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Revision 1.35 by root, Thu Dec 31 06:59:47 2009 UTC vs.
Revision 1.37 by root, Sat Oct 23 22:25:44 2010 UTC

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50 # MAINLOOP 50 # MAINLOOP
51 EV::loop; # loop until EV::unloop is called or all watchers stop 51 EV::loop; # loop until EV::unloop is called or all watchers stop
52 EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled 52 EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled
53 EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block 53 EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
54 54
55BEFORE YOU START USING THIS MODULE
56 If you only need timer, I/O, signal, child and idle watchers and not the
57 advanced functionality of this module, consider using AnyEvent instead,
58 specifically the simplified API described in AE.
59
60 When used with EV as backend, the AE API is as fast as the native EV
61 API, but your programs/modules will still run with many other event
62 loops.
63
55DESCRIPTION 64DESCRIPTION
56 This module provides an interface to libev 65 This module provides an interface to libev
57 (<http://software.schmorp.de/pkg/libev.html>). While the documentation 66 (<http://software.schmorp.de/pkg/libev.html>). While the documentation
58 below is comprehensive, one might also consult the documentation of 67 below is comprehensive, one might also consult the documentation of
59 libev itself (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or 68 libev itself (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
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66 can use it through the AnyEvent module, stay portable to other event 75 can use it through the AnyEvent module, stay portable to other event
67 loops (if you don't rely on any watcher types not available through it) 76 loops (if you don't rely on any watcher types not available through it)
68 and still be faster than with any other event loop currently supported 77 and still be faster than with any other event loop currently supported
69 in Perl. 78 in Perl.
70 79
80 PORTING FROM EV 3.X to 4.X
81 EV version 4 introduces a number of incompatible changes summarised
82 here. According to the depreciation strategy used by libev, there is a
83 compatibility layer in place so programs should continue to run
84 unchanged (the XS interface lacks this layer, so programs using that one
85 need to be updated).
86
87 This compatibility layer will be switched off in some future release.
88
89 All changes relevant to Perl are renames of symbols, functions and
90 methods:
91
92 EV::loop => EV::run
93 EV::LOOP_NONBLOCK => EV::RUN_NOWAIT
94 EV::LOOP_ONESHOT => EV::RUN_ONCE
95
96 EV::unloop => EV::break
97 EV::UNLOOP_CANCEL => EV::BREAK_CANCEL
98 EV::UNLOOP_ONE => EV::BREAK_ONE
99 EV::UNLOOP_ALL => EV::BREAK_ALL
100
101 EV::TIMEOUT => EV::TIMER
102
103 EV::loop_count => EV::iteration
104 EV::loop_depth => EV::depth
105 EV::loop_verify => EV::verify
106
107 The loop object methods corresponding to the functions above have been
108 similarly renamed.
109
71 MODULE EXPORTS 110 MODULE EXPORTS
72 This module does not export any symbols. 111 This module does not export any symbols.
73 112
74EVENT LOOPS 113EVENT LOOPS
75 EV supports multiple event loops: There is a single "default event loop" 114 EV supports multiple event loops: There is a single "default event loop"
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235 Otherwise a EV::timer with this value will be started. 274 Otherwise a EV::timer with this value will be started.
236 275
237 When an error occurs or either the timeout or I/O watcher triggers, 276 When an error occurs or either the timeout or I/O watcher triggers,
238 then the callback will be called with the received event set (in 277 then the callback will be called with the received event set (in
239 general you can expect it to be a combination of "EV::ERROR", 278 general you can expect it to be a combination of "EV::ERROR",
240 "EV::READ", "EV::WRITE" and "EV::TIMEOUT"). 279 "EV::READ", "EV::WRITE" and "EV::TIMER").
241 280
242 EV::once doesn't return anything: the watchers stay active till 281 EV::once doesn't return anything: the watchers stay active till
243 either of them triggers, then they will be stopped and freed, and 282 either of them triggers, then they will be stopped and freed, and
244 the callback invoked. 283 the callback invoked.
245 284
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290 329
291 Each watcher type has its associated bit in revents, so you can use the 330 Each watcher type has its associated bit in revents, so you can use the
292 same callback for multiple watchers. The event mask is named after the 331 same callback for multiple watchers. The event mask is named after the
293 type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, 332 type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
294 EV::periodic sets EV::PERIODIC and so on, with the exception of I/O 333 EV::periodic sets EV::PERIODIC and so on, with the exception of I/O
295 events (which can set both EV::READ and EV::WRITE bits), and EV::timer 334 events (which can set both EV::READ and EV::WRITE bits).
296 (which uses EV::TIMEOUT).
297 335
298 In the rare case where one wants to create a watcher but not start it at 336 In the rare case where one wants to create a watcher but not start it at
299 the same time, each constructor has a variant with a trailing "_ns" in 337 the same time, each constructor has a variant with a trailing "_ns" in
300 its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. 338 its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
301 339
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758 $w = $loop->check_ns ($callback) 796 $w = $loop->check_ns ($callback)
759 Call the callback just after the process wakes up again (after it 797 Call the callback just after the process wakes up again (after it
760 has gathered events), but before any other callbacks have been 798 has gathered events), but before any other callbacks have been
761 invoked. 799 invoked.
762 800
763 This is used to integrate other event-based software into the EV 801 This can be used to integrate other event-based software into the EV
764 mainloop: You register a prepare callback and in there, you create 802 mainloop: You register a prepare callback and in there, you create
765 io and timer watchers as required by the other software. Here is a 803 io and timer watchers as required by the other software. Here is a
766 real-world example of integrating Net::SNMP (with some details left 804 real-world example of integrating Net::SNMP (with some details left
767 out): 805 out):
768 806
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804 watchers are destroyed before this can happen (remember EV::check 842 watchers are destroyed before this can happen (remember EV::check
805 gets called first). 843 gets called first).
806 844
807 The "check_ns" variant doesn't start (activate) the newly created 845 The "check_ns" variant doesn't start (activate) the newly created
808 watcher. 846 watcher.
847
848 EV::CHECK constant issues
849 Like all other watcher types, there is a bitmask constant for use in
850 $revents and other places. The "EV::CHECK" is special as it has the
851 same name as the "CHECK" sub called by Perl. This doesn't cause big
852 issues on newer perls (beginning with 5.8.9), but it means thatthe
853 constant must be *inlined*, i.e. runtime calls will not work. That
854 means that as long as you always "use EV" and then "EV::CHECK" you
855 are on the safe side.
809 856
810 FORK WATCHERS - the audacity to resume the event loop after a fork 857 FORK WATCHERS - the audacity to resume the event loop after a fork
811 Fork watchers are called when a "fork ()" was detected. The invocation 858 Fork watchers are called when a "fork ()" was detected. The invocation
812 is done before the event loop blocks next and before "check" watchers 859 is done before the event loop blocks next and before "check" watchers
813 are being called, and only in the child after the fork. 860 are being called, and only in the child after the fork.

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