io.netty.util.internal.InternalThreadLocalMap#setIndexedVariable ( )源码实例Demo

@SuppressWarnings("unchecked")
private static void addToVariablesToRemove(InternalThreadLocalMap threadLocalMap, FastThreadLocal<?> variable) {
    Object v = threadLocalMap.indexedVariable(variablesToRemoveIndex);
    Set<FastThreadLocal<?>> variablesToRemove;
    if (v == InternalThreadLocalMap.UNSET || v == null) {
        variablesToRemove = Collections.newSetFromMap(new IdentityHashMap<FastThreadLocal<?>, Boolean>());
        threadLocalMap.setIndexedVariable(variablesToRemoveIndex, variablesToRemove);
    } else {
        variablesToRemove = (Set<FastThreadLocal<?>>) v;
    }

    variablesToRemove.add(variable);
}
 

private void registerCleaner(final InternalThreadLocalMap threadLocalMap) {
        Thread current = Thread.currentThread();
        if (FastThreadLocalThread.willCleanupFastThreadLocals(current) ||
            threadLocalMap.indexedVariable(cleanerFlagIndex) != InternalThreadLocalMap.UNSET) {
            return;
        }
        // removeIndexedVariable(cleanerFlagIndex) isn't necessary because the finally cleanup is tied to the lifetime
        // of the thread, and this Object will be discarded if the associated thread is GCed.
        // removeIndexedVariable(cleanerFlagIndex)不是必需的，因为最终的清理与生命周期有关
//线程，如果关联的线程是GCed，这个对象将被丢弃。
        threadLocalMap.setIndexedVariable(cleanerFlagIndex, Boolean.TRUE);

        // We will need to ensure we will trigger remove(InternalThreadLocalMap) so everything will be released
        // and FastThreadLocal.onRemoval(...) will be called.
        //我们需要确保我们将触发remove(InternalThreadLocalMap)，以便释放所有内容
//和fastthreadlocal.onremove(…)将被调用。
        ObjectCleaner.register(current, new Runnable() {
            @Override
            public void run() {
                remove(threadLocalMap);

                // It's fine to not call InternalThreadLocalMap.remove() here as this will only be triggered once
                // the Thread is collected by GC. In this case the ThreadLocal will be gone away already.在这里不调用InternalThreadLocalMap.remove()是可以的，因为它只会被触发一次
//线程被GC收集。在这种情况下，ThreadLocal已经消失了。
            }
        });
    }
 

private V initialize(InternalThreadLocalMap threadLocalMap) {
    V v = null;
    try {
        v = initialValue();
    } catch (Exception e) {
        PlatformDependent.throwException(e);
    }

    threadLocalMap.setIndexedVariable(index, v);
    addToVariablesToRemove(threadLocalMap, this);
    return v;
}
 

/**
     * @return see {@link InternalThreadLocalMap#setIndexedVariable(int, Object)}.
     */
//
    private boolean setKnownNotUnset(InternalThreadLocalMap threadLocalMap, V value) {
        if (threadLocalMap.setIndexedVariable(index, value)) {
            addToVariablesToRemove(threadLocalMap, this);
            return true;
        }
        return false;
    }
 

@SuppressWarnings("unchecked")
private static void addToVariablesToRemove(InternalThreadLocalMap threadLocalMap, FastThreadLocal<?> variable) {
    Object v = threadLocalMap.indexedVariable(variablesToRemoveIndex);
    Set<FastThreadLocal<?>> variablesToRemove;
    if (v == InternalThreadLocalMap.UNSET || v == null) {
        variablesToRemove = Collections.newSetFromMap(new IdentityHashMap<FastThreadLocal<?>, Boolean>());
        threadLocalMap.setIndexedVariable(variablesToRemoveIndex, variablesToRemove);
    } else {
        variablesToRemove = (Set<FastThreadLocal<?>>) v;
    }

    variablesToRemove.add(variable);
}
 

private V initialize(InternalThreadLocalMap threadLocalMap) {
    V v = null;
    try {
        v = initialValue();
    } catch (Exception e) {
        PlatformDependent.throwException(e);
    }

    threadLocalMap.setIndexedVariable(index, v);
    addToVariablesToRemove(threadLocalMap, this);
    return v;
}
 

/**
 * Set the value for the specified thread local map. The specified thread local map must be for the current thread.
 */
public final void set(InternalThreadLocalMap threadLocalMap, V value) {
    if (value != InternalThreadLocalMap.UNSET) {
        if (threadLocalMap.setIndexedVariable(index, value)) {
            addToVariablesToRemove(threadLocalMap, this);
        }
    } else {
        remove(threadLocalMap);
    }
}