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