… | |
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2 | |
2 | |
3 | Coro - coroutine process abstraction |
3 | Coro - coroutine process abstraction |
4 | |
4 | |
5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
6 | |
6 | |
7 | use Coro; |
7 | use Coro; |
8 | |
8 | |
9 | async { |
9 | async { |
10 | # some asynchronous thread of execution |
10 | # some asynchronous thread of execution |
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11 | print "2\n"; |
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12 | cede; # yield back to main |
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13 | print "4\n"; |
11 | }; |
14 | }; |
12 | |
15 | print "1\n"; |
13 | # alternatively create an async coroutine like this: |
16 | cede; # yield to coroutine |
14 | |
17 | print "3\n"; |
15 | sub some_func : Coro { |
18 | cede; # and again |
16 | # some more async code |
19 | |
17 | } |
20 | # use locking |
18 | |
21 | my $lock = new Coro::Semaphore; |
19 | cede; |
22 | my $locked; |
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23 | |
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24 | $lock->down; |
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25 | $locked = 1; |
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26 | $lock->up; |
20 | |
27 | |
21 | =head1 DESCRIPTION |
28 | =head1 DESCRIPTION |
22 | |
29 | |
23 | This module collection manages coroutines. Coroutines are similar to |
30 | This module collection manages coroutines. Coroutines are similar |
24 | threads but don't run in parallel. |
31 | to threads but don't run in parallel at the same time even on SMP |
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32 | machines. The specific flavor of coroutine used in this module also |
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33 | guarantees you that it will not switch between coroutines unless |
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34 | necessary, at easily-identified points in your program, so locking and |
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35 | parallel access are rarely an issue, making coroutine programming much |
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36 | safer than threads programming. |
25 | |
37 | |
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38 | (Perl, however, does not natively support real threads but instead does a |
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39 | very slow and memory-intensive emulation of processes using threads. This |
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40 | is a performance win on Windows machines, and a loss everywhere else). |
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41 | |
26 | In this module, coroutines are defined as "callchain + lexical variables |
42 | In this module, coroutines are defined as "callchain + lexical variables + |
27 | + @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own |
43 | @_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain, |
28 | callchain, it's own set of lexicals and it's own set of perl's most |
44 | its own set of lexicals and its own set of perls most important global |
29 | important global variables. |
45 | variables (see L<Coro::State> for more configuration). |
30 | |
46 | |
31 | =cut |
47 | =cut |
32 | |
48 | |
33 | package Coro; |
49 | package Coro; |
34 | |
50 | |
… | |
… | |
41 | |
57 | |
42 | our $idle; # idle handler |
58 | our $idle; # idle handler |
43 | our $main; # main coroutine |
59 | our $main; # main coroutine |
44 | our $current; # current coroutine |
60 | our $current; # current coroutine |
45 | |
61 | |
46 | our $VERSION = '3.01'; |
62 | our $VERSION = '4.51'; |
47 | |
63 | |
48 | our @EXPORT = qw(async cede schedule terminate current unblock_sub); |
64 | our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); |
49 | our %EXPORT_TAGS = ( |
65 | our %EXPORT_TAGS = ( |
50 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
66 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
51 | ); |
67 | ); |
52 | our @EXPORT_OK = @{$EXPORT_TAGS{prio}}; |
68 | our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready)); |
53 | |
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54 | { |
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55 | my @async; |
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56 | my $init; |
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57 | |
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58 | # this way of handling attributes simply is NOT scalable ;() |
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59 | sub import { |
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60 | no strict 'refs'; |
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61 | |
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62 | Coro->export_to_level (1, @_); |
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63 | |
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64 | my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; |
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65 | *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { |
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66 | my ($package, $ref) = (shift, shift); |
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67 | my @attrs; |
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68 | for (@_) { |
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69 | if ($_ eq "Coro") { |
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70 | push @async, $ref; |
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71 | unless ($init++) { |
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72 | eval q{ |
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73 | sub INIT { |
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74 | &async(pop @async) while @async; |
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75 | } |
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76 | }; |
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77 | } |
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78 | } else { |
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79 | push @attrs, $_; |
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80 | } |
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81 | } |
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82 | return $old ? $old->($package, $ref, @attrs) : @attrs; |
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83 | }; |
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84 | } |
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85 | |
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86 | } |
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87 | |
69 | |
88 | =over 4 |
70 | =over 4 |
89 | |
71 | |
90 | =item $main |
72 | =item $main |
91 | |
73 | |
… | |
… | |
99 | |
81 | |
100 | The current coroutine (the last coroutine switched to). The initial value |
82 | The current coroutine (the last coroutine switched to). The initial value |
101 | is C<$main> (of course). |
83 | is C<$main> (of course). |
102 | |
84 | |
103 | This variable is B<strictly> I<read-only>. It is provided for performance |
85 | This variable is B<strictly> I<read-only>. It is provided for performance |
104 | reasons. If performance is not essentiel you are encouraged to use the |
86 | reasons. If performance is not essential you are encouraged to use the |
105 | C<Coro::current> function instead. |
87 | C<Coro::current> function instead. |
106 | |
88 | |
107 | =cut |
89 | =cut |
108 | |
90 | |
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91 | $main->{desc} = "[main::]"; |
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92 | |
109 | # maybe some other module used Coro::Specific before... |
93 | # maybe some other module used Coro::Specific before... |
110 | $main->{specific} = $current->{specific} |
94 | $main->{_specific} = $current->{_specific} |
111 | if $current; |
95 | if $current; |
112 | |
96 | |
113 | _set_current $main; |
97 | _set_current $main; |
114 | |
98 | |
115 | sub current() { $current } |
99 | sub current() { $current } |
… | |
… | |
123 | This hook is overwritten by modules such as C<Coro::Timer> and |
107 | This hook is overwritten by modules such as C<Coro::Timer> and |
124 | C<Coro::Event> to wait on an external event that hopefully wake up a |
108 | C<Coro::Event> to wait on an external event that hopefully wake up a |
125 | coroutine so the scheduler can run it. |
109 | coroutine so the scheduler can run it. |
126 | |
110 | |
127 | Please note that if your callback recursively invokes perl (e.g. for event |
111 | Please note that if your callback recursively invokes perl (e.g. for event |
128 | handlers), then it must be prepared to be called recursively. |
112 | handlers), then it must be prepared to be called recursively itself. |
129 | |
113 | |
130 | =cut |
114 | =cut |
131 | |
115 | |
132 | $idle = sub { |
116 | $idle = sub { |
133 | print STDERR "FATAL: deadlock detected\n"; |
117 | require Carp; |
134 | exit (51); |
118 | Carp::croak ("FATAL: deadlock detected"); |
135 | }; |
119 | }; |
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120 | |
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121 | sub _cancel { |
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122 | my ($self) = @_; |
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123 | |
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124 | # free coroutine data and mark as destructed |
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125 | $self->_destroy |
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126 | or return; |
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127 | |
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128 | # call all destruction callbacks |
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129 | $_->(@{$self->{_status}}) |
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130 | for @{(delete $self->{_on_destroy}) || []}; |
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131 | } |
136 | |
132 | |
137 | # this coroutine is necessary because a coroutine |
133 | # this coroutine is necessary because a coroutine |
138 | # cannot destroy itself. |
134 | # cannot destroy itself. |
139 | my @destroy; |
135 | my @destroy; |
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136 | my $manager; |
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137 | |
140 | my $manager; $manager = new Coro sub { |
138 | $manager = new Coro sub { |
141 | while () { |
139 | while () { |
142 | # by overwriting the state object with the manager we destroy it |
140 | (shift @destroy)->_cancel |
143 | # while still being able to schedule this coroutine (in case it has |
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144 | # been readied multiple times. this is harmless since the manager |
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145 | # can be called as many times as neccessary and will always |
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146 | # remove itself from the runqueue |
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147 | while (@destroy) { |
141 | while @destroy; |
148 | my $coro = pop @destroy; |
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149 | $coro->{status} ||= []; |
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150 | $_->ready for @{delete $coro->{join} || []}; |
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151 | |
142 | |
152 | # the next line destroys the coro state, but keeps the |
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153 | # coroutine itself intact (we basically make it a zombie |
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154 | # coroutine that always runs the manager thread, so it's possible |
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155 | # to transfer() to this coroutine). |
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156 | $coro->_clone_state_from ($manager); |
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157 | } |
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158 | &schedule; |
143 | &schedule; |
159 | } |
144 | } |
160 | }; |
145 | }; |
161 | |
146 | $manager->desc ("[coro manager]"); |
162 | # static methods. not really. |
147 | $manager->prio (PRIO_MAX); |
163 | |
148 | |
164 | =back |
149 | =back |
165 | |
150 | |
166 | =head2 STATIC METHODS |
151 | =head2 STATIC METHODS |
167 | |
152 | |
… | |
… | |
173 | |
158 | |
174 | Create a new asynchronous coroutine and return it's coroutine object |
159 | Create a new asynchronous coroutine and return it's coroutine object |
175 | (usually unused). When the sub returns the new coroutine is automatically |
160 | (usually unused). When the sub returns the new coroutine is automatically |
176 | terminated. |
161 | terminated. |
177 | |
162 | |
178 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
163 | See the C<Coro::State::new> constructor for info about the coroutine |
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164 | environment in which coroutines run. |
179 | |
165 | |
180 | When the coroutine dies, the program will exit, just as in the main |
166 | Calling C<exit> in a coroutine will do the same as calling exit outside |
181 | program. |
167 | the coroutine. Likewise, when the coroutine dies, the program will exit, |
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168 | just as it would in the main program. |
182 | |
169 | |
183 | # create a new coroutine that just prints its arguments |
170 | # create a new coroutine that just prints its arguments |
184 | async { |
171 | async { |
185 | print "@_\n"; |
172 | print "@_\n"; |
186 | } 1,2,3,4; |
173 | } 1,2,3,4; |
187 | |
174 | |
188 | =cut |
175 | =cut |
189 | |
176 | |
190 | sub async(&@) { |
177 | sub async(&@) { |
191 | my $pid = new Coro @_; |
178 | my $coro = new Coro @_; |
192 | $pid->ready; |
179 | $coro->ready; |
193 | $pid |
180 | $coro |
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181 | } |
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182 | |
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183 | =item async_pool { ... } [@args...] |
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184 | |
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185 | Similar to C<async>, but uses a coroutine pool, so you should not call |
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186 | terminate or join (although you are allowed to), and you get a coroutine |
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187 | that might have executed other code already (which can be good or bad :). |
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188 | |
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189 | Also, the block is executed in an C<eval> context and a warning will be |
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190 | issued in case of an exception instead of terminating the program, as |
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191 | C<async> does. As the coroutine is being reused, stuff like C<on_destroy> |
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192 | will not work in the expected way, unless you call terminate or cancel, |
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193 | which somehow defeats the purpose of pooling. |
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194 | |
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195 | The priority will be reset to C<0> after each job, tracing will be |
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196 | disabled, the description will be reset and the default output filehandle |
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197 | gets restored, so you can change alkl these. Otherwise the coroutine will |
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198 | be re-used "as-is": most notably if you change other per-coroutine global |
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199 | stuff such as C<$/> you need to revert that change, which is most simply |
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200 | done by using local as in C< local $/ >. |
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201 | |
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202 | The pool size is limited to 8 idle coroutines (this can be adjusted by |
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203 | changing $Coro::POOL_SIZE), and there can be as many non-idle coros as |
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204 | required. |
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205 | |
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206 | If you are concerned about pooled coroutines growing a lot because a |
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207 | single C<async_pool> used a lot of stackspace you can e.g. C<async_pool |
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208 | { terminate }> once per second or so to slowly replenish the pool. In |
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209 | addition to that, when the stacks used by a handler grows larger than 16kb |
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210 | (adjustable with $Coro::POOL_RSS) it will also exit. |
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211 | |
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212 | =cut |
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213 | |
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214 | our $POOL_SIZE = 8; |
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215 | our $POOL_RSS = 16 * 1024; |
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216 | our @async_pool; |
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217 | |
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218 | sub pool_handler { |
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219 | my $cb; |
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220 | |
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221 | while () { |
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222 | eval { |
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223 | while () { |
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224 | _pool_1 $cb; |
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225 | &$cb; |
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226 | _pool_2 $cb; |
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227 | &schedule; |
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228 | } |
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229 | }; |
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230 | |
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231 | last if $@ eq "\3async_pool terminate\2\n"; |
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232 | warn $@ if $@; |
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233 | } |
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234 | } |
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235 | |
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236 | sub async_pool(&@) { |
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237 | # this is also inlined into the unlock_scheduler |
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238 | my $coro = (pop @async_pool) || new Coro \&pool_handler; |
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239 | |
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240 | $coro->{_invoke} = [@_]; |
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241 | $coro->ready; |
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242 | |
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243 | $coro |
194 | } |
244 | } |
195 | |
245 | |
196 | =item schedule |
246 | =item schedule |
197 | |
247 | |
198 | Calls the scheduler. Please note that the current coroutine will not be put |
248 | Calls the scheduler. Please note that the current coroutine will not be put |
… | |
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211 | # wake up sleeping coroutine |
261 | # wake up sleeping coroutine |
212 | $current->ready; |
262 | $current->ready; |
213 | undef $current; |
263 | undef $current; |
214 | }; |
264 | }; |
215 | |
265 | |
216 | # call schedule until event occured. |
266 | # call schedule until event occurred. |
217 | # in case we are woken up for other reasons |
267 | # in case we are woken up for other reasons |
218 | # (current still defined), loop. |
268 | # (current still defined), loop. |
219 | Coro::schedule while $current; |
269 | Coro::schedule while $current; |
220 | } |
270 | } |
221 | |
271 | |
… | |
… | |
223 | |
273 | |
224 | "Cede" to other coroutines. This function puts the current coroutine into the |
274 | "Cede" to other coroutines. This function puts the current coroutine into the |
225 | ready queue and calls C<schedule>, which has the effect of giving up the |
275 | ready queue and calls C<schedule>, which has the effect of giving up the |
226 | current "timeslice" to other coroutines of the same or higher priority. |
276 | current "timeslice" to other coroutines of the same or higher priority. |
227 | |
277 | |
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278 | =item Coro::cede_notself |
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279 | |
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280 | Works like cede, but is not exported by default and will cede to any |
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281 | coroutine, regardless of priority, once. |
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282 | |
228 | =item terminate [arg...] |
283 | =item terminate [arg...] |
229 | |
284 | |
230 | Terminates the current coroutine with the given status values (see L<cancel>). |
285 | Terminates the current coroutine with the given status values (see L<cancel>). |
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286 | |
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287 | =item killall |
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288 | |
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289 | Kills/terminates/cancels all coroutines except the currently running |
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290 | one. This is useful after a fork, either in the child or the parent, as |
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291 | usually only one of them should inherit the running coroutines. |
231 | |
292 | |
232 | =cut |
293 | =cut |
233 | |
294 | |
234 | sub terminate { |
295 | sub terminate { |
235 | $current->cancel (@_); |
296 | $current->cancel (@_); |
236 | } |
297 | } |
237 | |
298 | |
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299 | sub killall { |
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300 | for (Coro::State::list) { |
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301 | $_->cancel |
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302 | if $_ != $current && UNIVERSAL::isa $_, "Coro"; |
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303 | } |
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304 | } |
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305 | |
238 | =back |
306 | =back |
239 | |
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240 | # dynamic methods |
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241 | |
307 | |
242 | =head2 COROUTINE METHODS |
308 | =head2 COROUTINE METHODS |
243 | |
309 | |
244 | These are the methods you can call on coroutine objects. |
310 | These are the methods you can call on coroutine objects. |
245 | |
311 | |
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… | |
250 | Create a new coroutine and return it. When the sub returns the coroutine |
316 | Create a new coroutine and return it. When the sub returns the coroutine |
251 | automatically terminates as if C<terminate> with the returned values were |
317 | automatically terminates as if C<terminate> with the returned values were |
252 | called. To make the coroutine run you must first put it into the ready queue |
318 | called. To make the coroutine run you must first put it into the ready queue |
253 | by calling the ready method. |
319 | by calling the ready method. |
254 | |
320 | |
255 | Calling C<exit> in a coroutine will not work correctly, so do not do that. |
321 | See C<async> and C<Coro::State::new> for additional info about the |
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322 | coroutine environment. |
256 | |
323 | |
257 | =cut |
324 | =cut |
258 | |
325 | |
259 | sub _run_coro { |
326 | sub _run_coro { |
260 | terminate &{+shift}; |
327 | terminate &{+shift}; |
… | |
… | |
277 | Return wether the coroutine is currently the ready queue or not, |
344 | Return wether the coroutine is currently the ready queue or not, |
278 | |
345 | |
279 | =item $coroutine->cancel (arg...) |
346 | =item $coroutine->cancel (arg...) |
280 | |
347 | |
281 | Terminates the given coroutine and makes it return the given arguments as |
348 | Terminates the given coroutine and makes it return the given arguments as |
282 | status (default: the empty list). |
349 | status (default: the empty list). Never returns if the coroutine is the |
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350 | current coroutine. |
283 | |
351 | |
284 | =cut |
352 | =cut |
285 | |
353 | |
286 | sub cancel { |
354 | sub cancel { |
287 | my $self = shift; |
355 | my $self = shift; |
288 | $self->{status} = [@_]; |
356 | $self->{_status} = [@_]; |
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357 | |
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358 | if ($current == $self) { |
289 | push @destroy, $self; |
359 | push @destroy, $self; |
290 | $manager->ready; |
360 | $manager->ready; |
291 | &schedule if $current == $self; |
361 | &schedule while 1; |
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362 | } else { |
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363 | $self->_cancel; |
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364 | } |
292 | } |
365 | } |
293 | |
366 | |
294 | =item $coroutine->join |
367 | =item $coroutine->join |
295 | |
368 | |
296 | Wait until the coroutine terminates and return any values given to the |
369 | Wait until the coroutine terminates and return any values given to the |
297 | C<terminate> or C<cancel> functions. C<join> can be called multiple times |
370 | C<terminate> or C<cancel> functions. C<join> can be called concurrently |
298 | from multiple coroutine. |
371 | from multiple coroutines. |
299 | |
372 | |
300 | =cut |
373 | =cut |
301 | |
374 | |
302 | sub join { |
375 | sub join { |
303 | my $self = shift; |
376 | my $self = shift; |
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377 | |
304 | unless ($self->{status}) { |
378 | unless ($self->{_status}) { |
305 | push @{$self->{join}}, $current; |
379 | my $current = $current; |
306 | &schedule; |
380 | |
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381 | push @{$self->{_on_destroy}}, sub { |
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382 | $current->ready; |
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383 | undef $current; |
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384 | }; |
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385 | |
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386 | &schedule while $current; |
307 | } |
387 | } |
|
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388 | |
308 | wantarray ? @{$self->{status}} : $self->{status}[0]; |
389 | wantarray ? @{$self->{_status}} : $self->{_status}[0]; |
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390 | } |
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391 | |
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392 | =item $coroutine->on_destroy (\&cb) |
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393 | |
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394 | Registers a callback that is called when this coroutine gets destroyed, |
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395 | but before it is joined. The callback gets passed the terminate arguments, |
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396 | if any. |
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397 | |
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398 | =cut |
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399 | |
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400 | sub on_destroy { |
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401 | my ($self, $cb) = @_; |
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402 | |
|
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403 | push @{ $self->{_on_destroy} }, $cb; |
309 | } |
404 | } |
310 | |
405 | |
311 | =item $oldprio = $coroutine->prio ($newprio) |
406 | =item $oldprio = $coroutine->prio ($newprio) |
312 | |
407 | |
313 | Sets (or gets, if the argument is missing) the priority of the |
408 | Sets (or gets, if the argument is missing) the priority of the |
… | |
… | |
338 | =item $olddesc = $coroutine->desc ($newdesc) |
433 | =item $olddesc = $coroutine->desc ($newdesc) |
339 | |
434 | |
340 | Sets (or gets in case the argument is missing) the description for this |
435 | Sets (or gets in case the argument is missing) the description for this |
341 | coroutine. This is just a free-form string you can associate with a coroutine. |
436 | coroutine. This is just a free-form string you can associate with a coroutine. |
342 | |
437 | |
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438 | This method simply sets the C<< $coroutine->{desc} >> member to the given string. You |
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439 | can modify this member directly if you wish. |
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440 | |
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441 | =item $coroutine->throw ([$scalar]) |
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442 | |
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443 | If C<$throw> is specified and defined, it will be thrown as an exception |
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444 | inside the coroutine at the next convinient point in time (usually after |
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445 | it gains control at the next schedule/transfer/cede). Otherwise clears the |
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446 | exception object. |
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447 | |
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448 | The exception object will be thrown "as is" with the specified scalar in |
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449 | C<$@>, i.e. if it is a string, no line number or newline will be appended |
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450 | (unlike with C<die>). |
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451 | |
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452 | This can be used as a softer means than C<cancel> to ask a coroutine to |
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453 | end itself, although there is no guarentee that the exception will lead to |
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454 | termination, and if the exception isn't caught it might well end the whole |
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455 | program. |
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456 | |
343 | =cut |
457 | =cut |
344 | |
458 | |
345 | sub desc { |
459 | sub desc { |
346 | my $old = $_[0]{desc}; |
460 | my $old = $_[0]{desc}; |
347 | $_[0]{desc} = $_[1] if @_ > 1; |
461 | $_[0]{desc} = $_[1] if @_ > 1; |
348 | $old; |
462 | $old; |
349 | } |
463 | } |
350 | |
464 | |
351 | =back |
465 | =back |
352 | |
466 | |
353 | =head2 UTILITY FUNCTIONS |
467 | =head2 GLOBAL FUNCTIONS |
354 | |
468 | |
355 | =over 4 |
469 | =over 4 |
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470 | |
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471 | =item Coro::nready |
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472 | |
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473 | Returns the number of coroutines that are currently in the ready state, |
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474 | i.e. that can be switched to. The value C<0> means that the only runnable |
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475 | coroutine is the currently running one, so C<cede> would have no effect, |
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476 | and C<schedule> would cause a deadlock unless there is an idle handler |
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477 | that wakes up some coroutines. |
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478 | |
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479 | =item my $guard = Coro::guard { ... } |
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480 | |
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481 | This creates and returns a guard object. Nothing happens until the object |
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482 | gets destroyed, in which case the codeblock given as argument will be |
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483 | executed. This is useful to free locks or other resources in case of a |
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484 | runtime error or when the coroutine gets canceled, as in both cases the |
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485 | guard block will be executed. The guard object supports only one method, |
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486 | C<< ->cancel >>, which will keep the codeblock from being executed. |
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487 | |
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488 | Example: set some flag and clear it again when the coroutine gets canceled |
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489 | or the function returns: |
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490 | |
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491 | sub do_something { |
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492 | my $guard = Coro::guard { $busy = 0 }; |
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493 | $busy = 1; |
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494 | |
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495 | # do something that requires $busy to be true |
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496 | } |
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497 | |
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498 | =cut |
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499 | |
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500 | sub guard(&) { |
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501 | bless \(my $cb = $_[0]), "Coro::guard" |
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502 | } |
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503 | |
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504 | sub Coro::guard::cancel { |
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505 | ${$_[0]} = sub { }; |
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506 | } |
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507 | |
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508 | sub Coro::guard::DESTROY { |
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509 | ${$_[0]}->(); |
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510 | } |
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511 | |
356 | |
512 | |
357 | =item unblock_sub { ... } |
513 | =item unblock_sub { ... } |
358 | |
514 | |
359 | This utility function takes a BLOCK or code reference and "unblocks" it, |
515 | This utility function takes a BLOCK or code reference and "unblocks" it, |
360 | returning the new coderef. This means that the new coderef will return |
516 | returning the new coderef. This means that the new coderef will return |
361 | immediately without blocking, returning nothing, while the original code |
517 | immediately without blocking, returning nothing, while the original code |
362 | ref will be called (with parameters) from within its own coroutine. |
518 | ref will be called (with parameters) from within its own coroutine. |
363 | |
519 | |
364 | The reason this fucntion exists is that many event libraries (such as the |
520 | The reason this function exists is that many event libraries (such as the |
365 | venerable L<Event|Event> module) are not coroutine-safe (a weaker form |
521 | venerable L<Event|Event> module) are not coroutine-safe (a weaker form |
366 | of thread-safety). This means you must not block within event callbacks, |
522 | of thread-safety). This means you must not block within event callbacks, |
367 | otherwise you might suffer from crashes or worse. |
523 | otherwise you might suffer from crashes or worse. |
368 | |
524 | |
369 | This function allows your callbacks to block by executing them in another |
525 | This function allows your callbacks to block by executing them in another |
… | |
… | |
374 | In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when |
530 | In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when |
375 | creating event callbacks that want to block. |
531 | creating event callbacks that want to block. |
376 | |
532 | |
377 | =cut |
533 | =cut |
378 | |
534 | |
379 | our @unblock_pool; |
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380 | our @unblock_queue; |
535 | our @unblock_queue; |
381 | our $UNBLOCK_POOL_SIZE = 2; |
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382 | |
536 | |
383 | sub unblock_handler_ { |
537 | # we create a special coro because we want to cede, |
384 | while () { |
538 | # to reduce pressure on the coro pool (because most callbacks |
385 | my ($cb, @arg) = @{ delete $Coro::current->{arg} }; |
539 | # return immediately and can be reused) and because we cannot cede |
386 | $cb->(@arg); |
540 | # inside an event callback. |
387 | |
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388 | last if @unblock_pool >= $UNBLOCK_POOL_SIZE; |
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389 | push @unblock_pool, $Coro::current; |
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390 | schedule; |
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391 | } |
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392 | } |
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393 | |
|
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394 | our $unblock_scheduler = async { |
541 | our $unblock_scheduler = new Coro sub { |
395 | while () { |
542 | while () { |
396 | while (my $cb = pop @unblock_queue) { |
543 | while (my $cb = pop @unblock_queue) { |
397 | my $handler = (pop @unblock_pool or new Coro \&unblock_handler_); |
544 | # this is an inlined copy of async_pool |
398 | $handler->{arg} = $cb; |
545 | my $coro = (pop @async_pool) || new Coro \&pool_handler; |
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546 | |
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547 | $coro->{_invoke} = $cb; |
399 | $handler->ready; |
548 | $coro->ready; |
400 | cede; |
549 | cede; # for short-lived callbacks, this reduces pressure on the coro pool |
401 | } |
550 | } |
402 | |
551 | schedule; # sleep well |
403 | schedule; |
|
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404 | } |
552 | } |
405 | }; |
553 | }; |
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554 | $unblock_scheduler->desc ("[unblock_sub scheduler]"); |
406 | |
555 | |
407 | sub unblock_sub(&) { |
556 | sub unblock_sub(&) { |
408 | my $cb = shift; |
557 | my $cb = shift; |
409 | |
558 | |
410 | sub { |
559 | sub { |
411 | push @unblock_queue, [$cb, @_]; |
560 | unshift @unblock_queue, [$cb, @_]; |
412 | $unblock_scheduler->ready; |
561 | $unblock_scheduler->ready; |
413 | } |
562 | } |
414 | } |
563 | } |
415 | |
564 | |
416 | =back |
565 | =back |
… | |
… | |
423 | |
572 | |
424 | - you must make very sure that no coro is still active on global |
573 | - you must make very sure that no coro is still active on global |
425 | destruction. very bad things might happen otherwise (usually segfaults). |
574 | destruction. very bad things might happen otherwise (usually segfaults). |
426 | |
575 | |
427 | - this module is not thread-safe. You should only ever use this module |
576 | - this module is not thread-safe. You should only ever use this module |
428 | from the same thread (this requirement might be losened in the future |
577 | from the same thread (this requirement might be loosened in the future |
429 | to allow per-thread schedulers, but Coro::State does not yet allow |
578 | to allow per-thread schedulers, but Coro::State does not yet allow |
430 | this). |
579 | this). |
431 | |
580 | |
432 | =head1 SEE ALSO |
581 | =head1 SEE ALSO |
433 | |
582 | |
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583 | Lower level Configuration, Coroutine Environment: L<Coro::State>. |
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584 | |
|
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585 | Debugging: L<Coro::Debug>. |
|
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586 | |
434 | Support/Utility: L<Coro::Cont>, L<Coro::Specific>, L<Coro::State>, L<Coro::Util>. |
587 | Support/Utility: L<Coro::Specific>, L<Coro::Util>. |
435 | |
588 | |
436 | Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>. |
589 | Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>. |
437 | |
590 | |
438 | Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::Select>. |
591 | Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>. |
439 | |
592 | |
|
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593 | Compatibility: L<Coro::LWP>, L<Coro::Storable>, L<Coro::Select>. |
|
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594 | |
440 | Embedding: L<Coro:MakeMaker> |
595 | Embedding: L<Coro::MakeMaker>. |
441 | |
596 | |
442 | =head1 AUTHOR |
597 | =head1 AUTHOR |
443 | |
598 | |
444 | Marc Lehmann <schmorp@schmorp.de> |
599 | Marc Lehmann <schmorp@schmorp.de> |
445 | http://home.schmorp.de/ |
600 | http://home.schmorp.de/ |