1 | NAME |
1 | NAME |
2 | Coro - coroutine process abstraction |
2 | Coro - coroutine process abstraction |
3 | |
3 | |
4 | SYNOPSIS |
4 | SYNOPSIS |
5 | use Coro; |
5 | use Coro; |
6 | |
6 | |
7 | async { |
7 | async { |
8 | # some asynchronous thread of execution |
8 | # some asynchronous thread of execution |
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9 | print "2\n"; |
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10 | cede; # yield back to main |
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11 | print "4\n"; |
9 | }; |
12 | }; |
10 | |
13 | print "1\n"; |
11 | # alternatively create an async process like this: |
14 | cede; # yield to coroutine |
12 | |
15 | print "3\n"; |
13 | sub some_func : Coro { |
16 | cede; # and again |
14 | # some more async code |
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15 | } |
17 | |
16 | |
18 | # use locking |
17 | cede; |
19 | use Coro::Semaphore; |
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20 | my $lock = new Coro::Semaphore; |
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21 | my $locked; |
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22 | |
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23 | $lock->down; |
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24 | $locked = 1; |
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25 | $lock->up; |
18 | |
26 | |
19 | DESCRIPTION |
27 | DESCRIPTION |
20 | This module collection manages coroutines. Coroutines are similar to |
28 | This module collection manages coroutines. Coroutines are similar to |
21 | threads but don't run in parallel. |
29 | threads but don't (in general) run in parallel at the same time even on |
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30 | SMP machines. The specific flavor of coroutine used in this module also |
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31 | guarantees you that it will not switch between coroutines unless |
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32 | necessary, at easily-identified points in your program, so locking and |
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33 | parallel access are rarely an issue, making coroutine programming much |
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34 | safer and easier than threads programming. |
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35 | |
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36 | Unlike a normal perl program, however, coroutines allow you to have |
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37 | multiple running interpreters that share data, which is especially |
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38 | useful to code pseudo-parallel processes and for event-based |
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39 | programming, such as multiple HTTP-GET requests running concurrently. |
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40 | See Coro::AnyEvent to learn more. |
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41 | |
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42 | Coroutines are also useful because Perl has no support for threads (the |
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43 | so called "threads" that perl offers are nothing more than the (bad) |
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44 | process emulation coming from the Windows platform: On standard |
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45 | operating systems they serve no purpose whatsoever, except by making |
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46 | your programs slow and making them use a lot of memory. Best disable |
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47 | them when building perl, or aks your software vendor/distributor to do |
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48 | it for you). |
22 | |
49 | |
23 | In this module, coroutines are defined as "callchain + lexical variables |
50 | In this module, coroutines are defined as "callchain + lexical variables |
24 | + @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own |
51 | + @_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own |
25 | callchain, it's own set of lexicals and it's own set of perl's most |
52 | callchain, its own set of lexicals and its own set of perls most |
26 | important global variables. |
53 | important global variables (see Coro::State for more configuration). |
27 | |
54 | |
28 | $main |
55 | $Coro::main |
29 | This coroutine represents the main program. |
56 | This variable stores the coroutine object that represents the main |
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57 | program. While you cna "ready" it and do most other things you can |
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58 | do to coroutines, it is mainly useful to compare again |
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59 | $Coro::current, to see whether you are running in the main program |
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60 | or not. |
30 | |
61 | |
31 | $current (or as function: current) |
62 | $Coro::current |
32 | The current coroutine (the last coroutine switched to). The initial |
63 | The coroutine object representing the current coroutine (the last |
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64 | coroutine that the Coro scheduler switched to). The initial value is |
33 | value is $main (of course). |
65 | $Coro::main (of course). |
34 | |
66 | |
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67 | This variable is strictly *read-only*. You can take copies of the |
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68 | value stored in it and use it as any other coroutine object, but you |
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69 | must not otherwise modify the variable itself. |
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70 | |
35 | $idle |
71 | $Coro::idle |
36 | The coroutine to switch to when no other coroutine is running. The |
72 | This variable is mainly useful to integrate Coro into event loops. |
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73 | It is usually better to rely on Coro::AnyEvent or L"Coro::EV", as |
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74 | this is pretty low-level functionality. |
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75 | |
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76 | This variable stores a callback that is called whenever the |
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77 | scheduler finds no ready coroutines to run. The default |
37 | default implementation prints "FATAL: deadlock detected" and exits. |
78 | implementation prints "FATAL: deadlock detected" and exits, because |
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79 | the program has no other way to continue. |
38 | |
80 | |
39 | STATIC METHODS |
81 | This hook is overwritten by modules such as "Coro::Timer" and |
40 | Static methods are actually functions that operate on the current |
82 | "Coro::AnyEvent" to wait on an external event that hopefully wake up |
41 | process only. |
83 | a coroutine so the scheduler can run it. |
42 | |
84 | |
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85 | Note that the callback *must not*, under any circumstances, block |
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86 | the current coroutine. Normally, this is achieved by having an "idle |
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87 | coroutine" that calls the event loop and then blocks again, and then |
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88 | readying that coroutine in the idle handler. |
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89 | |
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90 | See Coro::Event or Coro::AnyEvent for examples of using this |
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91 | technique. |
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92 | |
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93 | Please note that if your callback recursively invokes perl (e.g. for |
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94 | event handlers), then it must be prepared to be called recursively |
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95 | itself. |
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96 | |
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97 | SIMPLE COROUTINE CREATION |
43 | async { ... } [@args...] |
98 | async { ... } [@args...] |
44 | Create a new asynchronous process and return it's process object |
99 | Create a new coroutine and return it's coroutine object (usually |
45 | (usually unused). When the sub returns the new process is |
100 | unused). The coroutine will be put into the ready queue, so it will |
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101 | start running automatically on the next scheduler run. |
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102 | |
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103 | The first argument is a codeblock/closure that should be executed in |
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104 | the coroutine. When it returns argument returns the coroutine is |
46 | automatically terminated. |
105 | automatically terminated. |
47 | |
106 | |
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107 | The remaining arguments are passed as arguments to the closure. |
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108 | |
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109 | See the "Coro::State::new" constructor for info about the coroutine |
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110 | environment in which coroutines are executed. |
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111 | |
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112 | Calling "exit" in a coroutine will do the same as calling exit |
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113 | outside the coroutine. Likewise, when the coroutine dies, the |
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114 | program will exit, just as it would in the main program. |
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115 | |
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116 | If you do not want that, you can provide a default "die" handler, or |
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117 | simply avoid dieing (by use of "eval"). |
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118 | |
48 | # create a new coroutine that just prints its arguments |
119 | Example: Create a new coroutine that just prints its arguments. |
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120 | |
49 | async { |
121 | async { |
50 | print "@_\n"; |
122 | print "@_\n"; |
51 | } 1,2,3,4; |
123 | } 1,2,3,4; |
52 | |
124 | |
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125 | async_pool { ... } [@args...] |
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126 | Similar to "async", but uses a coroutine pool, so you should not |
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127 | call terminate or join on it (although you are allowed to), and you |
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128 | get a coroutine that might have executed other code already (which |
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129 | can be good or bad :). |
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130 | |
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131 | On the plus side, this function is about twice as fast as creating |
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132 | (and destroying) a completely new coroutine, so if you need a lot of |
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133 | generic coroutines in quick successsion, use "async_pool", not |
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134 | "async". |
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135 | |
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136 | The code block is executed in an "eval" context and a warning will |
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137 | be issued in case of an exception instead of terminating the |
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138 | program, as "async" does. As the coroutine is being reused, stuff |
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139 | like "on_destroy" will not work in the expected way, unless you call |
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140 | terminate or cancel, which somehow defeats the purpose of pooling |
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141 | (but is fine in the exceptional case). |
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142 | |
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143 | The priority will be reset to 0 after each run, tracing will be |
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144 | disabled, the description will be reset and the default output |
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145 | filehandle gets restored, so you can change all these. Otherwise the |
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146 | coroutine will be re-used "as-is": most notably if you change other |
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147 | per-coroutine global stuff such as $/ you *must needs* revert that |
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148 | change, which is most simply done by using local as in: "local $/". |
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149 | |
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150 | The idle pool size is limited to 8 idle coroutines (this can be |
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151 | adjusted by changing $Coro::POOL_SIZE), but there can be as many |
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152 | non-idle coros as required. |
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153 | |
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154 | If you are concerned about pooled coroutines growing a lot because a |
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155 | single "async_pool" used a lot of stackspace you can e.g. |
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156 | "async_pool { terminate }" once per second or so to slowly replenish |
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157 | the pool. In addition to that, when the stacks used by a handler |
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158 | grows larger than 16kb (adjustable via $Coro::POOL_RSS) it will also |
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159 | be destroyed. |
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160 | |
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161 | STATIC METHODS |
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162 | Static methods are actually functions that operate on the current |
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163 | coroutine. |
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164 | |
53 | schedule |
165 | schedule |
54 | Calls the scheduler. Please note that the current process will not |
166 | Calls the scheduler. The scheduler will find the next coroutine that |
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167 | is to be run from the ready queue and switches to it. The next |
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168 | coroutine to be run is simply the one with the highest priority that |
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169 | is longest in its ready queue. If there is no coroutine ready, it |
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170 | will clal the $Coro::idle hook. |
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171 | |
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172 | Please note that the current coroutine will *not* be put into the |
55 | be put into the ready queue, so calling this function usually means |
173 | ready queue, so calling this function usually means you will never |
56 | you will never be called again. |
174 | be called again unless something else (e.g. an event handler) calls |
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175 | "->ready", thus waking you up. |
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176 | |
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177 | This makes "schedule" *the* generic method to use to block the |
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178 | current coroutine and wait for events: first you remember the |
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179 | current coroutine in a variable, then arrange for some callback of |
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180 | yours to call "->ready" on that once some event happens, and last |
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181 | you call "schedule" to put yourself to sleep. Note that a lot of |
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182 | things can wake your coroutine up, so you need to check whether the |
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183 | event indeed happened, e.g. by storing the status in a variable. |
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184 | |
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185 | See HOW TO WAIT FOR A CALLBACK, below, for some ways to wait for |
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186 | callbacks. |
57 | |
187 | |
58 | cede |
188 | cede |
59 | "Cede" to other processes. This function puts the current process |
189 | "Cede" to other coroutines. This function puts the current coroutine |
60 | into the ready queue and calls "schedule", which has the effect of |
190 | into the ready queue and calls "schedule", which has the effect of |
61 | giving up the current "timeslice" to other coroutines of the same or |
191 | giving up the current "timeslice" to other coroutines of the same or |
62 | higher priority. |
192 | higher priority. Once your coroutine gets its turn again it will |
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193 | automatically be resumed. |
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194 | |
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195 | This function is often called "yield" in other languages. |
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196 | |
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197 | Coro::cede_notself |
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198 | Works like cede, but is not exported by default and will cede to |
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199 | *any* coroutine, regardless of priority. This is useful sometimes to |
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200 | ensure progress is made. |
63 | |
201 | |
64 | terminate [arg...] |
202 | terminate [arg...] |
65 | Terminates the current process with the given status values (see |
203 | Terminates the current coroutine with the given status values (see |
66 | cancel). |
204 | cancel). |
67 | |
205 | |
68 | # dynamic methods |
206 | killall |
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207 | Kills/terminates/cancels all coroutines except the currently running |
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208 | one. This is useful after a fork, either in the child or the parent, |
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209 | as usually only one of them should inherit the running coroutines. |
69 | |
210 | |
70 | PROCESS METHODS |
211 | Note that while this will try to free some of the main programs |
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212 | resources, you cannot free all of them, so if a coroutine that is |
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213 | not the main program calls this function, there will be some |
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214 | one-time resource leak. |
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215 | |
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216 | COROUTINE METHODS |
71 | These are the methods you can call on process objects. |
217 | These are the methods you can call on coroutine objects (or to create |
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218 | them). |
72 | |
219 | |
73 | new Coro \&sub [, @args...] |
220 | new Coro \&sub [, @args...] |
74 | Create a new process and return it. When the sub returns the process |
221 | Create a new coroutine and return it. When the sub returns, the |
75 | automatically terminates as if "terminate" with the returned values |
222 | coroutine automatically terminates as if "terminate" with the |
76 | were called. To make the process run you must first put it into the |
223 | returned values were called. To make the coroutine run you must |
77 | ready queue by calling the ready method. |
224 | first put it into the ready queue by calling the ready method. |
78 | |
225 | |
79 | $process->ready |
226 | See "async" and "Coro::State::new" for additional info about the |
80 | Put the given process into the ready queue. |
227 | coroutine environment. |
81 | |
228 | |
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229 | $success = $coroutine->ready |
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230 | Put the given coroutine into the end of its ready queue (there is |
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231 | one queue for each priority) and return true. If the coroutine is |
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232 | already in the ready queue, do nothing and return false. |
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233 | |
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234 | This ensures that the scheduler will resume this coroutine |
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235 | automatically once all the coroutines of higher priority and all |
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236 | coroutines of the same priority that were put into the ready queue |
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237 | earlier have been resumed. |
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238 | |
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239 | $is_ready = $coroutine->is_ready |
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240 | Return whether the coroutine is currently the ready queue or not, |
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241 | |
82 | $process->cancel (arg...) |
242 | $coroutine->cancel (arg...) |
83 | Temrinates the given process and makes it return the given arguments |
243 | Terminates the given coroutine and makes it return the given |
84 | as status (default: the empty list). |
244 | arguments as status (default: the empty list). Never returns if the |
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245 | coroutine is the current coroutine. |
85 | |
246 | |
86 | $process->join |
247 | $coroutine->schedule_to |
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248 | Puts the current coroutine to sleep (like "Coro::schedule"), but |
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249 | instead of continuing with the next coro from the ready queue, |
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250 | always switch to the given coroutine object (regardless of priority |
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251 | etc.). The readyness state of that coroutine isn't changed. |
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252 | |
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253 | This is an advanced method for special cases - I'd love to hear |
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254 | about any uses for this one. |
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255 | |
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256 | $coroutine->cede_to |
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257 | Like "schedule_to", but puts the current coroutine into the ready |
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258 | queue. This has the effect of temporarily switching to the given |
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259 | coroutine, and continuing some time later. |
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260 | |
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261 | This is an advanced method for special cases - I'd love to hear |
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262 | about any uses for this one. |
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263 | |
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264 | $coroutine->throw ([$scalar]) |
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265 | If $throw is specified and defined, it will be thrown as an |
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266 | exception inside the coroutine at the next convenient point in time. |
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267 | Otherwise clears the exception object. |
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268 | |
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269 | Coro will check for the exception each time a schedule-like-function |
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270 | returns, i.e. after each "schedule", "cede", |
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271 | "Coro::Semaphore->down", "Coro::Handle->readable" and so on. Most of |
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272 | these functions detect this case and return early in case an |
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273 | exception is pending. |
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274 | |
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275 | The exception object will be thrown "as is" with the specified |
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276 | scalar in $@, i.e. if it is a string, no line number or newline will |
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277 | be appended (unlike with "die"). |
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278 | |
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279 | This can be used as a softer means than "cancel" to ask a coroutine |
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280 | to end itself, although there is no guarantee that the exception |
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281 | will lead to termination, and if the exception isn't caught it might |
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282 | well end the whole program. |
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283 | |
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284 | You might also think of "throw" as being the moral equivalent of |
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285 | "kill"ing a coroutine with a signal (in this case, a scalar). |
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286 | |
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287 | $coroutine->join |
87 | Wait until the coroutine terminates and return any values given to |
288 | Wait until the coroutine terminates and return any values given to |
88 | the "terminate" or "cancel" functions. "join" can be called multiple |
289 | the "terminate" or "cancel" functions. "join" can be called |
89 | times from multiple processes. |
290 | concurrently from multiple coroutines, and all will be resumed and |
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291 | given the status return once the $coroutine terminates. |
90 | |
292 | |
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293 | $coroutine->on_destroy (\&cb) |
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294 | Registers a callback that is called when this coroutine gets |
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295 | destroyed, but before it is joined. The callback gets passed the |
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296 | terminate arguments, if any, and *must not* die, under any |
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297 | circumstances. |
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298 | |
91 | $oldprio = $process->prio($newprio) |
299 | $oldprio = $coroutine->prio ($newprio) |
92 | Sets (or gets, if the argument is missing) the priority of the |
300 | Sets (or gets, if the argument is missing) the priority of the |
93 | process. Higher priority processes get run before lower priority |
301 | coroutine. Higher priority coroutines get run before lower priority |
94 | processes. Priorities are small signed integers (currently -4 .. |
302 | coroutines. Priorities are small signed integers (currently -4 .. |
95 | +3), that you can refer to using PRIO_xxx constants (use the import |
303 | +3), that you can refer to using PRIO_xxx constants (use the import |
96 | tag :prio to get then): |
304 | tag :prio to get then): |
97 | |
305 | |
98 | PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
306 | PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN |
99 | 3 > 1 > 0 > -1 > -3 > -4 |
307 | 3 > 1 > 0 > -1 > -3 > -4 |
… | |
… | |
102 | current->prio(PRIO_HIGH); |
310 | current->prio(PRIO_HIGH); |
103 | |
311 | |
104 | The idle coroutine ($Coro::idle) always has a lower priority than |
312 | The idle coroutine ($Coro::idle) always has a lower priority than |
105 | any existing coroutine. |
313 | any existing coroutine. |
106 | |
314 | |
107 | Changing the priority of the current process will take effect |
315 | Changing the priority of the current coroutine will take effect |
108 | immediately, but changing the priority of processes in the ready |
316 | immediately, but changing the priority of coroutines in the ready |
109 | queue (but not running) will only take effect after the next |
317 | queue (but not running) will only take effect after the next |
110 | schedule (of that process). This is a bug that will be fixed in some |
318 | schedule (of that coroutine). This is a bug that will be fixed in |
111 | future version. |
319 | some future version. |
112 | |
320 | |
113 | $newprio = $process->nice($change) |
321 | $newprio = $coroutine->nice ($change) |
114 | Similar to "prio", but subtract the given value from the priority |
322 | Similar to "prio", but subtract the given value from the priority |
115 | (i.e. higher values mean lower priority, just as in unix). |
323 | (i.e. higher values mean lower priority, just as in unix). |
116 | |
324 | |
117 | $olddesc = $process->desc($newdesc) |
325 | $olddesc = $coroutine->desc ($newdesc) |
118 | Sets (or gets in case the argument is missing) the description for |
326 | Sets (or gets in case the argument is missing) the description for |
119 | this process. This is just a free-form string you can associate with |
327 | this coroutine. This is just a free-form string you can associate |
120 | a process. |
328 | with a coroutine. |
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329 | |
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330 | This method simply sets the "$coroutine->{desc}" member to the given |
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331 | string. You can modify this member directly if you wish. |
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332 | |
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333 | GLOBAL FUNCTIONS |
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334 | Coro::nready |
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335 | Returns the number of coroutines that are currently in the ready |
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336 | state, i.e. that can be switched to by calling "schedule" directory |
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337 | or indirectly. The value 0 means that the only runnable coroutine is |
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338 | the currently running one, so "cede" would have no effect, and |
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339 | "schedule" would cause a deadlock unless there is an idle handler |
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340 | that wakes up some coroutines. |
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341 | |
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342 | my $guard = Coro::guard { ... } |
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343 | This creates and returns a guard object. Nothing happens until the |
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344 | object gets destroyed, in which case the codeblock given as argument |
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345 | will be executed. This is useful to free locks or other resources in |
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346 | case of a runtime error or when the coroutine gets canceled, as in |
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347 | both cases the guard block will be executed. The guard object |
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348 | supports only one method, "->cancel", which will keep the codeblock |
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349 | from being executed. |
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350 | |
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351 | Example: set some flag and clear it again when the coroutine gets |
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352 | canceled or the function returns: |
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353 | |
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354 | sub do_something { |
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355 | my $guard = Coro::guard { $busy = 0 }; |
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356 | $busy = 1; |
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357 | |
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358 | # do something that requires $busy to be true |
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359 | } |
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360 | |
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361 | unblock_sub { ... } |
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362 | This utility function takes a BLOCK or code reference and "unblocks" |
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363 | it, returning a new coderef. Unblocking means that calling the new |
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364 | coderef will return immediately without blocking, returning nothing, |
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365 | while the original code ref will be called (with parameters) from |
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366 | within another coroutine. |
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367 | |
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368 | The reason this function exists is that many event libraries (such |
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369 | as the venerable Event module) are not coroutine-safe (a weaker form |
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370 | of thread-safety). This means you must not block within event |
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371 | callbacks, otherwise you might suffer from crashes or worse. The |
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372 | only event library currently known that is safe to use without |
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373 | "unblock_sub" is EV. |
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374 | |
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375 | This function allows your callbacks to block by executing them in |
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376 | another coroutine where it is safe to block. One example where |
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377 | blocking is handy is when you use the Coro::AIO functions to save |
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378 | results to disk, for example. |
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379 | |
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380 | In short: simply use "unblock_sub { ... }" instead of "sub { ... }" |
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381 | when creating event callbacks that want to block. |
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382 | |
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383 | If your handler does not plan to block (e.g. simply sends a message |
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384 | to another coroutine, or puts some other coroutine into the ready |
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385 | queue), there is no reason to use "unblock_sub". |
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386 | |
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387 | Note that you also need to use "unblock_sub" for any other callbacks |
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388 | that are indirectly executed by any C-based event loop. For example, |
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389 | when you use a module that uses AnyEvent (and you use |
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390 | Coro::AnyEvent) and it provides callbacks that are the result of |
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391 | some event callback, then you must not block either, or use |
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392 | "unblock_sub". |
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393 | |
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394 | $cb = Coro::rouse_cb |
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395 | Create and return a "rouse callback". That's a code reference that, |
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396 | when called, will save its arguments and notify the owner coroutine |
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397 | of the callback. |
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398 | |
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399 | See the next function. |
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400 | |
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401 | @args = Coro::rouse_wait [$cb] |
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402 | Wait for the specified rouse callback (or the last one tht was |
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403 | created in this coroutine). |
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404 | |
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405 | As soon as the callback is invoked (or when the calback was invoked |
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406 | before "rouse_wait"), it will return a copy of the arguments |
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407 | originally passed to the rouse callback. |
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408 | |
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409 | See the section HOW TO WAIT FOR A CALLBACK for an actual usage |
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410 | example. |
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411 | |
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412 | HOW TO WAIT FOR A CALLBACK |
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413 | It is very common for a coroutine to wait for some callback to be |
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414 | called. This occurs naturally when you use coroutines in an otherwise |
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415 | event-based program, or when you use event-based libraries. |
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416 | |
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417 | These typically register a callback for some event, and call that |
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418 | callback when the event occured. In a coroutine, however, you typically |
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419 | want to just wait for the event, simplyifying things. |
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420 | |
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421 | For example "AnyEvent->child" registers a callback to be called when a |
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422 | specific child has exited: |
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423 | |
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424 | my $child_watcher = AnyEvent->child (pid => $pid, cb => sub { ... }); |
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425 | |
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426 | But from withina coroutine, you often just want to write this: |
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427 | |
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428 | my $status = wait_for_child $pid; |
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429 | |
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430 | Coro offers two functions specifically designed to make this easy, |
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431 | "Coro::rouse_cb" and "Coro::rouse_wait". |
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432 | |
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433 | The first function, "rouse_cb", generates and returns a callback that, |
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434 | when invoked, will save it's arguments and notify the coroutine that |
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435 | created the callback. |
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436 | |
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437 | The second function, "rouse_wait", waits for the callback to be called |
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438 | (by calling "schedule" to go to sleep) and returns the arguments |
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439 | originally passed to the callback. |
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440 | |
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441 | Using these functions, it becomes easy to write the "wait_for_child" |
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442 | function mentioned above: |
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443 | |
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444 | sub wait_for_child($) { |
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445 | my ($pid) = @_; |
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446 | |
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447 | my $watcher = AnyEvent->child (pid => $pid, cb => Coro::rouse_cb); |
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448 | |
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449 | my ($rpid, $rstatus) = Coro::rouse_wait; |
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450 | $rstatus |
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451 | } |
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452 | |
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453 | In the case where "rouse_cb" and "rouse_wait" are not flexible enough, |
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454 | you can roll your own, using "schedule": |
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455 | |
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456 | sub wait_for_child($) { |
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457 | my ($pid) = @_; |
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458 | |
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459 | # store the current coroutine in $current, |
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460 | # and provide result variables for the closure passed to ->child |
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461 | my $current = $Coro::current; |
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462 | my ($done, $rstatus); |
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463 | |
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464 | # pass a closure to ->child |
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465 | my $watcher = AnyEvent->child (pid => $pid, cb => sub { |
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466 | $rstatus = $_[1]; # remember rstatus |
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467 | $done = 1; # mark $rstatus as valud |
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468 | }); |
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469 | |
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470 | # wait until the closure has been called |
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471 | schedule while !$done; |
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472 | |
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473 | $rstatus |
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474 | } |
121 | |
475 | |
122 | BUGS/LIMITATIONS |
476 | BUGS/LIMITATIONS |
123 | - you must make very sure that no coro is still active on global |
477 | fork with pthread backend |
124 | destruction. very bad things might happen otherwise (usually segfaults). |
478 | When Coro is compiled using the pthread backend (which isn't |
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479 | recommended but required on many BSDs as their libcs are completely |
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480 | broken), then coroutines will not survive a fork. There is no known |
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481 | workaround except to fix your libc and use a saner backend. |
125 | |
482 | |
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483 | perl process emulation ("threads") |
126 | - this module is not thread-safe. You should only ever use this module |
484 | This module is not perl-pseudo-thread-safe. You should only ever use |
127 | from the same thread (this requirement might be losened in the future |
485 | this module from the same thread (this requirement might be removed |
128 | to allow per-thread schedulers, but Coro::State does not yet allow |
486 | in the future to allow per-thread schedulers, but Coro::State does |
129 | this). |
487 | not yet allow this). I recommend disabling thread support and using |
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488 | processes, as having the windows process emulation enabled under |
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489 | unix roughly halves perl performance, even when not used. |
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490 | |
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491 | coroutine switching not signal safe |
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492 | You must not switch to another coroutine from within a signal |
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493 | handler (only relevant with %SIG - most event libraries provide safe |
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494 | signals). |
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495 | |
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496 | That means you *MUST NOT* call any function that might "block" the |
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497 | current coroutine - "cede", "schedule" "Coro::Semaphore->down" or |
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498 | anything that calls those. Everything else, including calling |
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499 | "ready", works. |
130 | |
500 | |
131 | SEE ALSO |
501 | SEE ALSO |
132 | Coro::Channel, Coro::Cont, Coro::Specific, Coro::Semaphore, |
502 | Event-Loop integration: Coro::AnyEvent, Coro::EV, Coro::Event. |
133 | Coro::Signal, Coro::State, Coro::Timer, Coro::Event, Coro::Handle, |
503 | |
134 | Coro::RWLock, Coro::Socket. |
504 | Debugging: Coro::Debug. |
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505 | |
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506 | Support/Utility: Coro::Specific, Coro::Util. |
|
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507 | |
|
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508 | Locking/IPC: Coro::Signal, Coro::Channel, Coro::Semaphore, |
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509 | Coro::SemaphoreSet, Coro::RWLock. |
|
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510 | |
|
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511 | IO/Timers: Coro::Timer, Coro::Handle, Coro::Socket, Coro::AIO. |
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512 | |
|
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513 | Compatibility: Coro::LWP, Coro::BDB, Coro::Storable, Coro::Select. |
|
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514 | |
|
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515 | XS API: Coro::MakeMaker. |
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516 | |
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517 | Low level Configuration, Coroutine Environment: Coro::State. |
135 | |
518 | |
136 | AUTHOR |
519 | AUTHOR |
137 | Marc Lehmann <schmorp@schmorp.de> |
520 | Marc Lehmann <schmorp@schmorp.de> |
138 | http://home.schmorp.de/ |
521 | http://home.schmorp.de/ |
139 | |
522 | |