[ViewVC] Annotation of: cvs/Coro/README

NAME
    Coro - coroutine process abstraction

SYNOPSIS
     use Coro;

     async {
        # some asynchronous thread of execution
     };

     # alternatively create an async process like this:

     sub some_func : Coro {
        # some more async code
     }

     cede;

DESCRIPTION
    This module collection manages coroutines. Coroutines are similar to
    threads but don't run in parallel.

    In this module, coroutines are defined as "callchain + lexical variables
    + @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
    callchain, it's own set of lexicals and it's own set of perl's most
    important global variables.

    $main
        This coroutine represents the main program.

    $current (or as function: current)
        The current coroutine (the last coroutine switched to). The initial
        value is $main (of course).

    $idle
        The coroutine to switch to when no other coroutine is running. The
        default implementation prints "FATAL: deadlock detected" and exits.

  STATIC METHODS
    Static methods are actually functions that operate on the current
    process only.

    async { ... } [@args...]
        Create a new asynchronous process and return it's process object
        (usually unused). When the sub returns the new process is
        automatically terminated.

        When the coroutine dies, the program will exit, just as in the main
        program.

           # create a new coroutine that just prints its arguments
           async {
              print "@_\n";
           } 1,2,3,4;

    schedule
        Calls the scheduler. Please note that the current process will not
        be put into the ready queue, so calling this function usually means
        you will never be called again.

    cede
        "Cede" to other processes. This function puts the current process
        into the ready queue and calls "schedule", which has the effect of
        giving up the current "timeslice" to other coroutines of the same or
        higher priority.

    terminate [arg...]
        Terminates the current process with the given status values (see
        cancel).

    # dynamic methods

  PROCESS METHODS
    These are the methods you can call on process objects.

    new Coro \&sub [, @args...]
        Create a new process and return it. When the sub returns the process
        automatically terminates as if "terminate" with the returned values
        were called. To make the process run you must first put it into the
        ready queue by calling the ready method.

    $process->ready
        Put the given process into the ready queue.

    $process->cancel (arg...)
        Terminates the given process and makes it return the given arguments
        as status (default: the empty list).

    $process->join
        Wait until the coroutine terminates and return any values given to
        the "terminate" or "cancel" functions. "join" can be called multiple
        times from multiple processes.

    $oldprio = $process->prio($newprio)
        Sets (or gets, if the argument is missing) the priority of the
        process. Higher priority processes get run before lower priority
        processes. Priorities are small signed integers (currently -4 ..
        +3), that you can refer to using PRIO_xxx constants (use the import
        tag :prio to get then):

           PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
               3    >     1     >      0      >    -1    >    -3     >    -4

           # set priority to HIGH
           current->prio(PRIO_HIGH);

        The idle coroutine ($Coro::idle) always has a lower priority than
        any existing coroutine.

        Changing the priority of the current process will take effect
        immediately, but changing the priority of processes in the ready
        queue (but not running) will only take effect after the next
        schedule (of that process). This is a bug that will be fixed in some
        future version.

    $newprio = $process->nice($change)
        Similar to "prio", but subtract the given value from the priority
        (i.e. higher values mean lower priority, just as in unix).

    $olddesc = $process->desc($newdesc)
        Sets (or gets in case the argument is missing) the description for
        this process. This is just a free-form string you can associate with
        a process.

BUGS/LIMITATIONS
     - you must make very sure that no coro is still active on global
       destruction. very bad things might happen otherwise (usually segfaults).

     - this module is not thread-safe. You should only ever use this module
       from the same thread (this requirement might be losened in the future
       to allow per-thread schedulers, but Coro::State does not yet allow
       this).

SEE ALSO
    Support/Utility: Coro::Cont, Coro::Specific, Coro::State, Coro::Util.

    Locking/IPC: Coro::Signal, Coro::Channel, Coro::Semaphore,
    Coro::SemaphoreSet, Coro::RWLock.

    Event/IO: Coro::Timer, Coro::Event, Coro::Handle, Coro::Socket,
    Coro::Select.

    Embedding: <Coro:MakeMaker>

AUTHOR
     Marc Lehmann <schmorp@schmorp.de>
     http://home.schmorp.de/

Revision:	1.3
Committed:	Mon Nov 6 19:56:26 2006 UTC (17 years, 6 months ago) by root
Branch:	MAIN
CVS Tags:	rel-2_5, stack_sharing
Changes since 1.2:	+4 -1 lines
Log Message:	* empty log message *
#	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	root	1.3	When the coroutine dies, the program will exit, just as in the main
49			program.
50
51	root	1.1	# create a new coroutine that just prints its arguments
52			async {
53			print "@_\n";
54			} 1,2,3,4;
55
56			schedule
57			Calls the scheduler. Please note that the current process will not
58			be put into the ready queue, so calling this function usually means
59			you will never be called again.
60
61			cede
62			"Cede" to other processes. This function puts the current process
63			into the ready queue and calls "schedule", which has the effect of
64			giving up the current "timeslice" to other coroutines of the same or
65			higher priority.
66
67			terminate [arg...]
68			Terminates the current process with the given status values (see
69			cancel).
70
71			# dynamic methods
72
73			PROCESS METHODS
74			These are the methods you can call on process objects.
75
76			new Coro \&sub [, @args...]
77			Create a new process and return it. When the sub returns the process
78			automatically terminates as if "terminate" with the returned values
79			were called. To make the process run you must first put it into the
80			ready queue by calling the ready method.
81
82			$process->ready
83			Put the given process into the ready queue.
84
85			$process->cancel (arg...)
86	root	1.3	Terminates the given process and makes it return the given arguments
87	root	1.1	as status (default: the empty list).
88
89			$process->join
90			Wait until the coroutine terminates and return any values given to
91			the "terminate" or "cancel" functions. "join" can be called multiple
92			times from multiple processes.
93
94			$oldprio = $process->prio($newprio)
95			Sets (or gets, if the argument is missing) the priority of the
96			process. Higher priority processes get run before lower priority
97			processes. Priorities are small signed integers (currently -4 ..
98			+3), that you can refer to using PRIO_xxx constants (use the import
99			tag :prio to get then):
100
101			PRIO_MAX > PRIO_HIGH > PRIO_NORMAL > PRIO_LOW > PRIO_IDLE > PRIO_MIN
102			3 > 1 > 0 > -1 > -3 > -4
103
104			# set priority to HIGH
105			current->prio(PRIO_HIGH);
106
107			The idle coroutine ($Coro::idle) always has a lower priority than
108			any existing coroutine.
109
110			Changing the priority of the current process will take effect
111			immediately, but changing the priority of processes in the ready
112			queue (but not running) will only take effect after the next
113			schedule (of that process). This is a bug that will be fixed in some
114			future version.
115
116			$newprio = $process->nice($change)
117			Similar to "prio", but subtract the given value from the priority
118			(i.e. higher values mean lower priority, just as in unix).
119
120			$olddesc = $process->desc($newdesc)
121			Sets (or gets in case the argument is missing) the description for
122			this process. This is just a free-form string you can associate with
123			a process.
124
125			BUGS/LIMITATIONS
126			- you must make very sure that no coro is still active on global
127			destruction. very bad things might happen otherwise (usually segfaults).
128
129			- this module is not thread-safe. You should only ever use this module
130			from the same thread (this requirement might be losened in the future
131			to allow per-thread schedulers, but Coro::State does not yet allow
132			this).
133
134			SEE ALSO
135	root	1.2	Support/Utility: Coro::Cont, Coro::Specific, Coro::State, Coro::Util.
136
137			Locking/IPC: Coro::Signal, Coro::Channel, Coro::Semaphore,
138			Coro::SemaphoreSet, Coro::RWLock.
139
140			Event/IO: Coro::Timer, Coro::Event, Coro::Handle, Coro::Socket,
141			Coro::Select.
142
143			Embedding: <Coro:MakeMaker>
144	root	1.1
145			AUTHOR
146			Marc Lehmann <schmorp@schmorp.de>
147			http://home.schmorp.de/
148