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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

# User Rev Content
1 root 1.1 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 root 1.2 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 root 1.1
142     AUTHOR
143     Marc Lehmann <schmorp@schmorp.de>
144     http://home.schmorp.de/
145