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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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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 | |
28 | |
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 $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 | |
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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. |
31 | operating system supports. It is implemented as an interface to "libeio" |
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32 | (<http://software.schmorp.de/pkg/libeio.html>). |
55 | |
33 | |
56 | Asynchronous means that operations that can normally block your program |
34 | Asynchronous means that operations that can normally block your program |
57 | (e.g. reading from disk) will be done asynchronously: the operation will |
35 | (e.g. reading from disk) will be done asynchronously: the operation will |
58 | still block, but you can do something else in the meantime. This is |
36 | still block, but you can do something else in the meantime. This is |
59 | extremely useful for programs that need to stay interactive even when |
37 | extremely useful for programs that need to stay interactive even when |
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64 | operations concurrently. |
42 | operations concurrently. |
65 | |
43 | |
66 | While most of this works on all types of file descriptors (for example |
44 | While most of this works on all types of file descriptors (for example |
67 | sockets), using these functions on file descriptors that support |
45 | sockets), using these functions on file descriptors that support |
68 | nonblocking operation (again, sockets, pipes etc.) is very inefficient. |
46 | nonblocking operation (again, sockets, pipes etc.) is very inefficient. |
69 | Use an event loop for that (such as the Event module): IO::AIO will |
47 | Use an event loop for that (such as the EV module): IO::AIO will |
70 | naturally fit into such an event loop itself. |
48 | naturally fit into such an event loop itself. |
71 | |
49 | |
72 | In this version, a number of threads are started that execute your |
50 | In this version, a number of threads are started that execute your |
73 | requests and signal their completion. You don't need thread support in |
51 | requests and signal their completion. You don't need thread support in |
74 | perl, and the threads created by this module will not be visible to |
52 | perl, and the threads created by this module will not be visible to |
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83 | it is currently not reentrant in any way, so use appropriate locking |
61 | it is currently not reentrant in any way, so use appropriate locking |
84 | yourself, always call "poll_cb" from within the same thread, or never |
62 | yourself, always call "poll_cb" from within the same thread, or never |
85 | call "poll_cb" (or other "aio_" functions) recursively. |
63 | call "poll_cb" (or other "aio_" functions) recursively. |
86 | |
64 | |
87 | EXAMPLE |
65 | EXAMPLE |
88 | This is a simple example that uses the Event module and loads |
66 | This is a simple example that uses the EV module and loads /etc/passwd |
89 | /etc/passwd asynchronously: |
67 | asynchronously: |
90 | |
68 | |
91 | use Fcntl; |
69 | use Fcntl; |
92 | use Event; |
70 | use EV; |
93 | use IO::AIO; |
71 | use IO::AIO; |
94 | |
72 | |
95 | # register the IO::AIO callback with Event |
73 | # register the IO::AIO callback with EV |
96 | Event->io (fd => IO::AIO::poll_fileno, |
74 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
97 | poll => 'r', |
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98 | cb => \&IO::AIO::poll_cb); |
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99 | |
75 | |
100 | # queue the request to open /etc/passwd |
76 | # queue the request to open /etc/passwd |
101 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
77 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
102 | my $fh = shift |
78 | my $fh = shift |
103 | or die "error while opening: $!"; |
79 | or die "error while opening: $!"; |
104 | |
80 | |
105 | # stat'ing filehandles is generally non-blocking |
81 | # stat'ing filehandles is generally non-blocking |
106 | my $size = -s $fh; |
82 | my $size = -s $fh; |
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115 | |
91 | |
116 | # file contents now in $contents |
92 | # file contents now in $contents |
117 | print $contents; |
93 | print $contents; |
118 | |
94 | |
119 | # exit event loop and program |
95 | # exit event loop and program |
120 | Event::unloop; |
96 | EV::unloop; |
121 | }; |
97 | }; |
122 | }; |
98 | }; |
123 | |
99 | |
124 | # possibly queue up other requests, or open GUI windows, |
100 | # possibly queue up other requests, or open GUI windows, |
125 | # check for sockets etc. etc. |
101 | # check for sockets etc. etc. |
126 | |
102 | |
127 | # process events as long as there are some: |
103 | # process events as long as there are some: |
128 | Event::loop; |
104 | EV::loop; |
129 | |
105 | |
130 | REQUEST ANATOMY AND LIFETIME |
106 | REQUEST ANATOMY AND LIFETIME |
131 | Every "aio_*" function creates a request. which is a C data structure |
107 | Every "aio_*" function creates a request. which is a C data structure |
132 | not directly visible to Perl. |
108 | not directly visible to Perl. |
133 | |
109 | |
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169 | anymore (except possibly for the Perl object, but its connection to |
145 | anymore (except possibly for the Perl object, but its connection to |
170 | the actual aio request is severed and calling its methods will |
146 | the actual aio request is severed and calling its methods will |
171 | either do nothing or result in a runtime error). |
147 | either do nothing or result in a runtime error). |
172 | |
148 | |
173 | 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::max_outstanding $maxreqs |
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210 | IO::AIO::nreqs |
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211 | IO::AIO::nready |
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212 | IO::AIO::npending |
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213 | |
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214 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
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215 | IO::AIO::fadvise $fh, $offset, $len, $advice |
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216 | IO::AIO::madvise $scalar, $offset, $length, $advice |
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217 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
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218 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
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219 | IO::AIO::munlockall |
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220 | |
174 | AIO REQUEST FUNCTIONS |
221 | AIO REQUEST FUNCTIONS |
175 | All the "aio_*" calls are more or less thin wrappers around the syscall |
222 | All the "aio_*" calls are more or less thin wrappers around the syscall |
176 | with the same name (sans "aio_"). The arguments are similar or |
223 | with the same name (sans "aio_"). The arguments are similar or |
177 | identical, and they all accept an additional (and optional) $callback |
224 | identical, and they all accept an additional (and optional) $callback |
178 | argument which must be a code reference. This code reference will get |
225 | argument which must be a code reference. This code reference will get |
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249 | will be modified by the umask in effect then the request is being |
296 | will be modified by the umask in effect then the request is being |
250 | executed, so better never change the umask. |
297 | executed, so better never change the umask. |
251 | |
298 | |
252 | Example: |
299 | Example: |
253 | |
300 | |
254 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
301 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
255 | if ($_[0]) { |
302 | if ($_[0]) { |
256 | print "open successful, fh is $_[0]\n"; |
303 | print "open successful, fh is $_[0]\n"; |
257 | ... |
304 | ... |
258 | } else { |
305 | } else { |
259 | die "open failed: $!\n"; |
306 | die "open failed: $!\n"; |
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312 | reading at byte offset $in_offset, and starts writing at the current |
359 | reading at byte offset $in_offset, and starts writing at the current |
313 | file offset of $out_fh. Because of that, it is not safe to issue |
360 | file offset of $out_fh. Because of that, it is not safe to issue |
314 | more than one "aio_sendfile" per $out_fh, as they will interfere |
361 | more than one "aio_sendfile" per $out_fh, as they will interfere |
315 | with each other. |
362 | with each other. |
316 | |
363 | |
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364 | Please note that "aio_sendfile" can read more bytes from $in_fh than |
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365 | are written, and there is no way to find out how many bytes have |
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366 | been read from "aio_sendfile" alone, as "aio_sendfile" only provides |
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367 | the number of bytes written to $out_fh. Only if the result value |
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368 | equals $length one can assume that $length bytes have been read. |
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369 | |
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370 | Unlike with other "aio_" functions, it makes a lot of sense to use |
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371 | "aio_sendfile" on non-blocking sockets, as long as one end |
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372 | (typically the $in_fh) is a file - the file I/O will then be |
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373 | asynchronous, while the socket I/O will be non-blocking. Note, |
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374 | however, that you can run into a trap where "aio_sendfile" reads |
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375 | some data with readahead, then fails to write all data, and when the |
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376 | socket is ready the next time, the data in the cache is already |
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377 | lost, forcing "aio_sendfile" to again hit the disk. Explicit |
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378 | "aio_read" + "aio_write" let's you control resource usage much |
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379 | better. |
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380 | |
317 | This call tries to make use of a native "sendfile" syscall to |
381 | This call tries to make use of a native "sendfile" syscall to |
318 | provide zero-copy operation. For this to work, $out_fh should refer |
382 | provide zero-copy operation. For this to work, $out_fh should refer |
319 | to a socket, and $in_fh should refer to mmap'able file. |
383 | to a socket, and $in_fh should refer to an mmap'able file. |
320 | |
384 | |
321 | If the native sendfile call fails or is not implemented, it will be |
385 | If a native sendfile cannot be found or it fails with "ENOSYS", |
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386 | "ENOTSUP", "EOPNOTSUPP", "EAFNOSUPPORT", "EPROTOTYPE" or "ENOTSOCK", |
322 | emulated, so you can call "aio_sendfile" on any type of filehandle |
387 | it will be emulated, so you can call "aio_sendfile" on any type of |
323 | regardless of the limitations of the operating system. |
388 | 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 | |
389 | |
332 | aio_readahead $fh,$offset,$length, $callback->($retval) |
390 | aio_readahead $fh,$offset,$length, $callback->($retval) |
333 | "aio_readahead" populates the page cache with data from a file so |
391 | "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 |
392 | 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 |
393 | $offset argument specifies the starting point from which data is to |
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363 | aio_stat "/etc/passwd", sub { |
421 | aio_stat "/etc/passwd", sub { |
364 | $_[0] and die "stat failed: $!"; |
422 | $_[0] and die "stat failed: $!"; |
365 | print "size is ", -s _, "\n"; |
423 | print "size is ", -s _, "\n"; |
366 | }; |
424 | }; |
367 | |
425 | |
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426 | aio_statvfs $fh_or_path, $callback->($statvfs) |
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427 | Works like the POSIX "statvfs" or "fstatvfs" syscalls, depending on |
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428 | whether a file handle or path was passed. |
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429 | |
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430 | On success, the callback is passed a hash reference with the |
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431 | following members: "bsize", "frsize", "blocks", "bfree", "bavail", |
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432 | "files", "ffree", "favail", "fsid", "flag" and "namemax". On |
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433 | failure, "undef" is passed. |
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434 | |
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435 | The following POSIX IO::AIO::ST_* constants are defined: "ST_RDONLY" |
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436 | and "ST_NOSUID". |
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437 | |
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438 | The following non-POSIX IO::AIO::ST_* flag masks are defined to |
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439 | their correct value when available, or to 0 on systems that do not |
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440 | support them: "ST_NODEV", "ST_NOEXEC", "ST_SYNCHRONOUS", |
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441 | "ST_MANDLOCK", "ST_WRITE", "ST_APPEND", "ST_IMMUTABLE", |
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442 | "ST_NOATIME", "ST_NODIRATIME" and "ST_RELATIME". |
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443 | |
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444 | Example: stat "/wd" and dump out the data if successful. |
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445 | |
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446 | aio_statvfs "/wd", sub { |
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447 | my $f = $_[0] |
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448 | or die "statvfs: $!"; |
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449 | |
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450 | use Data::Dumper; |
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451 | say Dumper $f; |
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452 | }; |
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453 | |
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454 | # result: |
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455 | { |
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456 | bsize => 1024, |
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457 | bfree => 4333064312, |
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458 | blocks => 10253828096, |
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459 | files => 2050765568, |
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460 | flag => 4096, |
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461 | favail => 2042092649, |
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462 | bavail => 4333064312, |
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463 | ffree => 2042092649, |
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464 | namemax => 255, |
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465 | frsize => 1024, |
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466 | fsid => 1810 |
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467 | } |
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468 | |
368 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
469 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
369 | Works like perl's "utime" function (including the special case of |
470 | Works like perl's "utime" function (including the special case of |
370 | $atime and $mtime being undef). Fractional times are supported if |
471 | $atime and $mtime being undef). Fractional times are supported if |
371 | the underlying syscalls support them. |
472 | the underlying syscalls support them. |
372 | |
473 | |
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474 | you need to know, you have to run stat yourself. Also, for speed |
575 | you need to know, you have to run stat yourself. Also, for speed |
475 | reasons, the $type scalars are read-only: you can not modify |
576 | reasons, the $type scalars are read-only: you can not modify |
476 | them. |
577 | them. |
477 | |
578 | |
478 | $inode is the inode number (which might not be exact on systems |
579 | $inode is the inode number (which might not be exact on systems |
479 | with 64 bit inode numbers and 32 bit perls). On systems that do |
580 | with 64 bit inode numbers and 32 bit perls). This field has |
480 | not deliver the inode information, this will always be zero. |
581 | unspecified content on systems that do not deliver the inode |
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582 | information. |
481 | |
583 | |
482 | IO::AIO::READDIR_DIRS_FIRST |
584 | IO::AIO::READDIR_DIRS_FIRST |
483 | When this flag is set, then the names will be returned in an |
585 | When this flag is set, then the names will be returned in an |
484 | order where likely directories come first. This is useful when |
586 | order where likely directories come first. This is useful when |
485 | you need to quickly find directories, or you want to find all |
587 | you need to quickly find directories, or you want to find all |
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512 | into memory. Status is the same as with aio_read. |
614 | into memory. Status is the same as with aio_read. |
513 | |
615 | |
514 | aio_copy $srcpath, $dstpath, $callback->($status) |
616 | aio_copy $srcpath, $dstpath, $callback->($status) |
515 | Try to copy the *file* (directories not supported as either source |
617 | Try to copy the *file* (directories not supported as either source |
516 | or destination) from $srcpath to $dstpath and call the callback with |
618 | or destination) from $srcpath to $dstpath and call the callback with |
517 | the 0 (error) or -1 ok. |
619 | a status of 0 (ok) or -1 (error, see $!). |
518 | |
620 | |
519 | This is a composite request that creates the destination file with |
621 | This is a composite request that creates the destination file with |
520 | mode 0200 and copies the contents of the source file into it using |
622 | mode 0200 and copies the contents of the source file into it using |
521 | "aio_sendfile", followed by restoring atime, mtime, access mode and |
623 | "aio_sendfile", followed by restoring atime, mtime, access mode and |
522 | uid/gid, in that order. |
624 | uid/gid, in that order. |
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… | |
526 | uid/gid, where errors are being ignored. |
628 | uid/gid, where errors are being ignored. |
527 | |
629 | |
528 | aio_move $srcpath, $dstpath, $callback->($status) |
630 | aio_move $srcpath, $dstpath, $callback->($status) |
529 | Try to move the *file* (directories not supported as either source |
631 | Try to move the *file* (directories not supported as either source |
530 | or destination) from $srcpath to $dstpath and call the callback with |
632 | or destination) from $srcpath to $dstpath and call the callback with |
531 | the 0 (error) or -1 ok. |
633 | a status of 0 (ok) or -1 (error, see $!). |
532 | |
634 | |
533 | This is a composite request that tries to rename(2) the file first; |
635 | This is a composite request that tries to rename(2) the file first; |
534 | if rename fails with "EXDEV", it copies the file with "aio_copy" |
636 | if rename fails with "EXDEV", it copies the file with "aio_copy" |
535 | and, if that is successful, unlinks the $srcpath. |
637 | and, if that is successful, unlinks the $srcpath. |
536 | |
638 | |
… | |
… | |
631 | operations (E.g. rename). This might not work on all operating |
733 | operations (E.g. rename). This might not work on all operating |
632 | systems or have any specific effect, but usually it makes sure that |
734 | systems or have any specific effect, but usually it makes sure that |
633 | directory changes get written to disc. It works for anything that |
735 | directory changes get written to disc. It works for anything that |
634 | can be opened for read-only, not just directories. |
736 | can be opened for read-only, not just directories. |
635 | |
737 | |
|
|
738 | Future versions of this function might fall back to other methods |
|
|
739 | when "fsync" on the directory fails (such as calling "sync"). |
|
|
740 | |
636 | Passes 0 when everything went ok, and -1 on error. |
741 | Passes 0 when everything went ok, and -1 on error. |
|
|
742 | |
|
|
743 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, |
|
|
744 | $callback->($status) |
|
|
745 | This is a rather advanced IO::AIO call, which only works on |
|
|
746 | mmap(2)ed scalars (see the "IO::AIO::mmap" function, although it |
|
|
747 | also works on data scalars managed by the Sys::Mmap or Mmap modules, |
|
|
748 | note that the scalar must only be modified in-place while an aio |
|
|
749 | operation is pending on it). |
|
|
750 | |
|
|
751 | It calls the "msync" function of your OS, if available, with the |
|
|
752 | memory area starting at $offset in the string and ending $length |
|
|
753 | bytes later. If $length is negative, counts from the end, and if |
|
|
754 | $length is "undef", then it goes till the end of the string. The |
|
|
755 | flags can be a combination of "IO::AIO::MS_ASYNC", |
|
|
756 | "IO::AIO::MS_INVALIDATE" and "IO::AIO::MS_SYNC". |
|
|
757 | |
|
|
758 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, |
|
|
759 | $callback->($status) |
|
|
760 | This is a rather advanced IO::AIO call, which works best on |
|
|
761 | mmap(2)ed scalars. |
|
|
762 | |
|
|
763 | It touches (reads or writes) all memory pages in the specified range |
|
|
764 | inside the scalar. All caveats and parameters are the same as for |
|
|
765 | "aio_msync", above, except for flags, which must be either 0 (which |
|
|
766 | reads all pages and ensures they are instantiated) or |
|
|
767 | "IO::AIO::MT_MODIFY", which modifies the memory page s(by reading |
|
|
768 | and writing an octet from it, which dirties the page). |
|
|
769 | |
|
|
770 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
|
|
771 | This is a rather advanced IO::AIO call, which works best on |
|
|
772 | mmap(2)ed scalars. |
|
|
773 | |
|
|
774 | It reads in all the pages of the underlying storage into memory (if |
|
|
775 | any) and locks them, so they are not getting swapped/paged out or |
|
|
776 | removed. |
|
|
777 | |
|
|
778 | If $length is undefined, then the scalar will be locked till the |
|
|
779 | end. |
|
|
780 | |
|
|
781 | On systems that do not implement "mlock", this function returns -1 |
|
|
782 | and sets errno to "ENOSYS". |
|
|
783 | |
|
|
784 | Note that the corresponding "munlock" is synchronous and is |
|
|
785 | documented under "MISCELLANEOUS FUNCTIONS". |
|
|
786 | |
|
|
787 | Example: open a file, mmap and mlock it - both will be undone when |
|
|
788 | $data gets destroyed. |
|
|
789 | |
|
|
790 | open my $fh, "<", $path or die "$path: $!"; |
|
|
791 | my $data; |
|
|
792 | IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; |
|
|
793 | aio_mlock $data; # mlock in background |
|
|
794 | |
|
|
795 | aio_mlockall $flags, $callback->($status) |
|
|
796 | Calls the "mlockall" function with the given $flags (a combination |
|
|
797 | of "IO::AIO::MCL_CURRENT" and "IO::AIO::MCL_FUTURE"). |
|
|
798 | |
|
|
799 | On systems that do not implement "mlockall", this function returns |
|
|
800 | -1 and sets errno to "ENOSYS". |
|
|
801 | |
|
|
802 | Note that the corresponding "munlockall" is synchronous and is |
|
|
803 | documented under "MISCELLANEOUS FUNCTIONS". |
|
|
804 | |
|
|
805 | Example: asynchronously lock all current and future pages into |
|
|
806 | memory. |
|
|
807 | |
|
|
808 | aio_mlockall IO::AIO::MCL_FUTURE; |
637 | |
809 | |
638 | aio_group $callback->(...) |
810 | aio_group $callback->(...) |
639 | This is a very special aio request: Instead of doing something, it |
811 | This is a very special aio request: Instead of doing something, it |
640 | is a container for other aio requests, which is useful if you want |
812 | is a container for other aio requests, which is useful if you want |
641 | to bundle many requests into a single, composite, request with a |
813 | to bundle many requests into a single, composite, request with a |
… | |
… | |
684 | |
856 | |
685 | cancel $req |
857 | cancel $req |
686 | Cancels the request, if possible. Has the effect of skipping |
858 | Cancels the request, if possible. Has the effect of skipping |
687 | execution when entering the execute state and skipping calling the |
859 | execution when entering the execute state and skipping calling the |
688 | callback when entering the the result state, but will leave the |
860 | callback when entering the the result state, but will leave the |
689 | request otherwise untouched. That means that requests that currently |
861 | request otherwise untouched (with the exception of readdir). That |
690 | execute will not be stopped and resources held by the request will |
862 | means that requests that currently execute will not be stopped and |
691 | not be freed prematurely. |
863 | resources held by the request will not be freed prematurely. |
692 | |
864 | |
693 | cb $req $callback->(...) |
865 | cb $req $callback->(...) |
694 | Replace (or simply set) the callback registered to the request. |
866 | Replace (or simply set) the callback registered to the request. |
695 | |
867 | |
696 | IO::AIO::GRP CLASS |
868 | IO::AIO::GRP CLASS |
… | |
… | |
757 | |
929 | |
758 | $grp->cancel_subs |
930 | $grp->cancel_subs |
759 | Cancel all subrequests and clears any feeder, but not the group |
931 | Cancel all subrequests and clears any feeder, but not the group |
760 | request itself. Useful when you queued a lot of events but got a |
932 | request itself. Useful when you queued a lot of events but got a |
761 | result early. |
933 | result early. |
|
|
934 | |
|
|
935 | The group request will finish normally (you cannot add requests to |
|
|
936 | the group). |
762 | |
937 | |
763 | $grp->result (...) |
938 | $grp->result (...) |
764 | Set the result value(s) that will be passed to the group callback |
939 | Set the result value(s) that will be passed to the group callback |
765 | when all subrequests have finished and set the groups errno to the |
940 | when all subrequests have finished and set the groups errno to the |
766 | current value of errno (just like calling "errno" without an error |
941 | current value of errno (just like calling "errno" without an error |
… | |
… | |
826 | SUPPORT FUNCTIONS |
1001 | SUPPORT FUNCTIONS |
827 | EVENT PROCESSING AND EVENT LOOP INTEGRATION |
1002 | EVENT PROCESSING AND EVENT LOOP INTEGRATION |
828 | $fileno = IO::AIO::poll_fileno |
1003 | $fileno = IO::AIO::poll_fileno |
829 | Return the *request result pipe file descriptor*. This filehandle |
1004 | Return the *request result pipe file descriptor*. This filehandle |
830 | must be polled for reading by some mechanism outside this module |
1005 | must be polled for reading by some mechanism outside this module |
831 | (e.g. Event or select, see below or the SYNOPSIS). If the pipe |
1006 | (e.g. EV, Glib, select and so on, see below or the SYNOPSIS). If the |
832 | becomes readable you have to call "poll_cb" to check the results. |
1007 | pipe becomes readable you have to call "poll_cb" to check the |
|
|
1008 | results. |
833 | |
1009 | |
834 | See "poll_cb" for an example. |
1010 | See "poll_cb" for an example. |
835 | |
1011 | |
836 | IO::AIO::poll_cb |
1012 | IO::AIO::poll_cb |
837 | Process some outstanding events on the result pipe. You have to call |
1013 | Process some outstanding events on the result pipe. You have to call |
… | |
… | |
844 | If not all requests were processed for whatever reason, the |
1020 | If not all requests were processed for whatever reason, the |
845 | filehandle will still be ready when "poll_cb" returns, so normally |
1021 | filehandle will still be ready when "poll_cb" returns, so normally |
846 | you don't have to do anything special to have it called later. |
1022 | you don't have to do anything special to have it called later. |
847 | |
1023 | |
848 | Example: Install an Event watcher that automatically calls |
1024 | Example: Install an Event watcher that automatically calls |
849 | IO::AIO::poll_cb with high priority: |
1025 | IO::AIO::poll_cb with high priority (more examples can be found in |
|
|
1026 | the SYNOPSIS section, at the top of this document): |
850 | |
1027 | |
851 | Event->io (fd => IO::AIO::poll_fileno, |
1028 | Event->io (fd => IO::AIO::poll_fileno, |
852 | poll => 'r', async => 1, |
1029 | poll => 'r', async => 1, |
853 | cb => \&IO::AIO::poll_cb); |
1030 | cb => \&IO::AIO::poll_cb); |
|
|
1031 | |
|
|
1032 | IO::AIO::poll_wait |
|
|
1033 | If there are any outstanding requests and none of them in the result |
|
|
1034 | phase, wait till the result filehandle becomes ready for reading |
|
|
1035 | (simply does a "select" on the filehandle. This is useful if you |
|
|
1036 | want to synchronously wait for some requests to finish). |
|
|
1037 | |
|
|
1038 | See "nreqs" for an example. |
|
|
1039 | |
|
|
1040 | IO::AIO::poll |
|
|
1041 | Waits until some requests have been handled. |
|
|
1042 | |
|
|
1043 | Returns the number of requests processed, but is otherwise strictly |
|
|
1044 | equivalent to: |
|
|
1045 | |
|
|
1046 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
1047 | |
|
|
1048 | IO::AIO::flush |
|
|
1049 | Wait till all outstanding AIO requests have been handled. |
|
|
1050 | |
|
|
1051 | Strictly equivalent to: |
|
|
1052 | |
|
|
1053 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
1054 | while IO::AIO::nreqs; |
854 | |
1055 | |
855 | IO::AIO::max_poll_reqs $nreqs |
1056 | IO::AIO::max_poll_reqs $nreqs |
856 | IO::AIO::max_poll_time $seconds |
1057 | IO::AIO::max_poll_time $seconds |
857 | These set the maximum number of requests (default 0, meaning |
1058 | These set the maximum number of requests (default 0, meaning |
858 | infinity) that are being processed by "IO::AIO::poll_cb" in one |
1059 | infinity) that are being processed by "IO::AIO::poll_cb" in one |
… | |
… | |
882 | # use a low priority so other tasks have priority |
1083 | # use a low priority so other tasks have priority |
883 | Event->io (fd => IO::AIO::poll_fileno, |
1084 | Event->io (fd => IO::AIO::poll_fileno, |
884 | poll => 'r', nice => 1, |
1085 | poll => 'r', nice => 1, |
885 | cb => &IO::AIO::poll_cb); |
1086 | cb => &IO::AIO::poll_cb); |
886 | |
1087 | |
887 | IO::AIO::poll_wait |
|
|
888 | If there are any outstanding requests and none of them in the result |
|
|
889 | phase, wait till the result filehandle becomes ready for reading |
|
|
890 | (simply does a "select" on the filehandle. This is useful if you |
|
|
891 | want to synchronously wait for some requests to finish). |
|
|
892 | |
|
|
893 | See "nreqs" for an example. |
|
|
894 | |
|
|
895 | IO::AIO::poll |
|
|
896 | Waits until some requests have been handled. |
|
|
897 | |
|
|
898 | Returns the number of requests processed, but is otherwise strictly |
|
|
899 | equivalent to: |
|
|
900 | |
|
|
901 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
902 | |
|
|
903 | IO::AIO::flush |
|
|
904 | Wait till all outstanding AIO requests have been handled. |
|
|
905 | |
|
|
906 | Strictly equivalent to: |
|
|
907 | |
|
|
908 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
909 | while IO::AIO::nreqs; |
|
|
910 | |
|
|
911 | CONTROLLING THE NUMBER OF THREADS |
1088 | CONTROLLING THE NUMBER OF THREADS |
912 | IO::AIO::min_parallel $nthreads |
1089 | IO::AIO::min_parallel $nthreads |
913 | Set the minimum number of AIO threads to $nthreads. The current |
1090 | Set the minimum number of AIO threads to $nthreads. The current |
914 | default is 8, which means eight asynchronous operations can execute |
1091 | default is 8, which means eight asynchronous operations can execute |
915 | concurrently at any one time (the number of outstanding requests, |
1092 | concurrently at any one time (the number of outstanding requests, |
… | |
… | |
993 | executed). |
1170 | executed). |
994 | |
1171 | |
995 | IO::AIO::npending |
1172 | IO::AIO::npending |
996 | Returns the number of requests currently in the pending state |
1173 | Returns the number of requests currently in the pending state |
997 | (executed, but not yet processed by poll_cb). |
1174 | (executed, but not yet processed by poll_cb). |
|
|
1175 | |
|
|
1176 | MISCELLANEOUS FUNCTIONS |
|
|
1177 | IO::AIO implements some functions that might be useful, but are not |
|
|
1178 | asynchronous. |
|
|
1179 | |
|
|
1180 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
|
|
1181 | Calls the "eio_sendfile_sync" function, which is like |
|
|
1182 | "aio_sendfile", but is blocking (this makes most sense if you know |
|
|
1183 | the input data is likely cached already and the output filehandle is |
|
|
1184 | set to non-blocking operations). |
|
|
1185 | |
|
|
1186 | Returns the number of bytes copied, or -1 on error. |
|
|
1187 | |
|
|
1188 | IO::AIO::fadvise $fh, $offset, $len, $advice |
|
|
1189 | Simply calls the "posix_fadvise" function (see its manpage for |
|
|
1190 | details). The following advice constants are avaiable: |
|
|
1191 | "IO::AIO::FADV_NORMAL", "IO::AIO::FADV_SEQUENTIAL", |
|
|
1192 | "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", |
|
|
1193 | "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". |
|
|
1194 | |
|
|
1195 | On systems that do not implement "posix_fadvise", this function |
|
|
1196 | returns ENOSYS, otherwise the return value of "posix_fadvise". |
|
|
1197 | |
|
|
1198 | IO::AIO::madvise $scalar, $offset, $len, $advice |
|
|
1199 | Simply calls the "posix_madvise" function (see its manpage for |
|
|
1200 | details). The following advice constants are avaiable: |
|
|
1201 | "IO::AIO::MADV_NORMAL", "IO::AIO::MADV_SEQUENTIAL", |
|
|
1202 | "IO::AIO::MADV_RANDOM", "IO::AIO::MADV_WILLNEED", |
|
|
1203 | "IO::AIO::MADV_DONTNEED". |
|
|
1204 | |
|
|
1205 | On systems that do not implement "posix_madvise", this function |
|
|
1206 | returns ENOSYS, otherwise the return value of "posix_madvise". |
|
|
1207 | |
|
|
1208 | IO::AIO::mprotect $scalar, $offset, $len, $protect |
|
|
1209 | Simply calls the "mprotect" function on the preferably AIO::mmap'ed |
|
|
1210 | $scalar (see its manpage for details). The following protect |
|
|
1211 | constants are avaiable: "IO::AIO::PROT_NONE", "IO::AIO::PROT_READ", |
|
|
1212 | "IO::AIO::PROT_WRITE", "IO::AIO::PROT_EXEC". |
|
|
1213 | |
|
|
1214 | On systems that do not implement "mprotect", this function returns |
|
|
1215 | ENOSYS, otherwise the return value of "mprotect". |
|
|
1216 | |
|
|
1217 | IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
|
|
1218 | Memory-maps a file (or anonymous memory range) and attaches it to |
|
|
1219 | the given $scalar, which will act like a string scalar. |
|
|
1220 | |
|
|
1221 | The only operations allowed on the scalar are "substr"/"vec" that |
|
|
1222 | don't change the string length, and most read-only operations such |
|
|
1223 | as copying it or searching it with regexes and so on. |
|
|
1224 | |
|
|
1225 | Anything else is unsafe and will, at best, result in memory leaks. |
|
|
1226 | |
|
|
1227 | The memory map associated with the $scalar is automatically removed |
|
|
1228 | when the $scalar is destroyed, or when the "IO::AIO::mmap" or |
|
|
1229 | "IO::AIO::munmap" functions are called. |
|
|
1230 | |
|
|
1231 | This calls the "mmap"(2) function internally. See your system's |
|
|
1232 | manual page for details on the $length, $prot and $flags parameters. |
|
|
1233 | |
|
|
1234 | The $length must be larger than zero and smaller than the actual |
|
|
1235 | filesize. |
|
|
1236 | |
|
|
1237 | $prot is a combination of "IO::AIO::PROT_NONE", |
|
|
1238 | "IO::AIO::PROT_EXEC", "IO::AIO::PROT_READ" and/or |
|
|
1239 | "IO::AIO::PROT_WRITE", |
|
|
1240 | |
|
|
1241 | $flags can be a combination of "IO::AIO::MAP_SHARED" or |
|
|
1242 | "IO::AIO::MAP_PRIVATE", or a number of system-specific flags (when |
|
|
1243 | not available, the are defined as 0): "IO::AIO::MAP_ANONYMOUS" |
|
|
1244 | (which is set to "MAP_ANON" if your system only provides this |
|
|
1245 | constant), "IO::AIO::MAP_HUGETLB", "IO::AIO::MAP_LOCKED", |
|
|
1246 | "IO::AIO::MAP_NORESERVE", "IO::AIO::MAP_POPULATE" or |
|
|
1247 | "IO::AIO::MAP_NONBLOCK" |
|
|
1248 | |
|
|
1249 | If $fh is "undef", then a file descriptor of -1 is passed. |
|
|
1250 | |
|
|
1251 | $offset is the offset from the start of the file - it generally must |
|
|
1252 | be a multiple of "IO::AIO::PAGESIZE" and defaults to 0. |
|
|
1253 | |
|
|
1254 | Example: |
|
|
1255 | |
|
|
1256 | use Digest::MD5; |
|
|
1257 | use IO::AIO; |
|
|
1258 | |
|
|
1259 | open my $fh, "<verybigfile" |
|
|
1260 | or die "$!"; |
|
|
1261 | |
|
|
1262 | IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh |
|
|
1263 | or die "verybigfile: $!"; |
|
|
1264 | |
|
|
1265 | my $fast_md5 = md5 $data; |
|
|
1266 | |
|
|
1267 | IO::AIO::munmap $scalar |
|
|
1268 | Removes a previous mmap and undefines the $scalar. |
|
|
1269 | |
|
|
1270 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
|
|
1271 | Calls the "munlock" function, undoing the effects of a previous |
|
|
1272 | "aio_mlock" call (see its description for details). |
|
|
1273 | |
|
|
1274 | IO::AIO::munlockall |
|
|
1275 | Calls the "munlockall" function. |
|
|
1276 | |
|
|
1277 | On systems that do not implement "munlockall", this function returns |
|
|
1278 | ENOSYS, otherwise the return value of "munlockall". |
|
|
1279 | |
|
|
1280 | EVENT LOOP INTEGRATION |
|
|
1281 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
|
|
1282 | automatically into many event loops: |
|
|
1283 | |
|
|
1284 | # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...) |
|
|
1285 | use AnyEvent::AIO; |
|
|
1286 | |
|
|
1287 | You can also integrate IO::AIO manually into many event loops, here are |
|
|
1288 | some examples of how to do this: |
|
|
1289 | |
|
|
1290 | # EV integration |
|
|
1291 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
|
|
1292 | |
|
|
1293 | # Event integration |
|
|
1294 | Event->io (fd => IO::AIO::poll_fileno, |
|
|
1295 | poll => 'r', |
|
|
1296 | cb => \&IO::AIO::poll_cb); |
|
|
1297 | |
|
|
1298 | # Glib/Gtk2 integration |
|
|
1299 | add_watch Glib::IO IO::AIO::poll_fileno, |
|
|
1300 | in => sub { IO::AIO::poll_cb; 1 }; |
|
|
1301 | |
|
|
1302 | # Tk integration |
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1303 | Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "", |
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1304 | readable => \&IO::AIO::poll_cb); |
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1305 | |
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1306 | # Danga::Socket integration |
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1307 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
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1308 | \&IO::AIO::poll_cb); |
998 | |
1309 | |
999 | FORK BEHAVIOUR |
1310 | FORK BEHAVIOUR |
1000 | This module should do "the right thing" when the process using it forks: |
1311 | This module should do "the right thing" when the process using it forks: |
1001 | |
1312 | |
1002 | Before the fork, IO::AIO enters a quiescent state where no requests can |
1313 | Before the fork, IO::AIO enters a quiescent state where no requests can |