coroutine(3tcl) Coroutine utilities coroutine(3tcl)
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NAME
coroutine - Coroutine based event and IO handling
SYNOPSIS
package require Tcl 8.6
package require coroutine 1.2
coroutine::util after delay
coroutine::util await varname...
coroutine::util create arg...
coroutine::util exit ?status?
coroutine::util gets chan ?varname?
coroutine::util gets_safety chan limit varname
coroutine::util global varname...
coroutine::util read -nonewline chan ?n?
coroutine::util update ?idletasks?
coroutine::util vwait varname
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DESCRIPTION
The coroutine package provides coroutine-aware implementations of vari-
ous event- and channel related commands. It can be in multiple modes:
[1] Call the commands through their ensemble, in code which is ex-
plicitly written for use within coroutines.
[2] Import the commands into a namespace, either directly, or
through namespace path. This allows the use from within code
which is not coroutine-aware per se and restricted to specific
namespaces.
A more agressive form of making code coroutine-oblivious than point 2
above is available through the package coroutine::auto, which inter-
cepts the relevant builtin commands and changes their implementation
dependending on the context they are run in, i.e. inside or outside of
a coroutine.
API
All the commands listed below are synchronous with respect to the
coroutine invoking them, i.e. this coroutine blocks until the result is
available. The overall eventloop is not blocked however.
coroutine::util after delay
This command delays the coroutine invoking it by delay millisec-
onds.
coroutine::util await varname...
This command is an extension form of the coroutine::util vwait
command (see below) which waits on a write to one of many named
namespace variables.
coroutine::util create arg...
This command creates a new coroutine with an automatically as-
signed name and causes it to run the code specified by the argu-
ments.
coroutine::util exit ?status?
This command exits the current coroutine, causing it to return
status. If no status was specified the default 0 is returned.
coroutine::util gets chan ?varname?
This command reads a line from the channel chan and returns it
either as its result, or, if a varname was specified, writes it
to the named variable and returns the number of characters read.
coroutine::util gets_safety chan limit varname
This command reads a line from the channel chan up to size limit
and stores the result in varname. Of limit is reached before the
set first newline, an error is thrown. The command returns the
number of characters read.
coroutine::util global varname...
This command imports the named global variables of the coroutine
into the current scope. From the technical point of view these
variables reside in level #1 of the Tcl stack. I.e. these are
not the regular global variable in to the global namespace, and
each coroutine can have their own set, independent of all oth-
ers.
coroutine::util read -nonewline chan ?n?
This command reads n characters from the channel chan and re-
turns them as its result. If n is not specified the command will
read the channel until EOF is reached.
coroutine::util update ?idletasks?
This command causes the coroutine invoking it to run pending
events or idle handlers before proceeding.
coroutine::util vwait varname
This command causes the coroutine calling it to wait for a write
to the named namespace variable varname.
BUGS, IDEAS, FEEDBACK
This document, and the package it describes, will undoubtedly contain
bugs and other problems. Please report such in the category coroutine
of the Tcllib Trackers [http://core.tcl.tk/tcllib/reportlist]. Please
also report any ideas for enhancements you may have for either package
and/or documentation.
When proposing code changes, please provide unified diffs, i.e the out-
put of diff -u.
Note further that attachments are strongly preferred over inlined
patches. Attachments can be made by going to the Edit form of the
ticket immediately after its creation, and then using the left-most
button in the secondary navigation bar.
KEYWORDS
after, channel, coroutine, events, exit, gets, global, green threads,
read, threads, update, vwait
CATEGORY
Coroutine
COPYRIGHT
Copyright (c) 2010-2015 Andreas Kupries <andreas_kupries@users.sourceforge.net>
tcllib 1.2 coroutine(3tcl)