Deoptimization code of JIT compiler in JVM 1.5 seems to be leaking memory under some situation.
Posted Date : 2006-12-08 08:05:36.0

Use -client optoin.

When lazy deopt was added and the vframeArray code was rewritten this leak was introduced.

After going through the C2 code, found that these get deallocated in unpack_on_stack() which calls deallocate_monitor_chunks().

void vframeArray::deallocate_monitor_chunks() {
  JavaThread* jt = JavaThread::current();
  for (int index = 0; index < frames(); index++ ) {
     MonitorChunk* chunk = element(index)->monitors();
     if (chunk != NULL) {
       jt->remove_monitor_chunk(chunk);
     }
  }
}
void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
  guarantee(monitor_chunks() != NULL, "must be non empty");
  if (monitor_chunks() == chunk) {
    set_monitor_chunks(chunk->next());
  } else {
    MonitorChunk* prev = monitor_chunks();
    while (prev->next() != chunk) prev = prev->next();
    prev->set_next(chunk->next());
  }
}

In remove_monitor_chunk, we just set the pointer of the list to next chunk and don't actually delete the passed chunk.

Thanks to Poonam for finding this.
Posted Date : 2007-01-10 14:58:59.0