1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 | NAME IO::Event - Tied Filehandles for Nonblocking IO with Object Callbacks SYNOPSIS use IO::Event; use IO::Event 'emulate_Event'; use IO::Event 'AnyEvent'; my $ioe = IO::Event->new($filehandle); my $ioe = IO::Event::Socket::INET->new( [ARGS] ) my $ioe = IO::Event::Socket::UNIX->new( [ARGS] ) my $timer = IO::Event->timer( [after => $seconds], interval => $seconds, cb => CODE); my $idler = IO::Event->idle( [min => $seconds], [max => $seconds], [reentrant => 0], cb => CODE); IO::Event::loop(); IO::Event::unloop_all(); DESCRIPTION IO::Event provides a object-based callback system for handling nonblocking IO. The design goal is to provide a system that just does the right thing w/o the user needing to think about it much. All APIs are kept as simple as possible yet at the same time, all functionality is accesible if needed. Simple things are easy. Hard things are possible. Most of the time file handling syntax will work fine: "<$filehandle>" and "print $filehandle 'stuff'". IO::Event provides automatic buffering of output (with a callback to throttle). It provides automatic line-at-a-time input. After initial setup, call "IO::Event::loop()". IO::Event was originally written to use Event. IO::Event still defaults to using Event but it can now use AnyEvent or its own event loop. CHOOSING AN EVENT HANDLER Until you create your first IO::Event object, you can choose which underlying event handler to use. The default is Event. To choose an event handler, use one of the following lines, import "no_emulate_Event", "emulate_Event", or "AnyEvent". use IO::Event 'no_emulate_Event' use IO::Event 'emulate_Event' use IO::Event 'AnyEvent' The "no_emulate_Event" option means: use Event. The "emulate_Event" option means IO::Event should use its own event loop. Why? You should use AnyEvent if you want to have compatibility with other event loops. You should use "emulate_Event" if you don't need compatibility with other event loops and you have missing-event bugs when using Event. You should use Event if it works for you. The APIs are a bit different depending on which event loop you're using. Event To use Event's event loop: use IO::Event 'no_emulate_Event'; or just: use IO::Event IO::Event's definition for "loop()", "timer()", "idle()" and "unloop_all()" all default to the Event version unless "emulate_Event" or "AnyEvent" have been imported. This allows you to easily switch back and forth between Event's API and the others. AnyEvent To use AnyEvent's select loop, import "AnyEvent". use IO::Event 'AnyEvent'; You can use AnyEvent's API directly or you can use IO::Event's emulated APIs: "IO::Event::loop()", "IO::Event::unloop()", "IO::Event::timer()", and "IO::Event::idle()". These behave like Event's routines of the same name but use AnyEvent underneath. During testing, using the pure-perl event loop of AnyEvent::Impl::Perl from AnyEvent version 5.271, some read events were dropped. To work around this, a synthetic read-ready event is dispatched for all connected read filehandles every two seconds. Turn this off or adjust its frequency by changing $IO::Event::AnyEvent::lost_event_hack. A numeric value is the time (in seconds) between dispatching read events. A false value turns off this performance-sapping hack. AnyEvent only provides basic support for idle() events: it promises to invoke them "every now and then". "emulate_Event" To use IO::Event's own select loop, import "emulate_Event". use IO::Event 'emulate_Event'; IO::Event does not provide a complete emulation of everything that Event does. It provides the full timer API: my $timer = IO::Event::timer( [ARGS] ) instead of my $timer = Event::timer( [ARGS] ) However it does not provide timer events on filehandles, nor does it provide events for signals, or variable accesses. Use "IO::Event::loop()" instead of "Event::loop()". Use "IO::Event::unloop_all()" instead of "Event::unloop_all()". Use "IO::Event::idle()" instead of "Event::idle()". It does not provide any other methods or functions from Event. If you need them, please send a patch. CONSTRUCTORS IO::Event->new($filehandle, [ $handler, [ $options ]]) The basic "new" constructor takes a filehandle and returns a psuedo-filehandle. Treat the IO::Event object as a filehandle. Do not use the original filehandle without good reason (let us know if you find a good reason so we can fix the problem). The handler is the class or object where you provide callback functions to handle IO events. It defaults to the package of the calling context. If present, $options is a hash reference with the following possible keys: description A text description of this filehandle. Used for debugging and error messages. read_only Set to true if this is a read-only filehandle. Do not accept output. write_only Set to true if this is a write-only filehandle. Do not attept to read. autoread Set to 0 if this should not be an auto-read filehandle. IO::Event::Socket::INET->new( [ARGS] ) This constructor uses IO::Socket::INET->new() to create a socket using the ARGS provided. It returns an IO::Event object. The handler defaults as above or can be set with an additional pseudo-parameter for IO::Socket::UNIX->new(): "Handler". A description for the socket can be provided with an additional psuedo-parameter: "Description". IO::Event::Socket::UNIX->new( [ARGS] ) This constructor uses IO::Socket::UNIX->new() to create a socket using the ARGS provided. It returns an IO::Event object. The handler defaults as above or can be set with an additional pseudo-parameter for IO::Socket::UNIX->new(): "Handler". A description for the socket can be provided with an additional psuedo-parameter: "Description". MANDATORY HANDLERS These handler methods must be available in the handler object/class if the situation in which they would be called arises. ie_input($handler, $ioe, $input_buffer_reference) Invoked when there is fresh data in the input buffer. The input can be retrieved via directly reading it from $$input_buffer_reference or via "read()" from the $ioe filehandle, or by using a variety of standard methods for getting data: <$ioe> like IO::Handle $ioe->get() like Data::LineBuffer $ioe->read() like IO::Handle $ioe->sysread() like IO::Handle $ioe->getline() like IO::Handle $ioe->getlines() like IO::Handle $ioe->getsome() see below $ioe->ungets() like FileHandle::Unget At end-of-file, ie_input will only be invoked once. There may or may not be data in the input buffer. ie_connection($handler, $ioe) Invoked when a listen()ing socket is ready to accept(). It should call accept: sub ie_connection { my ($pkg, $ioe) = @_; my $newfh = $ioe->accept() } ie_read_ready($handler, $ioe, $underlying_file_handle) If autoreading is turned off then this will be invoked. ie_werror($handler, $ioe, $output_buffer_reference) A write error has occured when trying to drain the write buffer. Provide an empty subroutine if you don't care. OPTIONAL HANDLERS These handler methods will be called if they are defined but it is not required that they be defined. ie_eof($handler, $ioe, $input_buffer_reference) This is invoked when the read-side of the filehandle has been closed by its source. ie_output This is invoked when data has just been written to the underlying filehandle. ie_outputdone This is invoked when all pending data has just been written to the underlying filehandle. ie_connected This is invoked when a "connect()" completes. ie_connect_failed($handler, $ioe, $error_code) This is invoked when a "connect()" fails. For a timeout, the error code will be ETIMEOUT. ie_died($handler, $ioe, $method, $@) If another handler calls "die" then ie_died will be called with the IO::Event object, the name of the method just invoked, and the die string. If no ie_died() callback exists then execution will terminate. ie_timer This is invoked for timer events. ie_exception Invoked when an exceptional condition arises on the underlying filehandle ie_outputoverflow($handler, $ioe, $overflowing, $output_buffer_reference) Invoked when there is too much output data and the output buffers are overflowing. You can take some action to generate less output. This will be invoked exactly once (with $overflowing == 1) when there is too much data in the buffer and then exactly once again (with $overflowing == 0) when there is no longer too much data in the buffer. METHODS In addition to methods described in detail below, the following methods behave like their "IO" (mostly "IO::Socket") counterparts (except for being mostly non-blocking...): connect listen open read sysread syswrite print eof shutdown Through AUTOLOAD (see the SUBSTITUTED METHODS section) methods are passed to underlying "Event" objects: loop unloop and many more... Through AUTOLOAD (see the SUBSTITUTED METHODS section) methods are passed to underlying "IO" objects: fileno stat truncate error opened untaint and many more... IO::Event defines its own methods too: ->accept($handler, %options) accept() is nearly identical to the normal IO::Socket::accept() method except that instead of optionally passing a class specifier for the new socket, you optionally pass a handler object or class. The returned filehandle is an IO::Event object. Supported options: description Sets the description for the new socket autoread Set to 0 if you do not want auto-read ->can_read($amount) Returns true if $amount bytes worth of input is available for reading. Note: this does not return true at EOF so be careful not to hang forever at EOF. ->getsome($amount) Returns $amount bytes worth of input or undef if the request can't be filled. Returns what it can at EOF. ->get() get() is like getline() except that it pre-chomp()s the results and assumes the input_record_separator is "\n". This is like get() from Data::LineBuffer. ->unget() Push chomp()ed lines back into the input buffer. This is like unget() from Data::LineBuffer. ->ungetline(), ->xungetc(), ->ungets() This is what ungetc() should be: it pushes a string back into the input buffer. This is unlike IO::Handle->ungetc which takes an ordinal and pushes one character back into the the input buffer. This is like FileHandle::Unget. ->handler($new_handler) Sets the handler object/class if $new_handler is provided. Returns the old handler. ->filehandle() Returns the underlying "IO::Handle". ->event() Returns the underling "Event". ->listener($listening) Used to note that a filehandle is being used to listen for connections (instead of receiving data). A passed parameter of 0 does the opposite. Returns the old value. This is mostly used internally in IO::Event. ->input_record_separator($new_sep) IO::Handle doesn't allow input_record_separator's on a per filehandle basis. IO::Event does. If you don't ever set a filehandle's input record separator, then it contineously defaults to the current value of $/. If you set it, then it will use your value and never look at $/ again. ->readevents($readevents) Get/set listening for read-ready events on the underlying filehandle. This could be used by ie_outputoverflow to control input flows. ->output_bufsize($output_bufsize) Get/set the size of the output buffer. ->autoread($autoread) Get/set automatic reading if data when data can be read. Without autoread turned on, the input buffer ins't filled and none of the read methods will work. The point of this is for working with non-data filehandles. This is an experts-only method that kinda defeats the purpose of this module. This would be necessary using recv() to get data. ->drain() Used to start looking for write-ready events on the underlying filehandle. In normal operation this is handled automatically. Deprecated: use writeevents(1) instead. ->reentrant($reentrant) Get/set reentrant callbacks. By default, IO::Event avoids making reentrant callbacks. This is good because your code is less likely to break. This is bad because you won't learn about things right away. For example, you will not learn the the output buffer is overflowing during print(). You'll have to wait for the output buffer to begin draining to find out. This could be a problem. ->close() If there is output buffered, close will be delayed until the output buffer drains. ->forceclose Close close immediately, even if there is output buffered. ->ie_desc([new description]) Returns (and sets) the text description of the filehandle. For debugging. TIMER API The following timer construction arguments are supported by IO::Event's emulated event loop and IO::Event's API on top of AnyEvent: cb A callback to invoke when the timer goes off. The callback can either be a CODE reference or an array reference. If it's an array reference, the array should be a two element tuple: the first element is an object and the second object is a method to invoke on the object. The only argument to the method call a reference to the timer object: my ($object, $method) = @{$timer->{cb}} $object->$method($timer) at A time at which to invoke the callback. interval An interval, in seconds between repeat invocations of the callback. after The interval until the first invocation of the callback. After that, invoke every *interval*. The following methods (from Event) are supported on timer objects: start(), again(), now(), stop(), cancel(), is_cancelled(), is_running(), is_suspended(), pending. IDLE API The following idle construction arguments are supported by IO::Event's emulated event loop and IO::Event's API on top of AnyEvent: cb A callback to invoke when the event loop is idle. The callback can either be a CODE reference or an array reference. If it's an array reference, the array should be a two element tuple: the first element is an object and the second object is a method to invoke on the object. my ($object, $method) = @{$timer->{cb}} $object->$method(); min The minimum time between invocations of the callback. max The maximum time between invocations of the callback. The following methods (from Event) are supported on idle objects: start(), again(), now(), stop(), cancel(), is_cancelled(), is_running(), is_suspended(), pending. SUBSTITUED METHODS Any method invocations that fail because the method isn't defined in IO::Event will by tried twice more: once using trying for a method on the inner (hidden) filehandle and once more trying for a method on the Event object that's used to create the select loop for this module. This dispatch is now deprecated with the choice of event handlers. EXAMPLE SERVER # This is a tcp line echo server my $listener = IO::Event::Socket::INET->new( Listen => 10, Proto => 'tcp', LocalPort => 2821, ); Event::loop(); sub ie_connection { my ($pkg, $lstnr) = @_; my $client = $lstnr->accept(); printf "accepted connection from %s:%s\n", $client->peerhost, $client->peerport; } sub ie_input { my ($pkg, $client, $ibufref) = @_; print $client <$client>; } SYSREAD and EOF sysread() is incompatible with eof() because eof() uses getc(). Most of the time this isn't a problem. In other words, some of the time this is a problem: lines go missing. For this reason, IO::Event never uses sysread(). In fact, if you ask it to do a sysread() it does a read() for you instead. On the other hand, at the current time no problems with syswrite have come to light and IO::Event uses syswrite and never any other form of write/print etc. DESTRUCTION IO::Event keeps copies of all of its registered filehandles. If you want to close a filehandle, you'll need to actually call close on it. DATA STRUCTURE The filehandle object itself is a funny kind of hash reference. If you want to use it to store your own data, you can. Please don't use hash keys that begin "ie_" or "io_" as those are the prefixes used by "IO::Event" and "IO::Socket". The syntax is kinda funny: ${*$filehandle}{'your_hash_key'} SEE ALSO For a different API on top of IO::Event, see IO::Event::Callback. It uses IO::Event but provides a simpler and perhaps easier-to-use API. The following perl modules do something that is kinda similar to what is being done here: AnyEvent::Handle, AnyEvent::AIO, IO::AIO, IO::Multiplex, IO::NonBlocking, IO::Select Event, POE, POE::Component::Server::TCP, Net::Socket::NonBlock, Net::Server::Multiplex, NetServer::Generic The API borrows most heavily from IO::Multiplex. IO::Event uses Event.pm and thus can be used in programs that are already using Event or POE. Since the original writing of IO::Event, AnyEvent has been released and now AnyEvent::AIO and <AnyEvent:Handle> should be considered the only good alternatives to IO::Event. For an example program using IO::Event, see IO::Event::rinetd which used to be included in this package. BUGS The test suite only covers 40% of the code. The module is used by its author and seems solid. LICENSE Copyright (C) 2002-2009 David Muir Sharnoff <muir@idiom.org>. Copyright (C) 2011-2013 Google, Inc. This module may be used/copied/etc on the same terms as Perl itself. This module is packaged for Fedora by Emmanuel Seyman <emmanuel@seyman.fr> POD ERRORS Hey! The above document had some coding errors, which are explained below: Around line 476: '=item' outside of any '=over' |
Commit History @HEAD
0
»»
- debian/watch: use uscan version 4. gregor herrmann 4 years ago
- Email change Xavier Guimard -> yadd@debian.org Xavier Guimard 5 years ago
- update changelog gregor herrmann 5 years ago
- debian/*: update URLs from {search,www}.cpan.org to MetaCPAN. gregor herrmann 5 years ago
- update changelog Salvatore Bonaccorso 6 years ago
- Update Vcs-* headers for switch to salsa.debian.org Salvatore Bonaccorso 6 years ago
- update changelog gregor herrmann 7 years ago
- debian/copyright: change Copyright-Format 1.0 URL to HTTPS. gregor herrmann 7 years ago
- update changelog Salvatore Bonaccorso 8 years ago
- debian/control: Use HTTPS transport protocol for Vcs-Git URI Salvatore Bonaccorso 8 years ago
- releasing package libio-event-perl version 0.813-2 to unstable Niko Tyni 8 years ago
- Declare the package autopkgtestable Niko Tyni 8 years ago
- Patch the test suite to fix undeterministic test failures in t/forked2.t Niko Tyni 8 years ago
- update changelog Salvatore Bonaccorso 9 years ago
- Update Vcs-Browser URL to cgit web frontend Salvatore Bonaccorso 9 years ago
- releasing package libio-event-perl version 0.813-1 gregor herrmann 10 years ago
- Update years of upstream copyright. gregor herrmann 10 years ago
- Drop spelling-errors.patch, merged upstream. gregor herrmann 10 years ago
- New upstream release. gregor herrmann 10 years ago
- Merge tag 'upstream/0.813' gregor herrmann 10 years ago
- Imported Upstream version 0.813 gregor herrmann 10 years ago
- Add "libevent-perl | libanyevent-perl" in recommended deps Xavier Guimard 10 years ago
- Add Google Inc. in upstream copyright Xavier Guimard 10 years ago
- s/git\.debian\.org/anonscm.debian.org/ Xavier Guimard 10 years ago
- Update spelling errors patch (reported) Xavier Guimard 10 years ago
- back to UNRELEASED, TODO added to d/changelog gregor herrmann 10 years ago
- Imported Debian patch 0.812-1 Xavier Guimard 10 years ago
- Imported Upstream version 0.812 Xavier Guimard 10 years ago
0
»»