Re: [Sablevm-developer] sablevm hang

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Chris Pickett wrote:
> Joseph Paris wrote:
> 
>>Yeah, i made that sounds confusing ;p  I meant to say that i have no 
>>problem using the AwtUtils.init... by itself, nor do i have a problem 
>>burying an awt class way down in a series of class instantiations 
>>(currently tried about 6 levels down).  
>>
>>However, in the current code base (JXTA) if i remove the call to 
>>AwtUtils.init... the next call (which instantiates a class that displays a 
>>Frame)  hangs with the same problem and at VMObject.wait.  I'm not sure 
>>if i'm hitting a thread limit or what, it seems kind of odd that the same 
>>problem occurs regardless of whether or not i call AwtUtils.init or create 
>>a new Frame.
>>
>>I'll try your suggestions below and post some results.
> 
> 
> Let's work from the AwtUtils.java that I modified to have a main() 
> method.  It runs with Sun's JDK but hangs with sablevm AFAICT.  Try and 
> simplify just that until it doesn't hang, and give us the minimal 
> hanging example.  For example, you can remove the "f.dispose();" line 
> and it will still hang, but not the "Frame f = new Frame();" line.

Hi again ...

I narrowed down the test case a bit, and looked up some docs.  I'm going 
to bed now, but if someone feels inspired to look at it:

http://java.sun.com/j2se/1.4.2/docs/api/java/awt/Window.html#dispose()
http://java.sun.com/j2se/1.4.2/docs/api/java/awt/doc-files/AWTThreadIssues.html

Here is the more simple test case:

http://www.sable.mcgill.ca/~cpicke/sablevm/AwtUtils2.java

Also, if I run:

sablevm-switch-debug --property=sablevm.verbose.instructions=true 
--property=sablevm.verbose.methods=true -s -g -j AwtUtils2 &> log &

and then do:

tail -n 50 log

I get:

T1: [verbose instructions: executing @0x4152c37c ALOAD]
T1: [verbose instructions: executing @0x4152c384 ALOAD_0]
T1: [verbose instructions: executing @0x4152c388 GETFIELD_REFERENCE]
T1: [verbose instructions: executing @0x4152c394 ILOAD_3]
T1: [verbose instructions: executing @0x4152c398 AALOAD]
T1: [verbose instructions: executing @0x4152c39c PUTFIELD_REFERENCE]
T1: [verbose instructions: executing @0x4152c3a8 ALOAD_0]
T1: [verbose instructions: executing @0x4152c3ac GETFIELD_REFERENCE]
T1: [verbose instructions: executing @0x4152c3b8 ILOAD_3]
T1: [verbose instructions: executing @0x4152c3bc ALOAD]
T1: [verbose instructions: executing @0x4152c3c4 AASTORE]
T1: [verbose instructions: executing @0x4152c3c8 RETURN]
T1: [verbose methods: exiting  method 
java/util/HashMap.addEntry(Ljava/lang/Object;Ljava/lang/Object;IZ)V]
T1: [                   returning to 
java/util/HashMap.put(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;]
T1: [verbose instructions: executing @0x4152bf34 ACONST_NULL]
T1: [verbose instructions: executing @0x4152bf38 ARETURN]
T1: [verbose methods: exiting  method 
java/util/HashMap.put(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;]
T1: [                   returning to 
java/lang/ClassLoader.loadClass(Ljava/lang/String;Z)Ljava/lang/Class;]
T1: [verbose instructions: executing @0x413de548 POP]
T1: [verbose instructions: executing @0x413de54c ALOAD]
T1: [verbose instructions: executing @0x413de554 ALOAD_3]
T1: [verbose instructions: executing @0x413de558 MONITOREXIT]
T1: [verbose instructions: executing @0x413de55c ARETURN]
T1: [verbose methods: exiting  method 
java/lang/ClassLoader.loadClass(Ljava/lang/String;Z)Ljava/lang/Class;]
T1: [                   returning to 
java/lang/ClassLoader.loadClass(Ljava/lang/String;)Ljava/lang/Class;]
T1: [verbose instructions: executing @0x413de304 ARETURN]
T1: [verbose methods: exiting  method 
java/lang/ClassLoader.loadClass(Ljava/lang/String;)Ljava/lang/Class;]
T1: [                   returning to 
java/lang/VirtualMachine.createClass(Ljava/lang/ClassLoader;Ljava/lang/String;)Ljava/lang/Class;]
T1: [verbose instructions: executing @0x415418c4 ARETURN]
T1: [verbose methods: exiting  method 
java/lang/VirtualMachine.createClass(Ljava/lang/ClassLoader;Ljava/lang/String;)Ljava/lang/Class;]
T1: [                   returning to MyThread.run()V]
T1: [verbose instructions: executing @0x80511c0 INTERNAL_CALL_END]
T1: [verbose instructions: executing @0x413feb74 ASTORE_1]
T1: [verbose instructions: executing @0x413feb78 GOTO]
T1: [verbose instructions: executing @0x413feb80 RETURN]
T1: [verbose methods: exiting  method MyThread.run()V]
T1: [                   returning to AwtUtils.main([Ljava/lang/String;)V]
T1: [verbose instructions: executing @0x413fe570 REPLACE]
T1: [verbose instructions: executing @0x413fe57c GOTO]
T1: [verbose instructions: executing @0x413fe514 RETURN]
T1: [verbose methods: exiting  method AwtUtils.main([Ljava/lang/String;)V]
T1: [                   returning to 
java/lang/VirtualMachine.invokeMain(Ljava/lang/Class;[Ljava/lang/String;)V]
T1: [verbose instructions: executing @0x80511c0 INTERNAL_CALL_END]
[verbose methods: exiting  method 
java/lang/VirtualMachine.invokeMain(Ljava/lang/Class;[Ljava/lang/String;)V]
[                   returning to 
java/lang/VirtualMachine.main([Ljava/lang/String;)V]
T1: [verbose instructions: executing @0x413b2fc0 REPLACE]
T1: [verbose instructions: executing @0x413b2fcc GOTO]
T1: [verbose instructions: executing @0x413b2f1c RETURN]
T1: [verbose methods: exiting  method 
java/lang/VirtualMachine.main([Ljava/lang/String;)V]
T1: [verbose instructions: executing @0x80511c0 INTERNAL_CALL_END]

It now looks to me like the started AWT thread never dies.  If I remove 
the call to dispose(), actually everything is fine (oddly this was not 
the case with the more complex example).

Cheers,
Chris