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2 | IO::AIO - Asynchronous Input/Output |
2 | IO::AIO - Asynchronous Input/Output |
3 | |
3 | |
4 | SYNOPSIS |
4 | SYNOPSIS |
5 | use IO::AIO; |
5 | use IO::AIO; |
6 | |
6 | |
7 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
7 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
8 | my $fh = shift |
8 | my $fh = shift |
9 | or die "/etc/passwd: $!"; |
9 | or die "/etc/passwd: $!"; |
10 | ... |
10 | ... |
11 | }; |
11 | }; |
12 | |
12 | |
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23 | my $req = aio_unlink "/tmp/file", sub { }; |
23 | my $req = aio_unlink "/tmp/file", sub { }; |
24 | $req->cancel; # cancel request if still in queue |
24 | $req->cancel; # cancel request if still in queue |
25 | |
25 | |
26 | my $grp = aio_group sub { print "all stats done\n" }; |
26 | my $grp = aio_group sub { print "all stats done\n" }; |
27 | add $grp aio_stat "..." for ...; |
27 | add $grp aio_stat "..." for ...; |
28 | |
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29 | # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...) |
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30 | use AnyEvent::AIO; |
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31 | |
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32 | # EV integration |
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33 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
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34 | |
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35 | # Event integration |
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36 | Event->io (fd => IO::AIO::poll_fileno, |
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37 | poll => 'r', |
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38 | cb => \&IO::AIO::poll_cb); |
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39 | |
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40 | # Glib/Gtk2 integration |
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41 | add_watch Glib::IO IO::AIO::poll_fileno, |
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42 | in => sub { IO::AIO::poll_cb; 1 }; |
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43 | |
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44 | # Tk integration |
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45 | Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "", |
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46 | readable => \&IO::AIO::poll_cb); |
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47 | |
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48 | # Danga::Socket integration |
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49 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
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50 | \&IO::AIO::poll_cb); |
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51 | |
28 | |
52 | DESCRIPTION |
29 | DESCRIPTION |
53 | This module implements asynchronous I/O using whatever means your |
30 | This module implements asynchronous I/O using whatever means your |
54 | operating system supports. It is implemented as an interface to "libeio" |
31 | operating system supports. It is implemented as an interface to "libeio" |
55 | (<http://software.schmorp.de/pkg/libeio.html>). |
32 | (<http://software.schmorp.de/pkg/libeio.html>). |
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95 | |
72 | |
96 | # register the IO::AIO callback with EV |
73 | # register the IO::AIO callback with EV |
97 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
74 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
98 | |
75 | |
99 | # queue the request to open /etc/passwd |
76 | # queue the request to open /etc/passwd |
100 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
77 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
101 | my $fh = shift |
78 | my $fh = shift |
102 | or die "error while opening: $!"; |
79 | or die "error while opening: $!"; |
103 | |
80 | |
104 | # stat'ing filehandles is generally non-blocking |
81 | # stat'ing filehandles is generally non-blocking |
105 | my $size = -s $fh; |
82 | my $size = -s $fh; |
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168 | anymore (except possibly for the Perl object, but its connection to |
145 | anymore (except possibly for the Perl object, but its connection to |
169 | the actual aio request is severed and calling its methods will |
146 | the actual aio request is severed and calling its methods will |
170 | either do nothing or result in a runtime error). |
147 | either do nothing or result in a runtime error). |
171 | |
148 | |
172 | FUNCTIONS |
149 | FUNCTIONS |
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150 | QUICK OVERVIEW |
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151 | This section simply lists the prototypes of the most important functions |
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152 | for quick reference. See the following sections for function-by-function |
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153 | documentation. |
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154 | |
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155 | aio_open $pathname, $flags, $mode, $callback->($fh) |
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156 | aio_close $fh, $callback->($status) |
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157 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
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158 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
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159 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
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160 | aio_readahead $fh,$offset,$length, $callback->($retval) |
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161 | aio_stat $fh_or_path, $callback->($status) |
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162 | aio_lstat $fh, $callback->($status) |
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163 | aio_statvfs $fh_or_path, $callback->($statvfs) |
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164 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
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165 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
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166 | aio_truncate $fh_or_path, $offset, $callback->($status) |
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167 | aio_chmod $fh_or_path, $mode, $callback->($status) |
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168 | aio_unlink $pathname, $callback->($status) |
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169 | aio_mknod $path, $mode, $dev, $callback->($status) |
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170 | aio_link $srcpath, $dstpath, $callback->($status) |
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171 | aio_symlink $srcpath, $dstpath, $callback->($status) |
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172 | aio_readlink $path, $callback->($link) |
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173 | aio_rename $srcpath, $dstpath, $callback->($status) |
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174 | aio_mkdir $pathname, $mode, $callback->($status) |
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175 | aio_rmdir $pathname, $callback->($status) |
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176 | aio_readdir $pathname, $callback->($entries) |
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177 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
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178 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
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179 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
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180 | aio_load $path, $data, $callback->($status) |
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181 | aio_copy $srcpath, $dstpath, $callback->($status) |
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182 | aio_move $srcpath, $dstpath, $callback->($status) |
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183 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
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184 | aio_rmtree $path, $callback->($status) |
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185 | aio_sync $callback->($status) |
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186 | aio_fsync $fh, $callback->($status) |
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187 | aio_fdatasync $fh, $callback->($status) |
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188 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
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189 | aio_pathsync $path, $callback->($status) |
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190 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
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191 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
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192 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
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193 | aio_mlockall $flags, $callback->($status) |
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194 | aio_group $callback->(...) |
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195 | aio_nop $callback->() |
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196 | |
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197 | $prev_pri = aioreq_pri [$pri] |
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198 | aioreq_nice $pri_adjust |
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199 | |
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200 | IO::AIO::poll_wait |
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201 | IO::AIO::poll_cb |
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202 | IO::AIO::poll |
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203 | IO::AIO::flush |
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204 | IO::AIO::max_poll_reqs $nreqs |
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205 | IO::AIO::max_poll_time $seconds |
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206 | IO::AIO::min_parallel $nthreads |
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207 | IO::AIO::max_parallel $nthreads |
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208 | IO::AIO::max_idle $nthreads |
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209 | IO::AIO::idle_timeout $seconds |
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210 | IO::AIO::max_outstanding $maxreqs |
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211 | IO::AIO::nreqs |
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212 | IO::AIO::nready |
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213 | IO::AIO::npending |
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214 | |
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215 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
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216 | IO::AIO::fadvise $fh, $offset, $len, $advice |
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217 | IO::AIO::madvise $scalar, $offset, $length, $advice |
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218 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
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219 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
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220 | IO::AIO::munlockall |
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221 | |
173 | AIO REQUEST FUNCTIONS |
222 | AIO REQUEST FUNCTIONS |
174 | All the "aio_*" calls are more or less thin wrappers around the syscall |
223 | All the "aio_*" calls are more or less thin wrappers around the syscall |
175 | with the same name (sans "aio_"). The arguments are similar or |
224 | with the same name (sans "aio_"). The arguments are similar or |
176 | identical, and they all accept an additional (and optional) $callback |
225 | identical, and they all accept an additional (and optional) $callback |
177 | argument which must be a code reference. This code reference will get |
226 | argument which must be a code reference. This code reference will get |
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248 | will be modified by the umask in effect then the request is being |
297 | will be modified by the umask in effect then the request is being |
249 | executed, so better never change the umask. |
298 | executed, so better never change the umask. |
250 | |
299 | |
251 | Example: |
300 | Example: |
252 | |
301 | |
253 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
302 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
254 | if ($_[0]) { |
303 | if ($_[0]) { |
255 | print "open successful, fh is $_[0]\n"; |
304 | print "open successful, fh is $_[0]\n"; |
256 | ... |
305 | ... |
257 | } else { |
306 | } else { |
258 | die "open failed: $!\n"; |
307 | die "open failed: $!\n"; |
259 | } |
308 | } |
260 | }; |
309 | }; |
261 | |
310 | |
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311 | In addition to all the common open modes/flags ("O_RDONLY", |
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312 | "O_WRONLY", "O_RDWR", "O_CREAT", "O_TRUNC", "O_EXCL" and |
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313 | "O_APPEND"), the following POSIX and non-POSIX constants are |
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314 | available (missing ones on your system are, as usual, 0): |
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315 | |
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316 | "O_ASYNC", "O_DIRECT", "O_NOATIME", "O_CLOEXEC", "O_NOCTTY", |
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317 | "O_NOFOLLOW", "O_NONBLOCK", "O_EXEC", "O_SEARCH", "O_DIRECTORY", |
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318 | "O_DSYNC", "O_RSYNC", "O_SYNC" and "O_TTY_INIT". |
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319 | |
262 | aio_close $fh, $callback->($status) |
320 | aio_close $fh, $callback->($status) |
263 | Asynchronously close a file and call the callback with the result |
321 | Asynchronously close a file and call the callback with the result |
264 | code. |
322 | code. |
265 | |
323 | |
266 | Unfortunately, you can't do this to perl. Perl *insists* very |
324 | Unfortunately, you can't do this to perl. Perl *insists* very |
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311 | reading at byte offset $in_offset, and starts writing at the current |
369 | reading at byte offset $in_offset, and starts writing at the current |
312 | file offset of $out_fh. Because of that, it is not safe to issue |
370 | file offset of $out_fh. Because of that, it is not safe to issue |
313 | more than one "aio_sendfile" per $out_fh, as they will interfere |
371 | more than one "aio_sendfile" per $out_fh, as they will interfere |
314 | with each other. |
372 | with each other. |
315 | |
373 | |
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374 | Please note that "aio_sendfile" can read more bytes from $in_fh than |
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375 | are written, and there is no way to find out how many bytes have |
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376 | been read from "aio_sendfile" alone, as "aio_sendfile" only provides |
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377 | the number of bytes written to $out_fh. Only if the result value |
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378 | equals $length one can assume that $length bytes have been read. |
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379 | |
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380 | Unlike with other "aio_" functions, it makes a lot of sense to use |
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381 | "aio_sendfile" on non-blocking sockets, as long as one end |
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382 | (typically the $in_fh) is a file - the file I/O will then be |
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383 | asynchronous, while the socket I/O will be non-blocking. Note, |
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384 | however, that you can run into a trap where "aio_sendfile" reads |
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385 | some data with readahead, then fails to write all data, and when the |
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386 | socket is ready the next time, the data in the cache is already |
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387 | lost, forcing "aio_sendfile" to again hit the disk. Explicit |
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388 | "aio_read" + "aio_write" let's you control resource usage much |
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389 | better. |
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390 | |
316 | This call tries to make use of a native "sendfile" syscall to |
391 | This call tries to make use of a native "sendfile" syscall to |
317 | provide zero-copy operation. For this to work, $out_fh should refer |
392 | provide zero-copy operation. For this to work, $out_fh should refer |
318 | to a socket, and $in_fh should refer to mmap'able file. |
393 | to a socket, and $in_fh should refer to an mmap'able file. |
319 | |
394 | |
320 | If a native sendfile cannot be found or it fails with "ENOSYS", |
395 | If a native sendfile cannot be found or it fails with "ENOSYS", |
321 | "ENOTSUP", "EOPNOTSUPP", "EAFNOSUPPORT", "EPROTOTYPE" or "ENOTSOCK", |
396 | "ENOTSUP", "EOPNOTSUPP", "EAFNOSUPPORT", "EPROTOTYPE" or "ENOTSOCK", |
322 | it will be emulated, so you can call "aio_sendfile" on any type of |
397 | it will be emulated, so you can call "aio_sendfile" on any type of |
323 | filehandle regardless of the limitations of the operating system. |
398 | filehandle regardless of the limitations of the operating system. |
324 | |
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325 | Please note, however, that "aio_sendfile" can read more bytes from |
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326 | $in_fh than are written, and there is no way to find out how many |
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327 | bytes have been read from "aio_sendfile" alone, as "aio_sendfile" |
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328 | only provides the number of bytes written to $out_fh. Only if the |
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329 | result value equals $length one can assume that $length bytes have |
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330 | been read. |
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331 | |
399 | |
332 | aio_readahead $fh,$offset,$length, $callback->($retval) |
400 | aio_readahead $fh,$offset,$length, $callback->($retval) |
333 | "aio_readahead" populates the page cache with data from a file so |
401 | "aio_readahead" populates the page cache with data from a file so |
334 | that subsequent reads from that file will not block on disk I/O. The |
402 | that subsequent reads from that file will not block on disk I/O. The |
335 | $offset argument specifies the starting point from which data is to |
403 | $offset argument specifies the starting point from which data is to |
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355 | |
423 | |
356 | Currently, the stats are always 64-bit-stats, i.e. instead of |
424 | Currently, the stats are always 64-bit-stats, i.e. instead of |
357 | returning an error when stat'ing a large file, the results will be |
425 | returning an error when stat'ing a large file, the results will be |
358 | silently truncated unless perl itself is compiled with large file |
426 | silently truncated unless perl itself is compiled with large file |
359 | support. |
427 | support. |
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428 | |
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429 | To help interpret the mode and dev/rdev stat values, IO::AIO offers |
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430 | the following constants and functions (if not implemented, the |
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431 | constants will be 0 and the functions will either "croak" or fall |
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432 | back on traditional behaviour). |
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433 | |
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434 | "S_IFMT", "S_IFIFO", "S_IFCHR", "S_IFBLK", "S_IFLNK", "S_IFREG", |
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435 | "S_IFDIR", "S_IFWHT", "S_IFSOCK", "IO::AIO::major $dev_t", |
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436 | "IO::AIO::minor $dev_t", "IO::AIO::makedev $major, $minor". |
360 | |
437 | |
361 | Example: Print the length of /etc/passwd: |
438 | Example: Print the length of /etc/passwd: |
362 | |
439 | |
363 | aio_stat "/etc/passwd", sub { |
440 | aio_stat "/etc/passwd", sub { |
364 | $_[0] and die "stat failed: $!"; |
441 | $_[0] and die "stat failed: $!"; |
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453 | |
530 | |
454 | The only (POSIX-) portable way of calling this function is: |
531 | The only (POSIX-) portable way of calling this function is: |
455 | |
532 | |
456 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
533 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
457 | |
534 | |
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535 | See "aio_stat" for info about some potentially helpful extra |
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536 | constants and functions. |
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537 | |
458 | aio_link $srcpath, $dstpath, $callback->($status) |
538 | aio_link $srcpath, $dstpath, $callback->($status) |
459 | Asynchronously create a new link to the existing object at $srcpath |
539 | Asynchronously create a new link to the existing object at $srcpath |
460 | at the path $dstpath and call the callback with the result code. |
540 | at the path $dstpath and call the callback with the result code. |
461 | |
541 | |
462 | aio_symlink $srcpath, $dstpath, $callback->($status) |
542 | aio_symlink $srcpath, $dstpath, $callback->($status) |
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498 | The flags are a combination of the following constants, ORed |
578 | The flags are a combination of the following constants, ORed |
499 | together (the flags will also be passed to the callback, possibly |
579 | together (the flags will also be passed to the callback, possibly |
500 | modified): |
580 | modified): |
501 | |
581 | |
502 | IO::AIO::READDIR_DENTS |
582 | IO::AIO::READDIR_DENTS |
503 | When this flag is off, then the callback gets an arrayref with |
583 | When this flag is off, then the callback gets an arrayref |
504 | of names only (as with "aio_readdir"), otherwise it gets an |
584 | consisting of names only (as with "aio_readdir"), otherwise it |
505 | arrayref with "[$name, $type, $inode]" arrayrefs, each |
585 | gets an arrayref with "[$name, $type, $inode]" arrayrefs, each |
506 | describing a single directory entry in more detail. |
586 | describing a single directory entry in more detail. |
507 | |
587 | |
508 | $name is the name of the entry. |
588 | $name is the name of the entry. |
509 | |
589 | |
510 | $type is one of the "IO::AIO::DT_xxx" constants: |
590 | $type is one of the "IO::AIO::DT_xxx" constants: |
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523 | unspecified content on systems that do not deliver the inode |
603 | unspecified content on systems that do not deliver the inode |
524 | information. |
604 | information. |
525 | |
605 | |
526 | IO::AIO::READDIR_DIRS_FIRST |
606 | IO::AIO::READDIR_DIRS_FIRST |
527 | When this flag is set, then the names will be returned in an |
607 | When this flag is set, then the names will be returned in an |
528 | order where likely directories come first. This is useful when |
608 | order where likely directories come first, in optimal stat |
529 | you need to quickly find directories, or you want to find all |
609 | order. This is useful when you need to quickly find directories, |
530 | directories while avoiding to stat() each entry. |
610 | or you want to find all directories while avoiding to stat() |
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611 | each entry. |
531 | |
612 | |
532 | If the system returns type information in readdir, then this is |
613 | If the system returns type information in readdir, then this is |
533 | used to find directories directly. Otherwise, likely directories |
614 | used to find directories directly. Otherwise, likely directories |
534 | are files beginning with ".", or otherwise files with no dots, |
615 | are names beginning with ".", or otherwise names with no dots, |
535 | of which files with short names are tried first. |
616 | of which names with short names are tried first. |
536 | |
617 | |
537 | IO::AIO::READDIR_STAT_ORDER |
618 | IO::AIO::READDIR_STAT_ORDER |
538 | When this flag is set, then the names will be returned in an |
619 | When this flag is set, then the names will be returned in an |
539 | order suitable for stat()'ing each one. That is, when you plan |
620 | order suitable for stat()'ing each one. That is, when you plan |
540 | to stat() all files in the given directory, then the returned |
621 | to stat() all files in the given directory, then the returned |
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683 | Passes 0 when everything went ok, and -1 on error. |
764 | Passes 0 when everything went ok, and -1 on error. |
684 | |
765 | |
685 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, |
766 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, |
686 | $callback->($status) |
767 | $callback->($status) |
687 | This is a rather advanced IO::AIO call, which only works on |
768 | This is a rather advanced IO::AIO call, which only works on |
688 | mmap(2)ed scalars (see the Sys::Mmap or Mmap modules for details on |
769 | mmap(2)ed scalars (see the "IO::AIO::mmap" function, although it |
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770 | also works on data scalars managed by the Sys::Mmap or Mmap modules, |
689 | this, note that the scalar must only be modified in-place while an |
771 | note that the scalar must only be modified in-place while an aio |
690 | aio operation is pending on it). |
772 | operation is pending on it). |
691 | |
773 | |
692 | It calls the "msync" function of your OS, if available, with the |
774 | It calls the "msync" function of your OS, if available, with the |
693 | memory area starting at $offset in the string and ending $length |
775 | memory area starting at $offset in the string and ending $length |
694 | bytes later. If $length is negative, counts from the end, and if |
776 | bytes later. If $length is negative, counts from the end, and if |
695 | $length is "undef", then it goes till the end of the string. The |
777 | $length is "undef", then it goes till the end of the string. The |
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705 | inside the scalar. All caveats and parameters are the same as for |
787 | inside the scalar. All caveats and parameters are the same as for |
706 | "aio_msync", above, except for flags, which must be either 0 (which |
788 | "aio_msync", above, except for flags, which must be either 0 (which |
707 | reads all pages and ensures they are instantiated) or |
789 | reads all pages and ensures they are instantiated) or |
708 | "IO::AIO::MT_MODIFY", which modifies the memory page s(by reading |
790 | "IO::AIO::MT_MODIFY", which modifies the memory page s(by reading |
709 | and writing an octet from it, which dirties the page). |
791 | and writing an octet from it, which dirties the page). |
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792 | |
|
|
793 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
|
|
794 | This is a rather advanced IO::AIO call, which works best on |
|
|
795 | mmap(2)ed scalars. |
|
|
796 | |
|
|
797 | It reads in all the pages of the underlying storage into memory (if |
|
|
798 | any) and locks them, so they are not getting swapped/paged out or |
|
|
799 | removed. |
|
|
800 | |
|
|
801 | If $length is undefined, then the scalar will be locked till the |
|
|
802 | end. |
|
|
803 | |
|
|
804 | On systems that do not implement "mlock", this function returns -1 |
|
|
805 | and sets errno to "ENOSYS". |
|
|
806 | |
|
|
807 | Note that the corresponding "munlock" is synchronous and is |
|
|
808 | documented under "MISCELLANEOUS FUNCTIONS". |
|
|
809 | |
|
|
810 | Example: open a file, mmap and mlock it - both will be undone when |
|
|
811 | $data gets destroyed. |
|
|
812 | |
|
|
813 | open my $fh, "<", $path or die "$path: $!"; |
|
|
814 | my $data; |
|
|
815 | IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; |
|
|
816 | aio_mlock $data; # mlock in background |
|
|
817 | |
|
|
818 | aio_mlockall $flags, $callback->($status) |
|
|
819 | Calls the "mlockall" function with the given $flags (a combination |
|
|
820 | of "IO::AIO::MCL_CURRENT" and "IO::AIO::MCL_FUTURE"). |
|
|
821 | |
|
|
822 | On systems that do not implement "mlockall", this function returns |
|
|
823 | -1 and sets errno to "ENOSYS". |
|
|
824 | |
|
|
825 | Note that the corresponding "munlockall" is synchronous and is |
|
|
826 | documented under "MISCELLANEOUS FUNCTIONS". |
|
|
827 | |
|
|
828 | Example: asynchronously lock all current and future pages into |
|
|
829 | memory. |
|
|
830 | |
|
|
831 | aio_mlockall IO::AIO::MCL_FUTURE; |
710 | |
832 | |
711 | aio_group $callback->(...) |
833 | aio_group $callback->(...) |
712 | This is a very special aio request: Instead of doing something, it |
834 | This is a very special aio request: Instead of doing something, it |
713 | is a container for other aio requests, which is useful if you want |
835 | is a container for other aio requests, which is useful if you want |
714 | to bundle many requests into a single, composite, request with a |
836 | to bundle many requests into a single, composite, request with a |
… | |
… | |
910 | |
1032 | |
911 | See "poll_cb" for an example. |
1033 | See "poll_cb" for an example. |
912 | |
1034 | |
913 | IO::AIO::poll_cb |
1035 | IO::AIO::poll_cb |
914 | Process some outstanding events on the result pipe. You have to call |
1036 | Process some outstanding events on the result pipe. You have to call |
915 | this regularly. Returns 0 if all events could be processed, or -1 if |
1037 | this regularly. Returns 0 if all events could be processed (or there |
916 | it returned earlier for whatever reason. Returns immediately when no |
1038 | were no events to process), or -1 if it returned earlier for |
917 | events are outstanding. The amount of events processed depends on |
1039 | whatever reason. Returns immediately when no events are outstanding. |
918 | the settings of "IO::AIO::max_poll_req" and |
1040 | The amount of events processed depends on the settings of |
919 | "IO::AIO::max_poll_time". |
1041 | "IO::AIO::max_poll_req" and "IO::AIO::max_poll_time". |
920 | |
1042 | |
921 | If not all requests were processed for whatever reason, the |
1043 | If not all requests were processed for whatever reason, the |
922 | filehandle will still be ready when "poll_cb" returns, so normally |
1044 | filehandle will still be ready when "poll_cb" returns, so normally |
923 | you don't have to do anything special to have it called later. |
1045 | you don't have to do anything special to have it called later. |
924 | |
1046 | |
|
|
1047 | Apart from calling "IO::AIO::poll_cb" when the event filehandle |
|
|
1048 | becomes ready, it can be beneficial to call this function from loops |
|
|
1049 | which submit a lot of requests, to make sure the results get |
|
|
1050 | processed when they become available and not just when the loop is |
|
|
1051 | finished and the event loop takes over again. This function returns |
|
|
1052 | very fast when there are no outstanding requests. |
|
|
1053 | |
925 | Example: Install an Event watcher that automatically calls |
1054 | Example: Install an Event watcher that automatically calls |
926 | IO::AIO::poll_cb with high priority (more examples can be found in |
1055 | IO::AIO::poll_cb with high priority (more examples can be found in |
927 | the SYNOPSIS section, at the top of this document): |
1056 | the SYNOPSIS section, at the top of this document): |
928 | |
1057 | |
929 | Event->io (fd => IO::AIO::poll_fileno, |
1058 | Event->io (fd => IO::AIO::poll_fileno, |
930 | poll => 'r', async => 1, |
1059 | poll => 'r', async => 1, |
931 | cb => \&IO::AIO::poll_cb); |
1060 | cb => \&IO::AIO::poll_cb); |
|
|
1061 | |
|
|
1062 | IO::AIO::poll_wait |
|
|
1063 | If there are any outstanding requests and none of them in the result |
|
|
1064 | phase, wait till the result filehandle becomes ready for reading |
|
|
1065 | (simply does a "select" on the filehandle. This is useful if you |
|
|
1066 | want to synchronously wait for some requests to finish). |
|
|
1067 | |
|
|
1068 | See "nreqs" for an example. |
|
|
1069 | |
|
|
1070 | IO::AIO::poll |
|
|
1071 | Waits until some requests have been handled. |
|
|
1072 | |
|
|
1073 | Returns the number of requests processed, but is otherwise strictly |
|
|
1074 | equivalent to: |
|
|
1075 | |
|
|
1076 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
1077 | |
|
|
1078 | IO::AIO::flush |
|
|
1079 | Wait till all outstanding AIO requests have been handled. |
|
|
1080 | |
|
|
1081 | Strictly equivalent to: |
|
|
1082 | |
|
|
1083 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
1084 | while IO::AIO::nreqs; |
932 | |
1085 | |
933 | IO::AIO::max_poll_reqs $nreqs |
1086 | IO::AIO::max_poll_reqs $nreqs |
934 | IO::AIO::max_poll_time $seconds |
1087 | IO::AIO::max_poll_time $seconds |
935 | These set the maximum number of requests (default 0, meaning |
1088 | These set the maximum number of requests (default 0, meaning |
936 | infinity) that are being processed by "IO::AIO::poll_cb" in one |
1089 | infinity) that are being processed by "IO::AIO::poll_cb" in one |
… | |
… | |
960 | # use a low priority so other tasks have priority |
1113 | # use a low priority so other tasks have priority |
961 | Event->io (fd => IO::AIO::poll_fileno, |
1114 | Event->io (fd => IO::AIO::poll_fileno, |
962 | poll => 'r', nice => 1, |
1115 | poll => 'r', nice => 1, |
963 | cb => &IO::AIO::poll_cb); |
1116 | cb => &IO::AIO::poll_cb); |
964 | |
1117 | |
965 | IO::AIO::poll_wait |
|
|
966 | If there are any outstanding requests and none of them in the result |
|
|
967 | phase, wait till the result filehandle becomes ready for reading |
|
|
968 | (simply does a "select" on the filehandle. This is useful if you |
|
|
969 | want to synchronously wait for some requests to finish). |
|
|
970 | |
|
|
971 | See "nreqs" for an example. |
|
|
972 | |
|
|
973 | IO::AIO::poll |
|
|
974 | Waits until some requests have been handled. |
|
|
975 | |
|
|
976 | Returns the number of requests processed, but is otherwise strictly |
|
|
977 | equivalent to: |
|
|
978 | |
|
|
979 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
980 | |
|
|
981 | IO::AIO::flush |
|
|
982 | Wait till all outstanding AIO requests have been handled. |
|
|
983 | |
|
|
984 | Strictly equivalent to: |
|
|
985 | |
|
|
986 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
987 | while IO::AIO::nreqs; |
|
|
988 | |
|
|
989 | CONTROLLING THE NUMBER OF THREADS |
1118 | CONTROLLING THE NUMBER OF THREADS |
990 | IO::AIO::min_parallel $nthreads |
1119 | IO::AIO::min_parallel $nthreads |
991 | Set the minimum number of AIO threads to $nthreads. The current |
1120 | Set the minimum number of AIO threads to $nthreads. The current |
992 | default is 8, which means eight asynchronous operations can execute |
1121 | default is 8, which means eight asynchronous operations can execute |
993 | concurrently at any one time (the number of outstanding requests, |
1122 | concurrently at any one time (the number of outstanding requests, |
… | |
… | |
1022 | |
1151 | |
1023 | Under normal circumstances you don't need to call this function. |
1152 | Under normal circumstances you don't need to call this function. |
1024 | |
1153 | |
1025 | IO::AIO::max_idle $nthreads |
1154 | IO::AIO::max_idle $nthreads |
1026 | Limit the number of threads (default: 4) that are allowed to idle |
1155 | Limit the number of threads (default: 4) that are allowed to idle |
1027 | (i.e., threads that did not get a request to process within 10 |
1156 | (i.e., threads that did not get a request to process within the idle |
1028 | seconds). That means if a thread becomes idle while $nthreads other |
1157 | timeout (default: 10 seconds). That means if a thread becomes idle |
1029 | threads are also idle, it will free its resources and exit. |
1158 | while $nthreads other threads are also idle, it will free its |
|
|
1159 | resources and exit. |
1030 | |
1160 | |
1031 | This is useful when you allow a large number of threads (e.g. 100 or |
1161 | This is useful when you allow a large number of threads (e.g. 100 or |
1032 | 1000) to allow for extremely high load situations, but want to free |
1162 | 1000) to allow for extremely high load situations, but want to free |
1033 | resources under normal circumstances (1000 threads can easily |
1163 | resources under normal circumstances (1000 threads can easily |
1034 | consume 30MB of RAM). |
1164 | consume 30MB of RAM). |
1035 | |
1165 | |
1036 | The default is probably ok in most situations, especially if thread |
1166 | The default is probably ok in most situations, especially if thread |
1037 | creation is fast. If thread creation is very slow on your system you |
1167 | creation is fast. If thread creation is very slow on your system you |
1038 | might want to use larger values. |
1168 | might want to use larger values. |
|
|
1169 | |
|
|
1170 | IO::AIO::idle_timeout $seconds |
|
|
1171 | Sets the minimum idle timeout (default 10) after which worker |
|
|
1172 | threads are allowed to exit. SEe "IO::AIO::max_idle". |
1039 | |
1173 | |
1040 | IO::AIO::max_outstanding $maxreqs |
1174 | IO::AIO::max_outstanding $maxreqs |
1041 | This is a very bad function to use in interactive programs because |
1175 | This is a very bad function to use in interactive programs because |
1042 | it blocks, and a bad way to reduce concurrency because it is |
1176 | it blocks, and a bad way to reduce concurrency because it is |
1043 | inexact: Better use an "aio_group" together with a feed callback. |
1177 | inexact: Better use an "aio_group" together with a feed callback. |
… | |
… | |
1085 | set to non-blocking operations). |
1219 | set to non-blocking operations). |
1086 | |
1220 | |
1087 | Returns the number of bytes copied, or -1 on error. |
1221 | Returns the number of bytes copied, or -1 on error. |
1088 | |
1222 | |
1089 | IO::AIO::fadvise $fh, $offset, $len, $advice |
1223 | IO::AIO::fadvise $fh, $offset, $len, $advice |
1090 | Simply calls the "posix_fadvise" function (see it's manpage for |
1224 | Simply calls the "posix_fadvise" function (see its manpage for |
1091 | details). The following advice constants are avaiable: |
1225 | details). The following advice constants are avaiable: |
1092 | "IO::AIO::FADV_NORMAL", "IO::AIO::FADV_SEQUENTIAL", |
1226 | "IO::AIO::FADV_NORMAL", "IO::AIO::FADV_SEQUENTIAL", |
1093 | "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", |
1227 | "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", |
1094 | "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". |
1228 | "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". |
1095 | |
1229 | |
1096 | On systems that do not implement "posix_fadvise", this function |
1230 | On systems that do not implement "posix_fadvise", this function |
1097 | returns ENOSYS, otherwise the return value of "posix_fadvise". |
1231 | returns ENOSYS, otherwise the return value of "posix_fadvise". |
|
|
1232 | |
|
|
1233 | IO::AIO::madvise $scalar, $offset, $len, $advice |
|
|
1234 | Simply calls the "posix_madvise" function (see its manpage for |
|
|
1235 | details). The following advice constants are avaiable: |
|
|
1236 | "IO::AIO::MADV_NORMAL", "IO::AIO::MADV_SEQUENTIAL", |
|
|
1237 | "IO::AIO::MADV_RANDOM", "IO::AIO::MADV_WILLNEED", |
|
|
1238 | "IO::AIO::MADV_DONTNEED". |
|
|
1239 | |
|
|
1240 | On systems that do not implement "posix_madvise", this function |
|
|
1241 | returns ENOSYS, otherwise the return value of "posix_madvise". |
|
|
1242 | |
|
|
1243 | IO::AIO::mprotect $scalar, $offset, $len, $protect |
|
|
1244 | Simply calls the "mprotect" function on the preferably AIO::mmap'ed |
|
|
1245 | $scalar (see its manpage for details). The following protect |
|
|
1246 | constants are avaiable: "IO::AIO::PROT_NONE", "IO::AIO::PROT_READ", |
|
|
1247 | "IO::AIO::PROT_WRITE", "IO::AIO::PROT_EXEC". |
|
|
1248 | |
|
|
1249 | On systems that do not implement "mprotect", this function returns |
|
|
1250 | ENOSYS, otherwise the return value of "mprotect". |
|
|
1251 | |
|
|
1252 | IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
|
|
1253 | Memory-maps a file (or anonymous memory range) and attaches it to |
|
|
1254 | the given $scalar, which will act like a string scalar. |
|
|
1255 | |
|
|
1256 | The only operations allowed on the scalar are "substr"/"vec" that |
|
|
1257 | don't change the string length, and most read-only operations such |
|
|
1258 | as copying it or searching it with regexes and so on. |
|
|
1259 | |
|
|
1260 | Anything else is unsafe and will, at best, result in memory leaks. |
|
|
1261 | |
|
|
1262 | The memory map associated with the $scalar is automatically removed |
|
|
1263 | when the $scalar is destroyed, or when the "IO::AIO::mmap" or |
|
|
1264 | "IO::AIO::munmap" functions are called. |
|
|
1265 | |
|
|
1266 | This calls the "mmap"(2) function internally. See your system's |
|
|
1267 | manual page for details on the $length, $prot and $flags parameters. |
|
|
1268 | |
|
|
1269 | The $length must be larger than zero and smaller than the actual |
|
|
1270 | filesize. |
|
|
1271 | |
|
|
1272 | $prot is a combination of "IO::AIO::PROT_NONE", |
|
|
1273 | "IO::AIO::PROT_EXEC", "IO::AIO::PROT_READ" and/or |
|
|
1274 | "IO::AIO::PROT_WRITE", |
|
|
1275 | |
|
|
1276 | $flags can be a combination of "IO::AIO::MAP_SHARED" or |
|
|
1277 | "IO::AIO::MAP_PRIVATE", or a number of system-specific flags (when |
|
|
1278 | not available, the are defined as 0): "IO::AIO::MAP_ANONYMOUS" |
|
|
1279 | (which is set to "MAP_ANON" if your system only provides this |
|
|
1280 | constant), "IO::AIO::MAP_HUGETLB", "IO::AIO::MAP_LOCKED", |
|
|
1281 | "IO::AIO::MAP_NORESERVE", "IO::AIO::MAP_POPULATE" or |
|
|
1282 | "IO::AIO::MAP_NONBLOCK" |
|
|
1283 | |
|
|
1284 | If $fh is "undef", then a file descriptor of -1 is passed. |
|
|
1285 | |
|
|
1286 | $offset is the offset from the start of the file - it generally must |
|
|
1287 | be a multiple of "IO::AIO::PAGESIZE" and defaults to 0. |
|
|
1288 | |
|
|
1289 | Example: |
|
|
1290 | |
|
|
1291 | use Digest::MD5; |
|
|
1292 | use IO::AIO; |
|
|
1293 | |
|
|
1294 | open my $fh, "<verybigfile" |
|
|
1295 | or die "$!"; |
|
|
1296 | |
|
|
1297 | IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh |
|
|
1298 | or die "verybigfile: $!"; |
|
|
1299 | |
|
|
1300 | my $fast_md5 = md5 $data; |
|
|
1301 | |
|
|
1302 | IO::AIO::munmap $scalar |
|
|
1303 | Removes a previous mmap and undefines the $scalar. |
|
|
1304 | |
|
|
1305 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
|
|
1306 | Calls the "munlock" function, undoing the effects of a previous |
|
|
1307 | "aio_mlock" call (see its description for details). |
|
|
1308 | |
|
|
1309 | IO::AIO::munlockall |
|
|
1310 | Calls the "munlockall" function. |
|
|
1311 | |
|
|
1312 | On systems that do not implement "munlockall", this function returns |
|
|
1313 | ENOSYS, otherwise the return value of "munlockall". |
|
|
1314 | |
|
|
1315 | EVENT LOOP INTEGRATION |
|
|
1316 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
|
|
1317 | automatically into many event loops: |
|
|
1318 | |
|
|
1319 | # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...) |
|
|
1320 | use AnyEvent::AIO; |
|
|
1321 | |
|
|
1322 | You can also integrate IO::AIO manually into many event loops, here are |
|
|
1323 | some examples of how to do this: |
|
|
1324 | |
|
|
1325 | # EV integration |
|
|
1326 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
|
|
1327 | |
|
|
1328 | # Event integration |
|
|
1329 | Event->io (fd => IO::AIO::poll_fileno, |
|
|
1330 | poll => 'r', |
|
|
1331 | cb => \&IO::AIO::poll_cb); |
|
|
1332 | |
|
|
1333 | # Glib/Gtk2 integration |
|
|
1334 | add_watch Glib::IO IO::AIO::poll_fileno, |
|
|
1335 | in => sub { IO::AIO::poll_cb; 1 }; |
|
|
1336 | |
|
|
1337 | # Tk integration |
|
|
1338 | Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "", |
|
|
1339 | readable => \&IO::AIO::poll_cb); |
|
|
1340 | |
|
|
1341 | # Danga::Socket integration |
|
|
1342 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
|
|
1343 | \&IO::AIO::poll_cb); |
1098 | |
1344 | |
1099 | FORK BEHAVIOUR |
1345 | FORK BEHAVIOUR |
1100 | This module should do "the right thing" when the process using it forks: |
1346 | This module should do "the right thing" when the process using it forks: |
1101 | |
1347 | |
1102 | Before the fork, IO::AIO enters a quiescent state where no requests can |
1348 | Before the fork, IO::AIO enters a quiescent state where no requests can |