Implement JNI "weak global" references.
The VM now supports the NewWeakGlobalRef and DeleteWeakGlobalRef calls,
which create a kind of weak reference that's directly visible to native
code. While the JNI spec says that these can be used directly, the only
safe way to use them is to convert them to a strong local or global
reference first, so this is enforced.
The net result is very similar to manually creating a global reference to
a WeakReference object and manipulating it with method calls from native
code, but the JNI calls are faster and more convenient.
7 files changed