tree 7c5962dc198960dc90a3e769cb6eb33230bf3bdf
parent 6d049870baa1d29060eba373a68d85abd34d40d9
author Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com> 1623877766 +0300
committer Niraj Modi <niraj.modi@in.ibm.com> 1624291325 -0400

Bug 562408 - Various problems when native->java callback throws RuntimeException

The problem occurred with a single native API called multiple Java
callbacks, and one of such callbacks thrown a Java exception. In such
case, all subsequent callbacks were skipped until the native API
returned. Sometimes a caller does not expect that callback will be
skipped (or does not expect the default return value from callback)
and will do weird things or downright crash JVM.

A simple way to understand how a single native API could call multiple
callbacks is a Table with multiple items. A single "paint()" native API
will invoke Measure/Paint/etc callbacks per every item and will not
return until everything is done.

This patch fixes the problem: now even if one of the callbacks throws,
the others will still execute as normal.

One potential side effect is that some unexpected callbacks will now
be called. For example, consider a theoretical native API that invokes
3 callbacks: "init", "doWork" and "cleanup". Previously, if "init"
thrown, "doWork" and "cleanup" would be skipped, but this is no longer
the case.

I understand that this side effect is reasonable, because throwing
RuntimeException's is not a proper way to cancel something. If something
does indeed need to be canceled on exception, this shall be done with an
explicit cancel. Alternatively, SWT can be taught to explicitly skip
specific subsequent callbacks if the previous one thrown.

This patch also removes 'JNI_VERSION' which is not used since 569853.

Change-Id: Ic428e081dc19eeb65e40a690388538b87601977e
Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>
Reviewed-on: https://git.eclipse.org/r/c/platform/eclipse.platform.swt/+/182120
Tested-by: Platform Bot <platform-bot@eclipse.org>
Reviewed-by: Niraj Modi <niraj.modi@in.ibm.com>