1.1 --- a/src/share/vm/runtime/vframe.hpp Wed Apr 09 10:38:30 2008 -0400
1.2 +++ b/src/share/vm/runtime/vframe.hpp Wed Apr 09 15:10:22 2008 -0700
1.3 @@ -416,6 +416,48 @@
1.4 int decode_offset;
1.5 if (pc_desc == NULL) {
1.6 // Should not happen, but let fill_from_compiled_frame handle it.
1.7 +
1.8 + // If we are trying to walk the stack of a thread that is not
1.9 + // at a safepoint (like AsyncGetCallTrace would do) then this is an
1.10 + // acceptable result. [ This is assuming that safe_for_sender
1.11 + // is so bullet proof that we can trust the frames it produced. ]
1.12 + //
1.13 + // So if we see that the thread is not safepoint safe
1.14 + // then simply produce the method and a bci of zero
1.15 + // and skip the possibility of decoding any inlining that
1.16 + // may be present. That is far better than simply stopping (or
1.17 + // asserting. If however the thread is safepoint safe this
1.18 + // is the sign of a compiler bug and we'll let
1.19 + // fill_from_compiled_frame handle it.
1.20 +
1.21 +
1.22 + JavaThreadState state = _thread->thread_state();
1.23 +
1.24 + // in_Java should be good enough to test safepoint safety
1.25 + // if state were say in_Java_trans then we'd expect that
1.26 + // the pc would have already been slightly adjusted to
1.27 + // one that would produce a pcDesc since the trans state
1.28 + // would be one that might in fact anticipate a safepoint
1.29 +
1.30 + if (state == _thread_in_Java ) {
1.31 + // This will get a method a zero bci and no inlining.
1.32 + // Might be nice to have a unique bci to signify this
1.33 + // particular case but for now zero will do.
1.34 +
1.35 + fill_from_compiled_native_frame();
1.36 +
1.37 + // There is something to be said for setting the mode to
1.38 + // at_end_mode to prevent trying to walk further up the
1.39 + // stack. There is evidence that if we walk any further
1.40 + // that we could produce a bad stack chain. However until
1.41 + // we see evidence that allowing this causes us to find
1.42 + // frames bad enough to cause segv's or assertion failures
1.43 + // we don't do it as while we may get a bad call chain the
1.44 + // probability is much higher (several magnitudes) that we
1.45 + // get good data.
1.46 +
1.47 + return true;
1.48 + }
1.49 decode_offset = DebugInformationRecorder::serialized_null;
1.50 } else {
1.51 decode_offset = pc_desc->scope_decode_offset();
