🚀 go-pugleaf

Dear Programmer,




    I'm trying to understand what's involved in how threads and thread 
synchronization is implemented in the JVM.  


    Sunsoft's "The Java Virtual Machine" (ISBN ISBN 0-201-63452-X) is 
unreadable.  The O'Reilly "Java Virtual Machine" (ISBN 1-56592-194-1) is 
good, but fizzles out completely about threads:  it's Threads chapter is 
just 3 pages.  


    Bill "Under The Hood" Venners has written a book "Inside the Java 
Virtual Machine" (ISBN 0-07-913248-0) but it's not in print yet:


        http://www.artima.com/insidejvm/blurb.shtml


    In my investigating, I knocked up a couple of little text-mode apps 
to spark discussion on threads on behalf of a group implementating the 
JVM for Psion 3 handhelds.


    The source and documentation is at:


        http://www.mdx.ac.uk/~tr033/source_code/JAVA/PSION-JAVA/Philosophers.html


    This is a pretty neat, fairly compact example of a solution to the 
main "Dining Philosophers" problem (I think!).  It doesn't concern
itself with "starvation" at all.


    I would like to have it confirmed whether this solution can deadlock 
or not; and what is a better, clearer, more succinct solution.  In 
particular, can I dispense with the Chopsticks somehow and get the 
philosophers to synchronise on themselves?  I have a feeling there's 
something impossible about that though.  


    This is completely unrelated to my original aim, but where do I find 
out about proving properties of parallel systems?  It really bugs me 
that I only have a gut feeling that it's working.


    Also, in Chopstick.java, I have a wait() that's guarded by an 'if'
not a 'while'.  I am uneasy about this:  I got to the current solution 
by magic, it felt like.  How can I arrange for it to be guarded by a while 
loop?


Thanks in advance,




Sandy

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