From: Ralph Shnelvar <ralphs@...32.com>
Date: 2010-09-30T21:26:46+09:00
Subject: Re: Calling a method in the context of a specific thread

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Robert,

Thursday, September 30, 2010, 12:10:34 AM, you wrote:

RK> On 09/29/2010 03:22 AM, Ralph Shnelvar wrote:
>> [Note:  parts of this message were removed to make it a legal post.]

>> Background:

>> I am writing an FXRuby program.  My question should be independent of FXRuby, though.

>> FXRuby is a GUI for Ruby.

>> If I understand some of the comments made here (and I probably don't) [see subject: interpreter cannot enter in the context from another thread] it is a bad thing to attempt to run an FXRuby function in a non-main thread.




>> So ... I have a non-main thread that wants to display a message box (i.e. "call" FXMessageBox").

>> How can I invoke FXMessageBox in the context of the main thread?



>> I can think of all sorts of ugly solutions.

>> For instance:

>> 1) Set some global_variable indicating the task I want to perform in the main thread.
>> 2) Do a thread.stop
>> 3) have a timer in the main thread and have it dispatch based on global_variable
>> 4) save the return code of FXMessageBox in a thread local variable the not-main-thread
>> 5) Do a thread.run to wake up the stopped not-main-thread.

RK> 6) Have a task queue which is read in the main thread.  You can even 
RK> store lambdas in there.

Please explain more; a lot more.

I am particularly confused how a task queue would work given that nothing in the main thread can block since that would stop FXRuby's message pump.
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