WAS thread hung (AjTypeSystem)

最新推荐文章于 2025-01-02 17:49:04 发布

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文章详细介绍了如何通过升级 AjTypeSystem 类的实现版本，解决 WAS 系统中频繁出现的线程挂起问题。具体涉及到了 HashMap 和 WeakHashMap 的使用，以及如何优化 AjTypeSystem 类来提升系统性能。

最近WAS经常thread hung.

Owns Monitor Lock on java/util/HashMap@00002AAAB5A331C0/00002AAAB5A331D8

at java/util/WeakHashMap.getEntry(WeakHashMap.java:400(Compiled Code))
at java/util/WeakHashMap.containsKey(WeakHashMap.java:386(Compiled Code))
at org/aspectj/lang/reflect/AjTypeSystem.getAjType(AjTypeSystem.java:37(Compiled Code))

将AjTypeSystem.class 从aspectjrt-1.5.3.jar upgrade 到 aspectjrt-1.6.10.jar, 解决问题.

// Source File Name:   AjTypeSystem.java

package org.aspectj.lang.reflect;

import java.lang.ref.WeakReference;
import java.util.Map;
import java.util.WeakHashMap;
import org.aspectj.internal.lang.reflect.AjTypeImpl;

// Referenced classes of package org.aspectj.lang.reflect:
//            AjType

public class AjTypeSystem
{

    private static Map ajTypes = new WeakHashMap();

    public AjTypeSystem()
    {
    }

    public static AjType getAjType(Class fromClass)
    {
        if(ajTypes.containsKey(fromClass))
        {
            WeakReference weakRefToAjType = (WeakReference)ajTypes.get(fromClass);
            AjType theAjType = (AjType)weakRefToAjType.get();
            if(theAjType != null)
            {
                return theAjType;
            } else
            {
                theAjType = new AjTypeImpl(fromClass);
                ajTypes.put(fromClass, new WeakReference(theAjType));
                return theAjType;
            }
        } else
        {
            AjType theAjType = new AjTypeImpl(fromClass);
            ajTypes.put(fromClass, new WeakReference(theAjType));
            return theAjType;
        }
    }

}

// Source File Name:   AjTypeSystem.java

package org.aspectj.lang.reflect;

import java.lang.ref.WeakReference;
import java.util.*;
import org.aspectj.internal.lang.reflect.AjTypeImpl;

// Referenced classes of package org.aspectj.lang.reflect:
//            AjType

public class AjTypeSystem
{

    private static Map ajTypes = Collections.synchronizedMap(new WeakHashMap());

    public AjTypeSystem()
    {
    }

    public static AjType getAjType(Class fromClass)
    {
        WeakReference weakRefToAjType = (WeakReference)ajTypes.get(fromClass);
        if(weakRefToAjType != null)
        {
            AjType theAjType = (AjType)weakRefToAjType.get();
            if(theAjType != null)
            {
                return theAjType;
            } else
            {
                theAjType = new AjTypeImpl(fromClass);
                ajTypes.put(fromClass, new WeakReference(theAjType));
                return theAjType;
            }
        } else
        {
            AjType theAjType = new AjTypeImpl(fromClass);
            ajTypes.put(fromClass, new WeakReference(theAjType));
            return theAjType;
        }
    }

}