On Tue, 25 Oct 2022 19:43:14 GMT, Jorn Vernee <jver...@openjdk.org> wrote:
>> Is it possible to use filter/findfirst without using lambdas? I want to
>> avoid recursion inside the tracing code.
>>
>> I am not sure about dumping the call stack. It seems an overkill and not
>> useful in most cases. It’s easier to rebuild the JDK and add
>> Thread.dumpStack() in the rare occasion that you need to do this.
>
>> Is it possible to use filter/findfirst without using lambdas? I want to
>> avoid recursion inside the tracing code.
>
> You could do this I believe (if I've eye-balled that correctly :)):
> Suggestion:
>
> String callerName = caller.getName();
> String callerInfo = StackWalker.getInstance().walk(new
> Function<Stream<StackWalker.StackFrame>, String>() {
> // We use inner classes (instead of stream/lambda) to avoid
> triggering
> // further invokedynamic resolution, which would cause infinite
> recursion.
> // It's OK to use + for string concat, because java.base is
> compiled without
> // the use of indy string concat.
> @Override
> public String apply(Stream<StackWalker.StackFrame> s) {
> return s.filter(new Predicate<StackWalker.StackFrame>() {
> @Override
> public boolean test(StackWalker.StackFrame f) {
> return callerName.equals(f.getClassName());
> }
> }).findFirst().get().toStackTraceElement().toString();
> }
> });
>
>
>> I am not sure about dumping the call stack. It seems an overkill and not
>> useful in most cases. It’s easier to rebuild the JDK and add
>> Thread.dumpStack() in the rare occasion that you need to do this.
>
> Fair enough.
Or, maybe it's easier to use `Thread.currentThread().getStackTrace()` and avoid
messing around with streams altogether.
-------------
PR: https://git.openjdk.org/jdk/pull/10842
