Throwables#lazyStackTrace throws UnsupportedOperationException on AIX 5.3

[kyle-cackett]

The mechanism which detects whether to fallback on the non-lazy stack trace implementation seems to be broken on AIX 5.3 with IBMs JDK jdk-6.0.0.645-aix-powerpc. When iterating through the list returned by the method on such a system I get the following exception + trace

Caused by: java.lang.UnsupportedOperationException: You cannot access stack trace depth this way in this implementation
at sun.misc.SharedSecrets$1.getStackTraceDepth(SharedSecrets.java:172)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:60)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
at java.lang.reflect.Method.invoke(Method.java:611)
at com.google.common.base.Throwables.invokeAccessibleNonThrowingMethod(Throwables.java:292)
at com.google.common.base.Throwables.access$200(Throwables.java:48)
at com.google.common.base.Throwables$1.size(Throwables.java:284)
at java.util.AbstractList$SimpleListIterator.hasNext(AbstractList.java:51)
at com.google.common.collect.Iterators$PeekingImpl.hasNext(Iterators.java:1171)
at com.delphix.logger.Logger.getLogger(Logger.java:96)
at com.delphix.session.impl.common.SessionManager.(SessionManager.java:23)
at java.lang.J9VMInternals.initializeImpl(Native Method)
at java.lang.J9VMInternals.initialize(J9VMInternals.java:199)
... 21 more

Explicitly using new Throwable().getStackTrace resolved the problem.

[cpovirk]

Thanks, and sorry for the slow response. It's unfortunate that IBM would define this method only to make it not work, but I assume they have their reasons. If you're interested in adding catch (UnsupportedOperationException e) and an appropriate fallback, we could take a pull request.

[fdesu]

@cpovirk
I'm interested in this one, so if no one minds, I want to make an implementation for a fallback, however, should we care only for UnsupportedOperationException or it is worth to catch something generic e.g. RuntimeException? (hence I'm not a fan of such an idea)

[cpovirk]

Thanks! I would probably lean toward UnsupportedOperationException. That way, if we accidentally break our implementation, we're likely to still see the resulting exception, rather than silently catch it.

[fdesu]

@cpovirk
Agree, will do it then and create a PR soon. Thanks!

[ronshapiro]

@cpovirk can this be closed? Looks like the PR proposed for this issue was also closed.