Re: java package and MacOS

[Ben Abbott]

On Nov 27, 2012, at 10:31 PM, Ben Abbott wrote:

> On Nov 27, 2012, at 10:23 PM, Michael Goffioul wrote:
> 
>> On Tue, Nov 27, 2012 at 10:18 PM, Ben Abbott <address@hidden> 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).
>> 
>> There you obviously have a problem, you can't have Qt and Java running their 
>> own GUI loop in the main thread (at least not in a trivial way).
>> 
>> Michael.
> 
> Maybe I was confused,  Does the Java gui loop run in the main thread?
> 
> Ben

My tip is now ...

hg tip
changeset:   15777:b8bcb2c7f3e8
tag:         tip
user:        Rik <address@hidden>
date:        Wed Dec 12 16:03:46 2012 -0800
summary:     configure.ac: Search for jvm.dll on MingW/Cygwin platforms for 
Java.

Running dlgtest(1) results in ...

dlgtest (1)

0 ... STOP
1 ... listdlg tests
2 ... errordlg tests
3 ... warndlg tests
4 ... helpdlg tests
5 ... inputdlg tests
6 ... TeX code tests
Run which test?   [0] > 1
2012-12-12 21:11:45.716 octave[78603:2603] Apple AWT Java VM was loaded on 
first thread -- can't start AWT.

- test listdlg with selectionmode single. No caption, no prompt.
error: [java] java.lang.InternalError: Can't start the AWT because Java was 
started on the first thread.  Make sure StartOnFirstThread is not specified in 
your application's Info.plist or on the command line
error: called from:
error:   
/Users/bpabbott/Development/mercurial/default/sources/scripts/java/listdlg.m at 
line 131, column 8
error:   
/Users/bpabbott/Development/mercurial/default/sources/scripts/java/dlgtest.m at 
line 61, column 6
error:   
/Users/bpabbott/Development/mercurial/default/sources/scripts/java/dlgtest.m at 
line 30, column 9

Looks like the Java thread isn't main(), but the first thread spawned by main()?

Ben