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在链接上写的博客以不同的方式在并发哈希映射上提供了独占同步，并说它是面向性能的：并发哈希映射的独占锁。我很困惑在为并发哈希映射提供自定义功能时它是否真的会起作用。另外我想知道它是否使用与 ConcurrentHashMap 相同的锁

public class CMap<K, V> {
private final ConcurrentMap<K, V> map = new ConcurrentHashMap<K, V>();
private final Object[] locks = new Object[16]; {
    for(int i = 0;i<locks.length;i++) locks[i] = new Object();
}

public V put(K key, V value) {
    int hash = key.hashCode() & 0x7FFFFFFF;
    synchronized (locks[hash % locks.length]) { // allows concurrent writes.
        return map.put(key, value);
    }
}

public V get(K key) {
    return map.get(key); // concurrent reads.
}

public V putIfAbsentTheHardWay(K key, V value) {
    int hash = key.hashCode() & 0x7FFFFFFF;
    synchronized (locks[hash % locks.length]) { // supports custom operations.
        if (!map.containsKey(key))
            return map.put(key, value);
        else
            return map.get(key);
    }
}

}

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