Weldon Washburn wrote:
There was an unexpected and surprising parsing problem when running _209_db on JCHEVM. The procedure called, _jc_parse_classfile(), does some basic verification of a class file. In specific, it verifies that a class with the ACC_INTERFACE attribute set also has the ACC_ABSTRACT bit set. It turns out that _209_db has an interface without the abstract bit set. _209_db will run without warning or error on a product JVM but throws a "ClassFormatError" on JCHEVM. The temporary patch is to comment out JCHEVM code that throws the ClassFormatError. This problem needs further investigation.
JVM specification, section 4.1: http://java.sun.com/docs/books/vmspec/2nd-edition/html/ClassFile.doc.html#74353 If the ACC_INTERFACE flag of this class file is set, its ACC_ABSTRACT flag must also be set (ยง2.13.1) and its ACC_PUBLIC flag may be set. Such a class file may not have any of the other flags in Table 4.1 set. It's interesting to hear that Sun (I assume?) doesn't follow this.
Another problem is that JCHEVM seems to throw a fatal exception during load time if the code being loaded refers to a class that is nowhere to be found. I think the JVM Spec says this exception should be delayed until execution time. The specific problem is that _209_db code refers to AWT classes. Even though _209_db is run with the console configuration, when the classes load they cause JCHEVM to attempt to load AWT classes that can't be found. The workaround is really ugly -- comment out the AWT code in the spec benchmarks.
JCHEVM does agressive linking. This behavior is inherited from JCVM which was optimized for pre-compiled objects. Agressive linking is within the JVM spec, which allows flexibility in this area. The problem you see is one downside of the approach. -Archie __________________________________________________________________________ Archie Cobbs * CTO, Awarix * http://www.awarix.com --------------------------------------------------------------------- Terms of use : http://incubator.apache.org/harmony/mailing.html To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
