… | |
… | |
16 | cede; # yield to coroutine |
16 | cede; # yield to coroutine |
17 | print "3\n"; |
17 | print "3\n"; |
18 | cede; # and again |
18 | cede; # and again |
19 | |
19 | |
20 | # use locking |
20 | # use locking |
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21 | use Coro::Semaphore; |
21 | my $lock = new Coro::Semaphore; |
22 | my $lock = new Coro::Semaphore; |
22 | my $locked; |
23 | my $locked; |
23 | |
24 | |
24 | $lock->down; |
25 | $lock->down; |
25 | $locked = 1; |
26 | $locked = 1; |
26 | $lock->up; |
27 | $lock->up; |
27 | |
28 | |
28 | =head1 DESCRIPTION |
29 | =head1 DESCRIPTION |
29 | |
30 | |
30 | This module collection manages coroutines. Coroutines are similar |
31 | This module collection manages coroutines. Coroutines are similar to |
31 | to threads but don't run in parallel at the same time even on SMP |
32 | threads but don't (in general) run in parallel at the same time even |
32 | machines. The specific flavor of coroutine used in this module also |
33 | on SMP machines. The specific flavor of coroutine used in this module |
33 | guarantees you that it will not switch between coroutines unless |
34 | also guarantees you that it will not switch between coroutines unless |
34 | necessary, at easily-identified points in your program, so locking and |
35 | necessary, at easily-identified points in your program, so locking and |
35 | parallel access are rarely an issue, making coroutine programming much |
36 | parallel access are rarely an issue, making coroutine programming much |
36 | safer than threads programming. |
37 | safer and easier than threads programming. |
37 | |
38 | |
38 | (Perl, however, does not natively support real threads but instead does a |
39 | Unlike a normal perl program, however, coroutines allow you to have |
39 | very slow and memory-intensive emulation of processes using threads. This |
40 | multiple running interpreters that share data, which is especially useful |
40 | is a performance win on Windows machines, and a loss everywhere else). |
41 | to code pseudo-parallel processes and for event-based programming, such as |
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42 | multiple HTTP-GET requests running concurrently. See L<Coro::AnyEvent> to |
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43 | learn more. |
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44 | |
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45 | Coroutines are also useful because Perl has no support for threads (the so |
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46 | called "threads" that perl offers are nothing more than the (bad) process |
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47 | emulation coming from the Windows platform: On standard operating systems |
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48 | they serve no purpose whatsoever, except by making your programs slow and |
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49 | making them use a lot of memory. Best disable them when building perl, or |
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50 | aks your software vendor/distributor to do it for you). |
41 | |
51 | |
42 | In this module, coroutines are defined as "callchain + lexical variables + |
52 | In this module, coroutines are defined as "callchain + lexical variables + |
43 | @_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain, |
53 | @_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain, |
44 | its own set of lexicals and its own set of perls most important global |
54 | its own set of lexicals and its own set of perls most important global |
45 | variables (see L<Coro::State> for more configuration). |
55 | variables (see L<Coro::State> for more configuration). |
46 | |
56 | |
47 | =cut |
57 | =cut |
48 | |
58 | |
49 | package Coro; |
59 | package Coro; |
50 | |
60 | |
51 | use strict; |
61 | use strict qw(vars subs); |
52 | no warnings "uninitialized"; |
62 | no warnings "uninitialized"; |
53 | |
63 | |
54 | use Coro::State; |
64 | use Coro::State; |
55 | |
65 | |
56 | use base qw(Coro::State Exporter); |
66 | use base qw(Coro::State Exporter); |
57 | |
67 | |
58 | our $idle; # idle handler |
68 | our $idle; # idle handler |
59 | our $main; # main coroutine |
69 | our $main; # main coroutine |
60 | our $current; # current coroutine |
70 | our $current; # current coroutine |
61 | |
71 | |
62 | our $VERSION = '4.51'; |
72 | our $VERSION = 5.0; |
63 | |
73 | |
64 | our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); |
74 | our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); |
65 | our %EXPORT_TAGS = ( |
75 | our %EXPORT_TAGS = ( |
66 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
76 | prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], |
67 | ); |
77 | ); |
68 | our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready)); |
78 | our @EXPORT_OK = (@{$EXPORT_TAGS{prio}}, qw(nready)); |
69 | |
79 | |
70 | =over 4 |
80 | =over 4 |
71 | |
81 | |
72 | =item $main |
82 | =item $Coro::main |
73 | |
83 | |
74 | This coroutine represents the main program. |
84 | This variable stores the coroutine object that represents the main |
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85 | program. While you cna C<ready> it and do most other things you can do to |
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86 | coroutines, it is mainly useful to compare again C<$Coro::current>, to see |
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87 | whether you are running in the main program or not. |
75 | |
88 | |
76 | =cut |
89 | =cut |
77 | |
90 | |
78 | $main = new Coro; |
91 | # $main is now being initialised by Coro::State |
79 | |
92 | |
80 | =item $current (or as function: current) |
93 | =item $Coro::current |
81 | |
94 | |
82 | The current coroutine (the last coroutine switched to). The initial value |
95 | The coroutine object representing the current coroutine (the last |
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96 | coroutine that the Coro scheduler switched to). The initial value is |
83 | is C<$main> (of course). |
97 | C<$Coro::main> (of course). |
84 | |
98 | |
85 | This variable is B<strictly> I<read-only>. It is provided for performance |
99 | This variable is B<strictly> I<read-only>. You can take copies of the |
86 | reasons. If performance is not essential you are encouraged to use the |
100 | value stored in it and use it as any other coroutine object, but you must |
87 | C<Coro::current> function instead. |
101 | not otherwise modify the variable itself. |
88 | |
102 | |
89 | =cut |
103 | =cut |
90 | |
104 | |
91 | $main->{desc} = "[main::]"; |
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92 | |
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93 | # maybe some other module used Coro::Specific before... |
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94 | $main->{_specific} = $current->{_specific} |
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95 | if $current; |
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96 | |
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97 | _set_current $main; |
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98 | |
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99 | sub current() { $current } |
105 | sub current() { $current } # [DEPRECATED] |
100 | |
106 | |
101 | =item $idle |
107 | =item $Coro::idle |
102 | |
108 | |
103 | A callback that is called whenever the scheduler finds no ready coroutines |
109 | This variable is mainly useful to integrate Coro into event loops. It is |
104 | to run. The default implementation prints "FATAL: deadlock detected" and |
110 | usually better to rely on L<Coro::AnyEvent> or LC<Coro::EV>, as this is |
105 | exits, because the program has no other way to continue. |
111 | pretty low-level functionality. |
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112 | |
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113 | This variable stores a callback that is called whenever the scheduler |
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114 | finds no ready coroutines to run. The default implementation prints |
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115 | "FATAL: deadlock detected" and exits, because the program has no other way |
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116 | to continue. |
106 | |
117 | |
107 | This hook is overwritten by modules such as C<Coro::Timer> and |
118 | This hook is overwritten by modules such as C<Coro::Timer> and |
108 | C<Coro::Event> to wait on an external event that hopefully wake up a |
119 | C<Coro::AnyEvent> to wait on an external event that hopefully wake up a |
109 | coroutine so the scheduler can run it. |
120 | coroutine so the scheduler can run it. |
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121 | |
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122 | Note that the callback I<must not>, under any circumstances, block |
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123 | the current coroutine. Normally, this is achieved by having an "idle |
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124 | coroutine" that calls the event loop and then blocks again, and then |
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125 | readying that coroutine in the idle handler. |
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126 | |
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127 | See L<Coro::Event> or L<Coro::AnyEvent> for examples of using this |
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128 | technique. |
110 | |
129 | |
111 | Please note that if your callback recursively invokes perl (e.g. for event |
130 | Please note that if your callback recursively invokes perl (e.g. for event |
112 | handlers), then it must be prepared to be called recursively itself. |
131 | handlers), then it must be prepared to be called recursively itself. |
113 | |
132 | |
114 | =cut |
133 | =cut |
… | |
… | |
125 | $self->_destroy |
144 | $self->_destroy |
126 | or return; |
145 | or return; |
127 | |
146 | |
128 | # call all destruction callbacks |
147 | # call all destruction callbacks |
129 | $_->(@{$self->{_status}}) |
148 | $_->(@{$self->{_status}}) |
130 | for @{(delete $self->{_on_destroy}) || []}; |
149 | for @{ delete $self->{_on_destroy} || [] }; |
131 | } |
150 | } |
132 | |
151 | |
133 | # this coroutine is necessary because a coroutine |
152 | # this coroutine is necessary because a coroutine |
134 | # cannot destroy itself. |
153 | # cannot destroy itself. |
135 | my @destroy; |
154 | my @destroy; |
… | |
… | |
141 | while @destroy; |
160 | while @destroy; |
142 | |
161 | |
143 | &schedule; |
162 | &schedule; |
144 | } |
163 | } |
145 | }; |
164 | }; |
146 | $manager->desc ("[coro manager]"); |
165 | $manager->{desc} = "[coro manager]"; |
147 | $manager->prio (PRIO_MAX); |
166 | $manager->prio (PRIO_MAX); |
148 | |
167 | |
149 | =back |
168 | =back |
150 | |
169 | |
151 | =head2 STATIC METHODS |
170 | =head2 SIMPLE COROUTINE CREATION |
152 | |
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153 | Static methods are actually functions that operate on the current coroutine only. |
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154 | |
171 | |
155 | =over 4 |
172 | =over 4 |
156 | |
173 | |
157 | =item async { ... } [@args...] |
174 | =item async { ... } [@args...] |
158 | |
175 | |
159 | Create a new asynchronous coroutine and return it's coroutine object |
176 | Create a new coroutine and return it's coroutine object (usually |
160 | (usually unused). When the sub returns the new coroutine is automatically |
177 | unused). The coroutine will be put into the ready queue, so |
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178 | it will start running automatically on the next scheduler run. |
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179 | |
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180 | The first argument is a codeblock/closure that should be executed in the |
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181 | coroutine. When it returns argument returns the coroutine is automatically |
161 | terminated. |
182 | terminated. |
162 | |
183 | |
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184 | The remaining arguments are passed as arguments to the closure. |
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185 | |
163 | See the C<Coro::State::new> constructor for info about the coroutine |
186 | See the C<Coro::State::new> constructor for info about the coroutine |
164 | environment in which coroutines run. |
187 | environment in which coroutines are executed. |
165 | |
188 | |
166 | Calling C<exit> in a coroutine will do the same as calling exit outside |
189 | Calling C<exit> in a coroutine will do the same as calling exit outside |
167 | the coroutine. Likewise, when the coroutine dies, the program will exit, |
190 | the coroutine. Likewise, when the coroutine dies, the program will exit, |
168 | just as it would in the main program. |
191 | just as it would in the main program. |
169 | |
192 | |
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193 | If you do not want that, you can provide a default C<die> handler, or |
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194 | simply avoid dieing (by use of C<eval>). |
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195 | |
170 | # create a new coroutine that just prints its arguments |
196 | Example: Create a new coroutine that just prints its arguments. |
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197 | |
171 | async { |
198 | async { |
172 | print "@_\n"; |
199 | print "@_\n"; |
173 | } 1,2,3,4; |
200 | } 1,2,3,4; |
174 | |
201 | |
175 | =cut |
202 | =cut |
… | |
… | |
181 | } |
208 | } |
182 | |
209 | |
183 | =item async_pool { ... } [@args...] |
210 | =item async_pool { ... } [@args...] |
184 | |
211 | |
185 | Similar to C<async>, but uses a coroutine pool, so you should not call |
212 | Similar to C<async>, but uses a coroutine pool, so you should not call |
186 | terminate or join (although you are allowed to), and you get a coroutine |
213 | terminate or join on it (although you are allowed to), and you get a |
187 | that might have executed other code already (which can be good or bad :). |
214 | coroutine that might have executed other code already (which can be good |
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215 | or bad :). |
188 | |
216 | |
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217 | On the plus side, this function is faster than creating (and destroying) |
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218 | a completly new coroutine, so if you need a lot of generic coroutines in |
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219 | quick successsion, use C<async_pool>, not C<async>. |
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220 | |
189 | Also, the block is executed in an C<eval> context and a warning will be |
221 | The code block is executed in an C<eval> context and a warning will be |
190 | issued in case of an exception instead of terminating the program, as |
222 | issued in case of an exception instead of terminating the program, as |
191 | C<async> does. As the coroutine is being reused, stuff like C<on_destroy> |
223 | C<async> does. As the coroutine is being reused, stuff like C<on_destroy> |
192 | will not work in the expected way, unless you call terminate or cancel, |
224 | will not work in the expected way, unless you call terminate or cancel, |
193 | which somehow defeats the purpose of pooling. |
225 | which somehow defeats the purpose of pooling (but is fine in the |
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226 | exceptional case). |
194 | |
227 | |
195 | The priority will be reset to C<0> after each job, tracing will be |
228 | The priority will be reset to C<0> after each run, tracing will be |
196 | disabled, the description will be reset and the default output filehandle |
229 | disabled, the description will be reset and the default output filehandle |
197 | gets restored, so you can change alkl these. Otherwise the coroutine will |
230 | gets restored, so you can change all these. Otherwise the coroutine will |
198 | be re-used "as-is": most notably if you change other per-coroutine global |
231 | be re-used "as-is": most notably if you change other per-coroutine global |
199 | stuff such as C<$/> you need to revert that change, which is most simply |
232 | stuff such as C<$/> you I<must needs> revert that change, which is most |
200 | done by using local as in C< local $/ >. |
233 | simply done by using local as in: C<< local $/ >>. |
201 | |
234 | |
202 | The pool size is limited to 8 idle coroutines (this can be adjusted by |
235 | The idle pool size is limited to C<8> idle coroutines (this can be |
203 | changing $Coro::POOL_SIZE), and there can be as many non-idle coros as |
236 | adjusted by changing $Coro::POOL_SIZE), but there can be as many non-idle |
204 | required. |
237 | coros as required. |
205 | |
238 | |
206 | If you are concerned about pooled coroutines growing a lot because a |
239 | If you are concerned about pooled coroutines growing a lot because a |
207 | single C<async_pool> used a lot of stackspace you can e.g. C<async_pool |
240 | single C<async_pool> used a lot of stackspace you can e.g. C<async_pool |
208 | { terminate }> once per second or so to slowly replenish the pool. In |
241 | { terminate }> once per second or so to slowly replenish the pool. In |
209 | addition to that, when the stacks used by a handler grows larger than 16kb |
242 | addition to that, when the stacks used by a handler grows larger than 16kb |
210 | (adjustable with $Coro::POOL_RSS) it will also exit. |
243 | (adjustable via $Coro::POOL_RSS) it will also be destroyed. |
211 | |
244 | |
212 | =cut |
245 | =cut |
213 | |
246 | |
214 | our $POOL_SIZE = 8; |
247 | our $POOL_SIZE = 8; |
215 | our $POOL_RSS = 16 * 1024; |
248 | our $POOL_RSS = 16 * 1024; |
… | |
… | |
226 | _pool_2 $cb; |
259 | _pool_2 $cb; |
227 | &schedule; |
260 | &schedule; |
228 | } |
261 | } |
229 | }; |
262 | }; |
230 | |
263 | |
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264 | if ($@) { |
231 | last if $@ eq "\3async_pool terminate\2\n"; |
265 | last if $@ eq "\3async_pool terminate\2\n"; |
232 | warn $@ if $@; |
266 | warn $@; |
|
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267 | } |
233 | } |
268 | } |
234 | } |
269 | } |
235 | |
270 | |
236 | sub async_pool(&@) { |
271 | sub async_pool(&@) { |
237 | # this is also inlined into the unlock_scheduler |
272 | # this is also inlined into the unblock_scheduler |
238 | my $coro = (pop @async_pool) || new Coro \&pool_handler; |
273 | my $coro = (pop @async_pool) || new Coro \&pool_handler; |
239 | |
274 | |
240 | $coro->{_invoke} = [@_]; |
275 | $coro->{_invoke} = [@_]; |
241 | $coro->ready; |
276 | $coro->ready; |
242 | |
277 | |
243 | $coro |
278 | $coro |
244 | } |
279 | } |
245 | |
280 | |
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281 | =back |
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282 | |
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283 | =head2 STATIC METHODS |
|
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284 | |
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285 | Static methods are actually functions that operate on the current coroutine. |
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286 | |
|
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287 | =over 4 |
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288 | |
246 | =item schedule |
289 | =item schedule |
247 | |
290 | |
248 | Calls the scheduler. Please note that the current coroutine will not be put |
291 | Calls the scheduler. The scheduler will find the next coroutine that is |
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292 | to be run from the ready queue and switches to it. The next coroutine |
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293 | to be run is simply the one with the highest priority that is longest |
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294 | in its ready queue. If there is no coroutine ready, it will clal the |
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295 | C<$Coro::idle> hook. |
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296 | |
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297 | Please note that the current coroutine will I<not> be put into the ready |
249 | into the ready queue, so calling this function usually means you will |
298 | queue, so calling this function usually means you will never be called |
250 | never be called again unless something else (e.g. an event handler) calls |
299 | again unless something else (e.g. an event handler) calls C<< ->ready >>, |
251 | ready. |
300 | thus waking you up. |
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301 | |
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302 | This makes C<schedule> I<the> generic method to use to block the current |
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303 | coroutine and wait for events: first you remember the current coroutine in |
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304 | a variable, then arrange for some callback of yours to call C<< ->ready |
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305 | >> on that once some event happens, and last you call C<schedule> to put |
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306 | yourself to sleep. Note that a lot of things can wake your coroutine up, |
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307 | so you need to check whether the event indeed happened, e.g. by storing the |
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308 | status in a variable. |
252 | |
309 | |
253 | The canonical way to wait on external events is this: |
310 | The canonical way to wait on external events is this: |
254 | |
311 | |
255 | { |
312 | { |
256 | # remember current coroutine |
313 | # remember current coroutine |
… | |
… | |
269 | Coro::schedule while $current; |
326 | Coro::schedule while $current; |
270 | } |
327 | } |
271 | |
328 | |
272 | =item cede |
329 | =item cede |
273 | |
330 | |
274 | "Cede" to other coroutines. This function puts the current coroutine into the |
331 | "Cede" to other coroutines. This function puts the current coroutine into |
275 | ready queue and calls C<schedule>, which has the effect of giving up the |
332 | the ready queue and calls C<schedule>, which has the effect of giving |
276 | current "timeslice" to other coroutines of the same or higher priority. |
333 | up the current "timeslice" to other coroutines of the same or higher |
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334 | priority. Once your coroutine gets its turn again it will automatically be |
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335 | resumed. |
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336 | |
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337 | This function is often called C<yield> in other languages. |
277 | |
338 | |
278 | =item Coro::cede_notself |
339 | =item Coro::cede_notself |
279 | |
340 | |
280 | Works like cede, but is not exported by default and will cede to any |
341 | Works like cede, but is not exported by default and will cede to I<any> |
281 | coroutine, regardless of priority, once. |
342 | coroutine, regardless of priority. This is useful sometimes to ensure |
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343 | progress is made. |
282 | |
344 | |
283 | =item terminate [arg...] |
345 | =item terminate [arg...] |
284 | |
346 | |
285 | Terminates the current coroutine with the given status values (see L<cancel>). |
347 | Terminates the current coroutine with the given status values (see L<cancel>). |
286 | |
348 | |
287 | =item killall |
349 | =item killall |
288 | |
350 | |
289 | Kills/terminates/cancels all coroutines except the currently running |
351 | Kills/terminates/cancels all coroutines except the currently running |
290 | one. This is useful after a fork, either in the child or the parent, as |
352 | one. This is useful after a fork, either in the child or the parent, as |
291 | usually only one of them should inherit the running coroutines. |
353 | usually only one of them should inherit the running coroutines. |
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354 | |
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355 | Note that while this will try to free some of the main programs resources, |
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356 | you cannot free all of them, so if a coroutine that is not the main |
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357 | program calls this function, there will be some one-time resource leak. |
292 | |
358 | |
293 | =cut |
359 | =cut |
294 | |
360 | |
295 | sub terminate { |
361 | sub terminate { |
296 | $current->cancel (@_); |
362 | $current->cancel (@_); |
… | |
… | |
305 | |
371 | |
306 | =back |
372 | =back |
307 | |
373 | |
308 | =head2 COROUTINE METHODS |
374 | =head2 COROUTINE METHODS |
309 | |
375 | |
310 | These are the methods you can call on coroutine objects. |
376 | These are the methods you can call on coroutine objects (or to create |
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377 | them). |
311 | |
378 | |
312 | =over 4 |
379 | =over 4 |
313 | |
380 | |
314 | =item new Coro \&sub [, @args...] |
381 | =item new Coro \&sub [, @args...] |
315 | |
382 | |
316 | Create a new coroutine and return it. When the sub returns the coroutine |
383 | Create a new coroutine and return it. When the sub returns, the coroutine |
317 | automatically terminates as if C<terminate> with the returned values were |
384 | automatically terminates as if C<terminate> with the returned values were |
318 | called. To make the coroutine run you must first put it into the ready queue |
385 | called. To make the coroutine run you must first put it into the ready |
319 | by calling the ready method. |
386 | queue by calling the ready method. |
320 | |
387 | |
321 | See C<async> and C<Coro::State::new> for additional info about the |
388 | See C<async> and C<Coro::State::new> for additional info about the |
322 | coroutine environment. |
389 | coroutine environment. |
323 | |
390 | |
324 | =cut |
391 | =cut |
… | |
… | |
333 | $class->SUPER::new (\&_run_coro, @_) |
400 | $class->SUPER::new (\&_run_coro, @_) |
334 | } |
401 | } |
335 | |
402 | |
336 | =item $success = $coroutine->ready |
403 | =item $success = $coroutine->ready |
337 | |
404 | |
338 | Put the given coroutine into the ready queue (according to it's priority) |
405 | Put the given coroutine into the end of its ready queue (there is one |
339 | and return true. If the coroutine is already in the ready queue, do nothing |
406 | queue for each priority) and return true. If the coroutine is already in |
340 | and return false. |
407 | the ready queue, do nothing and return false. |
|
|
408 | |
|
|
409 | This ensures that the scheduler will resume this coroutine automatically |
|
|
410 | once all the coroutines of higher priority and all coroutines of the same |
|
|
411 | priority that were put into the ready queue earlier have been resumed. |
341 | |
412 | |
342 | =item $is_ready = $coroutine->is_ready |
413 | =item $is_ready = $coroutine->is_ready |
343 | |
414 | |
344 | Return wether the coroutine is currently the ready queue or not, |
415 | Return whether the coroutine is currently the ready queue or not, |
345 | |
416 | |
346 | =item $coroutine->cancel (arg...) |
417 | =item $coroutine->cancel (arg...) |
347 | |
418 | |
348 | Terminates the given coroutine and makes it return the given arguments as |
419 | Terminates the given coroutine and makes it return the given arguments as |
349 | status (default: the empty list). Never returns if the coroutine is the |
420 | status (default: the empty list). Never returns if the coroutine is the |
… | |
… | |
362 | } else { |
433 | } else { |
363 | $self->_cancel; |
434 | $self->_cancel; |
364 | } |
435 | } |
365 | } |
436 | } |
366 | |
437 | |
|
|
438 | =item $coroutine->throw ([$scalar]) |
|
|
439 | |
|
|
440 | If C<$throw> is specified and defined, it will be thrown as an exception |
|
|
441 | inside the coroutine at the next convenient point in time (usually after |
|
|
442 | it gains control at the next schedule/transfer/cede). Otherwise clears the |
|
|
443 | exception object. |
|
|
444 | |
|
|
445 | The exception object will be thrown "as is" with the specified scalar in |
|
|
446 | C<$@>, i.e. if it is a string, no line number or newline will be appended |
|
|
447 | (unlike with C<die>). |
|
|
448 | |
|
|
449 | This can be used as a softer means than C<cancel> to ask a coroutine to |
|
|
450 | end itself, although there is no guarantee that the exception will lead to |
|
|
451 | termination, and if the exception isn't caught it might well end the whole |
|
|
452 | program. |
|
|
453 | |
|
|
454 | You might also think of C<throw> as being the moral equivalent of |
|
|
455 | C<kill>ing a coroutine with a signal (in this case, a scalar). |
|
|
456 | |
367 | =item $coroutine->join |
457 | =item $coroutine->join |
368 | |
458 | |
369 | Wait until the coroutine terminates and return any values given to the |
459 | Wait until the coroutine terminates and return any values given to the |
370 | C<terminate> or C<cancel> functions. C<join> can be called concurrently |
460 | C<terminate> or C<cancel> functions. C<join> can be called concurrently |
371 | from multiple coroutines. |
461 | from multiple coroutines, and all will be resumed and given the status |
|
|
462 | return once the C<$coroutine> terminates. |
372 | |
463 | |
373 | =cut |
464 | =cut |
374 | |
465 | |
375 | sub join { |
466 | sub join { |
376 | my $self = shift; |
467 | my $self = shift; |
… | |
… | |
391 | |
482 | |
392 | =item $coroutine->on_destroy (\&cb) |
483 | =item $coroutine->on_destroy (\&cb) |
393 | |
484 | |
394 | Registers a callback that is called when this coroutine gets destroyed, |
485 | Registers a callback that is called when this coroutine gets destroyed, |
395 | but before it is joined. The callback gets passed the terminate arguments, |
486 | but before it is joined. The callback gets passed the terminate arguments, |
396 | if any. |
487 | if any, and I<must not> die, under any circumstances. |
397 | |
488 | |
398 | =cut |
489 | =cut |
399 | |
490 | |
400 | sub on_destroy { |
491 | sub on_destroy { |
401 | my ($self, $cb) = @_; |
492 | my ($self, $cb) = @_; |
… | |
… | |
431 | higher values mean lower priority, just as in unix). |
522 | higher values mean lower priority, just as in unix). |
432 | |
523 | |
433 | =item $olddesc = $coroutine->desc ($newdesc) |
524 | =item $olddesc = $coroutine->desc ($newdesc) |
434 | |
525 | |
435 | Sets (or gets in case the argument is missing) the description for this |
526 | Sets (or gets in case the argument is missing) the description for this |
436 | coroutine. This is just a free-form string you can associate with a coroutine. |
527 | coroutine. This is just a free-form string you can associate with a |
|
|
528 | coroutine. |
437 | |
529 | |
438 | This method simply sets the C<< $coroutine->{desc} >> member to the given string. You |
530 | This method simply sets the C<< $coroutine->{desc} >> member to the given |
439 | can modify this member directly if you wish. |
531 | string. You can modify this member directly if you wish. |
440 | |
|
|
441 | =item $coroutine->throw ([$scalar]) |
|
|
442 | |
|
|
443 | If C<$throw> is specified and defined, it will be thrown as an exception |
|
|
444 | inside the coroutine at the next convinient point in time (usually after |
|
|
445 | it gains control at the next schedule/transfer/cede). Otherwise clears the |
|
|
446 | exception object. |
|
|
447 | |
|
|
448 | The exception object will be thrown "as is" with the specified scalar in |
|
|
449 | C<$@>, i.e. if it is a string, no line number or newline will be appended |
|
|
450 | (unlike with C<die>). |
|
|
451 | |
|
|
452 | This can be used as a softer means than C<cancel> to ask a coroutine to |
|
|
453 | end itself, although there is no guarentee that the exception will lead to |
|
|
454 | termination, and if the exception isn't caught it might well end the whole |
|
|
455 | program. |
|
|
456 | |
532 | |
457 | =cut |
533 | =cut |
458 | |
534 | |
459 | sub desc { |
535 | sub desc { |
460 | my $old = $_[0]{desc}; |
536 | my $old = $_[0]{desc}; |
… | |
… | |
469 | =over 4 |
545 | =over 4 |
470 | |
546 | |
471 | =item Coro::nready |
547 | =item Coro::nready |
472 | |
548 | |
473 | Returns the number of coroutines that are currently in the ready state, |
549 | Returns the number of coroutines that are currently in the ready state, |
474 | i.e. that can be switched to. The value C<0> means that the only runnable |
550 | i.e. that can be switched to by calling C<schedule> directory or |
|
|
551 | indirectly. The value C<0> means that the only runnable coroutine is the |
475 | coroutine is the currently running one, so C<cede> would have no effect, |
552 | currently running one, so C<cede> would have no effect, and C<schedule> |
476 | and C<schedule> would cause a deadlock unless there is an idle handler |
553 | would cause a deadlock unless there is an idle handler that wakes up some |
477 | that wakes up some coroutines. |
554 | coroutines. |
478 | |
555 | |
479 | =item my $guard = Coro::guard { ... } |
556 | =item my $guard = Coro::guard { ... } |
480 | |
557 | |
481 | This creates and returns a guard object. Nothing happens until the object |
558 | This creates and returns a guard object. Nothing happens until the object |
482 | gets destroyed, in which case the codeblock given as argument will be |
559 | gets destroyed, in which case the codeblock given as argument will be |
… | |
… | |
511 | |
588 | |
512 | |
589 | |
513 | =item unblock_sub { ... } |
590 | =item unblock_sub { ... } |
514 | |
591 | |
515 | This utility function takes a BLOCK or code reference and "unblocks" it, |
592 | This utility function takes a BLOCK or code reference and "unblocks" it, |
516 | returning the new coderef. This means that the new coderef will return |
593 | returning a new coderef. Unblocking means that calling the new coderef |
517 | immediately without blocking, returning nothing, while the original code |
594 | will return immediately without blocking, returning nothing, while the |
518 | ref will be called (with parameters) from within its own coroutine. |
595 | original code ref will be called (with parameters) from within another |
|
|
596 | coroutine. |
519 | |
597 | |
520 | The reason this function exists is that many event libraries (such as the |
598 | The reason this function exists is that many event libraries (such as the |
521 | venerable L<Event|Event> module) are not coroutine-safe (a weaker form |
599 | venerable L<Event|Event> module) are not coroutine-safe (a weaker form |
522 | of thread-safety). This means you must not block within event callbacks, |
600 | of thread-safety). This means you must not block within event callbacks, |
523 | otherwise you might suffer from crashes or worse. |
601 | otherwise you might suffer from crashes or worse. The only event library |
|
|
602 | currently known that is safe to use without C<unblock_sub> is L<EV>. |
524 | |
603 | |
525 | This function allows your callbacks to block by executing them in another |
604 | This function allows your callbacks to block by executing them in another |
526 | coroutine where it is safe to block. One example where blocking is handy |
605 | coroutine where it is safe to block. One example where blocking is handy |
527 | is when you use the L<Coro::AIO|Coro::AIO> functions to save results to |
606 | is when you use the L<Coro::AIO|Coro::AIO> functions to save results to |
528 | disk. |
607 | disk, for example. |
529 | |
608 | |
530 | In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when |
609 | In short: simply use C<unblock_sub { ... }> instead of C<sub { ... }> when |
531 | creating event callbacks that want to block. |
610 | creating event callbacks that want to block. |
|
|
611 | |
|
|
612 | If your handler does not plan to block (e.g. simply sends a message to |
|
|
613 | another coroutine, or puts some other coroutine into the ready queue), |
|
|
614 | there is no reason to use C<unblock_sub>. |
|
|
615 | |
|
|
616 | Note that you also need to use C<unblock_sub> for any other callbacks that |
|
|
617 | are indirectly executed by any C-based event loop. For example, when you |
|
|
618 | use a module that uses L<AnyEvent> (and you use L<Coro::AnyEvent>) and it |
|
|
619 | provides callbacks that are the result of some event callback, then you |
|
|
620 | must not block either, or use C<unblock_sub>. |
532 | |
621 | |
533 | =cut |
622 | =cut |
534 | |
623 | |
535 | our @unblock_queue; |
624 | our @unblock_queue; |
536 | |
625 | |
… | |
… | |
549 | cede; # for short-lived callbacks, this reduces pressure on the coro pool |
638 | cede; # for short-lived callbacks, this reduces pressure on the coro pool |
550 | } |
639 | } |
551 | schedule; # sleep well |
640 | schedule; # sleep well |
552 | } |
641 | } |
553 | }; |
642 | }; |
554 | $unblock_scheduler->desc ("[unblock_sub scheduler]"); |
643 | $unblock_scheduler->{desc} = "[unblock_sub scheduler]"; |
555 | |
644 | |
556 | sub unblock_sub(&) { |
645 | sub unblock_sub(&) { |
557 | my $cb = shift; |
646 | my $cb = shift; |
558 | |
647 | |
559 | sub { |
648 | sub { |
… | |
… | |
568 | |
657 | |
569 | 1; |
658 | 1; |
570 | |
659 | |
571 | =head1 BUGS/LIMITATIONS |
660 | =head1 BUGS/LIMITATIONS |
572 | |
661 | |
573 | - you must make very sure that no coro is still active on global |
662 | =over 4 |
574 | destruction. very bad things might happen otherwise (usually segfaults). |
|
|
575 | |
663 | |
|
|
664 | =item fork with pthread backend |
|
|
665 | |
|
|
666 | When Coro is compiled using the pthread backend (which isn't recommended |
|
|
667 | but required on many BSDs as their libcs are completely broken), then |
|
|
668 | coroutines will not survive a fork. There is no known workaround except to |
|
|
669 | fix your libc and use a saner backend. |
|
|
670 | |
|
|
671 | =item perl process emulation ("threads") |
|
|
672 | |
576 | - this module is not thread-safe. You should only ever use this module |
673 | This module is not perl-pseudo-thread-safe. You should only ever use this |
577 | from the same thread (this requirement might be loosened in the future |
674 | module from the same thread (this requirement might be removed in the |
578 | to allow per-thread schedulers, but Coro::State does not yet allow |
675 | future to allow per-thread schedulers, but Coro::State does not yet allow |
579 | this). |
676 | this). I recommend disabling thread support and using processes, as having |
|
|
677 | the windows process emulation enabled under unix roughly halves perl |
|
|
678 | performance, even when not used. |
|
|
679 | |
|
|
680 | =item coroutine switching not signal safe |
|
|
681 | |
|
|
682 | You must not switch to another coroutine from within a signal handler |
|
|
683 | (only relevant with %SIG - most event libraries provide safe signals). |
|
|
684 | |
|
|
685 | That means you I<MUST NOT> call any function that might "block" the |
|
|
686 | current coroutine - C<cede>, C<schedule> C<< Coro::Semaphore->down >> or |
|
|
687 | anything that calls those. Everything else, including calling C<ready>, |
|
|
688 | works. |
|
|
689 | |
|
|
690 | =back |
|
|
691 | |
580 | |
692 | |
581 | =head1 SEE ALSO |
693 | =head1 SEE ALSO |
582 | |
694 | |
583 | Lower level Configuration, Coroutine Environment: L<Coro::State>. |
695 | Event-Loop integration: L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>. |
584 | |
696 | |
585 | Debugging: L<Coro::Debug>. |
697 | Debugging: L<Coro::Debug>. |
586 | |
698 | |
587 | Support/Utility: L<Coro::Specific>, L<Coro::Util>. |
699 | Support/Utility: L<Coro::Specific>, L<Coro::Util>. |
588 | |
700 | |
589 | Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>. |
701 | Locking/IPC: L<Coro::Signal>, L<Coro::Channel>, L<Coro::Semaphore>, L<Coro::SemaphoreSet>, L<Coro::RWLock>. |
590 | |
702 | |
591 | Event/IO: L<Coro::Timer>, L<Coro::Event>, L<Coro::Handle>, L<Coro::Socket>. |
703 | IO/Timers: L<Coro::Timer>, L<Coro::Handle>, L<Coro::Socket>, L<Coro::AIO>. |
592 | |
704 | |
593 | Compatibility: L<Coro::LWP>, L<Coro::Storable>, L<Coro::Select>. |
705 | Compatibility: L<Coro::LWP>, L<Coro::BDB>, L<Coro::Storable>, L<Coro::Select>. |
594 | |
706 | |
595 | Embedding: L<Coro::MakeMaker>. |
707 | XS API: L<Coro::MakeMaker>. |
|
|
708 | |
|
|
709 | Low level Configuration, Coroutine Environment: L<Coro::State>. |
596 | |
710 | |
597 | =head1 AUTHOR |
711 | =head1 AUTHOR |
598 | |
712 | |
599 | Marc Lehmann <schmorp@schmorp.de> |
713 | Marc Lehmann <schmorp@schmorp.de> |
600 | http://home.schmorp.de/ |
714 | http://home.schmorp.de/ |