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Revision: 1.2
Committed: Sat Aug 20 01:10:22 2005 UTC (19 years, 1 month ago) by root
Branch: MAIN
CVS Tags: rel-2_0, rel-2_1, rel-1_9, rel-1_2, rel-1_5, rel-1_4, rel-1_7, rel-1_6, rel-1_31
Changes since 1.1: +9 -3 lines
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File Contents

# Content
1 NAME
2 Coro - coroutine process abstraction
3
4 SYNOPSIS
5 use Coro;
6
7 async {
8 # some asynchronous thread of execution
9 };
10
11 # alternatively create an async process like this:
12
13 sub some_func : Coro {
14 # some more async code
15 }
16
17 cede;
18
19 DESCRIPTION
20 This module collection manages coroutines. Coroutines are similar to
21 threads but don't run in parallel.
22
23 In this module, coroutines are defined as "callchain + lexical variables
24 + @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
25 callchain, it's own set of lexicals and it's own set of perl's most
26 important global variables.
27
28 $main
29 This coroutine represents the main program.
30
31 $current (or as function: current)
32 The current coroutine (the last coroutine switched to). The initial
33 value is $main (of course).
34
35 $idle
36 The coroutine to switch to when no other coroutine is running. The
37 default implementation prints "FATAL: deadlock detected" and exits.
38
39 STATIC METHODS
40 Static methods are actually functions that operate on the current
41 process only.
42
43 async { ... } [@args...]
44 Create a new asynchronous process and return it's process object
45 (usually unused). When the sub returns the new process is
46 automatically terminated.
47
48 # create a new coroutine that just prints its arguments
49 async {
50 print "@_\n";
51 } 1,2,3,4;
52
53 schedule
54 Calls the scheduler. Please note that the current process will not
55 be put into the ready queue, so calling this function usually means
56 you will never be called again.
57
58 cede
59 "Cede" to other processes. This function puts the current process
60 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
62 higher priority.
63
64 terminate [arg...]
65 Terminates the current process with the given status values (see
66 cancel).
67
68 # dynamic methods
69
70 PROCESS METHODS
71 These are the methods you can call on process objects.
72
73 new Coro \&sub [, @args...]
74 Create a new process and return it. When the sub returns the process
75 automatically terminates as if "terminate" with the returned values
76 were called. To make the process run you must first put it into the
77 ready queue by calling the ready method.
78
79 $process->ready
80 Put the given process into the ready queue.
81
82 $process->cancel (arg...)
83 Temrinates the given process and makes it return the given arguments
84 as status (default: the empty list).
85
86 $process->join
87 Wait until the coroutine terminates and return any values given to
88 the "terminate" or "cancel" functions. "join" can be called multiple
89 times from multiple processes.
90
91 $oldprio = $process->prio($newprio)
92 Sets (or gets, if the argument is missing) the priority of the
93 process. Higher priority processes get run before lower priority
94 processes. Priorities are small signed integers (currently -4 ..
95 +3), that you can refer to using PRIO_xxx constants (use the import
96 tag :prio to get then):
97
98 PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
99 3 > 1 > 0 > -1 > -3 > -4
100
101 # set priority to HIGH
102 current->prio(PRIO_HIGH);
103
104 The idle coroutine ($Coro::idle) always has a lower priority than
105 any existing coroutine.
106
107 Changing the priority of the current process will take effect
108 immediately, but changing the priority of processes in the ready
109 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
111 future version.
112
113 $newprio = $process->nice($change)
114 Similar to "prio", but subtract the given value from the priority
115 (i.e. higher values mean lower priority, just as in unix).
116
117 $olddesc = $process->desc($newdesc)
118 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
120 a process.
121
122 BUGS/LIMITATIONS
123 - you must make very sure that no coro is still active on global
124 destruction. very bad things might happen otherwise (usually segfaults).
125
126 - this module is not thread-safe. You should only ever use this module
127 from the same thread (this requirement might be losened in the future
128 to allow per-thread schedulers, but Coro::State does not yet allow
129 this).
130
131 SEE ALSO
132 Support/Utility: Coro::Cont, Coro::Specific, Coro::State, Coro::Util.
133
134 Locking/IPC: Coro::Signal, Coro::Channel, Coro::Semaphore,
135 Coro::SemaphoreSet, Coro::RWLock.
136
137 Event/IO: Coro::Timer, Coro::Event, Coro::Handle, Coro::Socket,
138 Coro::Select.
139
140 Embedding: <Coro:MakeMaker>
141
142 AUTHOR
143 Marc Lehmann <schmorp@schmorp.de>
144 http://home.schmorp.de/
145