oracular (3) tcllib_coroutine.3tcl.gz

NAME

       coroutine - Coroutine based event and IO handling

SYNOPSIS

       package require Tcl  8.6

       package require coroutine  1.3

       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 puts ?-nonewline? channel string

       coroutine::util read -nonewline chan ?n?

       coroutine::util socket ?options...? host port

       coroutine::util update ?idletasks?

       coroutine::util vwait varname

________________________________________________________________________________________________________________

DESCRIPTION

       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.

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 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 puts ?-nonewline? channel string
              This commands writes the string to the specified channel.   Contrary  to  the  builtin  puts  this
              command waits until the channel is writable before actually writing to it.

       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 socket ?options...? host port
              This command connects to the specified host and port and returns when that is  done.  Contrary  to
              the  builtin  command  it  performs  a  non-blocking connect in the background. As such, while its
              blocks the calling coroutine, the overall application is not blocked.

       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 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.

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>