RFR: Finalizer support

[Man Cao]

Apology for the delay.

I don't see how the TSAN code is guarded by the build-time option. Does it
work with "--with-jvm-features=-tsan".

For checking whether TSAN is enabled, is it possible to use the following
directly? Then we don't need to change jvm.h/cpp and symbols-unix.
ManagementFactory.getRuntimeMXBean().getInputArguments().contains("-XX:+ThreadSanitizer");

In Finalizer.java
private static boolean TSAN_ENABLED = isTsanEnabled();
It is better to mark TSAN_ENABLED field as "final".

if (TSAN_ENABLED) {
  tsanFinalize();
}
I think we can keep the TODO for this code, that it could be moved to
when a batch of finalizers was queued.

In Finalizer.c, should it add this line?
#include "java_lang_ref_Finalizer.h"
I see other files in the directory have includes for corresponding .h files.

In NonRacyFinalizerLoopTest.java:
* @build AbstractLoop TsanRunner

public static void main(String[] args) throws InterruptedException {

We can remove "AbstractLoop" and "throws InterruptedException", right?


-Man


On Mon, Sep 9, 2019 at 3:27 PM Jean Christophe Beyler <jcbeyler at google.com>
wrote:

> Took me a while to get to this, my apologies Arthur :)
>
> I looks good to me!
> Jc
>
> On Tue, Sep 3, 2019 at 2:45 PM Arthur Eubanks <aeubanks at google.com> wrote:
>
> > webrev: http://cr.openjdk.java.net/~aeubanks/tsanfinalizer/webrev.00/
> >
> > This patch makes the finalizer thread call __tsan_java_finalize(),
> > preventing reports of false positives in finalizers.
> >
>
>
> --
>
> Thanks,
> Jc
>