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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 |
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30 | open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; |
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31 | my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb }); |
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32 | |
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33 | # Event integration |
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34 | Event->io (fd => IO::AIO::poll_fileno, |
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35 | poll => 'r', |
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36 | cb => \&IO::AIO::poll_cb); |
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37 | |
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38 | # Glib/Gtk2 integration |
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39 | add_watch Glib::IO IO::AIO::poll_fileno, |
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40 | in => sub { IO::AIO::poll_cb; 1 }; |
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41 | |
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42 | # Tk integration |
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43 | Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "", |
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44 | readable => \&IO::AIO::poll_cb); |
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45 | |
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46 | # Danga::Socket integration |
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47 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
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48 | \&IO::AIO::poll_cb); |
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49 | |
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50 | DESCRIPTION |
29 | DESCRIPTION |
51 | This module implements asynchronous I/O using whatever means your |
30 | This module implements asynchronous I/O using whatever means your |
52 | 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>). |
53 | |
33 | |
54 | Asynchronous means that operations that can normally block your program |
34 | Asynchronous means that operations that can normally block your program |
55 | (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 |
56 | 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 |
57 | 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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62 | operations concurrently. |
42 | operations concurrently. |
63 | |
43 | |
64 | 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 |
65 | sockets), using these functions on file descriptors that support |
45 | sockets), using these functions on file descriptors that support |
66 | nonblocking operation (again, sockets, pipes etc.) is very inefficient. |
46 | nonblocking operation (again, sockets, pipes etc.) is very inefficient. |
67 | 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 |
68 | naturally fit into such an event loop itself. |
48 | naturally fit into such an event loop itself. |
69 | |
49 | |
70 | 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 |
71 | 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 |
72 | 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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81 | 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 |
82 | 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 |
83 | call "poll_cb" (or other "aio_" functions) recursively. |
63 | call "poll_cb" (or other "aio_" functions) recursively. |
84 | |
64 | |
85 | EXAMPLE |
65 | EXAMPLE |
86 | 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 |
87 | /etc/passwd asynchronously: |
67 | asynchronously: |
88 | |
68 | |
89 | use Fcntl; |
69 | use Fcntl; |
90 | use Event; |
70 | use EV; |
91 | use IO::AIO; |
71 | use IO::AIO; |
92 | |
72 | |
93 | # register the IO::AIO callback with Event |
73 | # register the IO::AIO callback with EV |
94 | Event->io (fd => IO::AIO::poll_fileno, |
74 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
95 | poll => 'r', |
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96 | cb => \&IO::AIO::poll_cb); |
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97 | |
75 | |
98 | # queue the request to open /etc/passwd |
76 | # queue the request to open /etc/passwd |
99 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
77 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
100 | my $fh = shift |
78 | my $fh = shift |
101 | or die "error while opening: $!"; |
79 | or die "error while opening: $!"; |
102 | |
80 | |
103 | # stat'ing filehandles is generally non-blocking |
81 | # stat'ing filehandles is generally non-blocking |
104 | my $size = -s $fh; |
82 | my $size = -s $fh; |
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113 | |
91 | |
114 | # file contents now in $contents |
92 | # file contents now in $contents |
115 | print $contents; |
93 | print $contents; |
116 | |
94 | |
117 | # exit event loop and program |
95 | # exit event loop and program |
118 | Event::unloop; |
96 | EV::unloop; |
119 | }; |
97 | }; |
120 | }; |
98 | }; |
121 | |
99 | |
122 | # possibly queue up other requests, or open GUI windows, |
100 | # possibly queue up other requests, or open GUI windows, |
123 | # check for sockets etc. etc. |
101 | # check for sockets etc. etc. |
124 | |
102 | |
125 | # process events as long as there are some: |
103 | # process events as long as there are some: |
126 | Event::loop; |
104 | EV::loop; |
127 | |
105 | |
128 | REQUEST ANATOMY AND LIFETIME |
106 | REQUEST ANATOMY AND LIFETIME |
129 | 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 |
130 | not directly visible to Perl. |
108 | not directly visible to Perl. |
131 | |
109 | |
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167 | anymore (except possibly for the Perl object, but its connection to |
145 | anymore (except possibly for the Perl object, but its connection to |
168 | the actual aio request is severed and calling its methods will |
146 | the actual aio request is severed and calling its methods will |
169 | either do nothing or result in a runtime error). |
147 | either do nothing or result in a runtime error). |
170 | |
148 | |
171 | 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 | |
172 | AIO REQUEST FUNCTIONS |
221 | AIO REQUEST FUNCTIONS |
173 | 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 |
174 | with the same name (sans "aio_"). The arguments are similar or |
223 | with the same name (sans "aio_"). The arguments are similar or |
175 | identical, and they all accept an additional (and optional) $callback |
224 | identical, and they all accept an additional (and optional) $callback |
176 | 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 |
177 | called with the syscall return code (e.g. most syscalls return -1 on |
226 | called with the syscall return code (e.g. most syscalls return -1 on |
178 | error, unlike perl, which usually delivers "false") as it's sole |
227 | error, unlike perl, which usually delivers "false") as its sole argument |
179 | argument when the given syscall has been executed asynchronously. |
228 | after the given syscall has been executed asynchronously. |
180 | |
229 | |
181 | All functions expecting a filehandle keep a copy of the filehandle |
230 | All functions expecting a filehandle keep a copy of the filehandle |
182 | internally until the request has finished. |
231 | internally until the request has finished. |
183 | |
232 | |
184 | All functions return request objects of type IO::AIO::REQ that allow |
233 | All functions return request objects of type IO::AIO::REQ that allow |
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197 | the user environment, d) use Glib::filename_from_unicode on unicode |
246 | the user environment, d) use Glib::filename_from_unicode on unicode |
198 | filenames or e) use something else to ensure your scalar has the correct |
247 | filenames or e) use something else to ensure your scalar has the correct |
199 | contents. |
248 | contents. |
200 | |
249 | |
201 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
250 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
202 | handles correctly wether it is set or not. |
251 | handles correctly whether it is set or not. |
203 | |
252 | |
204 | $prev_pri = aioreq_pri [$pri] |
253 | $prev_pri = aioreq_pri [$pri] |
205 | Returns the priority value that would be used for the next request |
254 | Returns the priority value that would be used for the next request |
206 | and, if $pri is given, sets the priority for the next aio request. |
255 | and, if $pri is given, sets the priority for the next aio request. |
207 | |
256 | |
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247 | will be modified by the umask in effect then the request is being |
296 | will be modified by the umask in effect then the request is being |
248 | executed, so better never change the umask. |
297 | executed, so better never change the umask. |
249 | |
298 | |
250 | Example: |
299 | Example: |
251 | |
300 | |
252 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
301 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
253 | if ($_[0]) { |
302 | if ($_[0]) { |
254 | print "open successful, fh is $_[0]\n"; |
303 | print "open successful, fh is $_[0]\n"; |
255 | ... |
304 | ... |
256 | } else { |
305 | } else { |
257 | die "open failed: $!\n"; |
306 | die "open failed: $!\n"; |
258 | } |
307 | } |
259 | }; |
308 | }; |
260 | |
309 | |
261 | aio_close $fh, $callback->($status) |
310 | aio_close $fh, $callback->($status) |
262 | Asynchronously close a file and call the callback with the result |
311 | Asynchronously close a file and call the callback with the result |
263 | code. *WARNING:* although accepted, you should not pass in a perl |
312 | code. |
264 | filehandle here, as perl will likely close the file descriptor |
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265 | another time when the filehandle is destroyed. Normally, you can |
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266 | safely call perls "close" or just let filehandles go out of scope. |
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267 | |
313 | |
268 | This is supposed to be a bug in the API, so that might change. It's |
314 | Unfortunately, you can't do this to perl. Perl *insists* very |
269 | therefore best to avoid this function. |
315 | strongly on closing the file descriptor associated with the |
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316 | filehandle itself. |
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317 | |
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318 | Therefore, "aio_close" will not close the filehandle - instead it |
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319 | will use dup2 to overwrite the file descriptor with the write-end of |
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320 | a pipe (the pipe fd will be created on demand and will be cached). |
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321 | |
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322 | Or in other words: the file descriptor will be closed, but it will |
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323 | not be free for reuse until the perl filehandle is closed. |
270 | |
324 | |
271 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
325 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
272 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
326 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
273 | Reads or writes $length bytes from the specified $fh and $offset |
327 | Reads or writes $length bytes from or to the specified $fh and |
274 | into the scalar given by $data and offset $dataoffset and calls the |
328 | $offset into the scalar given by $data and offset $dataoffset and |
275 | callback without the actual number of bytes read (or -1 on error, |
329 | calls the callback without the actual number of bytes read (or -1 on |
276 | just like the syscall). |
330 | error, just like the syscall). |
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331 | |
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332 | "aio_read" will, like "sysread", shrink or grow the $data scalar to |
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333 | offset plus the actual number of bytes read. |
277 | |
334 | |
278 | If $offset is undefined, then the current file descriptor offset |
335 | If $offset is undefined, then the current file descriptor offset |
279 | will be used (and updated), otherwise the file descriptor offset |
336 | will be used (and updated), otherwise the file descriptor offset |
280 | will not be changed by these calls. |
337 | will not be changed by these calls. |
281 | |
338 | |
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304 | 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 |
305 | with each other. |
362 | with each other. |
306 | |
363 | |
307 | This call tries to make use of a native "sendfile" syscall to |
364 | This call tries to make use of a native "sendfile" syscall to |
308 | provide zero-copy operation. For this to work, $out_fh should refer |
365 | provide zero-copy operation. For this to work, $out_fh should refer |
309 | to a socket, and $in_fh should refer to mmap'able file. |
366 | to a socket, and $in_fh should refer to an mmap'able file. |
310 | |
367 | |
311 | If the native sendfile call fails or is not implemented, it will be |
368 | If a native sendfile cannot be found or it fails with "ENOSYS", |
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369 | "ENOTSUP", "EOPNOTSUPP", "EAFNOSUPPORT", "EPROTOTYPE" or "ENOTSOCK", |
312 | emulated, so you can call "aio_sendfile" on any type of filehandle |
370 | it will be emulated, so you can call "aio_sendfile" on any type of |
313 | regardless of the limitations of the operating system. |
371 | filehandle regardless of the limitations of the operating system. |
314 | |
372 | |
315 | Please note, however, that "aio_sendfile" can read more bytes from |
373 | Please note, however, that "aio_sendfile" can read more bytes from |
316 | $in_fh than are written, and there is no way to find out how many |
374 | $in_fh than are written, and there is no way to find out how many |
317 | bytes have been read from "aio_sendfile" alone, as "aio_sendfile" |
375 | bytes have been read from "aio_sendfile" alone, as "aio_sendfile" |
318 | only provides the number of bytes written to $out_fh. Only if the |
376 | only provides the number of bytes written to $out_fh. Only if the |
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353 | aio_stat "/etc/passwd", sub { |
411 | aio_stat "/etc/passwd", sub { |
354 | $_[0] and die "stat failed: $!"; |
412 | $_[0] and die "stat failed: $!"; |
355 | print "size is ", -s _, "\n"; |
413 | print "size is ", -s _, "\n"; |
356 | }; |
414 | }; |
357 | |
415 | |
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416 | aio_statvfs $fh_or_path, $callback->($statvfs) |
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417 | Works like the POSIX "statvfs" or "fstatvfs" syscalls, depending on |
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418 | whether a file handle or path was passed. |
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419 | |
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420 | On success, the callback is passed a hash reference with the |
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421 | following members: "bsize", "frsize", "blocks", "bfree", "bavail", |
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422 | "files", "ffree", "favail", "fsid", "flag" and "namemax". On |
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423 | failure, "undef" is passed. |
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424 | |
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425 | The following POSIX IO::AIO::ST_* constants are defined: "ST_RDONLY" |
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426 | and "ST_NOSUID". |
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427 | |
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428 | The following non-POSIX IO::AIO::ST_* flag masks are defined to |
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429 | their correct value when available, or to 0 on systems that do not |
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430 | support them: "ST_NODEV", "ST_NOEXEC", "ST_SYNCHRONOUS", |
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431 | "ST_MANDLOCK", "ST_WRITE", "ST_APPEND", "ST_IMMUTABLE", |
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432 | "ST_NOATIME", "ST_NODIRATIME" and "ST_RELATIME". |
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433 | |
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434 | Example: stat "/wd" and dump out the data if successful. |
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435 | |
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436 | aio_statvfs "/wd", sub { |
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437 | my $f = $_[0] |
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438 | or die "statvfs: $!"; |
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439 | |
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440 | use Data::Dumper; |
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441 | say Dumper $f; |
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442 | }; |
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443 | |
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444 | # result: |
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445 | { |
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446 | bsize => 1024, |
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447 | bfree => 4333064312, |
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448 | blocks => 10253828096, |
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449 | files => 2050765568, |
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450 | flag => 4096, |
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451 | favail => 2042092649, |
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452 | bavail => 4333064312, |
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453 | ffree => 2042092649, |
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454 | namemax => 255, |
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455 | frsize => 1024, |
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456 | fsid => 1810 |
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457 | } |
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458 | |
358 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
459 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
359 | Works like perl's "utime" function (including the special case of |
460 | Works like perl's "utime" function (including the special case of |
360 | $atime and $mtime being undef). Fractional times are supported if |
461 | $atime and $mtime being undef). Fractional times are supported if |
361 | the underlying syscalls support them. |
462 | the underlying syscalls support them. |
362 | |
463 | |
… | |
… | |
432 | aio_readdir $pathname, $callback->($entries) |
533 | aio_readdir $pathname, $callback->($entries) |
433 | Unlike the POSIX call of the same name, "aio_readdir" reads an |
534 | Unlike the POSIX call of the same name, "aio_readdir" reads an |
434 | entire directory (i.e. opendir + readdir + closedir). The entries |
535 | entire directory (i.e. opendir + readdir + closedir). The entries |
435 | will not be sorted, and will NOT include the "." and ".." entries. |
536 | will not be sorted, and will NOT include the "." and ".." entries. |
436 | |
537 | |
437 | The callback a single argument which is either "undef" or an |
538 | The callback is passed a single argument which is either "undef" or |
438 | array-ref with the filenames. |
539 | an array-ref with the filenames. |
|
|
540 | |
|
|
541 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
|
|
542 | Quite similar to "aio_readdir", but the $flags argument allows to |
|
|
543 | tune behaviour and output format. In case of an error, $entries will |
|
|
544 | be "undef". |
|
|
545 | |
|
|
546 | The flags are a combination of the following constants, ORed |
|
|
547 | together (the flags will also be passed to the callback, possibly |
|
|
548 | modified): |
|
|
549 | |
|
|
550 | IO::AIO::READDIR_DENTS |
|
|
551 | When this flag is off, then the callback gets an arrayref with |
|
|
552 | of names only (as with "aio_readdir"), otherwise it gets an |
|
|
553 | arrayref with "[$name, $type, $inode]" arrayrefs, each |
|
|
554 | describing a single directory entry in more detail. |
|
|
555 | |
|
|
556 | $name is the name of the entry. |
|
|
557 | |
|
|
558 | $type is one of the "IO::AIO::DT_xxx" constants: |
|
|
559 | |
|
|
560 | "IO::AIO::DT_UNKNOWN", "IO::AIO::DT_FIFO", "IO::AIO::DT_CHR", |
|
|
561 | "IO::AIO::DT_DIR", "IO::AIO::DT_BLK", "IO::AIO::DT_REG", |
|
|
562 | "IO::AIO::DT_LNK", "IO::AIO::DT_SOCK", "IO::AIO::DT_WHT". |
|
|
563 | |
|
|
564 | "IO::AIO::DT_UNKNOWN" means just that: readdir does not know. If |
|
|
565 | you need to know, you have to run stat yourself. Also, for speed |
|
|
566 | reasons, the $type scalars are read-only: you can not modify |
|
|
567 | them. |
|
|
568 | |
|
|
569 | $inode is the inode number (which might not be exact on systems |
|
|
570 | with 64 bit inode numbers and 32 bit perls). This field has |
|
|
571 | unspecified content on systems that do not deliver the inode |
|
|
572 | information. |
|
|
573 | |
|
|
574 | IO::AIO::READDIR_DIRS_FIRST |
|
|
575 | When this flag is set, then the names will be returned in an |
|
|
576 | order where likely directories come first. This is useful when |
|
|
577 | you need to quickly find directories, or you want to find all |
|
|
578 | directories while avoiding to stat() each entry. |
|
|
579 | |
|
|
580 | If the system returns type information in readdir, then this is |
|
|
581 | used to find directories directly. Otherwise, likely directories |
|
|
582 | are files beginning with ".", or otherwise files with no dots, |
|
|
583 | of which files with short names are tried first. |
|
|
584 | |
|
|
585 | IO::AIO::READDIR_STAT_ORDER |
|
|
586 | When this flag is set, then the names will be returned in an |
|
|
587 | order suitable for stat()'ing each one. That is, when you plan |
|
|
588 | to stat() all files in the given directory, then the returned |
|
|
589 | order will likely be fastest. |
|
|
590 | |
|
|
591 | If both this flag and "IO::AIO::READDIR_DIRS_FIRST" are |
|
|
592 | specified, then the likely dirs come first, resulting in a less |
|
|
593 | optimal stat order. |
|
|
594 | |
|
|
595 | IO::AIO::READDIR_FOUND_UNKNOWN |
|
|
596 | This flag should not be set when calling "aio_readdirx". |
|
|
597 | Instead, it is being set by "aio_readdirx", when any of the |
|
|
598 | $type's found were "IO::AIO::DT_UNKNOWN". The absense of this |
|
|
599 | flag therefore indicates that all $type's are known, which can |
|
|
600 | be used to speed up some algorithms. |
439 | |
601 | |
440 | aio_load $path, $data, $callback->($status) |
602 | aio_load $path, $data, $callback->($status) |
441 | This is a composite request that tries to fully load the given file |
603 | This is a composite request that tries to fully load the given file |
442 | into memory. Status is the same as with aio_read. |
604 | into memory. Status is the same as with aio_read. |
443 | |
605 | |
444 | aio_copy $srcpath, $dstpath, $callback->($status) |
606 | aio_copy $srcpath, $dstpath, $callback->($status) |
445 | Try to copy the *file* (directories not supported as either source |
607 | Try to copy the *file* (directories not supported as either source |
446 | or destination) from $srcpath to $dstpath and call the callback with |
608 | or destination) from $srcpath to $dstpath and call the callback with |
447 | the 0 (error) or -1 ok. |
609 | a status of 0 (ok) or -1 (error, see $!). |
448 | |
610 | |
449 | This is a composite request that it creates the destination file |
611 | This is a composite request that creates the destination file with |
450 | with mode 0200 and copies the contents of the source file into it |
612 | mode 0200 and copies the contents of the source file into it using |
451 | using "aio_sendfile", followed by restoring atime, mtime, access |
613 | "aio_sendfile", followed by restoring atime, mtime, access mode and |
452 | mode and uid/gid, in that order. |
614 | uid/gid, in that order. |
453 | |
615 | |
454 | If an error occurs, the partial destination file will be unlinked, |
616 | If an error occurs, the partial destination file will be unlinked, |
455 | if possible, except when setting atime, mtime, access mode and |
617 | if possible, except when setting atime, mtime, access mode and |
456 | uid/gid, where errors are being ignored. |
618 | uid/gid, where errors are being ignored. |
457 | |
619 | |
458 | aio_move $srcpath, $dstpath, $callback->($status) |
620 | aio_move $srcpath, $dstpath, $callback->($status) |
459 | Try to move the *file* (directories not supported as either source |
621 | Try to move the *file* (directories not supported as either source |
460 | or destination) from $srcpath to $dstpath and call the callback with |
622 | or destination) from $srcpath to $dstpath and call the callback with |
461 | the 0 (error) or -1 ok. |
623 | a status of 0 (ok) or -1 (error, see $!). |
462 | |
624 | |
463 | This is a composite request that tries to rename(2) the file first. |
625 | This is a composite request that tries to rename(2) the file first; |
464 | If rename files with "EXDEV", it copies the file with "aio_copy" |
626 | if rename fails with "EXDEV", it copies the file with "aio_copy" |
465 | and, if that is successful, unlinking the $srcpath. |
627 | and, if that is successful, unlinks the $srcpath. |
466 | |
628 | |
467 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
629 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
468 | Scans a directory (similar to "aio_readdir") but additionally tries |
630 | Scans a directory (similar to "aio_readdir") but additionally tries |
469 | to efficiently separate the entries of directory $path into two sets |
631 | to efficiently separate the entries of directory $path into two sets |
470 | of names, directories you can recurse into (directories), and ones |
632 | of names, directories you can recurse into (directories), and ones |
… | |
… | |
490 | Implementation notes. |
652 | Implementation notes. |
491 | |
653 | |
492 | The "aio_readdir" cannot be avoided, but "stat()"'ing every entry |
654 | The "aio_readdir" cannot be avoided, but "stat()"'ing every entry |
493 | can. |
655 | can. |
494 | |
656 | |
|
|
657 | If readdir returns file type information, then this is used directly |
|
|
658 | to find directories. |
|
|
659 | |
495 | After reading the directory, the modification time, size etc. of the |
660 | Otherwise, after reading the directory, the modification time, size |
496 | directory before and after the readdir is checked, and if they match |
661 | etc. of the directory before and after the readdir is checked, and |
497 | (and isn't the current time), the link count will be used to decide |
662 | if they match (and isn't the current time), the link count will be |
498 | how many entries are directories (if >= 2). Otherwise, no knowledge |
663 | used to decide how many entries are directories (if >= 2). |
499 | of the number of subdirectories will be assumed. |
664 | Otherwise, no knowledge of the number of subdirectories will be |
|
|
665 | assumed. |
500 | |
666 | |
501 | Then entries will be sorted into likely directories (everything |
667 | Then entries will be sorted into likely directories a non-initial |
502 | without a non-initial dot currently) and likely non-directories |
668 | dot currently) and likely non-directories (see "aio_readdirx"). Then |
503 | (everything else). Then every entry plus an appended "/." will be |
669 | every entry plus an appended "/." will be "stat"'ed, likely |
504 | "stat"'ed, likely directories first. If that succeeds, it assumes |
670 | directories first, in order of their inode numbers. If that |
505 | that the entry is a directory or a symlink to directory (which will |
671 | succeeds, it assumes that the entry is a directory or a symlink to |
506 | be checked seperately). This is often faster than stat'ing the entry |
672 | directory (which will be checked seperately). This is often faster |
507 | itself because filesystems might detect the type of the entry |
673 | than stat'ing the entry itself because filesystems might detect the |
508 | without reading the inode data (e.g. ext2fs filetype feature). |
674 | type of the entry without reading the inode data (e.g. ext2fs |
|
|
675 | filetype feature), even on systems that cannot return the filetype |
|
|
676 | information on readdir. |
509 | |
677 | |
510 | If the known number of directories (link count - 2) has been |
678 | If the known number of directories (link count - 2) has been |
511 | reached, the rest of the entries is assumed to be non-directories. |
679 | reached, the rest of the entries is assumed to be non-directories. |
512 | |
680 | |
513 | This only works with certainty on POSIX (= UNIX) filesystems, which |
681 | This only works with certainty on POSIX (= UNIX) filesystems, which |
… | |
… | |
521 | Delete a directory tree starting (and including) $path, return the |
689 | Delete a directory tree starting (and including) $path, return the |
522 | status of the final "rmdir" only. This is a composite request that |
690 | status of the final "rmdir" only. This is a composite request that |
523 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
691 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
524 | everything else. |
692 | everything else. |
525 | |
693 | |
|
|
694 | aio_sync $callback->($status) |
|
|
695 | Asynchronously call sync and call the callback when finished. |
|
|
696 | |
526 | aio_fsync $fh, $callback->($status) |
697 | aio_fsync $fh, $callback->($status) |
527 | Asynchronously call fsync on the given filehandle and call the |
698 | Asynchronously call fsync on the given filehandle and call the |
528 | callback with the fsync result code. |
699 | callback with the fsync result code. |
529 | |
700 | |
530 | aio_fdatasync $fh, $callback->($status) |
701 | aio_fdatasync $fh, $callback->($status) |
531 | Asynchronously call fdatasync on the given filehandle and call the |
702 | Asynchronously call fdatasync on the given filehandle and call the |
532 | callback with the fdatasync result code. |
703 | callback with the fdatasync result code. |
533 | |
704 | |
534 | If this call isn't available because your OS lacks it or it couldn't |
705 | If this call isn't available because your OS lacks it or it couldn't |
535 | be detected, it will be emulated by calling "fsync" instead. |
706 | be detected, it will be emulated by calling "fsync" instead. |
|
|
707 | |
|
|
708 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
|
|
709 | Sync the data portion of the file specified by $offset and $length |
|
|
710 | to disk (but NOT the metadata), by calling the Linux-specific |
|
|
711 | sync_file_range call. If sync_file_range is not available or it |
|
|
712 | returns ENOSYS, then fdatasync or fsync is being substituted. |
|
|
713 | |
|
|
714 | $flags can be a combination of |
|
|
715 | "IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE", |
|
|
716 | "IO::AIO::SYNC_FILE_RANGE_WRITE" and |
|
|
717 | "IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER": refer to the sync_file_range |
|
|
718 | manpage for details. |
|
|
719 | |
|
|
720 | aio_pathsync $path, $callback->($status) |
|
|
721 | This request tries to open, fsync and close the given path. This is |
|
|
722 | a composite request intended to sync directories after directory |
|
|
723 | operations (E.g. rename). This might not work on all operating |
|
|
724 | systems or have any specific effect, but usually it makes sure that |
|
|
725 | directory changes get written to disc. It works for anything that |
|
|
726 | can be opened for read-only, not just directories. |
|
|
727 | |
|
|
728 | Future versions of this function might fall back to other methods |
|
|
729 | when "fsync" on the directory fails (such as calling "sync"). |
|
|
730 | |
|
|
731 | Passes 0 when everything went ok, and -1 on error. |
|
|
732 | |
|
|
733 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, |
|
|
734 | $callback->($status) |
|
|
735 | This is a rather advanced IO::AIO call, which only works on |
|
|
736 | mmap(2)ed scalars (see the "IO::AIO::mmap" function, although it |
|
|
737 | also works on data scalars managed by the Sys::Mmap or Mmap modules, |
|
|
738 | note that the scalar must only be modified in-place while an aio |
|
|
739 | operation is pending on it). |
|
|
740 | |
|
|
741 | It calls the "msync" function of your OS, if available, with the |
|
|
742 | memory area starting at $offset in the string and ending $length |
|
|
743 | bytes later. If $length is negative, counts from the end, and if |
|
|
744 | $length is "undef", then it goes till the end of the string. The |
|
|
745 | flags can be a combination of "IO::AIO::MS_ASYNC", |
|
|
746 | "IO::AIO::MS_INVALIDATE" and "IO::AIO::MS_SYNC". |
|
|
747 | |
|
|
748 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, |
|
|
749 | $callback->($status) |
|
|
750 | This is a rather advanced IO::AIO call, which works best on |
|
|
751 | mmap(2)ed scalars. |
|
|
752 | |
|
|
753 | It touches (reads or writes) all memory pages in the specified range |
|
|
754 | inside the scalar. All caveats and parameters are the same as for |
|
|
755 | "aio_msync", above, except for flags, which must be either 0 (which |
|
|
756 | reads all pages and ensures they are instantiated) or |
|
|
757 | "IO::AIO::MT_MODIFY", which modifies the memory page s(by reading |
|
|
758 | and writing an octet from it, which dirties the page). |
|
|
759 | |
|
|
760 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
|
|
761 | This is a rather advanced IO::AIO call, which works best on |
|
|
762 | mmap(2)ed scalars. |
|
|
763 | |
|
|
764 | It reads in all the pages of the underlying storage into memory (if |
|
|
765 | any) and locks them, so they are not getting swapped/paged out or |
|
|
766 | removed. |
|
|
767 | |
|
|
768 | If $length is undefined, then the scalar will be locked till the |
|
|
769 | end. |
|
|
770 | |
|
|
771 | On systems that do not implement "mlock", this function returns -1 |
|
|
772 | and sets errno to "ENOSYS". |
|
|
773 | |
|
|
774 | Note that the corresponding "munlock" is synchronous and is |
|
|
775 | documented under "MISCELLANEOUS FUNCTIONS". |
|
|
776 | |
|
|
777 | Example: open a file, mmap and mlock it - both will be undone when |
|
|
778 | $data gets destroyed. |
|
|
779 | |
|
|
780 | open my $fh, "<", $path or die "$path: $!"; |
|
|
781 | my $data; |
|
|
782 | IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; |
|
|
783 | aio_mlock $data; # mlock in background |
|
|
784 | |
|
|
785 | aio_mlockall $flags, $callback->($status) |
|
|
786 | Calls the "mlockall" function with the given $flags (a combination |
|
|
787 | of "IO::AIO::MCL_CURRENT" and "IO::AIO::MCL_FUTURE"). |
|
|
788 | |
|
|
789 | On systems that do not implement "mlockall", this function returns |
|
|
790 | -1 and sets errno to "ENOSYS". |
|
|
791 | |
|
|
792 | Note that the corresponding "munlockall" is synchronous and is |
|
|
793 | documented under "MISCELLANEOUS FUNCTIONS". |
|
|
794 | |
|
|
795 | Example: asynchronously lock all current and future pages into |
|
|
796 | memory. |
|
|
797 | |
|
|
798 | aio_mlockall IO::AIO::MCL_FUTURE; |
536 | |
799 | |
537 | aio_group $callback->(...) |
800 | aio_group $callback->(...) |
538 | This is a very special aio request: Instead of doing something, it |
801 | This is a very special aio request: Instead of doing something, it |
539 | is a container for other aio requests, which is useful if you want |
802 | is a container for other aio requests, which is useful if you want |
540 | to bundle many requests into a single, composite, request with a |
803 | to bundle many requests into a single, composite, request with a |
… | |
… | |
583 | |
846 | |
584 | cancel $req |
847 | cancel $req |
585 | Cancels the request, if possible. Has the effect of skipping |
848 | Cancels the request, if possible. Has the effect of skipping |
586 | execution when entering the execute state and skipping calling the |
849 | execution when entering the execute state and skipping calling the |
587 | callback when entering the the result state, but will leave the |
850 | callback when entering the the result state, but will leave the |
588 | request otherwise untouched. That means that requests that currently |
851 | request otherwise untouched (with the exception of readdir). That |
589 | execute will not be stopped and resources held by the request will |
852 | means that requests that currently execute will not be stopped and |
590 | not be freed prematurely. |
853 | resources held by the request will not be freed prematurely. |
591 | |
854 | |
592 | cb $req $callback->(...) |
855 | cb $req $callback->(...) |
593 | Replace (or simply set) the callback registered to the request. |
856 | Replace (or simply set) the callback registered to the request. |
594 | |
857 | |
595 | IO::AIO::GRP CLASS |
858 | IO::AIO::GRP CLASS |
… | |
… | |
622 | }; |
885 | }; |
623 | |
886 | |
624 | This makes it very easy to create composite requests (see the source of |
887 | This makes it very easy to create composite requests (see the source of |
625 | "aio_move" for an application) that work and feel like simple requests. |
888 | "aio_move" for an application) that work and feel like simple requests. |
626 | |
889 | |
627 | * The IO::AIO::GRP objects will be cleaned up during calls to |
890 | * The IO::AIO::GRP objects will be cleaned up during calls to |
628 | "IO::AIO::poll_cb", just like any other request. |
891 | "IO::AIO::poll_cb", just like any other request. |
|
|
892 | |
629 | * They can be canceled like any other request. Canceling will cancel not |
893 | * They can be canceled like any other request. Canceling will cancel |
630 | only the request itself, but also all requests it contains. |
894 | not only the request itself, but also all requests it contains. |
|
|
895 | |
631 | * They can also can also be added to other IO::AIO::GRP objects. |
896 | * They can also can also be added to other IO::AIO::GRP objects. |
|
|
897 | |
632 | * You must not add requests to a group from within the group callback |
898 | * You must not add requests to a group from within the group callback |
633 | (or any later time). |
899 | (or any later time). |
634 | |
900 | |
635 | Their lifetime, simplified, looks like this: when they are empty, they |
901 | Their lifetime, simplified, looks like this: when they are empty, they |
636 | will finish very quickly. If they contain only requests that are in the |
902 | will finish very quickly. If they contain only requests that are in the |
637 | "done" state, they will also finish. Otherwise they will continue to |
903 | "done" state, they will also finish. Otherwise they will continue to |
638 | exist. |
904 | exist. |
639 | |
905 | |
640 | That means after creating a group you have some time to add requests. |
906 | That means after creating a group you have some time to add requests |
641 | And in the callbacks of those requests, you can add further requests to |
907 | (precisely before the callback has been invoked, which is only done |
642 | the group. And only when all those requests have finished will the the |
908 | within the "poll_cb"). And in the callbacks of those requests, you can |
643 | group itself finish. |
909 | add further requests to the group. And only when all those requests have |
|
|
910 | finished will the the group itself finish. |
644 | |
911 | |
645 | add $grp ... |
912 | add $grp ... |
646 | $grp->add (...) |
913 | $grp->add (...) |
647 | Add one or more requests to the group. Any type of IO::AIO::REQ can |
914 | Add one or more requests to the group. Any type of IO::AIO::REQ can |
648 | be added, including other groups, as long as you do not create |
915 | be added, including other groups, as long as you do not create |
… | |
… | |
653 | $grp->cancel_subs |
920 | $grp->cancel_subs |
654 | Cancel all subrequests and clears any feeder, but not the group |
921 | Cancel all subrequests and clears any feeder, but not the group |
655 | request itself. Useful when you queued a lot of events but got a |
922 | request itself. Useful when you queued a lot of events but got a |
656 | result early. |
923 | result early. |
657 | |
924 | |
|
|
925 | The group request will finish normally (you cannot add requests to |
|
|
926 | the group). |
|
|
927 | |
658 | $grp->result (...) |
928 | $grp->result (...) |
659 | Set the result value(s) that will be passed to the group callback |
929 | Set the result value(s) that will be passed to the group callback |
660 | when all subrequests have finished and set thre groups errno to the |
930 | when all subrequests have finished and set the groups errno to the |
661 | current value of errno (just like calling "errno" without an error |
931 | current value of errno (just like calling "errno" without an error |
662 | number). By default, no argument will be passed and errno is zero. |
932 | number). By default, no argument will be passed and errno is zero. |
663 | |
933 | |
664 | $grp->errno ([$errno]) |
934 | $grp->errno ([$errno]) |
665 | Sets the group errno value to $errno, or the current value of errno |
935 | Sets the group errno value to $errno, or the current value of errno |
… | |
… | |
691 | does not impose any limits). |
961 | does not impose any limits). |
692 | |
962 | |
693 | If the feed does not queue more requests when called, it will be |
963 | If the feed does not queue more requests when called, it will be |
694 | automatically removed from the group. |
964 | automatically removed from the group. |
695 | |
965 | |
696 | If the feed limit is 0, it will be set to 2 automatically. |
966 | If the feed limit is 0 when this method is called, it will be set to |
|
|
967 | 2 automatically. |
697 | |
968 | |
698 | Example: |
969 | Example: |
699 | |
970 | |
700 | # stat all files in @files, but only ever use four aio requests concurrently: |
971 | # stat all files in @files, but only ever use four aio requests concurrently: |
701 | |
972 | |
… | |
… | |
712 | Sets the feeder limit for the group: The feeder will be called |
983 | Sets the feeder limit for the group: The feeder will be called |
713 | whenever the group contains less than this many requests. |
984 | whenever the group contains less than this many requests. |
714 | |
985 | |
715 | Setting the limit to 0 will pause the feeding process. |
986 | Setting the limit to 0 will pause the feeding process. |
716 | |
987 | |
|
|
988 | The default value for the limit is 0, but note that setting a feeder |
|
|
989 | automatically bumps it up to 2. |
|
|
990 | |
717 | SUPPORT FUNCTIONS |
991 | SUPPORT FUNCTIONS |
718 | EVENT PROCESSING AND EVENT LOOP INTEGRATION |
992 | EVENT PROCESSING AND EVENT LOOP INTEGRATION |
719 | $fileno = IO::AIO::poll_fileno |
993 | $fileno = IO::AIO::poll_fileno |
720 | Return the *request result pipe file descriptor*. This filehandle |
994 | Return the *request result pipe file descriptor*. This filehandle |
721 | must be polled for reading by some mechanism outside this module |
995 | must be polled for reading by some mechanism outside this module |
722 | (e.g. Event or select, see below or the SYNOPSIS). If the pipe |
996 | (e.g. EV, Glib, select and so on, see below or the SYNOPSIS). If the |
723 | becomes readable you have to call "poll_cb" to check the results. |
997 | pipe becomes readable you have to call "poll_cb" to check the |
|
|
998 | results. |
724 | |
999 | |
725 | See "poll_cb" for an example. |
1000 | See "poll_cb" for an example. |
726 | |
1001 | |
727 | IO::AIO::poll_cb |
1002 | IO::AIO::poll_cb |
728 | Process some outstanding events on the result pipe. You have to call |
1003 | Process some outstanding events on the result pipe. You have to call |
729 | this regularly. Returns the number of events processed. Returns |
1004 | this regularly. Returns 0 if all events could be processed, or -1 if |
730 | immediately when no events are outstanding. The amount of events |
1005 | it returned earlier for whatever reason. Returns immediately when no |
|
|
1006 | events are outstanding. The amount of events processed depends on |
731 | processed depends on the settings of "IO::AIO::max_poll_req" and |
1007 | the settings of "IO::AIO::max_poll_req" and |
732 | "IO::AIO::max_poll_time". |
1008 | "IO::AIO::max_poll_time". |
733 | |
1009 | |
734 | If not all requests were processed for whatever reason, the |
1010 | If not all requests were processed for whatever reason, the |
735 | filehandle will still be ready when "poll_cb" returns. |
1011 | filehandle will still be ready when "poll_cb" returns, so normally |
|
|
1012 | you don't have to do anything special to have it called later. |
736 | |
1013 | |
737 | Example: Install an Event watcher that automatically calls |
1014 | Example: Install an Event watcher that automatically calls |
738 | IO::AIO::poll_cb with high priority: |
1015 | IO::AIO::poll_cb with high priority (more examples can be found in |
|
|
1016 | the SYNOPSIS section, at the top of this document): |
739 | |
1017 | |
740 | Event->io (fd => IO::AIO::poll_fileno, |
1018 | Event->io (fd => IO::AIO::poll_fileno, |
741 | poll => 'r', async => 1, |
1019 | poll => 'r', async => 1, |
742 | cb => \&IO::AIO::poll_cb); |
1020 | cb => \&IO::AIO::poll_cb); |
|
|
1021 | |
|
|
1022 | IO::AIO::poll_wait |
|
|
1023 | If there are any outstanding requests and none of them in the result |
|
|
1024 | phase, wait till the result filehandle becomes ready for reading |
|
|
1025 | (simply does a "select" on the filehandle. This is useful if you |
|
|
1026 | want to synchronously wait for some requests to finish). |
|
|
1027 | |
|
|
1028 | See "nreqs" for an example. |
|
|
1029 | |
|
|
1030 | IO::AIO::poll |
|
|
1031 | Waits until some requests have been handled. |
|
|
1032 | |
|
|
1033 | Returns the number of requests processed, but is otherwise strictly |
|
|
1034 | equivalent to: |
|
|
1035 | |
|
|
1036 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
1037 | |
|
|
1038 | IO::AIO::flush |
|
|
1039 | Wait till all outstanding AIO requests have been handled. |
|
|
1040 | |
|
|
1041 | Strictly equivalent to: |
|
|
1042 | |
|
|
1043 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
1044 | while IO::AIO::nreqs; |
743 | |
1045 | |
744 | IO::AIO::max_poll_reqs $nreqs |
1046 | IO::AIO::max_poll_reqs $nreqs |
745 | IO::AIO::max_poll_time $seconds |
1047 | IO::AIO::max_poll_time $seconds |
746 | These set the maximum number of requests (default 0, meaning |
1048 | These set the maximum number of requests (default 0, meaning |
747 | infinity) that are being processed by "IO::AIO::poll_cb" in one |
1049 | infinity) that are being processed by "IO::AIO::poll_cb" in one |
… | |
… | |
771 | # use a low priority so other tasks have priority |
1073 | # use a low priority so other tasks have priority |
772 | Event->io (fd => IO::AIO::poll_fileno, |
1074 | Event->io (fd => IO::AIO::poll_fileno, |
773 | poll => 'r', nice => 1, |
1075 | poll => 'r', nice => 1, |
774 | cb => &IO::AIO::poll_cb); |
1076 | cb => &IO::AIO::poll_cb); |
775 | |
1077 | |
776 | IO::AIO::poll_wait |
|
|
777 | If there are any outstanding requests and none of them in the result |
|
|
778 | phase, wait till the result filehandle becomes ready for reading |
|
|
779 | (simply does a "select" on the filehandle. This is useful if you |
|
|
780 | want to synchronously wait for some requests to finish). |
|
|
781 | |
|
|
782 | See "nreqs" for an example. |
|
|
783 | |
|
|
784 | IO::AIO::poll |
|
|
785 | Waits until some requests have been handled. |
|
|
786 | |
|
|
787 | Returns the number of requests processed, but is otherwise strictly |
|
|
788 | equivalent to: |
|
|
789 | |
|
|
790 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
791 | |
|
|
792 | IO::AIO::flush |
|
|
793 | Wait till all outstanding AIO requests have been handled. |
|
|
794 | |
|
|
795 | Strictly equivalent to: |
|
|
796 | |
|
|
797 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
798 | while IO::AIO::nreqs; |
|
|
799 | |
|
|
800 | CONTROLLING THE NUMBER OF THREADS |
1078 | CONTROLLING THE NUMBER OF THREADS |
801 | IO::AIO::min_parallel $nthreads |
1079 | IO::AIO::min_parallel $nthreads |
802 | Set the minimum number of AIO threads to $nthreads. The current |
1080 | Set the minimum number of AIO threads to $nthreads. The current |
803 | default is 8, which means eight asynchronous operations can execute |
1081 | default is 8, which means eight asynchronous operations can execute |
804 | concurrently at any one time (the number of outstanding requests, |
1082 | concurrently at any one time (the number of outstanding requests, |
… | |
… | |
846 | |
1124 | |
847 | The default is probably ok in most situations, especially if thread |
1125 | The default is probably ok in most situations, especially if thread |
848 | creation is fast. If thread creation is very slow on your system you |
1126 | creation is fast. If thread creation is very slow on your system you |
849 | might want to use larger values. |
1127 | might want to use larger values. |
850 | |
1128 | |
851 | $oldmaxreqs = IO::AIO::max_outstanding $maxreqs |
1129 | IO::AIO::max_outstanding $maxreqs |
852 | This is a very bad function to use in interactive programs because |
1130 | This is a very bad function to use in interactive programs because |
853 | it blocks, and a bad way to reduce concurrency because it is |
1131 | it blocks, and a bad way to reduce concurrency because it is |
854 | inexact: Better use an "aio_group" together with a feed callback. |
1132 | inexact: Better use an "aio_group" together with a feed callback. |
855 | |
1133 | |
856 | Sets the maximum number of outstanding requests to $nreqs. If you do |
1134 | Sets the maximum number of outstanding requests to $nreqs. If you do |
… | |
… | |
860 | |
1138 | |
861 | The default value is very large, so there is no practical limit on |
1139 | The default value is very large, so there is no practical limit on |
862 | the number of outstanding requests. |
1140 | the number of outstanding requests. |
863 | |
1141 | |
864 | You can still queue as many requests as you want. Therefore, |
1142 | You can still queue as many requests as you want. Therefore, |
865 | "max_oustsanding" is mainly useful in simple scripts (with low |
1143 | "max_outstanding" is mainly useful in simple scripts (with low |
866 | values) or as a stop gap to shield against fatal memory overflow |
1144 | values) or as a stop gap to shield against fatal memory overflow |
867 | (with large values). |
1145 | (with large values). |
868 | |
1146 | |
869 | STATISTICAL INFORMATION |
1147 | STATISTICAL INFORMATION |
870 | IO::AIO::nreqs |
1148 | IO::AIO::nreqs |
… | |
… | |
882 | executed). |
1160 | executed). |
883 | |
1161 | |
884 | IO::AIO::npending |
1162 | IO::AIO::npending |
885 | Returns the number of requests currently in the pending state |
1163 | Returns the number of requests currently in the pending state |
886 | (executed, but not yet processed by poll_cb). |
1164 | (executed, but not yet processed by poll_cb). |
|
|
1165 | |
|
|
1166 | MISCELLANEOUS FUNCTIONS |
|
|
1167 | IO::AIO implements some functions that might be useful, but are not |
|
|
1168 | asynchronous. |
|
|
1169 | |
|
|
1170 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
|
|
1171 | Calls the "eio_sendfile_sync" function, which is like |
|
|
1172 | "aio_sendfile", but is blocking (this makes most sense if you know |
|
|
1173 | the input data is likely cached already and the output filehandle is |
|
|
1174 | set to non-blocking operations). |
|
|
1175 | |
|
|
1176 | Returns the number of bytes copied, or -1 on error. |
|
|
1177 | |
|
|
1178 | IO::AIO::fadvise $fh, $offset, $len, $advice |
|
|
1179 | Simply calls the "posix_fadvise" function (see its manpage for |
|
|
1180 | details). The following advice constants are avaiable: |
|
|
1181 | "IO::AIO::FADV_NORMAL", "IO::AIO::FADV_SEQUENTIAL", |
|
|
1182 | "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", |
|
|
1183 | "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". |
|
|
1184 | |
|
|
1185 | On systems that do not implement "posix_fadvise", this function |
|
|
1186 | returns ENOSYS, otherwise the return value of "posix_fadvise". |
|
|
1187 | |
|
|
1188 | IO::AIO::madvise $scalar, $offset, $len, $advice |
|
|
1189 | Simply calls the "posix_madvise" function (see its manpage for |
|
|
1190 | details). The following advice constants are avaiable: |
|
|
1191 | "IO::AIO::MADV_NORMAL", "IO::AIO::MADV_SEQUENTIAL", |
|
|
1192 | "IO::AIO::MADV_RANDOM", "IO::AIO::MADV_WILLNEED", |
|
|
1193 | "IO::AIO::MADV_DONTNEED". |
|
|
1194 | |
|
|
1195 | On systems that do not implement "posix_madvise", this function |
|
|
1196 | returns ENOSYS, otherwise the return value of "posix_madvise". |
|
|
1197 | |
|
|
1198 | IO::AIO::mprotect $scalar, $offset, $len, $protect |
|
|
1199 | Simply calls the "mprotect" function on the preferably AIO::mmap'ed |
|
|
1200 | $scalar (see its manpage for details). The following protect |
|
|
1201 | constants are avaiable: "IO::AIO::PROT_NONE", "IO::AIO::PROT_READ", |
|
|
1202 | "IO::AIO::PROT_WRITE", "IO::AIO::PROT_EXEC". |
|
|
1203 | |
|
|
1204 | On systems that do not implement "mprotect", this function returns |
|
|
1205 | ENOSYS, otherwise the return value of "mprotect". |
|
|
1206 | |
|
|
1207 | IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
|
|
1208 | Memory-maps a file (or anonymous memory range) and attaches it to |
|
|
1209 | the given $scalar, which will act like a string scalar. |
|
|
1210 | |
|
|
1211 | The only operations allowed on the scalar are "substr"/"vec" that |
|
|
1212 | don't change the string length, and most read-only operations such |
|
|
1213 | as copying it or searching it with regexes and so on. |
|
|
1214 | |
|
|
1215 | Anything else is unsafe and will, at best, result in memory leaks. |
|
|
1216 | |
|
|
1217 | The memory map associated with the $scalar is automatically removed |
|
|
1218 | when the $scalar is destroyed, or when the "IO::AIO::mmap" or |
|
|
1219 | "IO::AIO::munmap" functions are called. |
|
|
1220 | |
|
|
1221 | This calls the "mmap"(2) function internally. See your system's |
|
|
1222 | manual page for details on the $length, $prot and $flags parameters. |
|
|
1223 | |
|
|
1224 | The $length must be larger than zero and smaller than the actual |
|
|
1225 | filesize. |
|
|
1226 | |
|
|
1227 | $prot is a combination of "IO::AIO::PROT_NONE", |
|
|
1228 | "IO::AIO::PROT_EXEC", "IO::AIO::PROT_READ" and/or |
|
|
1229 | "IO::AIO::PROT_WRITE", |
|
|
1230 | |
|
|
1231 | $flags can be a combination of "IO::AIO::MAP_SHARED" or |
|
|
1232 | "IO::AIO::MAP_PRIVATE", or a number of system-specific flags (when |
|
|
1233 | not available, the are defined as 0): "IO::AIO::MAP_ANONYMOUS" |
|
|
1234 | (which is set to "MAP_ANON" if your system only provides this |
|
|
1235 | constant), "IO::AIO::MAP_HUGETLB", "IO::AIO::MAP_LOCKED", |
|
|
1236 | "IO::AIO::MAP_NORESERVE", "IO::AIO::MAP_POPULATE" or |
|
|
1237 | "IO::AIO::MAP_NONBLOCK" |
|
|
1238 | |
|
|
1239 | If $fh is "undef", then a file descriptor of -1 is passed. |
|
|
1240 | |
|
|
1241 | $offset is the offset from the start of the file - it generally must |
|
|
1242 | be a multiple of "IO::AIO::PAGESIZE" and defaults to 0. |
|
|
1243 | |
|
|
1244 | Example: |
|
|
1245 | |
|
|
1246 | use Digest::MD5; |
|
|
1247 | use IO::AIO; |
|
|
1248 | |
|
|
1249 | open my $fh, "<verybigfile" |
|
|
1250 | or die "$!"; |
|
|
1251 | |
|
|
1252 | IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh |
|
|
1253 | or die "verybigfile: $!"; |
|
|
1254 | |
|
|
1255 | my $fast_md5 = md5 $data; |
|
|
1256 | |
|
|
1257 | IO::AIO::munmap $scalar |
|
|
1258 | Removes a previous mmap and undefines the $scalar. |
|
|
1259 | |
|
|
1260 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
|
|
1261 | Calls the "munlock" function, undoing the effects of a previous |
|
|
1262 | "aio_mlock" call (see its description for details). |
|
|
1263 | |
|
|
1264 | IO::AIO::munlockall |
|
|
1265 | Calls the "munlockall" function. |
|
|
1266 | |
|
|
1267 | On systems that do not implement "munlockall", this function returns |
|
|
1268 | ENOSYS, otherwise the return value of "munlockall". |
|
|
1269 | |
|
|
1270 | EVENT LOOP INTEGRATION |
|
|
1271 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
|
|
1272 | automatically into many event loops: |
|
|
1273 | |
|
|
1274 | # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...) |
|
|
1275 | use AnyEvent::AIO; |
|
|
1276 | |
|
|
1277 | You can also integrate IO::AIO manually into many event loops, here are |
|
|
1278 | some examples of how to do this: |
|
|
1279 | |
|
|
1280 | # EV integration |
|
|
1281 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
|
|
1282 | |
|
|
1283 | # Event integration |
|
|
1284 | Event->io (fd => IO::AIO::poll_fileno, |
|
|
1285 | poll => 'r', |
|
|
1286 | cb => \&IO::AIO::poll_cb); |
|
|
1287 | |
|
|
1288 | # Glib/Gtk2 integration |
|
|
1289 | add_watch Glib::IO IO::AIO::poll_fileno, |
|
|
1290 | in => sub { IO::AIO::poll_cb; 1 }; |
|
|
1291 | |
|
|
1292 | # Tk integration |
|
|
1293 | Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "", |
|
|
1294 | readable => \&IO::AIO::poll_cb); |
|
|
1295 | |
|
|
1296 | # Danga::Socket integration |
|
|
1297 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
|
|
1298 | \&IO::AIO::poll_cb); |
887 | |
1299 | |
888 | FORK BEHAVIOUR |
1300 | FORK BEHAVIOUR |
889 | This module should do "the right thing" when the process using it forks: |
1301 | This module should do "the right thing" when the process using it forks: |
890 | |
1302 | |
891 | Before the fork, IO::AIO enters a quiescent state where no requests can |
1303 | Before the fork, IO::AIO enters a quiescent state where no requests can |
… | |
… | |
920 | |
1332 | |
921 | KNOWN BUGS |
1333 | KNOWN BUGS |
922 | Known bugs will be fixed in the next release. |
1334 | Known bugs will be fixed in the next release. |
923 | |
1335 | |
924 | SEE ALSO |
1336 | SEE ALSO |
925 | Coro::AIO. |
1337 | AnyEvent::AIO for easy integration into event loops, Coro::AIO for a |
|
|
1338 | more natural syntax. |
926 | |
1339 | |
927 | AUTHOR |
1340 | AUTHOR |
928 | Marc Lehmann <schmorp@schmorp.de> |
1341 | Marc Lehmann <schmorp@schmorp.de> |
929 | http://home.schmorp.de/ |
1342 | http://home.schmorp.de/ |
930 | |
1343 | |