat $wd, sub {
1109 return $grp->result () if $_[0]; 1134 return $grp->result () if $_[0];
1110 my $now = time; 1135 my $now = time;
1111 my $hash1 = join ":", (stat _)[0,1,3,7,9]; 1136 my $hash1 = join ":", (stat _)[0,1,3,7,9];
1137 my $rdxflags = READDIR_DIRS_FIRST;
1138
1139 if ((stat _)[3] < 2) {
1140 # at least one non-POSIX filesystem exists
1141 # that returns useful DT_type values: btrfs,
1142 # so optimise for this here by requesting dents
1143 $rdxflags |= READDIR_DENTS;
1144 }
1112 1145
1113 # read the directory entries 1146 # read the directory entries
1114 aioreq_pri $pri; 1147 aioreq_pri $pri;
1115 add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub { 1148 add $grp aio_readdirx $wd, $rdxflags, sub {
1116 my $entries = shift 1149 my ($entries, $flags) = @_
1117 or return $grp->result (); 1150 or return $grp->result ();
1151
1152 if ($rdxflags & READDIR_DENTS) {
1153 # if we requested type values, see if we can use them directly.
1154
1155 # if there were any DT_UNKNOWN entries then we assume we
1156 # don't know. alternatively, we could assume that if we get
1157 # one DT_DIR, then all directories are indeed marked with
1158 # DT_DIR, but this seems not required for btrfs, and this
1159 # is basically the "btrfs can't get it's act together" code
1160 # branch.
1161 unless ($flags & READDIR_FOUND_UNKNOWN) {
1162 # now we have valid DT_ information for all entries,
1163 # so use it as an optimisation without further stat's.
1164 # they must also all be at the beginning of @$entries
1165 # by now.
1166
1167 my $dirs;
1168
1169 if (@$entries) {
1170 for (0 .. $#$entries) {
1171 if ($entries->[$_][1] != DT_DIR) {
1172 # splice out directories
1173 $dirs = [splice @$entries, 0, $_];
1174 last;
1175 }
1176 }
1177
1178 # if we didn't find any non-dir, then all entries are dirs
1179 unless ($dirs) {
1180 ($dirs, $entries) = ($entries, []);
1181 }
1182 } else {
1183 # directory is empty, so there are no sbdirs
1184 $dirs = [];
1185 }
1186
1187 # either splice'd the directories out or the dir was empty.
1188 # convert dents to filenames
1189 $_ = $_->[0] for @$dirs;
1190 $_ = $_->[0] for @$entries;
1191
1192 return $grp->result ($dirs, $entries);
1193 }
1194
1195 # cannot use, so return to our old ways
1196 # by pretending we only scanned for names.
1197 $_ = $_->[0] for @$entries;
1198 }
1118 1199
1119 # stat the dir another time 1200 # stat the dir another time
1120 aioreq_pri $pri; 1201 aioreq_pri $pri;
1121 add $grp aio_stat $wd, sub { 1202 add $grp aio_stat $wd, sub {
1122 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 1203 my $hash2 = join ":", (stat _)[0,1,3,7,9];
1228So in general, you should only use these calls for things that do 1309So 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, 1310(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, 1311other processes), although if you are careful and know what you are doing,
1231you still can. 1312you still can.
1232 1313
1233The following constants are available (missing ones are, as usual C<0>): 1314The following constants are available and can be used for normal C<ioctl>
1315and C<fcntl> as well (missing ones are, as usual C<0>):
1234 1316
1235C<F_DUPFD_CLOEXEC>, 1317C<F_DUPFD_CLOEXEC>,
1236 1318
1237C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>, 1319C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
1238 1320
1239C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>. 1321C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
1322
1323C<F_ADD_SEALS>, C<F_GET_SEALS>, C<F_SEAL_SEAL>, C<F_SEAL_SHRINK>, C<F_SEAL_GROW> and
1324C<F_SEAL_WRITE>.
1240 1325
1241C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>, 1326C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
1242C<FS_IOC_FIEMAP>. 1327C<FS_IOC_FIEMAP>.
1243 1328
1244C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>, 1329C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
1383 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; 1468 IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
1384 aio_mlock $data; # mlock in background 1469 aio_mlock $data; # mlock in background
1385 1470
1386=item aio_mlockall $flags, $callback->($status) 1471=item aio_mlockall $flags, $callback->($status)
1387 1472
1388Calls the C<mlockall> function with the given C<$flags> (a combination of 1473Calls the C<mlockall> function with the given C<$flags> (a
1389C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>). 1474combination of C<IO::AIO::MCL_CURRENT>, C<IO::AIO::MCL_FUTURE> and
1475C<IO::AIO::MCL_ONFAULT>).
1390 1476
1391On systems that do not implement C<mlockall>, this function returns C<-1> 1477On systems that do not implement C<mlockall>, this function returns C<-1>
1392and sets errno to C<ENOSYS>. 1478and sets errno to C<ENOSYS>. Similarly, flag combinations not supported
1479by the system result in a return value of C<-1> with errno being set to
1480C<EINVAL>.
1393 1481
1394Note that the corresponding C<munlockall> is synchronous and is 1482Note that the corresponding C<munlockall> is synchronous and is
1395documented under L<MISCELLANEOUS FUNCTIONS>. 1483documented under L<MISCELLANEOUS FUNCTIONS>.
1396 1484
1397Example: asynchronously lock all current and future pages into memory. 1485Example: asynchronously lock all current and future pages into memory.
1591C<aio_wd> callback, as future requests using the value will fail in the 1679C<aio_wd> callback, as future requests using the value will fail in the
1592expected way. 1680expected way.
1593 1681
1594=item IO::AIO::CWD 1682=item IO::AIO::CWD
1595 1683
1596This is a compiletime constant (object) that represents the process 1684This is a compile time constant (object) that represents the process
1597current working directory. 1685current working directory.
1598 1686
1599Specifying this object as working directory object for a pathname is as if 1687Specifying this object as working directory object for a pathname is as if
1600the pathname would be specified directly, without a directory object. For 1688the pathname would be specified directly, without a directory object. For
1601example, these calls are functionally identical: 1689example, these calls are functionally identical:
1782The default value for the limit is C<0>, but note that setting a feeder 1870The default value for the limit is C<0>, but note that setting a feeder
1783automatically bumps it up to C<2>. 1871automatically bumps it up to C<2>.
1784 1872
1785=back 1873=back
1786 1874
1875
1787=head2 SUPPORT FUNCTIONS 1876=head2 SUPPORT FUNCTIONS
1788 1877
1789=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1878=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1790 1879
1791=over 4 1880=over 4
1856Strictly equivalent to: 1945Strictly equivalent to:
1857 1946
1858 IO::AIO::poll_wait, IO::AIO::poll_cb 1947 IO::AIO::poll_wait, IO::AIO::poll_cb
1859 while IO::AIO::nreqs; 1948 while IO::AIO::nreqs;
1860 1949
1950This function can be useful at program aborts, to make sure outstanding
1951I/O has been done (C<IO::AIO> uses an C<END> block which already calls
1952this function on normal exits), or when you are merely using C<IO::AIO>
1953for its more advanced functions, rather than for async I/O, e.g.:
1954
1955 my ($dirs, $nondirs);
1956 IO::AIO::aio_scandir "/tmp", 0, sub { ($dirs, $nondirs) = @_ };
1957 IO::AIO::flush;
1958 # $dirs, $nondirs are now set
1959
1861=item IO::AIO::max_poll_reqs $nreqs 1960=item IO::AIO::max_poll_reqs $nreqs
1862 1961
1863=item IO::AIO::max_poll_time $seconds 1962=item IO::AIO::max_poll_time $seconds
1864 1963
1865These set the maximum number of requests (default C<0>, meaning infinity) 1964These set the maximum number of requests (default C<0>, meaning infinity)
1891 poll => 'r', nice => 1, 1990 poll => 'r', nice => 1,
1892 cb => &IO::AIO::poll_cb); 1991 cb => &IO::AIO::poll_cb);
1893 1992
1894=back 1993=back
1895 1994
1995
1896=head3 CONTROLLING THE NUMBER OF THREADS 1996=head3 CONTROLLING THE NUMBER OF THREADS
1897 1997
1898=over 1998=over
1899 1999
1900=item IO::AIO::min_parallel $nthreads 2000=item IO::AIO::min_parallel $nthreads
1961longer exceeded. 2061longer exceeded.
1962 2062
1963In other words, this setting does not enforce a queue limit, but can be 2063In other words, this setting does not enforce a queue limit, but can be
1964used to make poll functions block if the limit is exceeded. 2064used to make poll functions block if the limit is exceeded.
1965 2065
1966This is a very bad function to use in interactive programs because it 2066This 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 2067and a bad way to reduce concurrency because it is inexact. If you need to
2068issue many requests without being able to call a poll function on demand,
1968use an C<aio_group> together with a feed callback. 2069it is better to use an C<aio_group> together with a feed callback.
1969 2070
1970Its main use is in scripts without an event loop - when you want to stat 2071Its 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: 2072lot of files, you can write something like this:
1972 2073
1973 IO::AIO::max_outstanding 32; 2074 IO::AIO::max_outstanding 32;
1974 2075
1975 for my $path (...) { 2076 for my $path (...) {
1976 aio_stat $path , ...; 2077 aio_stat $path , ...;
1977 IO::AIO::poll_cb; 2078 IO::AIO::poll_cb;
1978 } 2079 }
1979 2080
1980 IO::AIO::flush; 2081 IO::AIO::flush;
1981 2082
1982The call to C<poll_cb> inside the loop will normally return instantly, but 2083The 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 2084allowing 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 2085are in-flight, it will block until some requests have been handled. This
1985number of C<aio_stat> requests onto the queue. 2086keeps the loop from pushing a large number of C<aio_stat> requests onto
2087the queue (which, with many paths to stat, can use up a lot of memory).
1986 2088
1987The default value for C<max_outstanding> is very large, so there is no 2089The default value for C<max_outstanding> is very large, so there is no
1988practical limit on the number of outstanding requests. 2090practical limit on the number of outstanding requests.
1989 2091
1990=back 2092=back
1991 2093
2094
1992=head3 STATISTICAL INFORMATION 2095=head3 STATISTICAL INFORMATION
1993 2096
1994=over 2097=over
1995 2098
1996=item IO::AIO::nreqs 2099=item IO::AIO::nreqs
2012 2115
2013Returns the number of requests currently in the pending state (executed, 2116Returns the number of requests currently in the pending state (executed,
2014but not yet processed by poll_cb). 2117but not yet processed by poll_cb).
2015 2118
2016=back 2119=back
2120
2017 2121
2018=head3 SUBSECOND STAT TIME ACCESS 2122=head3 SUBSECOND STAT TIME ACCESS
2019 2123
2020Both C<aio_stat>/C<aio_lstat> and perl's C<stat>/C<lstat> functions can 2124Both 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 2125generally find access/modification and change times with subsecond time
2037not supported or could not be detected, a fractional part of C<0> is 2141not supported or could not be detected, a fractional part of C<0> is
2038returned, so it is always safe to call these functions. 2142returned, so it is always safe to call these functions.
2039 2143
2040=over 4 2144=over 4
2041 2145
2042=item $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime 2146=item $seconds = IO::AIO::st_atime, IO::AIO::st_mtime, IO::AIO::st_ctime, IO::AIO::st_btime
2043 2147
2044Return the access, modication or change time, respectively, including 2148Return the access, modication, change or birth time, respectively,
2045fractional part. Due to the limited precision of floating point, the 2149including fractional part. Due to the limited precision of floating point,
2046accuracy on most platforms is only a bit better than milliseconds for 2150the accuracy on most platforms is only a bit better than milliseconds
2047times around now - see the I<nsec> function family, below, for full 2151for times around now - see the I<nsec> function family, below, for full
2048accuracy. 2152accuracy.
2049 2153
2154File birth time is only available when the OS and perl support it (on
2155FreeBSD and NetBSD at the time of this writing, although support is
2156adaptive, so if your OS/perl gains support, IO::AIO can take advantage of
2157it). On systems where it isn't available, C<0> is currently returned, but
2158this might change to C<undef> in a future version.
2159
2050=item ($atime, $mtime, $ctime, ...) = IO::AIO::st_xtime 2160=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtime
2051 2161
2052Returns access, modification and change time all in one go, and maybe more 2162Returns access, modification, change and birth time all in one go, and
2053times in the future version. 2163maybe more times in the future version.
2054 2164
2055=item $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec 2165=item $nanoseconds = IO::AIO::st_atimensec, IO::AIO::st_mtimensec, IO::AIO::st_ctimensec, IO::AIO::st_btimensec
2056 2166
2057Return the fractional access, modifcation or change time, in nanoseconds, 2167Return the fractional access, modifcation, change or birth time, in nanoseconds,
2058as an integer in the range C<0> to C<999999999>. 2168as an integer in the range C<0> to C<999999999>.
2059 2169
2170Note that no accessors are provided for access, modification and
2171change times - you need to get those from C<stat _> if required (C<int
2172IO::AIO::st_atime> and so on will I<not> generally give you the correct
2173value).
2174
2175=item $seconds = IO::AIO::st_btimesec
2176
2177The (integral) seconds part of the file birth time, if available.
2178
2060=item ($atime, $mtime, $ctime, ...) = IO::AIO::st_xtimensec 2179=item ($atime, $mtime, $ctime, $btime, ...) = IO::AIO::st_xtimensec
2061 2180
2062Like the functions above, but returns all three times in one go (and maybe 2181Like the functions above, but returns all four times in one go (and maybe
2063more in future versions). 2182more in future versions).
2183
2184=item $counter = IO::AIO::st_gen
2185
2186Returns the generation counter (in practice this is just a random number)
2187of the file. This is only available on platforms which have this member in
2188their C<struct stat> (most BSDs at the time of this writing) and generally
2189only to the root usert. If unsupported, C<0> is returned, but this might
2190change to C<undef> in a future version.
2064 2191
2065=back 2192=back
2066 2193
2067Example: print the high resolution modification time of F</etc>, using 2194Example: print the high resolution modification time of F</etc>, using
2068C<stat>, and C<IO::AIO::aio_stat>. 2195C<stat>, and C<IO::AIO::aio_stat>.
2082 2209
2083Output of the awbove on my system, showing reduced and full accuracy: 2210Output of the awbove on my system, showing reduced and full accuracy:
2084 2211
2085 stat(/etc) mtime: 1534043702.020808 2212 stat(/etc) mtime: 1534043702.020808
2086 aio_stat(/etc) mtime: 1534043702.020807792 2213 aio_stat(/etc) mtime: 1534043702.020807792
2214
2087 2215
2088=head3 MISCELLANEOUS FUNCTIONS 2216=head3 MISCELLANEOUS FUNCTIONS
2089 2217
2090IO::AIO implements some functions that are useful when you want to use 2218IO::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 2219some "Advanced I/O" function not available to in Perl, without going the
2094 2222
2095=over 4 2223=over 4
2096 2224
2097=item $numfd = IO::AIO::get_fdlimit 2225=item $numfd = IO::AIO::get_fdlimit
2098 2226
2099This function is I<EXPERIMENTAL> and subject to change.
2100
2101Tries to find the current file descriptor limit and returns it, or 2227Tries to find the current file descriptor limit and returns it, or
2102C<undef> and sets C<$!> in case of an error. The limit is one larger than 2228C<undef> and sets C<$!> in case of an error. The limit is one larger than
2103the highest valid file descriptor number. 2229the highest valid file descriptor number.
2104 2230
2105=item IO::AIO::min_fdlimit [$numfd] 2231=item IO::AIO::min_fdlimit [$numfd]
2106
2107This function is I<EXPERIMENTAL> and subject to change.
2108 2232
2109Try to increase the current file descriptor limit(s) to at least C<$numfd> 2233Try 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> 2234by changing the soft or hard file descriptor resource limit. If C<$numfd>
2111is missing, it will try to set a very high limit, although this is not 2235is missing, it will try to set a very high limit, although this is not
2112recommended when you know the actual minimum that you require. 2236recommended when you know the actual minimum that you require.
2207C<IO::AIO::MAP_POPULATE>, 2331C<IO::AIO::MAP_POPULATE>,
2208C<IO::AIO::MAP_NONBLOCK>, 2332C<IO::AIO::MAP_NONBLOCK>,
2209C<IO::AIO::MAP_FIXED>, 2333C<IO::AIO::MAP_FIXED>,
2210C<IO::AIO::MAP_GROWSDOWN>, 2334C<IO::AIO::MAP_GROWSDOWN>,
2211C<IO::AIO::MAP_32BIT>, 2335C<IO::AIO::MAP_32BIT>,
2212C<IO::AIO::MAP_HUGETLB> or 2336C<IO::AIO::MAP_HUGETLB>,
2213C<IO::AIO::MAP_STACK>. 2337C<IO::AIO::MAP_STACK>,
2338C<IO::AIO::MAP_FIXED_NOREPLACE>,
2339C<IO::AIO::MAP_SHARED_VALIDATE>,
2340C<IO::AIO::MAP_SYNC> or
2341C<IO::AIO::MAP_UNINITIALIZED>.
2214 2342
2215If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. 2343If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
2216 2344
2217C<$offset> is the offset from the start of the file - it generally must be 2345C<$offset> is the offset from the start of the file - it generally must be
2218a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. 2346a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
2255implemented, but not supported and might go away in a future version. 2383implemented, but not supported and might go away in a future version.
2256 2384
2257On systems where this call is not supported or is not emulated, this call 2385On systems where this call is not supported or is not emulated, this call
2258returns falls and sets C<$!> to C<ENOSYS>. 2386returns falls and sets C<$!> to C<ENOSYS>.
2259 2387
2388=item IO::AIO::mlockall $flags
2389
2390Calls the C<eio_mlockall_sync> function, which is like C<aio_mlockall>,
2391but is blocking.
2392
2260=item IO::AIO::munlock $scalar, $offset = 0, $length = undef 2393=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
2261 2394
2262Calls the C<munlock> function, undoing the effects of a previous 2395Calls the C<munlock> function, undoing the effects of a previous
2263C<aio_mlock> call (see its description for details). 2396C<aio_mlock> call (see its description for details).
2264 2397
2266 2399
2267Calls the C<munlockall> function. 2400Calls the C<munlockall> function.
2268 2401
2269On systems that do not implement C<munlockall>, this function returns 2402On systems that do not implement C<munlockall>, this function returns
2270ENOSYS, otherwise the return value of C<munlockall>. 2403ENOSYS, otherwise the return value of C<munlockall>.
2404
2405=item $fh = IO::AIO::accept4 $r_fh, $sockaddr, $sockaddr_maxlen, $flags
2406
2407Uses the GNU/Linux C<accept4(2)> syscall, if available, to accept a socket
2408and return the new file handle on success, or sets C<$!> and returns
2409C<undef> on error.
2410
2411The remote name of the new socket will be stored in C<$sockaddr>, which
2412will be extended to allow for at least C<$sockaddr_maxlen> octets. If the
2413socket name does not fit into C<$sockaddr_maxlen> octets, this is signaled
2414by returning a longer string in C<$sockaddr>, which might or might not be
2415truncated.
2416
2417To accept name-less sockets, use C<undef> for C<$sockaddr> and C<0> for
2418C<$sockaddr_maxlen>.
2419
2420The main reasons to use this syscall rather than portable C<accept(2)>
2421are that you can specify C<SOCK_NONBLOCK> and/or C<SOCK_CLOEXEC>
2422flags and you can accept name-less sockets by specifying C<0> for
2423C<$sockaddr_maxlen>, which is sadly not possible with perl's interface to
2424C<accept>.
2271 2425
2272=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags 2426=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
2273 2427
2274Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or 2428Calls 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 2429C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
2319Example: create a pipe race-free w.r.t. threads and fork: 2473Example: create a pipe race-free w.r.t. threads and fork:
2320 2474
2321 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC 2475 my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
2322 or die "pipe2: $!\n"; 2476 or die "pipe2: $!\n";
2323 2477
2478=item $fh = IO::AIO::memfd_create $pathname[, $flags]
2479
2480This is a direct interface to the Linux L<memfd_create(2)> system
2481call. The (unhelpful) default for C<$flags> is C<0>, but your default
2482should be C<IO::AIO::MFD_CLOEXEC>.
2483
2484On success, the new memfd filehandle is returned, otherwise returns
2485C<undef>. If the memfd_create syscall is missing, fails with C<ENOSYS>.
2486
2487Please refer to L<memfd_create(2)> for more info on this call.
2488
2489The following C<$flags> values are available: C<IO::AIO::MFD_CLOEXEC>,
2490C<IO::AIO::MFD_ALLOW_SEALING>, C<IO::AIO::MFD_HUGETLB>,
2491C<IO::AIO::MFD_HUGETLB_2MB> and C<IO::AIO::MFD_HUGETLB_1GB>.
2492
2493Example: create a new memfd.
2494
2495 my $fh = IO::AIO::memfd_create "somenameforprocfd", IO::AIO::MFD_CLOEXEC
2496 or die "memfd_create: $!\n";
2497
2498=item $fh = IO::AIO::pidfd_open $pid[, $flags]
2499
2500This is an interface to the Linux L<pidfd_open(2)> system call. The
2501default for C<$flags> is C<0>.
2502
2503On success, a new pidfd filehandle is returned (that is already set to
2504close-on-exec), otherwise returns C<undef>. If the syscall is missing,
2505fails with C<ENOSYS>.
2506
2507Example: open pid 6341 as pidfd.
2508
2509 my $fh = IO::AIO::pidfd_open 6341
2510 or die "pidfd_open: $!\n";
2511
2512=item $status = IO::AIO::pidfd_send_signal $pidfh, $signal[, $siginfo[, $flags]]
2513
2514This is an interface to the Linux L<pidfd_send_signal> system call. The
2515default for C<$siginfo> is C<undef> and the default for C<$flags> is C<0>.
2516
2517Returns the system call status. If the syscall is missing, fails with
2518C<ENOSYS>.
2519
2520When specified, C<$siginfo> must be a reference to a hash with one or more
2521of the following members:
2522
2523=over
2524
2525=item code - the C<si_code> member
2526
2527=item pid - the C<si_pid> member
2528
2529=item uid - the C<si_uid> member
2530
2531=item value_int - the C<si_value.sival_int> member
2532
2533=item value_ptr - the C<si_value.sival_ptr> member, specified as an integer
2534
2535=back
2536
2537Example: send a SIGKILL to the specified process.
2538
2539 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, undef
2540 and die "pidfd_send_signal: $!\n";
2541
2542Example: send a SIGKILL to the specified process with extra data.
2543
2544 my $status = IO::AIO::pidfd_send_signal $pidfh, 9, { code => -1, value_int => 7 }
2545 and die "pidfd_send_signal: $!\n";
2546
2547=item $fh = IO::AIO::pidfd_getfd $pidfh, $targetfd[, $flags]
2548
2549This is an interface to the Linux L<pidfd_getfd> system call. The default
2550for C<$flags> is C<0>.
2551
2552On success, returns a dup'ed copy of the target file descriptor (specified
2553as an integer) returned (that is already set to close-on-exec), otherwise
2554returns C<undef>. If the syscall is missing, fails with C<ENOSYS>.
2555
2556Example: get a copy of standard error of another process and print soemthing to it.
2557
2558 my $errfh = IO::AIO::pidfd_getfd $pidfh, 2
2559 or die "pidfd_getfd: $!\n";
2560 print $errfh "stderr\n";
2561
2324=item $fh = IO::AIO::eventfd [$initval, [$flags]] 2562=item $fh = IO::AIO::eventfd [$initval, [$flags]]
2325 2563
2326This is a direct interface to the Linux L<eventfd(2)> system call. The 2564This is a direct interface to the Linux L<eventfd(2)> system call. The
2327(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both. 2565(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
2328 2566
2334The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>, 2572The 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). 2573C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
2336 2574
2337Example: create a new eventfd filehandle: 2575Example: create a new eventfd filehandle:
2338 2576
2339 $fh = IO::AIO::eventfd 0, IO::AIO::O_CLOEXEC 2577 $fh = IO::AIO::eventfd 0, IO::AIO::EFD_CLOEXEC
2340 or die "eventfd: $!\n"; 2578 or die "eventfd: $!\n";
2341 2579
2342=item $fh = IO::AIO::timerfd_create $clockid[, $flags] 2580=item $fh = IO::AIO::timerfd_create $clockid[, $flags]
2343 2581
2344This is a direct interface to the Linux L<timerfd_create(2)> system call. The 2582This is a direct interface to the Linux L<timerfd_create(2)> system
2345(unhelpful) default for C<$flags> is C<0>. 2583call. The (unhelpful) default for C<$flags> is C<0>, but your default
2584should be C<IO::AIO::TFD_CLOEXEC>.
2346 2585
2347On success, the new timerfd filehandle is returned, otherwise returns 2586On success, the new timerfd filehandle is returned, otherwise returns
2348C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>. 2587C<undef>. If the timerfd_create syscall is missing, fails with C<ENOSYS>.
2349 2588
2350Please refer to L<timerfd_create(2)> for more info on this call. 2589Please refer to L<timerfd_create(2)> for more info on this call.
2351 2590
2352The following C<$clockid> values are 2591The following C<$clockid> values are
2353available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC> 2592available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
2519known issue, rather than a bug. 2758known issue, rather than a bug.
2520 2759
2521=head1 SEE ALSO 2760=head1 SEE ALSO
2522 2761
2523L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a 2762L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
2524more natural syntax. 2763more natural syntax and L<IO::FDPass> for file descriptor passing.
2525 2764
2526=head1 AUTHOR 2765=head1 AUTHOR
2527 2766
2528 Marc Lehmann <schmorp@schmorp.de> 2767 Marc Lehmann <schmorp@schmorp.de>
2529 http://home.schmorp.de/ 2768 http://home.schmorp.de/

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