bionic (3) tcllib_coroutine.3tcl.gz

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

________________________________________________________________________________________________________________

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 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.

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>