Question about a comment in _Jv_StackTrace::UnwindTraceFn
Dave Korn
dave.korn.cygwin@googlemail.com
Thu May 21 19:13:00 GMT 2009
Dave Korn wrote:
> So, I think maybe I have *two* problems:
>
> i) The gcj::Core::root chain is empty. Should it be? Do I have a problem
> with static c/dtors? I don't have JCR_SECTIONS turned on yet, so maybe I need
> to enable it?
To half-answer my own question there, __Jv_global_static_constructor is at
least being called at static ctor time, so I should be OK on most fronts.
> ii) I don't think the library is able to handle an exception being thrown this
> early in startup because the code that segfaults filling out the stacktrace
> does assume it's inside at least one nested interpreter frame, and it wouldn't
> be called at all if it wasn't for what looks like a race-condition failure of
> the safety check at the top of java::lang::VMThrowable::fillInStackTrace.
> Should nothing be throwing at this early stage, or should we perhaps not set
> runtimeInitialized until later? I note that it gets set true a second time,
> apparently redundantly, at the very end of _Jv_CreateJavaVM, so perhaps an
> accident of some sort has occurred here? I'll take a look through the svn
> history.
Yes, this looks like a regression. The setting of runtimeInitialized was
moved to the end of the function in r115791
Revision 115791 - (view) (download) - [select for diffs]
Modified Fri Jul 28 07:40:17 2006 UTC (2 years, 9 months ago) by gary
File length: 45045 byte(s)
Diff to previous 114300 (colored)
2006-07-28 Gary Benson <gbenson@redhat.com>
* prims.cc (_Jv_CreateJavaVM): Move setting runtimeInitialized
from the start to the end of the function. Remove references
to VMThrowable.trace_enabled.
* java/lang/natVMThrowable.cc (fillInStackTrace): Use
runtimeInitialized rather than trace_enabled to decide
whether to inhibit stack trace generation.
* java/lang/VMThrowable.java (trace_enabled): Removed.
... and apparently re-added at the start, almost certainly inadvertently, when
Tom merged the gcj-eclipse branch to trunk at r120621.
I will prepare and test a patch that simply removes the re-added set at the
top of the function.
cheers,
DaveK
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