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3 | EV - perl interface to libev, a high performance full-featured event loop |
3 | EV - perl interface to libev, a high performance full-featured event loop |
4 | |
4 | |
5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
6 | |
6 | |
7 | use EV; |
7 | use EV; |
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8 | |
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9 | # TIMERS |
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10 | |
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11 | my $w = EV::timer 2, 0, sub { |
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12 | warn "is called after 2s"; |
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13 | }; |
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14 | |
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15 | my $w = EV::timer 2, 2, sub { |
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16 | warn "is called roughly every 2s (repeat = 2)"; |
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17 | }; |
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18 | |
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19 | undef $w; # destroy event watcher again |
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20 | |
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21 | my $w = EV::periodic 0, 60, 0, sub { |
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22 | warn "is called every minute, on the minute, exactly"; |
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23 | }; |
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24 | |
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25 | # IO |
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26 | |
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27 | my $w = EV::io *STDIN, EV::READ, sub { |
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28 | my ($w, $revents) = @_; # all callbacks receive the watcher and event mask |
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29 | warn "stdin is readable, you entered: ", <STDIN>; |
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30 | }; |
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31 | |
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32 | # SIGNALS |
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33 | |
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34 | my $w = EV::signal 'QUIT', sub { |
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35 | warn "sigquit received\n"; |
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36 | }; |
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37 | |
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38 | # CHILD/PID STATUS CHANGES |
8 | |
39 | |
9 | # TIMERS |
40 | my $w = EV::child 666, 0, sub { |
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41 | my ($w, $revents) = @_; |
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42 | my $status = $w->rstatus; |
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43 | }; |
10 | |
44 | |
11 | my $w = EV::timer 2, 0, sub { |
45 | # STAT CHANGES |
12 | warn "is called after 2s"; |
46 | my $w = EV::stat "/etc/passwd", 10, sub { |
13 | }; |
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14 | |
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15 | my $w = EV::timer 2, 1, sub { |
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16 | warn "is called roughly every 2s (repeat = 1)"; |
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17 | }; |
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18 | |
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19 | undef $w; # destroy event watcher again |
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20 | |
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21 | my $w = EV::periodic 0, 60, 0, sub { |
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22 | warn "is called every minute, on the minute, exactly"; |
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23 | }; |
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24 | |
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25 | # IO |
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26 | |
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27 | my $w = EV::io *STDIN, EV::READ, sub { |
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28 | my ($w, $revents) = @_; # all callbacks get the watcher object and event mask |
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29 | warn "stdin is readable, you entered: ", <STDIN>; |
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30 | }; |
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31 | |
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32 | # SIGNALS |
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33 | |
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34 | my $w = EV::signal 'QUIT', sub { |
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35 | warn "sigquit received\n"; |
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36 | }; |
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37 | |
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38 | my $w = EV::signal 3, sub { |
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39 | warn "sigquit received (this is GNU/Linux, right?)\n"; |
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40 | }; |
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41 | |
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42 | # CHILD/PID STATUS CHANGES |
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43 | |
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44 | my $w = EV::child 666, sub { |
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45 | my ($w, $revents) = @_; |
47 | my ($w, $revents) = @_; |
46 | # my $pid = $w->rpid; |
48 | warn $w->path, " has changed somehow.\n"; |
47 | my $status = $w->rstatus; |
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48 | }; |
49 | }; |
49 | |
50 | |
50 | # MAINLOOP |
51 | # MAINLOOP |
51 | EV::loop; # loop until EV::loop_done is called |
52 | 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 |
53 | 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 |
54 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
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55 | |
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56 | =head1 BEFORE YOU START USING THIS MODULE |
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57 | |
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58 | If you only need timer, I/O, signal, child and idle watchers and not the |
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59 | advanced functionality of this module, consider using L<AnyEvent> instead, |
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60 | specifically the simplified API described in L<AE>. |
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61 | |
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62 | When used with EV as backend, the L<AE> API is as fast as the native L<EV> |
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63 | API, but your programs/modules will still run with many other event loops. |
54 | |
64 | |
55 | =head1 DESCRIPTION |
65 | =head1 DESCRIPTION |
56 | |
66 | |
57 | This module provides an interface to libev |
67 | This module provides an interface to libev |
58 | (L<http://software.schmorp.de/pkg/libev.html>). |
68 | (L<http://software.schmorp.de/pkg/libev.html>). While the documentation |
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69 | below is comprehensive, one might also consult the documentation of |
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70 | libev itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or |
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71 | F<perldoc EV::libev>) for more subtle details on watcher semantics or some |
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72 | discussion on the available backends, or how to force a specific backend |
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73 | with C<LIBEV_FLAGS>, or just about in any case because it has much more |
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74 | detailed information. |
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75 | |
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76 | This module is very fast and scalable. It is actually so fast that you |
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77 | can use it through the L<AnyEvent> module, stay portable to other event |
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78 | loops (if you don't rely on any watcher types not available through it) |
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79 | and still be faster than with any other event loop currently supported in |
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80 | Perl. |
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81 | |
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82 | =head2 PORTING FROM EV 3.X to 4.X |
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83 | |
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84 | EV version 4 introduces a number of incompatible changes summarised |
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85 | here. According to the depreciation strategy used by libev, there is a |
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86 | compatibility layer in place so programs should continue to run unchanged |
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87 | (the XS interface lacks this layer, so programs using that one need to be |
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88 | updated). |
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89 | |
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90 | This compatibility layer will be switched off in some future release. |
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91 | |
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92 | All changes relevant to Perl are renames of symbols, functions and |
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93 | methods: |
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94 | |
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95 | EV::loop => EV::run |
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96 | EV::LOOP_NONBLOCK => EV::RUN_NOWAIT |
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97 | EV::LOOP_ONESHOT => EV::RUN_ONCE |
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98 | |
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99 | EV::unloop => EV::break |
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100 | EV::UNLOOP_CANCEL => EV::BREAK_CANCEL |
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101 | EV::UNLOOP_ONE => EV::BREAK_ONE |
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102 | EV::UNLOOP_ALL => EV::BREAK_ALL |
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103 | |
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104 | EV::TIMEOUT => EV::TIMER |
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105 | |
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106 | EV::loop_count => EV::iteration |
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107 | EV::loop_depth => EV::depth |
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108 | EV::loop_verify => EV::verify |
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109 | |
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110 | The loop object methods corresponding to the functions above have been |
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111 | similarly renamed. |
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112 | |
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113 | =head2 MODULE EXPORTS |
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114 | |
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115 | This module does not export any symbols. |
59 | |
116 | |
60 | =cut |
117 | =cut |
61 | |
118 | |
62 | package EV; |
119 | package EV; |
63 | |
120 | |
64 | use strict; |
121 | use common::sense; |
65 | |
122 | |
66 | BEGIN { |
123 | BEGIN { |
67 | our $VERSION = '0.51'; |
124 | our $VERSION = '4.01'; |
68 | use XSLoader; |
125 | use XSLoader; |
69 | XSLoader::load "EV", $VERSION; |
126 | XSLoader::load "EV", $VERSION; |
70 | } |
127 | } |
71 | |
128 | |
72 | @EV::Io::ISA = |
129 | @EV::IO::ISA = |
73 | @EV::Timer::ISA = |
130 | @EV::Timer::ISA = |
74 | @EV::Periodic::ISA = |
131 | @EV::Periodic::ISA = |
75 | @EV::Signal::ISA = |
132 | @EV::Signal::ISA = |
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133 | @EV::Child::ISA = |
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134 | @EV::Stat::ISA = |
76 | @EV::Idle::ISA = |
135 | @EV::Idle::ISA = |
77 | @EV::Prepare::ISA = |
136 | @EV::Prepare::ISA = |
78 | @EV::Check::ISA = |
137 | @EV::Check::ISA = |
79 | @EV::Child::ISA = "EV::Watcher"; |
138 | @EV::Embed::ISA = |
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139 | @EV::Fork::ISA = |
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140 | @EV::Async::ISA = |
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141 | "EV::Watcher"; |
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142 | |
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143 | @EV::Loop::Default::ISA = "EV::Loop"; |
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144 | |
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145 | =head1 EVENT LOOPS |
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146 | |
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147 | EV supports multiple event loops: There is a single "default event loop" |
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148 | that can handle everything including signals and child watchers, and any |
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149 | number of "dynamic event loops" that can use different backends (with |
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150 | various limitations), but no child and signal watchers. |
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151 | |
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152 | You do not have to do anything to create the default event loop: When |
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153 | the module is loaded a suitable backend is selected on the premise of |
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154 | selecting a working backend (which for example rules out kqueue on most |
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155 | BSDs). Modules should, unless they have "special needs" always use the |
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156 | default loop as this is fastest (perl-wise), best supported by other |
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157 | modules (e.g. AnyEvent or Coro) and most portable event loop. |
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158 | |
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159 | For specific programs you can create additional event loops dynamically. |
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160 | |
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161 | If you want to take advantage of kqueue (which often works properly for |
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162 | sockets only) even though the default loop doesn't enable it, you can |
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163 | I<embed> a kqueue loop into the default loop: running the default loop |
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164 | will then also service the kqueue loop to some extent. See the example in |
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165 | the section about embed watchers for an example on how to achieve that. |
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166 | |
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167 | =over 4 |
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168 | |
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169 | =item $loop = new EV::Loop [$flags] |
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170 | |
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171 | Create a new event loop as per the specified flags. Please refer to |
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172 | the C<ev_loop_new ()> function description in the libev documentation |
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173 | (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>, |
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174 | or locally-installed as F<EV::libev> manpage) for more info. |
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175 | |
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176 | The loop will automatically be destroyed when it is no longer referenced |
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177 | by any watcher and the loop object goes out of scope. |
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178 | |
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179 | If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK> |
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180 | is recommended, as only the default event loop is protected by this |
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181 | module. If you I<are> embedding this loop in the default loop, this is not |
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182 | necessary, as C<EV::embed> automatically does the right thing on fork. |
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183 | |
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184 | =item $loop->loop_fork |
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185 | |
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186 | Must be called after a fork in the child, before entering or continuing |
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187 | the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls |
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188 | this function automatically, at some performance loss (refer to the libev |
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189 | documentation). |
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190 | |
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191 | =item $loop->loop_verify |
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192 | |
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193 | Calls C<ev_verify> to make internal consistency checks (for debugging |
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194 | libev) and abort the program if any data structures were found to be |
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195 | corrupted. |
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196 | |
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197 | =item $loop = EV::default_loop [$flags] |
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198 | |
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199 | Return the default loop (which is a singleton object). Since this module |
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200 | already creates the default loop with default flags, specifying flags here |
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201 | will not have any effect unless you destroy the default loop first, which |
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202 | isn't supported. So in short: don't do it, and if you break it, you get to |
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203 | keep the pieces. |
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204 | |
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205 | =back |
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206 | |
80 | |
207 | |
81 | =head1 BASIC INTERFACE |
208 | =head1 BASIC INTERFACE |
82 | |
209 | |
83 | =over 4 |
210 | =over 4 |
84 | |
211 | |
85 | =item $EV::DIED |
212 | =item $EV::DIED |
86 | |
213 | |
87 | Must contain a reference to a function that is called when a callback |
214 | Must contain a reference to a function that is called when a callback |
88 | throws an exception (with $@ containing thr error). The default prints an |
215 | throws an exception (with $@ containing the error). The default prints an |
89 | informative message and continues. |
216 | informative message and continues. |
90 | |
217 | |
91 | If this callback throws an exception it will be silently ignored. |
218 | If this callback throws an exception it will be silently ignored. |
92 | |
219 | |
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220 | =item $flags = EV::supported_backends |
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221 | |
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222 | =item $flags = EV::recommended_backends |
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223 | |
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224 | =item $flags = EV::embeddable_backends |
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225 | |
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226 | Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this |
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227 | instance of EV, the set of recommended backends (supposed to be good) for |
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228 | this platform and the set of embeddable backends (see EMBED WATCHERS). |
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229 | |
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230 | =item EV::sleep $seconds |
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231 | |
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232 | Block the process for the given number of (fractional) seconds. |
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233 | |
93 | =item $time = EV::time |
234 | =item $time = EV::time |
94 | |
235 | |
95 | Returns the current time in (fractional) seconds since the epoch. |
236 | Returns the current time in (fractional) seconds since the epoch. |
96 | |
237 | |
97 | =item $time = EV::now |
238 | =item $time = EV::now |
98 | |
239 | |
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240 | =item $time = $loop->now |
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241 | |
99 | Returns the time the last event loop iteration has been started. This |
242 | Returns the time the last event loop iteration has been started. This |
100 | is the time that (relative) timers are based on, and refering to it is |
243 | is the time that (relative) timers are based on, and referring to it is |
101 | usually faster then calling EV::time. |
244 | usually faster then calling EV::time. |
102 | |
245 | |
103 | =item $method = EV::ev_method |
246 | =item EV::now_update |
104 | |
247 | |
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248 | =item $loop->now_update |
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249 | |
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250 | Establishes the current time by querying the kernel, updating the time |
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251 | returned by C<EV::now> in the progress. This is a costly operation and |
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252 | is usually done automatically within C<EV::loop>. |
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253 | |
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254 | This function is rarely useful, but when some event callback runs for a |
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255 | very long time without entering the event loop, updating libev's idea of |
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256 | the current time is a good idea. |
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257 | |
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258 | =item EV::suspend |
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259 | |
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260 | =item $loop->suspend |
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261 | |
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262 | =item EV::resume |
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263 | |
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264 | =item $loop->resume |
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265 | |
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266 | These two functions suspend and resume a loop, for use when the loop is |
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267 | not used for a while and timeouts should not be processed. |
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268 | |
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269 | A typical use case would be an interactive program such as a game: When |
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270 | the user presses C<^Z> to suspend the game and resumes it an hour later it |
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271 | would be best to handle timeouts as if no time had actually passed while |
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272 | the program was suspended. This can be achieved by calling C<suspend> |
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273 | in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling |
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274 | C<resume> directly afterwards to resume timer processing. |
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275 | |
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276 | Effectively, all C<timer> watchers will be delayed by the time spend |
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277 | between C<suspend> and C<resume>, and all C<periodic> watchers |
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278 | will be rescheduled (that is, they will lose any events that would have |
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279 | occured while suspended). |
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280 | |
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281 | After calling C<suspend> you B<must not> call I<any> function on the given |
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282 | loop other than C<resume>, and you B<must not> call C<resume> |
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283 | without a previous call to C<suspend>. |
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284 | |
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285 | Calling C<suspend>/C<resume> has the side effect of updating the event |
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286 | loop time (see C<now_update>). |
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287 | |
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288 | =item $backend = EV::backend |
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289 | |
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290 | =item $backend = $loop->backend |
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291 | |
105 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
292 | Returns an integer describing the backend used by libev (EV::BACKEND_SELECT |
106 | or EV::METHOD_EPOLL). |
293 | or EV::BACKEND_EPOLL). |
107 | |
294 | |
108 | =item EV::loop [$flags] |
295 | =item EV::loop [$flags] |
109 | |
296 | |
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297 | =item $loop->loop ([$flags]) |
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298 | |
110 | Begin checking for events and calling callbacks. It returns when a |
299 | Begin checking for events and calling callbacks. It returns when a |
111 | callback calls EV::loop_done. |
300 | callback calls EV::unloop. |
112 | |
301 | |
113 | The $flags argument can be one of the following: |
302 | The $flags argument can be one of the following: |
114 | |
303 | |
115 | 0 as above |
304 | 0 as above |
116 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
305 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
117 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
306 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
118 | |
307 | |
119 | =item EV::loop_done [$how] |
308 | =item EV::unloop [$how] |
120 | |
309 | |
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310 | =item $loop->unloop ([$how]) |
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311 | |
121 | When called with no arguments or an argument of 1, makes the innermost |
312 | When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
122 | call to EV::loop return. |
313 | innermost call to EV::loop return. |
123 | |
314 | |
124 | When called with an agrument of 2, all calls to EV::loop will return as |
315 | When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
125 | fast as possible. |
316 | fast as possible. |
126 | |
317 | |
127 | =back |
318 | =item $count = EV::loop_count |
128 | |
319 | |
129 | =head2 WATCHER |
320 | =item $count = $loop->loop_count |
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321 | |
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322 | Return the number of times the event loop has polled for new |
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323 | events. Sometimes useful as a generation counter. |
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324 | |
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325 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
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326 | |
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327 | =item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) |
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328 | |
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329 | This function rolls together an I/O and a timer watcher for a single |
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330 | one-shot event without the need for managing a watcher object. |
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331 | |
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332 | If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events> |
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333 | must be a bitset containing either C<EV::READ>, C<EV::WRITE> or C<EV::READ |
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334 | | EV::WRITE>, indicating the type of I/O event you want to wait for. If |
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335 | you do not want to wait for some I/O event, specify C<undef> for |
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336 | C<$fh_or_undef> and C<0> for C<$events>). |
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337 | |
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338 | If timeout is C<undef> or negative, then there will be no |
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339 | timeout. Otherwise a EV::timer with this value will be started. |
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340 | |
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341 | When an error occurs or either the timeout or I/O watcher triggers, then |
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342 | the callback will be called with the received event set (in general |
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343 | you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, |
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344 | C<EV::WRITE> and C<EV::TIMER>). |
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345 | |
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346 | EV::once doesn't return anything: the watchers stay active till either |
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347 | of them triggers, then they will be stopped and freed, and the callback |
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348 | invoked. |
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349 | |
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350 | =item EV::feed_fd_event ($fd, $revents) |
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351 | |
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352 | =item $loop->feed_fd_event ($fd, $revents) |
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353 | |
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354 | Feed an event on a file descriptor into EV. EV will react to this call as |
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355 | if the readyness notifications specified by C<$revents> (a combination of |
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356 | C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. |
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357 | |
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358 | =item EV::feed_signal_event ($signal) |
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359 | |
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360 | Feed a signal event into EV. EV will react to this call as if the signal |
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361 | specified by C<$signal> had occured. |
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362 | |
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363 | =item EV::set_io_collect_interval $time |
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364 | |
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365 | =item $loop->set_io_collect_interval ($time) |
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366 | |
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367 | =item EV::set_timeout_collect_interval $time |
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368 | |
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|
369 | =item $loop->set_timeout_collect_interval ($time) |
|
|
370 | |
|
|
371 | These advanced functions set the minimum block interval when polling for I/O events and the minimum |
|
|
372 | wait interval for timer events. See the libev documentation at |
|
|
373 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> |
|
|
374 | (locally installed as F<EV::libev>) for a more detailed discussion. |
|
|
375 | |
|
|
376 | =item $count = EV::pending_count |
|
|
377 | |
|
|
378 | =item $count = $loop->pending_count |
|
|
379 | |
|
|
380 | Returns the number of currently pending watchers. |
|
|
381 | |
|
|
382 | =item EV::invoke_pending |
|
|
383 | |
|
|
384 | =item $loop->invoke_pending |
|
|
385 | |
|
|
386 | Invoke all currently pending watchers. |
|
|
387 | |
|
|
388 | =back |
|
|
389 | |
|
|
390 | |
|
|
391 | =head1 WATCHER OBJECTS |
130 | |
392 | |
131 | A watcher is an object that gets created to record your interest in some |
393 | A watcher is an object that gets created to record your interest in some |
132 | event. For instance, if you want to wait for STDIN to become readable, you |
394 | event. For instance, if you want to wait for STDIN to become readable, you |
133 | would create an EV::io watcher for that: |
395 | would create an EV::io watcher for that: |
134 | |
396 | |
135 | my $watcher = EV::io *STDIN, EV::READ, sub { |
397 | my $watcher = EV::io *STDIN, EV::READ, sub { |
136 | my ($watcher, $revents) = @_; |
398 | my ($watcher, $revents) = @_; |
137 | warn "yeah, STDIN should not be readable without blocking!\n" |
399 | warn "yeah, STDIN should now be readable without blocking!\n" |
138 | }; |
400 | }; |
139 | |
401 | |
140 | All watchers can be active (waiting for events) or inactive (paused). Only |
402 | All watchers can be active (waiting for events) or inactive (paused). Only |
141 | active watchers will have their callbacks invoked. All callbacks will be |
403 | active watchers will have their callbacks invoked. All callbacks will be |
142 | called with at least two arguments: the watcher and a bitmask of received |
404 | called with at least two arguments: the watcher and a bitmask of received |
143 | events. |
405 | events. |
144 | |
406 | |
145 | Each watcher type has its associated bit in revents, so you can use the |
407 | Each watcher type has its associated bit in revents, so you can use the |
146 | same callback for multiple watchers. The event mask is named after the |
408 | same callback for multiple watchers. The event mask is named after the |
147 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
409 | type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
148 | EV::periodic sets EV::PERIODIC and so on, with the exception of IO events |
410 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events |
149 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
411 | (which can set both EV::READ and EV::WRITE bits). |
150 | uses EV::TIMEOUT). |
|
|
151 | |
412 | |
152 | In the rare case where one wants to create a watcher but not start it at |
413 | In the rare case where one wants to create a watcher but not start it at |
153 | the same time, each constructor has a variant with a trailing C<_ns> in |
414 | the same time, each constructor has a variant with a trailing C<_ns> in |
154 | its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
415 | its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
155 | |
416 | |
… | |
… | |
159 | |
420 | |
160 | Also, all methods changing some aspect of a watcher (->set, ->priority, |
421 | Also, all methods changing some aspect of a watcher (->set, ->priority, |
161 | ->fh and so on) automatically stop and start it again if it is active, |
422 | ->fh and so on) automatically stop and start it again if it is active, |
162 | which means pending events get lost. |
423 | which means pending events get lost. |
163 | |
424 | |
164 | =head2 WATCHER TYPES |
425 | =head2 COMMON WATCHER METHODS |
165 | |
426 | |
166 | Now lets move to the existing watcher types and asociated methods. |
427 | This section lists methods common to all watchers. |
167 | |
|
|
168 | The following methods are available for all watchers. Then followes a |
|
|
169 | description of each watcher constructor (EV::io, EV::timer, EV::periodic, |
|
|
170 | EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by |
|
|
171 | any type-specific methods (if any). |
|
|
172 | |
428 | |
173 | =over 4 |
429 | =over 4 |
174 | |
430 | |
175 | =item $w->start |
431 | =item $w->start |
176 | |
432 | |
… | |
… | |
180 | |
436 | |
181 | =item $w->stop |
437 | =item $w->stop |
182 | |
438 | |
183 | Stop a watcher if it is active. Also clear any pending events (events that |
439 | Stop a watcher if it is active. Also clear any pending events (events that |
184 | have been received but that didn't yet result in a callback invocation), |
440 | have been received but that didn't yet result in a callback invocation), |
185 | regardless of wether the watcher was active or not. |
441 | regardless of whether the watcher was active or not. |
186 | |
442 | |
187 | =item $bool = $w->is_active |
443 | =item $bool = $w->is_active |
188 | |
444 | |
189 | Returns true if the watcher is active, false otherwise. |
445 | Returns true if the watcher is active, false otherwise. |
190 | |
446 | |
… | |
… | |
215 | watchers with higher priority will be invoked first. The valid range of |
471 | watchers with higher priority will be invoked first. The valid range of |
216 | priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default |
472 | priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default |
217 | -2). If the priority is outside this range it will automatically be |
473 | -2). If the priority is outside this range it will automatically be |
218 | normalised to the nearest valid priority. |
474 | normalised to the nearest valid priority. |
219 | |
475 | |
220 | The default priority of any newly-created weatcher is 0. |
476 | The default priority of any newly-created watcher is 0. |
221 | |
477 | |
|
|
478 | Note that the priority semantics have not yet been fleshed out and are |
|
|
479 | subject to almost certain change. |
|
|
480 | |
222 | =item $w->trigger ($revents) |
481 | =item $w->invoke ($revents) |
223 | |
482 | |
224 | Call the callback *now* with the given event mask. |
483 | Call the callback *now* with the given event mask. |
225 | |
484 | |
|
|
485 | =item $w->feed_event ($revents) |
|
|
486 | |
|
|
487 | Feed some events on this watcher into EV. EV will react to this call as if |
|
|
488 | the watcher had received the given C<$revents> mask. |
|
|
489 | |
|
|
490 | =item $revents = $w->clear_pending |
|
|
491 | |
|
|
492 | If the watcher is pending, this function clears its pending status and |
|
|
493 | returns its C<$revents> bitset (as if its callback was invoked). If the |
|
|
494 | watcher isn't pending it does nothing and returns C<0>. |
|
|
495 | |
|
|
496 | =item $previous_state = $w->keepalive ($bool) |
|
|
497 | |
|
|
498 | Normally, C<EV::loop> will return when there are no active watchers |
|
|
499 | (which is a "deadlock" because no progress can be made anymore). This is |
|
|
500 | convenient because it allows you to start your watchers (and your jobs), |
|
|
501 | call C<EV::loop> once and when it returns you know that all your jobs are |
|
|
502 | finished (or they forgot to register some watchers for their task :). |
|
|
503 | |
|
|
504 | Sometimes, however, this gets in your way, for example when the module |
|
|
505 | that calls C<EV::loop> (usually the main program) is not the same module |
|
|
506 | as a long-living watcher (for example a DNS client module written by |
|
|
507 | somebody else even). Then you might want any outstanding requests to be |
|
|
508 | handled, but you would not want to keep C<EV::loop> from returning just |
|
|
509 | because you happen to have this long-running UDP port watcher. |
|
|
510 | |
|
|
511 | In this case you can clear the keepalive status, which means that even |
|
|
512 | though your watcher is active, it won't keep C<EV::loop> from returning. |
|
|
513 | |
|
|
514 | The initial value for keepalive is true (enabled), and you can change it |
|
|
515 | any time. |
|
|
516 | |
|
|
517 | Example: Register an I/O watcher for some UDP socket but do not keep the |
|
|
518 | event loop from running just because of that watcher. |
|
|
519 | |
|
|
520 | my $udp_socket = ... |
|
|
521 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
|
|
522 | $udp_watcher->keepalive (0); |
|
|
523 | |
|
|
524 | =item $loop = $w->loop |
|
|
525 | |
|
|
526 | Return the loop that this watcher is attached to. |
|
|
527 | |
|
|
528 | =back |
|
|
529 | |
|
|
530 | |
|
|
531 | =head1 WATCHER TYPES |
|
|
532 | |
|
|
533 | Each of the following subsections describes a single watcher type. |
|
|
534 | |
|
|
535 | =head3 I/O WATCHERS - is this file descriptor readable or writable? |
|
|
536 | |
|
|
537 | =over 4 |
226 | |
538 | |
227 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
539 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
228 | |
540 | |
229 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
541 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
230 | |
542 | |
|
|
543 | =item $w = $loop->io ($fileno_or_fh, $eventmask, $callback) |
|
|
544 | |
|
|
545 | =item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback) |
|
|
546 | |
231 | As long as the returned watcher object is alive, call the C<$callback> |
547 | As long as the returned watcher object is alive, call the C<$callback> |
232 | when the events specified in C<$eventmask>. |
548 | when at least one of events specified in C<$eventmask> occurs. |
233 | |
549 | |
234 | The $eventmask can be one or more of these constants ORed together: |
550 | The $eventmask can be one or more of these constants ORed together: |
235 | |
551 | |
236 | EV::READ wait until read() wouldn't block anymore |
552 | EV::READ wait until read() wouldn't block anymore |
237 | EV::WRITE wait until write() wouldn't block anymore |
553 | EV::WRITE wait until write() wouldn't block anymore |
… | |
… | |
253 | |
569 | |
254 | =item $old_eventmask = $w->events ($new_eventmask) |
570 | =item $old_eventmask = $w->events ($new_eventmask) |
255 | |
571 | |
256 | Returns the previously set event mask and optionally set a new one. |
572 | Returns the previously set event mask and optionally set a new one. |
257 | |
573 | |
|
|
574 | =back |
|
|
575 | |
|
|
576 | |
|
|
577 | =head3 TIMER WATCHERS - relative and optionally repeating timeouts |
|
|
578 | |
|
|
579 | =over 4 |
258 | |
580 | |
259 | =item $w = EV::timer $after, $repeat, $callback |
581 | =item $w = EV::timer $after, $repeat, $callback |
260 | |
582 | |
261 | =item $w = EV::timer_ns $after, $repeat, $callback |
583 | =item $w = EV::timer_ns $after, $repeat, $callback |
262 | |
584 | |
263 | Calls the callback after C<$after> seconds. If C<$repeat> is non-zero, |
585 | =item $w = $loop->timer ($after, $repeat, $callback) |
264 | the timer will be restarted (with the $repeat value as $after) after the |
586 | |
265 | callback returns. |
587 | =item $w = $loop->timer_ns ($after, $repeat, $callback) |
|
|
588 | |
|
|
589 | Calls the callback after C<$after> seconds (which may be fractional). If |
|
|
590 | C<$repeat> is non-zero, the timer will be restarted (with the $repeat |
|
|
591 | value as $after) after the callback returns. |
266 | |
592 | |
267 | This means that the callback would be called roughly after C<$after> |
593 | This means that the callback would be called roughly after C<$after> |
268 | seconds, and then every C<$repeat> seconds. "Roughly" because the time of |
594 | seconds, and then every C<$repeat> seconds. The timer does his best not |
269 | callback processing is not taken into account, so the timer will slowly |
595 | to drift, but it will not invoke the timer more often then once per event |
270 | drift. If that isn't acceptable, look at EV::periodic. |
596 | loop iteration, and might drift in other cases. If that isn't acceptable, |
|
|
597 | look at EV::periodic, which can provide long-term stable timers. |
271 | |
598 | |
272 | The timer is based on a monotonic clock, that is if somebody is sitting |
599 | The timer is based on a monotonic clock, that is, if somebody is sitting |
273 | in front of the machine while the timer is running and changes the system |
600 | in front of the machine while the timer is running and changes the system |
274 | clock, the timer will nevertheless run (roughly) the same time. |
601 | clock, the timer will nevertheless run (roughly) the same time. |
275 | |
602 | |
276 | The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
603 | The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
277 | |
604 | |
278 | =item $w->set ($after, $repeat) |
605 | =item $w->set ($after, $repeat) |
279 | |
606 | |
280 | Reconfigures the watcher, see the constructor above for details. Can be at |
607 | Reconfigures the watcher, see the constructor above for details. Can be called at |
281 | any time. |
608 | any time. |
282 | |
609 | |
283 | =item $w->again |
610 | =item $w->again |
284 | |
611 | |
285 | Similar to the C<start> method, but has special semantics for repeating timers: |
612 | Similar to the C<start> method, but has special semantics for repeating timers: |
|
|
613 | |
|
|
614 | If the timer is active and non-repeating, it will be stopped. |
286 | |
615 | |
287 | If the timer is active and repeating, reset the timeout to occur |
616 | If the timer is active and repeating, reset the timeout to occur |
288 | C<$repeat> seconds after now. |
617 | C<$repeat> seconds after now. |
289 | |
618 | |
290 | If the timer is active and non-repeating, it will be stopped. |
|
|
291 | |
|
|
292 | If the timer is in active and repeating, start it. |
619 | If the timer is inactive and repeating, start it using the repeat value. |
293 | |
620 | |
294 | Otherwise do nothing. |
621 | Otherwise do nothing. |
295 | |
622 | |
296 | This behaviour is useful when you have a timeout for some IO |
623 | This behaviour is useful when you have a timeout for some IO |
297 | operation. You create a timer object with the same value for C<$after> and |
624 | operation. You create a timer object with the same value for C<$after> and |
298 | C<$repeat>, and then, in the read/write watcher, run the C<again> method |
625 | C<$repeat>, and then, in the read/write watcher, run the C<again> method |
299 | on the timeout. |
626 | on the timeout. |
300 | |
627 | |
|
|
628 | =back |
|
|
629 | |
|
|
630 | |
|
|
631 | =head3 PERIODIC WATCHERS - to cron or not to cron? |
|
|
632 | |
|
|
633 | =over 4 |
301 | |
634 | |
302 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
635 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
303 | |
636 | |
304 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
637 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
|
|
638 | |
|
|
639 | =item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback) |
|
|
640 | |
|
|
641 | =item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback) |
305 | |
642 | |
306 | Similar to EV::timer, but is not based on relative timeouts but on |
643 | Similar to EV::timer, but is not based on relative timeouts but on |
307 | absolute times. Apart from creating "simple" timers that trigger "at" the |
644 | absolute times. Apart from creating "simple" timers that trigger "at" the |
308 | specified time, it can also be used for non-drifting absolute timers and |
645 | specified time, it can also be used for non-drifting absolute timers and |
309 | more complex, cron-like, setups that are not adversely affected by time |
646 | more complex, cron-like, setups that are not adversely affected by time |
… | |
… | |
319 | This time simply fires at the wallclock time C<$at> and doesn't repeat. It |
656 | This time simply fires at the wallclock time C<$at> and doesn't repeat. It |
320 | will not adjust when a time jump occurs, that is, if it is to be run |
657 | will not adjust when a time jump occurs, that is, if it is to be run |
321 | at January 1st 2011 then it will run when the system time reaches or |
658 | at January 1st 2011 then it will run when the system time reaches or |
322 | surpasses this time. |
659 | surpasses this time. |
323 | |
660 | |
324 | =item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) |
661 | =item * repeating interval timer ($interval > 0, $reschedule_cb = 0) |
325 | |
662 | |
326 | In this mode the watcher will always be scheduled to time out at the |
663 | In this mode the watcher will always be scheduled to time out at the |
327 | next C<$at + N * $interval> time (for some integer N) and then repeat, |
664 | next C<$at + N * $interval> time (for some integer N) and then repeat, |
328 | regardless of any time jumps. |
665 | regardless of any time jumps. |
329 | |
666 | |
… | |
… | |
341 | possible time where C<$time = $at (mod $interval)>, regardless of any time |
678 | possible time where C<$time = $at (mod $interval)>, regardless of any time |
342 | jumps. |
679 | jumps. |
343 | |
680 | |
344 | =item * manual reschedule mode ($reschedule_cb = coderef) |
681 | =item * manual reschedule mode ($reschedule_cb = coderef) |
345 | |
682 | |
346 | In this mode $interval and $at are both being ignored. Instead, each time |
683 | In this mode $interval and $at are both being ignored. Instead, each |
347 | the periodic watcher gets scheduled, the first callback ($reschedule_cb) |
684 | time the periodic watcher gets scheduled, the reschedule callback |
348 | will be called with the watcher as first, and the current time as second |
685 | ($reschedule_cb) will be called with the watcher as first, and the current |
349 | argument. |
686 | time as second argument. |
350 | |
687 | |
351 | I<This callback MUST NOT stop or destroy the event watcher, ever.> |
688 | I<This callback MUST NOT stop or destroy this or any other periodic |
|
|
689 | watcher, ever, and MUST NOT call any event loop functions or methods>. If |
|
|
690 | you need to stop it, return 1e30 and stop it afterwards. You may create |
|
|
691 | and start a C<EV::prepare> watcher for this task. |
352 | |
692 | |
353 | It must return the next time to trigger, based on the passed time value |
693 | It must return the next time to trigger, based on the passed time value |
354 | (that is, the lowest time value larger than to the second argument). It |
694 | (that is, the lowest time value larger than or equal to to the second |
355 | will usually be called just before the callback will be triggered, but |
695 | argument). It will usually be called just before the callback will be |
356 | might be called at other times, too. |
696 | triggered, but might be called at other times, too. |
357 | |
697 | |
358 | This can be used to create very complex timers, such as a timer that |
698 | This can be used to create very complex timers, such as a timer that |
359 | triggers on each midnight, local time (actually 24 hours after the last |
699 | triggers on each midnight, local time (actually 24 hours after the last |
360 | midnight, to keep the example simple. If you know a way to do it correctly |
700 | midnight, to keep the example simple. If you know a way to do it correctly |
361 | in about the same space (without requiring elaborate modules), drop me a |
701 | in about the same space (without requiring elaborate modules), drop me a |
… | |
… | |
375 | |
715 | |
376 | The C<periodic_ns> variant doesn't start (activate) the newly created watcher. |
716 | The C<periodic_ns> variant doesn't start (activate) the newly created watcher. |
377 | |
717 | |
378 | =item $w->set ($at, $interval, $reschedule_cb) |
718 | =item $w->set ($at, $interval, $reschedule_cb) |
379 | |
719 | |
380 | Reconfigures the watcher, see the constructor above for details. Can be at |
720 | Reconfigures the watcher, see the constructor above for details. Can be called at |
381 | any time. |
721 | any time. |
382 | |
722 | |
383 | =item $w->again |
723 | =item $w->again |
384 | |
724 | |
385 | Simply stops and starts the watcher again. |
725 | Simply stops and starts the watcher again. |
386 | |
726 | |
|
|
727 | =item $time = $w->at |
|
|
728 | |
|
|
729 | Return the time that the watcher is expected to trigger next. |
|
|
730 | |
|
|
731 | =back |
|
|
732 | |
|
|
733 | |
|
|
734 | =head3 SIGNAL WATCHERS - signal me when a signal gets signalled! |
|
|
735 | |
|
|
736 | =over 4 |
387 | |
737 | |
388 | =item $w = EV::signal $signal, $callback |
738 | =item $w = EV::signal $signal, $callback |
389 | |
739 | |
390 | =item $w = EV::signal_ns $signal, $callback |
740 | =item $w = EV::signal_ns $signal, $callback |
391 | |
741 | |
|
|
742 | =item $w = $loop->signal ($signal, $callback) |
|
|
743 | |
|
|
744 | =item $w = $loop->signal_ns ($signal, $callback) |
|
|
745 | |
392 | Call the callback when $signal is received (the signal can be specified |
746 | Call the callback when $signal is received (the signal can be specified by |
393 | by number or by name, just as with kill or %SIG). |
747 | number or by name, just as with C<kill> or C<%SIG>). |
|
|
748 | |
|
|
749 | Only one event loop can grab a given signal - attempting to grab the same |
|
|
750 | signal from two EV loops will crash the program immediately or cause data |
|
|
751 | corruption. |
394 | |
752 | |
395 | EV will grab the signal for the process (the kernel only allows one |
753 | EV will grab the signal for the process (the kernel only allows one |
396 | component to receive a signal at a time) when you start a signal watcher, |
754 | component to receive a signal at a time) when you start a signal watcher, |
397 | and removes it again when you stop it. Perl does the same when you |
755 | and removes it again when you stop it. Perl does the same when you |
398 | add/remove callbacks to %SIG, so watch out. |
756 | add/remove callbacks to C<%SIG>, so watch out. |
399 | |
757 | |
400 | You can have as many signal watchers per signal as you want. |
758 | You can have as many signal watchers per signal as you want. |
401 | |
759 | |
402 | The C<signal_ns> variant doesn't start (activate) the newly created watcher. |
760 | The C<signal_ns> variant doesn't start (activate) the newly created watcher. |
403 | |
761 | |
404 | =item $w->set ($signal) |
762 | =item $w->set ($signal) |
405 | |
763 | |
406 | Reconfigures the watcher, see the constructor above for details. Can be at |
764 | Reconfigures the watcher, see the constructor above for details. Can be |
407 | any time. |
765 | called at any time. |
408 | |
766 | |
409 | =item $current_signum = $w->signal |
767 | =item $current_signum = $w->signal |
410 | |
768 | |
411 | =item $old_signum = $w->signal ($new_signal) |
769 | =item $old_signum = $w->signal ($new_signal) |
412 | |
770 | |
413 | Returns the previously set signal (always as a number not name) and |
771 | Returns the previously set signal (always as a number not name) and |
414 | optionally set a new one. |
772 | optionally set a new one. |
415 | |
773 | |
|
|
774 | =back |
416 | |
775 | |
|
|
776 | |
|
|
777 | =head3 CHILD WATCHERS - watch out for process status changes |
|
|
778 | |
|
|
779 | =over 4 |
|
|
780 | |
417 | =item $w = EV::child $pid, $callback |
781 | =item $w = EV::child $pid, $trace, $callback |
418 | |
782 | |
419 | =item $w = EV::child_ns $pid, $callback |
783 | =item $w = EV::child_ns $pid, $trace, $callback |
|
|
784 | |
|
|
785 | =item $w = $loop->child ($pid, $trace, $callback) |
|
|
786 | |
|
|
787 | =item $w = $loop->child_ns ($pid, $trace, $callback) |
420 | |
788 | |
421 | Call the callback when a status change for pid C<$pid> (or any pid |
789 | Call the callback when a status change for pid C<$pid> (or any pid |
422 | if C<$pid> is 0) has been received. More precisely: when the process |
790 | if C<$pid> is 0) has been received (a status change happens when the |
|
|
791 | process terminates or is killed, or, when trace is true, additionally when |
|
|
792 | it is stopped or continued). More precisely: when the process receives |
423 | receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all |
793 | a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all |
424 | changed/zombie children and call the callback. |
794 | changed/zombie children and call the callback. |
425 | |
795 | |
426 | You can access both status and pid by using the C<rstatus> and C<rpid> |
796 | It is valid (and fully supported) to install a child watcher after a child |
427 | methods on the watcher object. |
797 | has exited but before the event loop has started its next iteration (for |
|
|
798 | example, first you C<fork>, then the new child process might exit, and |
|
|
799 | only then do you install a child watcher in the parent for the new pid). |
428 | |
800 | |
|
|
801 | You can access both exit (or tracing) status and pid by using the |
|
|
802 | C<rstatus> and C<rpid> methods on the watcher object. |
|
|
803 | |
429 | You can have as many pid watchers per pid as you want. |
804 | You can have as many pid watchers per pid as you want, they will all be |
|
|
805 | called. |
430 | |
806 | |
431 | The C<child_ns> variant doesn't start (activate) the newly created watcher. |
807 | The C<child_ns> variant doesn't start (activate) the newly created watcher. |
432 | |
808 | |
433 | =item $w->set ($pid) |
809 | =item $w->set ($pid, $trace) |
434 | |
810 | |
435 | Reconfigures the watcher, see the constructor above for details. Can be at |
811 | Reconfigures the watcher, see the constructor above for details. Can be called at |
436 | any time. |
812 | any time. |
437 | |
813 | |
438 | =item $current_pid = $w->pid |
814 | =item $current_pid = $w->pid |
439 | |
|
|
440 | =item $old_pid = $w->pid ($new_pid) |
|
|
441 | |
815 | |
442 | Returns the previously set process id and optionally set a new one. |
816 | Returns the previously set process id and optionally set a new one. |
443 | |
817 | |
444 | =item $exit_status = $w->rstatus |
818 | =item $exit_status = $w->rstatus |
445 | |
819 | |
… | |
… | |
449 | =item $pid = $w->rpid |
823 | =item $pid = $w->rpid |
450 | |
824 | |
451 | Return the pid of the awaited child (useful when you have installed a |
825 | Return the pid of the awaited child (useful when you have installed a |
452 | watcher for all pids). |
826 | watcher for all pids). |
453 | |
827 | |
|
|
828 | =back |
|
|
829 | |
|
|
830 | |
|
|
831 | =head3 STAT WATCHERS - did the file attributes just change? |
|
|
832 | |
|
|
833 | =over 4 |
|
|
834 | |
|
|
835 | =item $w = EV::stat $path, $interval, $callback |
|
|
836 | |
|
|
837 | =item $w = EV::stat_ns $path, $interval, $callback |
|
|
838 | |
|
|
839 | =item $w = $loop->stat ($path, $interval, $callback) |
|
|
840 | |
|
|
841 | =item $w = $loop->stat_ns ($path, $interval, $callback) |
|
|
842 | |
|
|
843 | Call the callback when a file status change has been detected on |
|
|
844 | C<$path>. The C<$path> does not need to exist, changing from "path exists" |
|
|
845 | to "path does not exist" is a status change like any other. |
|
|
846 | |
|
|
847 | The C<$interval> is a recommended polling interval for systems where |
|
|
848 | OS-supported change notifications don't exist or are not supported. If |
|
|
849 | you use C<0> then an unspecified default is used (which is highly |
|
|
850 | recommended!), which is to be expected to be around five seconds usually. |
|
|
851 | |
|
|
852 | This watcher type is not meant for massive numbers of stat watchers, |
|
|
853 | as even with OS-supported change notifications, this can be |
|
|
854 | resource-intensive. |
|
|
855 | |
|
|
856 | The C<stat_ns> variant doesn't start (activate) the newly created watcher. |
|
|
857 | |
|
|
858 | =item ... = $w->stat |
|
|
859 | |
|
|
860 | This call is very similar to the perl C<stat> built-in: It stats (using |
|
|
861 | C<lstat>) the path specified in the watcher and sets perls stat cache (as |
|
|
862 | well as EV's idea of the current stat values) to the values found. |
|
|
863 | |
|
|
864 | In scalar context, a boolean is return indicating success or failure of |
|
|
865 | the stat. In list context, the same 13-value list as with stat is returned |
|
|
866 | (except that the blksize and blocks fields are not reliable). |
|
|
867 | |
|
|
868 | In the case of an error, errno is set to C<ENOENT> (regardless of the |
|
|
869 | actual error value) and the C<nlink> value is forced to zero (if the stat |
|
|
870 | was successful then nlink is guaranteed to be non-zero). |
|
|
871 | |
|
|
872 | See also the next two entries for more info. |
|
|
873 | |
|
|
874 | =item ... = $w->attr |
|
|
875 | |
|
|
876 | Just like C<< $w->stat >>, but without the initial stat'ing: this returns |
|
|
877 | the values most recently detected by EV. See the next entry for more info. |
|
|
878 | |
|
|
879 | =item ... = $w->prev |
|
|
880 | |
|
|
881 | Just like C<< $w->stat >>, but without the initial stat'ing: this returns |
|
|
882 | the previous set of values, before the change. |
|
|
883 | |
|
|
884 | That is, when the watcher callback is invoked, C<< $w->prev >> will be set |
|
|
885 | to the values found I<before> a change was detected, while C<< $w->attr >> |
|
|
886 | returns the values found leading to the change detection. The difference (if any) |
|
|
887 | between C<prev> and C<attr> is what triggered the callback. |
|
|
888 | |
|
|
889 | If you did something to the filesystem object and do not want to trigger |
|
|
890 | yet another change, you can call C<stat> to update EV's idea of what the |
|
|
891 | current attributes are. |
|
|
892 | |
|
|
893 | =item $w->set ($path, $interval) |
|
|
894 | |
|
|
895 | Reconfigures the watcher, see the constructor above for details. Can be |
|
|
896 | called at any time. |
|
|
897 | |
|
|
898 | =item $current_path = $w->path |
|
|
899 | |
|
|
900 | =item $old_path = $w->path ($new_path) |
|
|
901 | |
|
|
902 | Returns the previously set path and optionally set a new one. |
|
|
903 | |
|
|
904 | =item $current_interval = $w->interval |
|
|
905 | |
|
|
906 | =item $old_interval = $w->interval ($new_interval) |
|
|
907 | |
|
|
908 | Returns the previously set interval and optionally set a new one. Can be |
|
|
909 | used to query the actual interval used. |
|
|
910 | |
|
|
911 | =back |
|
|
912 | |
|
|
913 | |
|
|
914 | =head3 IDLE WATCHERS - when you've got nothing better to do... |
|
|
915 | |
|
|
916 | =over 4 |
454 | |
917 | |
455 | =item $w = EV::idle $callback |
918 | =item $w = EV::idle $callback |
456 | |
919 | |
457 | =item $w = EV::idle_ns $callback |
920 | =item $w = EV::idle_ns $callback |
458 | |
921 | |
459 | Call the callback when there are no pending io, timer/periodic, signal or |
922 | =item $w = $loop->idle ($callback) |
460 | child events, i.e. when the process is idle. |
923 | |
|
|
924 | =item $w = $loop->idle_ns ($callback) |
|
|
925 | |
|
|
926 | Call the callback when there are no other pending watchers of the same or |
|
|
927 | higher priority (excluding check, prepare and other idle watchers of the |
|
|
928 | same or lower priority, of course). They are called idle watchers because |
|
|
929 | when the watcher is the highest priority pending event in the process, the |
|
|
930 | process is considered to be idle at that priority. |
|
|
931 | |
|
|
932 | If you want a watcher that is only ever called when I<no> other events are |
|
|
933 | outstanding you have to set the priority to C<EV::MINPRI>. |
461 | |
934 | |
462 | The process will not block as long as any idle watchers are active, and |
935 | The process will not block as long as any idle watchers are active, and |
463 | they will be called repeatedly until stopped. |
936 | they will be called repeatedly until stopped. |
464 | |
937 | |
|
|
938 | For example, if you have idle watchers at priority C<0> and C<1>, and |
|
|
939 | an I/O watcher at priority C<0>, then the idle watcher at priority C<1> |
|
|
940 | and the I/O watcher will always run when ready. Only when the idle watcher |
|
|
941 | at priority C<1> is stopped and the I/O watcher at priority C<0> is not |
|
|
942 | pending with the C<0>-priority idle watcher be invoked. |
|
|
943 | |
465 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
944 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
466 | |
945 | |
|
|
946 | =back |
|
|
947 | |
|
|
948 | |
|
|
949 | =head3 PREPARE WATCHERS - customise your event loop! |
|
|
950 | |
|
|
951 | =over 4 |
467 | |
952 | |
468 | =item $w = EV::prepare $callback |
953 | =item $w = EV::prepare $callback |
469 | |
954 | |
470 | =item $w = EV::prepare_ns $callback |
955 | =item $w = EV::prepare_ns $callback |
|
|
956 | |
|
|
957 | =item $w = $loop->prepare ($callback) |
|
|
958 | |
|
|
959 | =item $w = $loop->prepare_ns ($callback) |
471 | |
960 | |
472 | Call the callback just before the process would block. You can still |
961 | Call the callback just before the process would block. You can still |
473 | create/modify any watchers at this point. |
962 | create/modify any watchers at this point. |
474 | |
963 | |
475 | See the EV::check watcher, below, for explanations and an example. |
964 | See the EV::check watcher, below, for explanations and an example. |
476 | |
965 | |
477 | The C<prepare_ns> variant doesn't start (activate) the newly created watcher. |
966 | The C<prepare_ns> variant doesn't start (activate) the newly created watcher. |
478 | |
967 | |
|
|
968 | =back |
|
|
969 | |
|
|
970 | |
|
|
971 | =head3 CHECK WATCHERS - customise your event loop even more! |
|
|
972 | |
|
|
973 | =over 4 |
479 | |
974 | |
480 | =item $w = EV::check $callback |
975 | =item $w = EV::check $callback |
481 | |
976 | |
482 | =item $w = EV::check_ns $callback |
977 | =item $w = EV::check_ns $callback |
|
|
978 | |
|
|
979 | =item $w = $loop->check ($callback) |
|
|
980 | |
|
|
981 | =item $w = $loop->check_ns ($callback) |
483 | |
982 | |
484 | Call the callback just after the process wakes up again (after it has |
983 | Call the callback just after the process wakes up again (after it has |
485 | gathered events), but before any other callbacks have been invoked. |
984 | gathered events), but before any other callbacks have been invoked. |
486 | |
985 | |
487 | This is used to integrate other event-based software into the EV |
986 | This can be used to integrate other event-based software into the EV |
488 | mainloop: You register a prepare callback and in there, you create io and |
987 | mainloop: You register a prepare callback and in there, you create io and |
489 | timer watchers as required by the other software. Here is a real-world |
988 | timer watchers as required by the other software. Here is a real-world |
490 | example of integrating Net::SNMP (with some details left out): |
989 | example of integrating Net::SNMP (with some details left out): |
491 | |
990 | |
492 | our @snmp_watcher; |
991 | our @snmp_watcher; |
… | |
… | |
495 | # do nothing unless active |
994 | # do nothing unless active |
496 | $dispatcher->{_event_queue_h} |
995 | $dispatcher->{_event_queue_h} |
497 | or return; |
996 | or return; |
498 | |
997 | |
499 | # make the dispatcher handle any outstanding stuff |
998 | # make the dispatcher handle any outstanding stuff |
|
|
999 | ... not shown |
500 | |
1000 | |
501 | # create an IO watcher for each and every socket |
1001 | # create an I/O watcher for each and every socket |
502 | @snmp_watcher = ( |
1002 | @snmp_watcher = ( |
503 | (map { EV::io $_, EV::READ, sub { } } |
1003 | (map { EV::io $_, EV::READ, sub { } } |
504 | keys %{ $dispatcher->{_descriptors} }), |
1004 | keys %{ $dispatcher->{_descriptors} }), |
|
|
1005 | |
|
|
1006 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
|
|
1007 | ? $event->[Net::SNMP::Dispatcher::_TIME] - EV::now : 0), |
|
|
1008 | 0, sub { }, |
505 | ); |
1009 | ); |
506 | |
|
|
507 | # if there are any timeouts, also create a timer |
|
|
508 | push @snmp_watcher, EV::timer $event->[Net::SNMP::Dispatcher::_TIME] - EV::now, 0, sub { } |
|
|
509 | if $event->[Net::SNMP::Dispatcher::_ACTIVE]; |
|
|
510 | }; |
1010 | }; |
511 | |
1011 | |
512 | The callbacks are irrelevant, the only purpose of those watchers is |
1012 | The callbacks are irrelevant (and are not even being called), the |
513 | to wake up the process as soon as one of those events occurs (socket |
1013 | only purpose of those watchers is to wake up the process as soon as |
514 | readable, or timer timed out). The corresponding EV::check watcher will then |
1014 | one of those events occurs (socket readable, or timer timed out). The |
515 | clean up: |
1015 | corresponding EV::check watcher will then clean up: |
516 | |
1016 | |
517 | our $snmp_check = EV::check sub { |
1017 | our $snmp_check = EV::check sub { |
518 | # destroy all watchers |
1018 | # destroy all watchers |
519 | @snmp_watcher = (); |
1019 | @snmp_watcher = (); |
520 | |
1020 | |
521 | # make the dispatcher handle any new stuff |
1021 | # make the dispatcher handle any new stuff |
|
|
1022 | ... not shown |
522 | }; |
1023 | }; |
523 | |
1024 | |
524 | The callbacks of the created watchers will not be called as the watchers |
1025 | The callbacks of the created watchers will not be called as the watchers |
525 | are destroyed before this cna happen (remember EV::check gets called |
1026 | are destroyed before this can happen (remember EV::check gets called |
526 | first). |
1027 | first). |
527 | |
1028 | |
528 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
1029 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
529 | |
1030 | |
530 | =back |
1031 | =item EV::CHECK constant issues |
531 | |
1032 | |
|
|
1033 | Like all other watcher types, there is a bitmask constant for use in |
|
|
1034 | C<$revents> and other places. The C<EV::CHECK> is special as it has |
|
|
1035 | the same name as the C<CHECK> sub called by Perl. This doesn't cause |
|
|
1036 | big issues on newer perls (beginning with 5.8.9), but it means thatthe |
|
|
1037 | constant must be I<inlined>, i.e. runtime calls will not work. That means |
|
|
1038 | that as long as you always C<use EV> and then C<EV::CHECK> you are on the |
|
|
1039 | safe side. |
|
|
1040 | |
|
|
1041 | =back |
|
|
1042 | |
|
|
1043 | |
|
|
1044 | =head3 FORK WATCHERS - the audacity to resume the event loop after a fork |
|
|
1045 | |
|
|
1046 | Fork watchers are called when a C<fork ()> was detected. The invocation |
|
|
1047 | is done before the event loop blocks next and before C<check> watchers |
|
|
1048 | are being called, and only in the child after the fork. |
|
|
1049 | |
|
|
1050 | =over 4 |
|
|
1051 | |
|
|
1052 | =item $w = EV::fork $callback |
|
|
1053 | |
|
|
1054 | =item $w = EV::fork_ns $callback |
|
|
1055 | |
|
|
1056 | =item $w = $loop->fork ($callback) |
|
|
1057 | |
|
|
1058 | =item $w = $loop->fork_ns ($callback) |
|
|
1059 | |
|
|
1060 | Call the callback before the event loop is resumed in the child process |
|
|
1061 | after a fork. |
|
|
1062 | |
|
|
1063 | The C<fork_ns> variant doesn't start (activate) the newly created watcher. |
|
|
1064 | |
|
|
1065 | =back |
|
|
1066 | |
|
|
1067 | |
|
|
1068 | =head3 EMBED WATCHERS - when one backend isn't enough... |
|
|
1069 | |
|
|
1070 | This is a rather advanced watcher type that lets you embed one event loop |
|
|
1071 | into another (currently only IO events are supported in the embedded |
|
|
1072 | loop, other types of watchers might be handled in a delayed or incorrect |
|
|
1073 | fashion and must not be used). |
|
|
1074 | |
|
|
1075 | See the libev documentation at |
|
|
1076 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> |
|
|
1077 | (locally installed as F<EV::libev>) for more details. |
|
|
1078 | |
|
|
1079 | In short, this watcher is most useful on BSD systems without working |
|
|
1080 | kqueue to still be able to handle a large number of sockets: |
|
|
1081 | |
|
|
1082 | my $socket_loop; |
|
|
1083 | |
|
|
1084 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
|
|
1085 | if ( |
|
|
1086 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
|
|
1087 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
|
|
1088 | ) { |
|
|
1089 | # use kqueue for sockets |
|
|
1090 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
|
|
1091 | } |
|
|
1092 | |
|
|
1093 | # use the default loop otherwise |
|
|
1094 | $socket_loop ||= EV::default_loop; |
|
|
1095 | |
|
|
1096 | =over 4 |
|
|
1097 | |
|
|
1098 | =item $w = EV::embed $otherloop[, $callback] |
|
|
1099 | |
|
|
1100 | =item $w = EV::embed_ns $otherloop[, $callback] |
|
|
1101 | |
|
|
1102 | =item $w = $loop->embed ($otherloop[, $callback]) |
|
|
1103 | |
|
|
1104 | =item $w = $loop->embed_ns ($otherloop[, $callback]) |
|
|
1105 | |
|
|
1106 | Call the callback when the embedded event loop (C<$otherloop>) has any |
|
|
1107 | I/O activity. The C<$callback> is optional: if it is missing, then the |
|
|
1108 | embedded event loop will be managed automatically (which is recommended), |
|
|
1109 | otherwise you have to invoke C<sweep> yourself. |
|
|
1110 | |
|
|
1111 | The C<embed_ns> variant doesn't start (activate) the newly created watcher. |
|
|
1112 | |
|
|
1113 | =back |
|
|
1114 | |
|
|
1115 | =head3 ASYNC WATCHERS - how to wake up another event loop |
|
|
1116 | |
|
|
1117 | Async watchers are provided by EV, but have little use in perl directly, |
|
|
1118 | as perl neither supports threads running in parallel nor direct access to |
|
|
1119 | signal handlers or other contexts where they could be of value. |
|
|
1120 | |
|
|
1121 | It is, however, possible to use them from the XS level. |
|
|
1122 | |
|
|
1123 | Please see the libev documentation for further details. |
|
|
1124 | |
|
|
1125 | =over 4 |
|
|
1126 | |
|
|
1127 | =item $w = EV::async $callback |
|
|
1128 | |
|
|
1129 | =item $w = EV::async_ns $callback |
|
|
1130 | |
|
|
1131 | =item $w->send |
|
|
1132 | |
|
|
1133 | =item $bool = $w->async_pending |
|
|
1134 | |
|
|
1135 | =back |
|
|
1136 | |
|
|
1137 | |
|
|
1138 | =head1 PERL SIGNALS |
|
|
1139 | |
|
|
1140 | While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour |
|
|
1141 | with EV is as the same as any other C library: Perl-signals will only be |
|
|
1142 | handled when Perl runs, which means your signal handler might be invoked |
|
|
1143 | only the next time an event callback is invoked. |
|
|
1144 | |
|
|
1145 | The solution is to use EV signal watchers (see C<EV::signal>), which will |
|
|
1146 | ensure proper operations with regards to other event watchers. |
|
|
1147 | |
|
|
1148 | If you cannot do this for whatever reason, you can also force a watcher |
|
|
1149 | to be called on every event loop iteration by installing a C<EV::check> |
|
|
1150 | watcher: |
|
|
1151 | |
|
|
1152 | my $async_check = EV::check sub { }; |
|
|
1153 | |
|
|
1154 | This ensures that perl gets into control for a short time to handle any |
|
|
1155 | pending signals, and also ensures (slightly) slower overall operation. |
|
|
1156 | |
532 | =head1 THREADS |
1157 | =head1 ITHREADS |
533 | |
1158 | |
534 | Threads are not supported by this in any way. Perl pseudo-threads is evil |
1159 | Ithreads are not supported by this module in any way. Perl pseudo-threads |
535 | stuff and must die. |
1160 | is evil stuff and must die. Real threads as provided by Coro are fully |
|
|
1161 | supported (and enhanced support is available via L<Coro::EV>). |
|
|
1162 | |
|
|
1163 | =head1 FORK |
|
|
1164 | |
|
|
1165 | Most of the "improved" event delivering mechanisms of modern operating |
|
|
1166 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
|
|
1167 | not supported and usually destructive). Libev makes it possible to work |
|
|
1168 | around this by having a function that recreates the kernel state after |
|
|
1169 | fork in the child. |
|
|
1170 | |
|
|
1171 | On non-win32 platforms, this module requires the pthread_atfork |
|
|
1172 | functionality to do this automatically for you. This function is quite |
|
|
1173 | buggy on most BSDs, though, so YMMV. The overhead for this is quite |
|
|
1174 | negligible, because everything the function currently does is set a flag |
|
|
1175 | that is checked only when the event loop gets used the next time, so when |
|
|
1176 | you do fork but not use EV, the overhead is minimal. |
|
|
1177 | |
|
|
1178 | On win32, there is no notion of fork so all this doesn't apply, of course. |
536 | |
1179 | |
537 | =cut |
1180 | =cut |
538 | |
1181 | |
539 | our $DIED = sub { |
1182 | our $DIED = sub { |
540 | warn "EV: error in callback (ignoring): $@"; |
1183 | warn "EV: error in callback (ignoring): $@"; |
541 | }; |
1184 | }; |
542 | |
1185 | |
543 | default_loop |
1186 | default_loop |
544 | or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?'; |
1187 | or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?'; |
545 | |
|
|
546 | push @AnyEvent::REGISTRY, [EV => "EV::AnyEvent"]; |
|
|
547 | |
1188 | |
548 | 1; |
1189 | 1; |
549 | |
1190 | |
550 | =head1 SEE ALSO |
1191 | =head1 SEE ALSO |
551 | |
1192 | |
552 | L<EV::DNS>, L<EV::AnyEvent>. |
1193 | L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS> |
|
|
1194 | (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as event |
|
|
1195 | loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient thread |
|
|
1196 | integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for |
|
|
1197 | event-loop agnostic and portable event driven programming. |
553 | |
1198 | |
554 | =head1 AUTHOR |
1199 | =head1 AUTHOR |
555 | |
1200 | |
556 | Marc Lehmann <schmorp@schmorp.de> |
1201 | Marc Lehmann <schmorp@schmorp.de> |
557 | http://home.schmorp.de/ |
1202 | http://home.schmorp.de/ |
558 | |
1203 | |
559 | =cut |
1204 | =cut |
560 | |
1205 | |