| 1 | =head1 NAME |
1 | =head1 NAME |
| 2 | |
2 | |
| 3 | Coro - create and manage coroutines |
3 | Coro - coroutine process abstraction |
| 4 | |
4 | |
| 5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
| 6 | |
6 | |
| 7 | use Coro; |
7 | use Coro; |
| 8 | |
8 | |
| 9 | $new = new Coro sub { |
9 | async { |
| 10 | print "in coroutine, switching back\n"; |
10 | # some asynchronous thread of execution |
| 11 | $Coro::main->resume; |
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| 12 | print "in coroutine again, switching back\n"; |
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| 13 | $Coro::main->resume; |
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| 14 | }; |
11 | }; |
| 15 | |
12 | |
| 16 | print "in main, switching to coroutine\n"; |
13 | # alternatively create an async process like this: |
| 17 | $new->resume; |
14 | |
| 18 | print "back in main, switch to coroutine again\n"; |
15 | sub some_func : Coro { |
| 19 | $new->resume; |
16 | # some more async code |
| 20 | print "back in main\n"; |
17 | } |
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18 | |
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19 | yield; |
| 21 | |
20 | |
| 22 | =head1 DESCRIPTION |
21 | =head1 DESCRIPTION |
| 23 | |
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| 24 | This module implements coroutines. Coroutines, similar to continuations, |
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| 25 | allow you to run more than one "thread of execution" in parallel. Unlike |
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| 26 | threads this, only voluntary switching is used so locking problems are |
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| 27 | greatly reduced. |
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| 28 | |
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| 29 | Although this is the "main" module of the Coro family it provides only |
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| 30 | low-level functionality. See L<Coro::Process> and related modules for a |
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| 31 | more useful process abstraction including scheduling. |
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| 32 | |
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| 33 | =over 4 |
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| 34 | |
22 | |
| 35 | =cut |
23 | =cut |
| 36 | |
24 | |
| 37 | package Coro; |
25 | package Coro; |
| 38 | |
26 | |
| 39 | BEGIN { |
27 | use Coro::State; |
| 40 | $VERSION = 0.01; |
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| 41 | |
28 | |
| 42 | require XSLoader; |
29 | use base Exporter; |
| 43 | XSLoader::load Coro, $VERSION; |
30 | |
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31 | $VERSION = 0.03; |
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32 | |
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33 | @EXPORT = qw(async yield schedule); |
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34 | @EXPORT_OK = qw($current); |
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35 | |
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36 | { |
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37 | use subs 'async'; |
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38 | |
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39 | my @async; |
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40 | |
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41 | # this way of handling attributes simply is NOT scalable ;() |
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42 | sub import { |
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43 | Coro->export_to_level(1, @_); |
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44 | my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE}; |
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45 | *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub { |
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46 | my ($package, $ref) = (shift, shift); |
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47 | my @attrs; |
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48 | for (@_) { |
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49 | if ($_ eq "Coro") { |
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50 | push @async, $ref; |
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51 | } else { |
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52 | push @attrs, @_; |
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53 | } |
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54 | } |
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55 | return $old ? $old->($package, $name, @attrs) : @attrs; |
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56 | }; |
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57 | } |
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58 | |
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59 | sub INIT { |
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60 | async pop @async while @async; |
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61 | } |
| 44 | } |
62 | } |
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63 | |
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64 | my $idle = new Coro sub { |
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65 | &yield while 1; |
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66 | }; |
| 45 | |
67 | |
| 46 | =item $main |
68 | =item $main |
| 47 | |
69 | |
| 48 | This coroutine represents the main program. |
70 | This coroutine represents the main program. |
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71 | |
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72 | =cut |
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73 | |
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74 | $main = new Coro; |
| 49 | |
75 | |
| 50 | =item $current |
76 | =item $current |
| 51 | |
77 | |
| 52 | The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). |
78 | The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course). |
| 53 | |
79 | |
| 54 | =cut |
80 | =cut |
| 55 | |
81 | |
| 56 | $main = $current = _newprocess { |
82 | # maybe some other module used Coro::Specific before... |
| 57 | # never being called |
83 | if ($current) { |
| 58 | }; |
84 | $main->{specific} = $current->{specific}; |
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85 | } |
| 59 | |
86 | |
| 60 | =item $error, $error_msg, $error_coro |
87 | $current = $main; |
| 61 | |
88 | |
| 62 | This coroutine will be called on fatal errors. C<$error_msg> and |
89 | # we really need priorities... |
| 63 | C<$error_coro> return the error message and the error-causing coroutine, |
90 | my @ready = (); # the ready queue. hehe, rather broken ;) |
| 64 | respectively. |
91 | |
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92 | # static methods. not really. |
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93 | |
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94 | =head2 STATIC METHODS |
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95 | |
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96 | Static methods are actually functions that operate on the current process only. |
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97 | |
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98 | =over 4 |
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99 | |
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100 | =item async { ... }; |
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101 | |
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102 | Create a new asynchronous process and return it's process object |
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103 | (usually unused). When the sub returns the new process is automatically |
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104 | terminated. |
| 65 | |
105 | |
| 66 | =cut |
106 | =cut |
| 67 | |
107 | |
| 68 | $error_msg = |
108 | sub async(&) { |
| 69 | $error_coro = undef; |
109 | (new Coro $_[0])->ready; |
| 70 | |
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| 71 | $error = _newprocess { |
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| 72 | print STDERR "FATAL: $error_msg\nprogram aborted\n"; |
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| 73 | exit 250; |
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| 74 | }; |
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| 75 | |
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| 76 | =item $coro = new $coderef [, @args] |
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| 77 | |
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| 78 | Create a new coroutine and return it. The first C<resume> call to this |
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| 79 | coroutine will start execution at the given coderef. If it returns it |
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| 80 | should return a coroutine to switch to. If, after returning, the coroutine |
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| 81 | is C<resume>d again it starts execution again at the givne coderef. |
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| 82 | |
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| 83 | =cut |
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| 84 | |
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| 85 | sub new { |
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| 86 | my $class = $_[0]; |
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| 87 | my $proc = $_[1]; |
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| 88 | bless _newprocess { |
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| 89 | do { |
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| 90 | eval { &$proc->resume }; |
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| 91 | if ($@) { |
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| 92 | ($error_msg, $error_coro) = ($@, $current); |
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| 93 | $error->resume; |
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| 94 | } |
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| 95 | } while (); |
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| 96 | }, $class; |
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| 97 | } |
110 | } |
| 98 | |
111 | |
| 99 | =item $coro->resume |
112 | =item schedule |
| 100 | |
113 | |
| 101 | Resume execution at the given coroutine. |
114 | Calls the scheduler. Please note that the current process will not be put |
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115 | into the ready queue, so calling this function usually means you will |
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116 | never be called again. |
| 102 | |
117 | |
| 103 | =cut |
118 | =cut |
| 104 | |
119 | |
| 105 | my $prev; |
120 | my $prev; |
| 106 | |
121 | |
| 107 | sub resume { |
122 | sub schedule { |
| 108 | $prev = $current; $current = $_[0]; |
123 | ($prev, $current) = ($current, shift @ready); |
| 109 | _transfer($prev, $current); |
124 | Coro::State::transfer($prev, $current); |
| 110 | } |
125 | } |
| 111 | |
126 | |
| 112 | 1; |
127 | =item yield |
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128 | |
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129 | Yield to other processes. This function puts the current process into the |
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130 | ready queue and calls C<schedule>. |
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131 | |
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132 | =cut |
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133 | |
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134 | sub yield { |
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135 | $current->ready; |
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136 | &schedule; |
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137 | } |
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138 | |
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139 | =item terminate |
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140 | |
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141 | Terminates the current process. |
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142 | |
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143 | =cut |
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144 | |
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145 | sub terminate { |
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146 | &schedule; |
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147 | } |
| 113 | |
148 | |
| 114 | =back |
149 | =back |
| 115 | |
150 | |
| 116 | =head1 BUGS |
151 | # dynamic methods |
| 117 | |
152 | |
| 118 | This module has not yet been extensively tested. |
153 | =head2 PROCESS METHODS |
| 119 | |
154 | |
| 120 | =head1 SEE ALSO |
155 | These are the methods you can call on process objects. |
| 121 | |
156 | |
| 122 | L<Coro::Process>, L<Coro::Signal>. |
157 | =over 4 |
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158 | |
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159 | =item new Coro \⊂ |
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160 | |
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161 | Create a new process and return it. When the sub returns the process |
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162 | automatically terminates. To start the process you must first put it into |
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163 | the ready queue by calling the ready method. |
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164 | |
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165 | =cut |
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166 | |
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167 | sub new { |
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168 | my $class = shift; |
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169 | my $proc = $_[0]; |
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170 | bless { |
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171 | _coro_state => new Coro::State ($proc ? sub { &$proc; &terminate } : $proc), |
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172 | }, $class; |
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173 | } |
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174 | |
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175 | =item $process->ready |
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176 | |
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177 | Put the current process into the ready queue. |
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178 | |
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179 | =cut |
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180 | |
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181 | sub ready { |
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182 | push @ready, $_[0]; |
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183 | } |
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184 | |
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185 | =back |
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186 | |
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187 | =cut |
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188 | |
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189 | 1; |
| 123 | |
190 | |
| 124 | =head1 AUTHOR |
191 | =head1 AUTHOR |
| 125 | |
192 | |
| 126 | Marc Lehmann <pcg@goof.com> |
193 | Marc Lehmann <pcg@goof.com> |
| 127 | http://www.goof.com/pcg/marc/ |
194 | http://www.goof.com/pcg/marc/ |
