The problem only occurs with the Server compiler, not with its client counterpart. The problem occurs on HotSpot 1.3.1_X only, not with earlier releases (HotSpot 2.0 or 1.3.0) or HotSpot 1.4 beta3 release.

The problem is that inadequate recompilations occur with some of their code. Customer has reported this problem on his specific environment (TeleORB platform), but this can be reproduced using the attached test cases on Linux platform. The HotSpot 1.3.1 server VM assumes that some code recompilation is due, and therefore flush the compiled code and start a new compilation on the same code.

java_g [-client|-server] -XX:+PrintCompilation -XX:+TraceDeoptimization -cp . Test
You will see lot of "uncommon trap" messages like this one in the log file :

Uncommon trap occurred in Test::test3 (@0x4292197e) unloaded_class_index = -5, t
hread = 3888
Deoptimization: deoptimize frame (pc=0x4292197e, sp=0xbfffd004)
 - frames stored in vframeArray(0x8263570)
Deoptimization: unpacking vframeArray(0x8263570)
      >> {method} 'test3' '(LDialogueManager;)V' in 'Test'
      >> {method} 'handleComponents' '(LInputStream;)V' in 'DialogueManager'
      >> {method} 'read_int' '()I' in 'InputStream'