AnnotationUtils should use threadsafe ConcurrentMap (contention) [SPR-12878]

[spring-projects-issues]

Johann Burkard opened SPR-12878 and commented

	private static final Map<Class<?>, Boolean> annotatedInterfaceCache = new WeakHashMap<Class<?>, Boolean>();
...
	private static boolean isInterfaceWithAnnotatedMethods(Class<?> iface) {
		synchronized (annotatedInterfaceCache) {
			Boolean flag = annotatedInterfaceCache.get(iface);

is a point of contention in my app and should be replaced by something like ConcurrentSkipListMap (but not ConcurrentHashMap because ConcurrentSkipListMap uses 1/10th the memory initially). Here's a Comparator for WeakReference:

import java.lang.ref.WeakReference;
import java.util.Comparator;

import org.springframework.util.ObjectUtils;

public class WeakReferenceClassComparator implements Comparator<WeakReference<Class>> {

    @Override
    public int compare(WeakReference<Class> o1, WeakReference<Class> o2) {
        if (o1.get() == null && o2.get() == null) {
            return 0;
        }
        return new Integer(ObjectUtils.nullSafeHashCode(o1.get())).compareTo(ObjectUtils.nullSafeHashCode(o2.get()));
    }

}

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Affects: 4.0.5, 4.0.8

Issue Links:

• #16501 ReflectionUtils slow down application startup on WebSphere

[spring-projects-issues]

Juergen Hoeller commented

This has been addressed in the 4.1 line already, as part of #16501, using our own ConcurrentReferenceHashMap there now.

Note that the 4.0.x line has ended in the meantime, with no further releases planned. Please upgrade to 4.1.6 right away!

Juergen

[spring-projects-issues]

Johann Burkard commented

Thanks for the update, Jürgen. I'll tro to update.