Re: java package and MacOS

[Ben Abbott]

On Nov 27, 2012, at 10:18 PM, Ben Abbott wrote:

> 
> On Nov 27, 2012, at 10:01 PM, Daniel J Sebald wrote:
> 
>> On 11/27/2012 08:45 PM, Ben Abbott wrote:
>>> 
>>> On Nov 27, 2012, at 6:14 PM, Daniel J Sebald wrote:
>> [snip]
>>>> Well, if you have Java on your system (which I assume is the case if you 
>>>> do any web browsing...type "java" or "javac" at a shell command line to 
>>>> confirm) then this should be a configuration issue (emphasis "should").  
>>>> Java is supposed to be a very portable environment.
>>>> 
>>>> Perhaps your definition of JAVA_HOME is wrong, but in my case I can set 
>>>> JAVA_HOME to any valid directory and "dlgtest(0)" functions properly.
>>>> 
>>>> Dan
>>> 
>>> MacOS X has Java.  If I understand the problem correctly ,.. the problem is 
>>> that for MacOS X, the GUI loop must be in the main program thread.  What 
>>> I'm not sure of is if the GUI loop  can support both a Qt and Java (I 
>>> suspect it can not, but don't know).
>> 
>> Oh, you are running Octave as its GUI?  I think several of us have been 
>> running with the --no-gui option.
>> 
>> I just found out a little while ago that running these Java commands while 
>> inside the GUI doesn't work.  Nothing happens or it crashes.
>> 
>> Dan
> 
> No.  The gui does not work yet on MacOS X.
> 
> The problem with Qt is not the same as the problem for Java.  For the Qt GUI, 
> the main thread includes the GUI loop (at least that is my understanding).  
> The problem for the gui on MacOS X has to do with forking.  I get the error 
> below.
> 
> The process has forked and you cannot use this CoreFoundation functionality 
> safely. You MUST exec().
> Break on 
> __THE_PROCESS_HAS_FORKED_AND_YOU_CANNOT_USE_THIS_COREFOUNDATION_FUNCTIONALITY___YOU_MUST_EXEC__()
>  to debug.
> 
> The problem with Java is that the GUI loop is not the main thread, but MacOS 
> requires that the first thread spawned  be the main()/GUI thread (I'm not an 
> expert in how Cocoa works, and am only repeating what I've read here and else 
> were).
> 
> Ben

After some time browsing and googling, I came across the discussion below.

        
http://www.cocoabuilder.com/archive/cocoa/315103-why-is-the-threading-and-ui-updating-designed-to-be-done-only-on-main-thread.html

[Q] Why is the threading and UI updating designed to be done only on a main 
thread?


Ben