coroutine - Coroutine based event and IO handling
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
The coroutine package provides coroutine-aware
implementations of various event- and channel related commands. It can be in
multiple modes:
- [1]
- Call the commands through their ensemble, in code which is explicitly
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
intercepts the relevant builtin commands and changes their implementation
dependending on the context they are run in, i.e. inside or outside of a
coroutine.
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
milliseconds.
- 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 assigned name
and causes it to run the code specified by the arguments.
- 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 others.
- coroutine::util
read -nonewline chan ?n?
- This command reads n characters from the channel chan and
returns 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.
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 output 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.
after, channel, coroutine, events, exit, gets, global, green
threads, read, threads, update, vwait
Copyright (c) 2010-2015 Andreas Kupries <andreas_kupries@users.sourceforge.net>