com.alibaba.dubbo.rpc.RpcStatus Java Examples

public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
    URL url = invoker.getUrl();
    String methodName = invocation.getMethodName();
    int max = url.getMethodParameter(methodName, Constants.EXECUTES_KEY, 0);
    if (max > 0) {
        RpcStatus count = RpcStatus.getStatus(url, invocation.getMethodName());
        if (count.getActive() >= max) {
            throw new RpcException("Failed to invoke method " + invocation.getMethodName() + " in provider " + url + ", cause: The service using threads greater than <dubbo:service executes=\"" + max + "\" /> limited.");
        }
    }
    long begin = System.currentTimeMillis();
    boolean isException = false;
    RpcStatus.beginCount(url, methodName);
    try {
        Result result = invoker.invoke(invocation);
        return result;
    } catch (Throwable t) {
        isException = true;
        if(t instanceof RuntimeException) {
            throw (RuntimeException) t;
        }
        else {
            throw new RpcException("unexpected exception when ExecuteLimitFilter", t);
        }
    }
    finally {
        RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, isException);
    }
}
 

public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
    URL url = invoker.getUrl();
    String methodName = invocation.getMethodName();
    int max = url.getMethodParameter(methodName, Constants.EXECUTES_KEY, 0);
    if (max > 0) {
        RpcStatus count = RpcStatus.getStatus(url, invocation.getMethodName());
        if (count.getActive() >= max) {
            throw new RpcException("Failed to invoke method " + invocation.getMethodName() + " in provider " + url + ", cause: The service using threads greater than <dubbo:service executes=\"" + max + "\" /> limited.");
        }
    }
    long begin = System.currentTimeMillis();
    boolean isException = false;
    RpcStatus.beginCount(url, methodName);
    try {
        Result result = invoker.invoke(invocation);
        return result;
    } catch (Throwable t) {
        isException = true;
        if(t instanceof RuntimeException) {
            throw (RuntimeException) t;
        }
        else {
            throw new RpcException("unexpected exception when ExecuteLimitFilter", t);
        }
    }
    finally {
        RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, isException);
    }
}
 

public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
    URL url = invoker.getUrl();
    String methodName = invocation.getMethodName();
    int max = url.getMethodParameter(methodName, Constants.EXECUTES_KEY, 0);
    if (max > 0) {
        RpcStatus count = RpcStatus.getStatus(url, invocation.getMethodName());
        if (count.getActive() >= max) {
            throw new RpcException("Failed to invoke method " + invocation.getMethodName() + " in provider " + url + ", cause: The service using threads greater than <dubbo:service executes=\"" + max + "\" /> limited.");
        }
    }
    long begin = System.currentTimeMillis();
    boolean isException = false;
    RpcStatus.beginCount(url, methodName);
    try {
        Result result = invoker.invoke(invocation);
        return result;
    } catch (Throwable t) {
        isException = true;
        if(t instanceof RuntimeException) {
            throw (RuntimeException) t;
        }
        else {
            throw new RpcException("unexpected exception when ExecuteLimitFilter", t);
        }
    }
    finally {
        RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, isException);
    }
}
 

public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
    URL url = invoker.getUrl();
    String methodName = invocation.getMethodName();
    int max = url.getMethodParameter(methodName, Constants.EXECUTES_KEY, 0);
    if (max > 0) {
        RpcStatus count = RpcStatus.getStatus(url, invocation.getMethodName());
        if (count.getActive() >= max) {
            throw new RpcException("Failed to invoke method " + invocation.getMethodName() + " in provider " + url + ", cause: The service using threads greater than <dubbo:service executes=\"" + max + "\" /> limited.");
        }
    }
    long begin = System.currentTimeMillis();
    boolean isException = false;
    RpcStatus.beginCount(url, methodName);
    try {
        return invoker.invoke(invocation);
    } catch (Throwable t) {
        isException = true;
        if(t instanceof RuntimeException) {
            throw (RuntimeException) t;
        }
        else {
            throw new RpcException("unexpected exception when ExecuteLimitFilter", t);
        }
    }
    finally {
        RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, isException);
    }
}
 

public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
    URL url = invoker.getUrl();
    String methodName = invocation.getMethodName();
    int max = url.getMethodParameter(methodName, Constants.EXECUTES_KEY, 0);
    if (max > 0) {
        RpcStatus count = RpcStatus.getStatus(url, invocation.getMethodName());
        if (count.getActive() >= max) {
            throw new RpcException("Failed to invoke method " + invocation.getMethodName() + " in provider " + url + ", cause: The service using threads greater than <dubbo:service executes=\"" + max + "\" /> limited.");
        }
    }
    long begin = System.currentTimeMillis();
    boolean isException = false;
    RpcStatus.beginCount(url, methodName);
    try {
        Result result = invoker.invoke(invocation);
        return result;
    } catch (Throwable t) {
        isException = true;
        if(t instanceof RuntimeException) {
            throw (RuntimeException) t;
        }
        else {
            throw new RpcException("unexpected exception when ExecuteLimitFilter", t);
        }
    }
    finally {
        RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, isException);
    }
}
 

public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
    URL url = invoker.getUrl();
    String methodName = invocation.getMethodName();
    int max = invoker.getUrl().getMethodParameter(methodName, Constants.ACTIVES_KEY, 0);
    RpcStatus count = RpcStatus.getStatus(invoker.getUrl(), invocation.getMethodName());
    if (max > 0) {
        long timeout = invoker.getUrl().getMethodParameter(invocation.getMethodName(), Constants.TIMEOUT_KEY, 0);
        long start = System.currentTimeMillis();
        long remain = timeout;
        int active = count.getActive();
        if (active >= max) {
            synchronized (count) {
                while ((active = count.getActive()) >= max) {
                    try {
                        count.wait(remain);
                    } catch (InterruptedException e) {
                    }
                    long elapsed = System.currentTimeMillis() - start;
                    remain = timeout - elapsed;
                    if (remain <= 0) {
                        throw new RpcException("Waiting concurrent invoke timeout in client-side for service:  "
                                               + invoker.getInterface().getName() + ", method: "
                                               + invocation.getMethodName() + ", elapsed: " + elapsed
                                               + ", timeout: " + timeout + ". concurrent invokes: " + active
                                               + ". max concurrent invoke limit: " + max);
                    }
                }
            }
        }
    }
    try {
        long begin = System.currentTimeMillis();
        RpcStatus.beginCount(url, methodName);
        try {
            Result result = invoker.invoke(invocation);
            RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, true);
            return result;
        } catch (RuntimeException t) {
            RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, false);
            throw t;
        }
    } finally {
        if(max>0){
            synchronized (count) {
                count.notify();
            } 
        }
    }
}
 

protected <T> Invoker<T> doSelect(List<Invoker<T>> invokers, URL url, Invocation invocation) {
    int length = invokers.size(); // 总个数
    int leastActive = -1; // 最小的活跃数
    int leastCount = 0; // 相同最小活跃数的个数
    int[] leastIndexs = new int[length]; // 相同最小活跃数的下标
    int totalWeight = 0; // 总权重
    int firstWeight = 0; // 第一个权重，用于于计算是否相同
    boolean sameWeight = true; // 是否所有权重相同
    for (int i = 0; i < length; i++) {
    	Invoker<T> invoker = invokers.get(i);
        int active = RpcStatus.getStatus(invoker.getUrl(), invocation.getMethodName()).getActive(); // 活跃数
        int weight = invoker.getUrl().getMethodParameter(invocation.getMethodName(), Constants.WEIGHT_KEY, Constants.DEFAULT_WEIGHT); // 权重
        if (leastActive == -1 || active < leastActive) { // 发现更小的活跃数，重新开始
            leastActive = active; // 记录最小活跃数
            leastCount = 1; // 重新统计相同最小活跃数的个数
            leastIndexs[0] = i; // 重新记录最小活跃数下标
            totalWeight = weight; // 重新累计总权重
            firstWeight = weight; // 记录第一个权重
            sameWeight = true; // 还原权重相同标识
        } else if (active == leastActive) { // 累计相同最小的活跃数
            leastIndexs[leastCount ++] = i; // 累计相同最小活跃数下标
            totalWeight += weight; // 累计总权重
            // 判断所有权重是否一样
            if (sameWeight && i > 0 
                    && weight != firstWeight) {
                sameWeight = false;
            }
        }
    }
    // assert(leastCount > 0)
    if (leastCount == 1) {
        // 如果只有一个最小则直接返回
        return invokers.get(leastIndexs[0]);
    }
    if (! sameWeight && totalWeight > 0) {
        // 如果权重不相同且权重大于0则按总权重数随机
        int offsetWeight = random.nextInt(totalWeight);
        // 并确定随机值落在哪个片断上
        for (int i = 0; i < leastCount; i++) {
            int leastIndex = leastIndexs[i];
            offsetWeight -= getWeight(invokers.get(leastIndex), invocation);
            if (offsetWeight <= 0)
                return invokers.get(leastIndex);
        }
    }
    // 如果权重相同或权重为0则均等随机
    return invokers.get(leastIndexs[random.nextInt(leastCount)]);
}
 

protected <T> Invoker<T> doSelect(List<Invoker<T>> invokers, URL url, Invocation invocation) {
    int length = invokers.size(); // 总个数
    int leastActive = -1; // 最小的活跃数
    int leastCount = 0; // 相同最小活跃数的个数
    int[] leastIndexs = new int[length]; // 相同最小活跃数的下标
    int totalWeight = 0; // 总权重
    int firstWeight = 0; // 第一个权重，用于于计算是否相同
    boolean sameWeight = true; // 是否所有权重相同
    for (int i = 0; i < length; i++) {
    	Invoker<T> invoker = invokers.get(i);
        int active = RpcStatus.getStatus(invoker.getUrl(), invocation.getMethodName()).getActive(); // 活跃数
        int weight = invoker.getUrl().getMethodParameter(invocation.getMethodName(), Constants.WEIGHT_KEY, Constants.DEFAULT_WEIGHT); // 权重
        if (leastActive == -1 || active < leastActive) { // 发现更小的活跃数，重新开始
            leastActive = active; // 记录最小活跃数
            leastCount = 1; // 重新统计相同最小活跃数的个数
            leastIndexs[0] = i; // 重新记录最小活跃数下标
            totalWeight = weight; // 重新累计总权重
            firstWeight = weight; // 记录第一个权重
            sameWeight = true; // 还原权重相同标识
        } else if (active == leastActive) { // 累计相同最小的活跃数
            leastIndexs[leastCount ++] = i; // 累计相同最小活跃数下标
            totalWeight += weight; // 累计总权重
            // 判断所有权重是否一样
            if (sameWeight && i > 0 
                    && weight != firstWeight) {
                sameWeight = false;
            }
        }
    }
    // assert(leastCount > 0)
    if (leastCount == 1) {
        // 如果只有一个最小则直接返回
        return invokers.get(leastIndexs[0]);
    }
    if (! sameWeight && totalWeight > 0) {
        // 如果权重不相同且权重大于0则按总权重数随机
        int offsetWeight = random.nextInt(totalWeight);
        // 并确定随机值落在哪个片断上
        for (int i = 0; i < leastCount; i++) {
            int leastIndex = leastIndexs[i];
            offsetWeight -= getWeight(invokers.get(leastIndex), invocation);
            if (offsetWeight <= 0)
                return invokers.get(leastIndex);
        }
    }
    // 如果权重相同或权重为0则均等随机
    return invokers.get(leastIndexs[random.nextInt(leastCount)]);
}
 

public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
    URL url = invoker.getUrl();
    String methodName = invocation.getMethodName();
    int max = invoker.getUrl().getMethodParameter(methodName, Constants.ACTIVES_KEY, 0);
    RpcStatus count = RpcStatus.getStatus(invoker.getUrl(), invocation.getMethodName());
    if (max > 0) {
        long timeout = invoker.getUrl().getMethodParameter(invocation.getMethodName(), Constants.TIMEOUT_KEY, 0);
        long start = System.currentTimeMillis();
        long remain = timeout;
        int active = count.getActive();
        if (active >= max) {
            synchronized (count) {
                while ((active = count.getActive()) >= max) {
                    try {
                        count.wait(remain);
                    } catch (InterruptedException e) {
                    }
                    long elapsed = System.currentTimeMillis() - start;
                    remain = timeout - elapsed;
                    if (remain <= 0) {
                        throw new RpcException("Waiting concurrent invoke timeout in client-side for service:  "
                                               + invoker.getInterface().getName() + ", method: "
                                               + invocation.getMethodName() + ", elapsed: " + elapsed
                                               + ", timeout: " + timeout + ". concurrent invokes: " + active
                                               + ". max concurrent invoke limit: " + max);
                    }
                }
            }
        }
    }
    try {
        long begin = System.currentTimeMillis();
        RpcStatus.beginCount(url, methodName);
        try {
            Result result = invoker.invoke(invocation);
            RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, true);
            return result;
        } catch (RuntimeException t) {
            RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, false);
            throw t;
        }
    } finally {
        if(max>0){
            synchronized (count) {
                count.notify();
            } 
        }
    }
}
 

@Override
    protected <T> Invoker<T> doSelect(List<Invoker<T>> invokers, URL url, Invocation invocation) {
        int length = invokers.size(); // Number of invokers
        int leastActive = -1; // The least active value of all invokers 所有调用者中最不活跃的值
        int leastCount = 0; // The number of invokers having the same least active value (leastActive) 具有相同最小活动值(最小活动)的调用程序的数量
        int[] leastIndexs = new int[length]; // The index of invokers having the same least active value (leastActive) 具有相同最小活动值(最小活动)的调用程序索引
        int totalWeight = 0; // The sum of with warmup weights
        int firstWeight = 0; // Initial value, used for comparision
        boolean sameWeight = true; // Every invoker has the same weight value?
        for (int i = 0; i < length; i++) {
            Invoker<T> invoker = invokers.get(i);
//            获取方法正在执行的个数
            int active = RpcStatus.getStatus(invoker.getUrl(), invocation.getMethodName()).getActive(); // Active number
//            获取权重
            int afterWarmup = getWeight(invoker, invocation); // Weight
            if (leastActive == -1 || active < leastActive) { // Restart, when find a invoker having smaller least active value. 重新启动，当发现一个最小活动值的调用程序时。
                leastActive = active; // Record the current least active value 记录当前最不活跃的值
                leastCount = 1; // Reset leastCount, count again based on current leastCount 重置最小计数，根据当前最小计数再次计数
                leastIndexs[0] = i; // Reset
                totalWeight = afterWarmup; // Reset
                firstWeight = afterWarmup; // Record the weight the first invoker 记录第一个调用者的权重
                sameWeight = true; // Reset, every invoker has the same weight value? 重置，每个调用程序都有相同的权值?
            } else if (active == leastActive) { // If current invoker's active value equals with leaseActive, then accumulating. 如果当前调用者的活动值等于leaseActive，则累加。
                leastIndexs[leastCount++] = i; // Record index number of this invoker 记录此调用程序的索引号
                totalWeight += afterWarmup; // Add this invoker's weight to totalWeight. 将此调用程序的权值添加到总权值。
                // If every invoker has the same weight?
                if (sameWeight && i > 0
                        && afterWarmup != firstWeight) {
                    sameWeight = false;
                }
            }
        }
        // assert(leastCount > 0)
        if (leastCount == 1) {
            // If we got exactly one invoker having the least active value, return this invoker directly.如果我们恰好得到一个具有最小活动值的调用程序，则直接返回该调用程序。
            return invokers.get(leastIndexs[0]);
        }
        if (!sameWeight && totalWeight > 0) {
            // If (not every invoker has the same weight & at least one invoker's weight>0), select randomly based on totalWeight.如果(并非每个调用程序的权值都相同&至少有一个调用程序的权值>0)，则根据总权值随机选择。
            int offsetWeight = random.nextInt(totalWeight) + 1;
            // Return a invoker based on the random value.根据随机值返回调用程序。
            for (int i = 0; i < leastCount; i++) {
                int leastIndex = leastIndexs[i];
                offsetWeight -= getWeight(invokers.get(leastIndex), invocation);
                if (offsetWeight <= 0)
                    return invokers.get(leastIndex);
            }
        }
        // If all invokers have the same weight value or totalWeight=0, return evenly.如果所有调用者的权值相同或totalWeight=0，则均匀返回。
        return invokers.get(leastIndexs[random.nextInt(leastCount)]);
    }
 

protected <T> Invoker<T> doSelect(List<Invoker<T>> invokers, URL url, Invocation invocation) {
    int length = invokers.size(); // 总个数
    int leastActive = -1; // 最小的活跃数
    int leastCount = 0; // 相同最小活跃数的个数
    int[] leastIndexs = new int[length]; // 相同最小活跃数的下标
    int totalWeight = 0; // 总权重
    int firstWeight = 0; // 第一个权重，用于于计算是否相同
    boolean sameWeight = true; // 是否所有权重相同
    for (int i = 0; i < length; i++) {
    	Invoker<T> invoker = invokers.get(i);
        int active = RpcStatus.getStatus(invoker.getUrl(), invocation.getMethodName()).getActive(); // 活跃数
        int weight = invoker.getUrl().getMethodParameter(invocation.getMethodName(), Constants.WEIGHT_KEY, Constants.DEFAULT_WEIGHT); // 权重
        if (leastActive == -1 || active < leastActive) { // 发现更小的活跃数，重新开始
            leastActive = active; // 记录最小活跃数
            leastCount = 1; // 重新统计相同最小活跃数的个数
            leastIndexs[0] = i; // 重新记录最小活跃数下标
            totalWeight = weight; // 重新累计总权重
            firstWeight = weight; // 记录第一个权重
            sameWeight = true; // 还原权重相同标识
        } else if (active == leastActive) { // 累计相同最小的活跃数
            leastIndexs[leastCount ++] = i; // 累计相同最小活跃数下标
            totalWeight += weight; // 累计总权重
            // 判断所有权重是否一样
            if (sameWeight && i > 0 
                    && weight != firstWeight) {
                sameWeight = false;
            }
        }
    }
    // assert(leastCount > 0)
    if (leastCount == 1) {
        // 如果只有一个最小则直接返回
        return invokers.get(leastIndexs[0]);
    }
    if (! sameWeight && totalWeight > 0) {
        // 如果权重不相同且权重大于0则按总权重数随机
        int offsetWeight = random.nextInt(totalWeight);
        // 并确定随机值落在哪个片断上
        for (int i = 0; i < leastCount; i++) {
            int leastIndex = leastIndexs[i];
            offsetWeight -= getWeight(invokers.get(leastIndex), invocation);
            if (offsetWeight <= 0)
                return invokers.get(leastIndex);
        }
    }
    // 如果权重相同或权重为0则均等随机
    return invokers.get(leastIndexs[random.nextInt(leastCount)]);
}
 

public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
    URL url = invoker.getUrl();
    String methodName = invocation.getMethodName();
    int max = invoker.getUrl().getMethodParameter(methodName, Constants.ACTIVES_KEY, 0);
    RpcStatus count = RpcStatus.getStatus(invoker.getUrl(), invocation.getMethodName());
    if (max > 0) {
        long timeout = invoker.getUrl().getMethodParameter(invocation.getMethodName(), Constants.TIMEOUT_KEY, 0);
        long start = System.currentTimeMillis();
        long remain = timeout;
        int active = count.getActive();
        if (active >= max) {
            synchronized (count) {
                while ((active = count.getActive()) >= max) {
                    try {
                        count.wait(remain);
                    } catch (InterruptedException ignore) {
                    }
                    long elapsed = System.currentTimeMillis() - start;
                    remain = timeout - elapsed;
                    if (remain <= 0) {
                        throw new RpcException("Waiting concurrent invoke timeout in client-side for service:  "
                                               + invoker.getInterface().getName() + ", method: "
                                               + invocation.getMethodName() + ", elapsed: " + elapsed
                                               + ", timeout: " + timeout + ". concurrent invokes: " + active
                                               + ". max concurrent invoke limit: " + max);
                    }
                }
            }
        }
    }
    try {
        long begin = System.currentTimeMillis();
        RpcStatus.beginCount(url, methodName);
        try {
            Result result = invoker.invoke(invocation);
            RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, true);
            return result;
        } catch (RuntimeException t) {
            RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, false);
            throw t;
        }
    } finally {
        if(max>0){
            synchronized (count) {
                count.notify();
            } 
        }
    }
}
 

@Override
    public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
        URL url = invoker.getUrl();
//        查询执行方法名
        String methodName = invocation.getMethodName();
        Semaphore executesLimit = null;
        boolean acquireResult = false;
//        executes参数是用Semaphore限制并发的，默认是0标识无限制
        int max = url.getMethodParameter(methodName, Constants.EXECUTES_KEY, 0);
        if (max > 0) {
            RpcStatus count = RpcStatus.getStatus(url, invocation.getMethodName());
//            if (count.getActive() >= max) {
            /**
             * http://manzhizhen.iteye.com/blog/2386408
             * use semaphore for concurrency control (to limit thread number)
             */
            executesLimit = count.getSemaphore(max);
            if(executesLimit != null && !(acquireResult = executesLimit.tryAcquire())) {
                throw new RpcException("Failed to invoke method " + invocation.getMethodName() + " in provider " + url + ", cause: The service using threads greater than <dubbo:service executes=\"" + max + "\" /> limited.");
            }
        }
        long begin = System.currentTimeMillis();
        boolean isSuccess = true;
//        执行业务方法之前开始计数
        RpcStatus.beginCount(url, methodName);
        try {
//            执行业务方法
            Result result = invoker.invoke(invocation);
            return result;
        } catch (Throwable t) {
            isSuccess = false;
            if (t instanceof RuntimeException) {
                throw (RuntimeException) t;
            } else {
                throw new RpcException("unexpected exception when ExecuteLimitFilter", t);
            }
        } finally {
//            执行业务方法之后结束计数
            RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, isSuccess);
            if(acquireResult) {
                executesLimit.release();
            }
        }
    }
 

protected <T> Invoker<T> doSelect(List<Invoker<T>> invokers, URL url, Invocation invocation) {
    int length = invokers.size(); // 总个数
    int leastActive = -1; // 最小的活跃数
    int leastCount = 0; // 相同最小活跃数的个数
    int[] leastIndexs = new int[length]; // 相同最小活跃数的下标
    int totalWeight = 0; // 总权重
    int firstWeight = 0; // 第一个权重，用于于计算是否相同
    boolean sameWeight = true; // 是否所有权重相同
    for (int i = 0; i < length; i++) {
    	Invoker<T> invoker = invokers.get(i);
        int active = RpcStatus.getStatus(invoker.getUrl(), invocation.getMethodName()).getActive(); // 活跃数
        int weight = invoker.getUrl().getMethodParameter(invocation.getMethodName(), Constants.WEIGHT_KEY, Constants.DEFAULT_WEIGHT); // 权重
        if (leastActive == -1 || active < leastActive) { // 发现更小的活跃数，重新开始
            leastActive = active; // 记录最小活跃数
            leastCount = 1; // 重新统计相同最小活跃数的个数
            leastIndexs[0] = i; // 重新记录最小活跃数下标
            totalWeight = weight; // 重新累计总权重
            firstWeight = weight; // 记录第一个权重
            sameWeight = true; // 还原权重相同标识
        } else if (active == leastActive) { // 累计相同最小的活跃数
            leastIndexs[leastCount ++] = i; // 累计相同最小活跃数下标
            totalWeight += weight; // 累计总权重
            // 判断所有权重是否一样
            if (sameWeight && i > 0 
                    && weight != firstWeight) {
                sameWeight = false;
            }
        }
    }
    // assert(leastCount > 0)
    if (leastCount == 1) {
        // 如果只有一个最小则直接返回
        return invokers.get(leastIndexs[0]);
    }
    if (! sameWeight && totalWeight > 0) {
        // 如果权重不相同且权重大于0则按总权重数随机
        int offsetWeight = random.nextInt(totalWeight);
        // 并确定随机值落在哪个片断上
        for (int i = 0; i < leastCount; i++) {
            int leastIndex = leastIndexs[i];
            offsetWeight -= getWeight(invokers.get(leastIndex), invocation);
            if (offsetWeight <= 0)
                return invokers.get(leastIndex);
        }
    }
    // 如果权重相同或权重为0则均等随机
    return invokers.get(leastIndexs[random.nextInt(leastCount)]);
}
 

public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
    URL url = invoker.getUrl();
    String methodName = invocation.getMethodName();
    int max = invoker.getUrl().getMethodParameter(methodName, Constants.ACTIVES_KEY, 0);
    RpcStatus count = RpcStatus.getStatus(invoker.getUrl(), invocation.getMethodName());
    if (max > 0) {
        long timeout = invoker.getUrl().getMethodParameter(invocation.getMethodName(), Constants.TIMEOUT_KEY, 0);
        long start = System.currentTimeMillis();
        long remain = timeout;
        int active = count.getActive();
        if (active >= max) {
            synchronized (count) {
                while ((active = count.getActive()) >= max) {
                    try {
                        count.wait(remain);
                    } catch (InterruptedException e) {
                    }
                    long elapsed = System.currentTimeMillis() - start;
                    remain = timeout - elapsed;
                    if (remain <= 0) {
                        throw new RpcException("Waiting concurrent invoke timeout in client-side for service:  "
                                               + invoker.getInterface().getName() + ", method: "
                                               + invocation.getMethodName() + ", elapsed: " + elapsed
                                               + ", timeout: " + timeout + ". concurrent invokes: " + active
                                               + ". max concurrent invoke limit: " + max);
                    }
                }
            }
        }
    }
    try {
        long begin = System.currentTimeMillis();
        RpcStatus.beginCount(url, methodName);
        try {
            Result result = invoker.invoke(invocation);
            RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, true);
            return result;
        } catch (RuntimeException t) {
            RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, false);
            throw t;
        }
    } finally {
        if(max>0){
            synchronized (count) {
                count.notify();
            } 
        }
    }
}
 

@Override
    public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
        URL url = invoker.getUrl();
//        查询执行的方法名
        String methodName = invocation.getMethodName();
//        actives属性值执行限制，默认值是0代表无限制
        int max = invoker.getUrl().getMethodParameter(methodName, Constants.ACTIVES_KEY, 0);
        RpcStatus count = RpcStatus.getStatus(invoker.getUrl(), invocation.getMethodName());
        if (max > 0) {
//            查询timeout超时参数值
            long timeout = invoker.getUrl().getMethodParameter(invocation.getMethodName(), Constants.TIMEOUT_KEY, 0);
            long start = System.currentTimeMillis();
            long remain = timeout;
//            原子计数器变量
            int active = count.getActive();
            if (active >= max) {
                synchronized (count) {
                    while ((active = count.getActive()) >= max) {
                        try {
//                            执行线程数超过设置的最大线程数，线程等待超时
                            count.wait(remain);
                        } catch (InterruptedException e) {
                        }
                        long elapsed = System.currentTimeMillis() - start;
                        remain = timeout - elapsed;
                        if (remain <= 0) {
                            throw new RpcException("Waiting concurrent invoke timeout in client-side for service:  "
                                    + invoker.getInterface().getName() + ", method: "
                                    + invocation.getMethodName() + ", elapsed: " + elapsed
                                    + ", timeout: " + timeout + ". concurrent invokes: " + active
                                    + ". max concurrent invoke limit: " + max);
                        }
                    }
                }
            }
        }
        try {
            long begin = System.currentTimeMillis();
//            执行业务方法前开始计数
            RpcStatus.beginCount(url, methodName);
            try {
//                执行业务方法
                Result result = invoker.invoke(invocation);
                RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, true);
                return result;
            } catch (RuntimeException t) {
//                执行业务方法之后结束计数
                RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, false);
                throw t;
            }
        } finally {
            if (max > 0) {
                synchronized (count) {
//                    唤醒等待的线程
                    count.notify();
                }
            }
        }
    }
 

protected <T> Invoker<T> doSelect(List<Invoker<T>> invokers, URL url, Invocation invocation) {
    int length = invokers.size(); // 总个数
    int leastActive = -1; // 最小的活跃数
    int leastCount = 0; // 相同最小活跃数的个数
    int[] leastIndexs = new int[length]; // 相同最小活跃数的下标
    int totalWeight = 0; // 总权重
    int firstWeight = 0; // 第一个权重，用于于计算是否相同
    boolean sameWeight = true; // 是否所有权重相同
    for (int i = 0; i < length; i++) {
    	Invoker<T> invoker = invokers.get(i);
        int active = RpcStatus.getStatus(invoker.getUrl(), invocation.getMethodName()).getActive(); // 活跃数
        int weight = invoker.getUrl().getMethodParameter(invocation.getMethodName(), Constants.WEIGHT_KEY, Constants.DEFAULT_WEIGHT); // 权重
        if (leastActive == -1 || active < leastActive) { // 发现更小的活跃数，重新开始
            leastActive = active; // 记录最小活跃数
            leastCount = 1; // 重新统计相同最小活跃数的个数
            leastIndexs[0] = i; // 重新记录最小活跃数下标
            totalWeight = weight; // 重新累计总权重
            firstWeight = weight; // 记录第一个权重
            sameWeight = true; // 还原权重相同标识
        } else if (active == leastActive) { // 累计相同最小的活跃数
            leastIndexs[leastCount ++] = i; // 累计相同最小活跃数下标
            totalWeight += weight; // 累计总权重
            // 判断所有权重是否一样
            if (sameWeight && i > 0 
                    && weight != firstWeight) {
                sameWeight = false;
            }
        }
    }
    // assert(leastCount > 0)
    if (leastCount == 1) {
        // 如果只有一个最小则直接返回
        return invokers.get(leastIndexs[0]);
    }
    if (! sameWeight && totalWeight > 0) {
        // 如果权重不相同且权重大于0则按总权重数随机
        int offsetWeight = random.nextInt(totalWeight);
        // 并确定随机值落在哪个片断上
        for (int i = 0; i < leastCount; i++) {
            int leastIndex = leastIndexs[i];
            offsetWeight -= getWeight(invokers.get(leastIndex), invocation);
            if (offsetWeight <= 0)
                return invokers.get(leastIndex);
        }
    }
    // 如果权重相同或权重为0则均等随机
    return invokers.get(leastIndexs[random.nextInt(leastCount)]);
}
 

public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
    URL url = invoker.getUrl();
    String methodName = invocation.getMethodName();
    int max = invoker.getUrl().getMethodParameter(methodName, Constants.ACTIVES_KEY, 0);
    RpcStatus count = RpcStatus.getStatus(invoker.getUrl(), invocation.getMethodName());
    if (max > 0) {
        long timeout = invoker.getUrl().getMethodParameter(invocation.getMethodName(), Constants.TIMEOUT_KEY, 0);
        long start = System.currentTimeMillis();
        long remain = timeout;
        int active = count.getActive();
        if (active >= max) {
            synchronized (count) {
                while ((active = count.getActive()) >= max) {
                    try {
                        count.wait(remain);
                    } catch (InterruptedException e) {
                    }
                    long elapsed = System.currentTimeMillis() - start;
                    remain = timeout - elapsed;
                    if (remain <= 0) {
                        throw new RpcException("Waiting concurrent invoke timeout in client-side for service:  "
                                               + invoker.getInterface().getName() + ", method: "
                                               + invocation.getMethodName() + ", elapsed: " + elapsed
                                               + ", timeout: " + timeout + ". concurrent invokes: " + active
                                               + ". max concurrent invoke limit: " + max);
                    }
                }
            }
        }
    }
    try {
        long begin = System.currentTimeMillis();
        RpcStatus.beginCount(url, methodName);
        try {
            Result result = invoker.invoke(invocation);
            RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, true);
            return result;
        } catch (RuntimeException t) {
            RpcStatus.endCount(url, methodName, System.currentTimeMillis() - begin, false);
            throw t;
        }
    } finally {
        if(max>0){
            synchronized (count) {
                count.notify();
            } 
        }
    }
}
 

@Before
public void setUpWeightInvokers() throws Exception {
    weightInvoker1 = mock(Invoker.class);
    weightInvoker2 = mock(Invoker.class);
    weightInvoker3 = mock(Invoker.class);
    weightInvokerTmp = mock(Invoker.class);
    
    weightTestInvocation = new RpcInvocation();
    weightTestInvocation.setMethodName("test");
    
    URL url1 = URL.valueOf("test1://127.0.0.1:11/DemoService?weight=11&active=0");
    URL url2 = URL.valueOf("test2://127.0.0.1:12/DemoService?weight=97&active=0");
    URL url3 = URL.valueOf("test3://127.0.0.1:13/DemoService?weight=67&active=1");
    URL urlTmp = URL.valueOf("test4://127.0.0.1:9999/DemoService?weight=601&active=0");
    
    given(weightInvoker1.isAvailable()).willReturn(true);
    given(weightInvoker1.getInterface()).willReturn(LoadBalanceTest.class);
    given(weightInvoker1.getUrl()).willReturn(url1);
    
    given(weightInvoker2.isAvailable()).willReturn(true);
    given(weightInvoker2.getInterface()).willReturn(LoadBalanceTest.class);
    given(weightInvoker2.getUrl()).willReturn(url2);
    
    given(weightInvoker3.isAvailable()).willReturn(true);
    given(weightInvoker3.getInterface()).willReturn(LoadBalanceTest.class);
    given(weightInvoker3.getUrl()).willReturn(url3);
    
    given(weightInvokerTmp.isAvailable()).willReturn(true);
    given(weightInvokerTmp.getInterface()).willReturn(LoadBalanceTest.class);
    given(weightInvokerTmp.getUrl()).willReturn(urlTmp);
    
    weightInvokers.add(weightInvoker1);
    weightInvokers.add(weightInvoker2);
    weightInvokers.add(weightInvoker3);
    
    weightTestRpcStatus1 = RpcStatus.getStatus(weightInvoker1.getUrl(), weightTestInvocation.getMethodName());
    weightTestRpcStatus2 = RpcStatus.getStatus(weightInvoker2.getUrl(), weightTestInvocation.getMethodName());
    weightTestRpcStatus3 = RpcStatus.getStatus(weightInvoker3.getUrl(), weightTestInvocation.getMethodName());
    
    // weightTestRpcStatus3 active is 1
    RpcStatus.beginCount(weightInvoker3.getUrl(), weightTestInvocation.getMethodName());
}