vwait(n) Tcl (7.5) vwait(n)
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NAME
vwait - Process events until a variable is written
SYNOPSIS
vwait varName
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DESCRIPTION
This command enters the Tcl event loop to process events,
blocking the application if no events are ready. It
continues processing events until some event handler sets
the value of variable varName. Once varName has been set,
the vwait command will return as soon as the event handler
that modified varName completes.
In some cases the vwait command may not return immediately
after varName is set. This can happen if the event handler
that sets varName does not complete immediately. For
example, if an event handler sets varName and then itself
calls vwait to wait for a different variable, then it may
not return for a long time. During this time the top-level
vwait is blocked waiting for the event handler to complete,
so it cannot return either.
KEYWORDS
event, variable, wait
Page 1 (printed 2/19/99)
