Update the latest branch

FAQ.md

@@ -22,4 +22,4 @@ For committers, make sure select the right label and target branch for every PR,
 
 [Example question](https://github.com/alibaba/dubbo/issues/742)  
 
-Dubbo support to specify ip/port via system environment variables, examples can be found [here](https://github.com/dubbo/dubbo-samples/tree/master/dubbo-samples-docker).
+Dubbo supports specifying ip/port via system environment variables, examples can be found [here](https://github.com/dubbo/dubbo-samples/tree/master/dubbo-samples-docker).

PULL_REQUEST_TEMPLATE.md

@@ -12,7 +12,7 @@ XXXXX
 
 Follow this checklist to help us incorporate your contribution quickly and easily:
 
-- [x] Make sure there is a [GITHUB_issue](https://github.com/apache/incubator-dubbo/issues) filed for the change (usually before you start working on it). Trivial changes like typos do not require a GITHUB issue. Your pull request should address just this issue, without pulling in other changes - one PR resolves one issue.
+- [x] Make sure there is a [GITHUB_issue](https://github.com/apache/incubator-dubbo/issues) field for the change (usually before you start working on it). Trivial changes like typos do not require a GITHUB issue. Your pull request should address just this issue, without pulling in other changes - one PR resolves one issue.
 - [ ] Format the pull request title like `[Dubbo-XXX] Fix UnknownException when host config not exist #XXX`. Each commit in the pull request should have a meaningful subject line and body.
 - [ ] Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
 - [ ] Write necessary unit-test to verify your logic correction, more mock a little better when cross module dependency exist. If the new feature or significant change is committed, please remember to add integration-test in [test module](https://github.com/apache/incubator-dubbo/tree/master/dubbo-test).

README.md

@@ -43,7 +43,7 @@ There's a [README](https://github.com/dubbo/dubbo-samples/blob/master/dubbo-samp
 <dependency>
     <groupId>com.alibaba</groupId>
     <artifactId>dubbo</artifactId>
-    <version>2.6.4</version>
+    <version>2.6.5</version>
 </dependency>
 ```
 

codestyle/checkstyle.xml

@@ -20,5 +20,11 @@
         <module name="NoLineWrap"/>
         <module name="OuterTypeFilename"/>
         <module name="UnusedImports"/>
+
+        <module name="CustomImportOrder">
+            <property name="specialImportsRegExp" value="org.apache.dubbo.*"/>
+            <property name="sortImportsInGroupAlphabetically" value="false"/>
+            <property name="customImportOrderRules" value="SPECIAL_IMPORTS###THIRD_PARTY_PACKAGE###STANDARD_JAVA_PACKAGE###STATIC"/>
+        </module>
     </module>
 </module>

codestyle/dubbo_codestyle_for_idea.xml

@@ -5,8 +5,6 @@
         <value>
             <package name="org.apache.dubbo" withSubpackages="true" static="false"/>
             <emptyLine/>
-            <package name="com.taobao" withSubpackages="true" static="false"/>
-            <emptyLine/>
             <package name="" withSubpackages="true" static="false"/>
             <emptyLine/>
             <package name="javax" withSubpackages="true" static="false"/>

dubbo-all/pom.xml

@@ -320,7 +320,7 @@
         </dependency>
         <dependency>
             <groupId>org.apache.dubbo</groupId>
-            <artifactId>dubbo-bootstrap</artifactId>
+            <artifactId>dubbo-serialization-protostuff</artifactId>
             <version>${project.version}</version>
             <scope>compile</scope>
             <optional>true</optional>
@@ -431,7 +431,7 @@
                                     <include>org.apache.dubbo:dubbo-serialization-fst</include>
                                     <include>org.apache.dubbo:dubbo-serialization-kryo</include>
                                     <include>org.apache.dubbo:dubbo-serialization-jdk</include>
-                                    <include>org.apache.dubbo:dubbo-bootstrap</include>
+                                    <include>org.apache.dubbo:dubbo-serialization-protostuff</include>
                                 </includes>
                             </artifactSet>
                             <transformers>
@@ -595,4 +595,4 @@
             </build>
         </profile>
     </profiles>
-</project>
+</project>

dubbo-bom/pom.xml

@@ -280,7 +280,7 @@
             </dependency>
             <dependency>
                 <groupId>org.apache.dubbo</groupId>
-                <artifactId>dubbo-bootstrap</artifactId>
+                <artifactId>dubbo-serialization-protostuff</artifactId>
                 <version>${project.version}</version>
             </dependency>
             <dependency>

dubbo-cluster/src/main/java/org/apache/dubbo/rpc/cluster/loadbalance/RandomLoadBalance.java

@@ -34,13 +34,13 @@ public class RandomLoadBalance extends AbstractLoadBalance {
     @Override
     protected <T> Invoker<T> doSelect(List<Invoker<T>> invokers, URL url, Invocation invocation) {
         int length = invokers.size(); // Number of invokers
-        int totalWeight = 0; // The sum of weights
         boolean sameWeight = true; // Every invoker has the same weight?
-        for (int i = 0; i < length; i++) {
+        int firstWeight = getWeight(invokers.get(0), invocation);
+        int totalWeight = firstWeight; // The sum of weights
+        for (int i = 1; i < length; i++) {
             int weight = getWeight(invokers.get(i), invocation);
             totalWeight += weight; // Sum
-            if (sameWeight && i > 0
-                    && weight != getWeight(invokers.get(i - 1), invocation)) {
+            if (sameWeight && weight != firstWeight) {
                 sameWeight = false;
             }
         }

dubbo-cluster/src/main/java/org/apache/dubbo/rpc/cluster/loadbalance/RoundRobinLoadBalance.java

@@ -17,68 +17,137 @@
 package org.apache.dubbo.rpc.cluster.loadbalance;
 
 import org.apache.dubbo.common.URL;
-import org.apache.dubbo.common.utils.AtomicPositiveInteger;
 import org.apache.dubbo.rpc.Invocation;
 import org.apache.dubbo.rpc.Invoker;
 
-import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Iterator;
 import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicLong;
 
 /**
  * Round robin load balance.
  */
 public class RoundRobinLoadBalance extends AbstractLoadBalance {
-
     public static final String NAME = "roundrobin";
+
+    private static int RECYCLE_PERIOD = 60000;
+
+    protected static class WeightedRoundRobin {
+        private int weight;
+        private AtomicLong current = new AtomicLong(0);
+        private long lastUpdate;
+        public int getWeight() {
+            return weight;
+        }
+        public void setWeight(int weight) {
+            this.weight = weight;
+            current.set(0);
+        }
+        public long increaseCurrent() {
+            return current.addAndGet(weight);
+        }
+        public void sel(int total) {
+            current.addAndGet(-1 * total);
+        }
+        public long getLastUpdate() {
+            return lastUpdate;
+        }
+        public void setLastUpdate(long lastUpdate) {
+            this.lastUpdate = lastUpdate;
+        }
+    }
 
-    private final ConcurrentMap<String, AtomicPositiveInteger> sequences = new ConcurrentHashMap<String, AtomicPositiveInteger>();
-
-    private final ConcurrentMap<String, AtomicPositiveInteger> indexSeqs = new ConcurrentHashMap<String, AtomicPositiveInteger>();
-
+    private ConcurrentMap<String, ConcurrentMap<String, WeightedRoundRobin>> methodWeightMap = new ConcurrentHashMap<String, ConcurrentMap<String, WeightedRoundRobin>>();
+    private AtomicBoolean updateLock = new AtomicBoolean();
+
+    /**
+     * get invoker addr list cached for specified invocation
+     * <p>
+     * <b>for unit test only</b>
+     * 
+     * @param invokers
+     * @param invocation
+     * @return
+     */
+    protected <T> Collection<String> getInvokerAddrList(List<Invoker<T>> invokers, Invocation invocation) {
+        String key = invokers.get(0).getUrl().getServiceKey() + "." + invocation.getMethodName();
+        Map<String, WeightedRoundRobin> map = methodWeightMap.get(key);
+        if (map != null) {
+            return map.keySet();
+        }
+        return null;
+    }
+
     @Override
     protected <T> Invoker<T> doSelect(List<Invoker<T>> invokers, URL url, Invocation invocation) {
         String key = invokers.get(0).getUrl().getServiceKey() + "." + invocation.getMethodName();
-        int length = invokers.size(); // Number of invokers
-        int maxWeight = 0; // The maximum weight
-        int minWeight = Integer.MAX_VALUE; // The minimum weight
-        final List<Invoker<T>> nonZeroWeightedInvokers = new ArrayList<>();
-        for (int i = 0; i < length; i++) {
-            int weight = getWeight(invokers.get(i), invocation);
-            maxWeight = Math.max(maxWeight, weight); // Choose the maximum weight
-            minWeight = Math.min(minWeight, weight); // Choose the minimum weight
-            if (weight > 0) {
-                nonZeroWeightedInvokers.add(invokers.get(i));
-            }
-        }
-        AtomicPositiveInteger sequence = sequences.get(key);
-        if (sequence == null) {
-            sequences.putIfAbsent(key, new AtomicPositiveInteger());
-            sequence = sequences.get(key);
+        ConcurrentMap<String, WeightedRoundRobin> map = methodWeightMap.get(key);
+        if (map == null) {
+            methodWeightMap.putIfAbsent(key, new ConcurrentHashMap<String, WeightedRoundRobin>());
+            map = methodWeightMap.get(key);
         }
-
-        if (maxWeight > 0 && minWeight < maxWeight) {
-            AtomicPositiveInteger indexSeq = indexSeqs.get(key);
-            if (indexSeq == null) {
-                indexSeqs.putIfAbsent(key, new AtomicPositiveInteger(-1));
-                indexSeq = indexSeqs.get(key);
+        int totalWeight = 0;
+        long maxCurrent = Long.MIN_VALUE;
+        long now = System.currentTimeMillis();
+        Invoker<T> selectedInvoker = null;
+        WeightedRoundRobin selectedWRR = null;
+        for (Invoker<T> invoker : invokers) {
+            String identifyString = invoker.getUrl().toIdentityString();
+            WeightedRoundRobin weightedRoundRobin = map.get(identifyString);
+            int weight = getWeight(invoker, invocation);
+            if (weight < 0) {
+                weight = 0;
             }
-            length = nonZeroWeightedInvokers.size();
-            while (true) {
-                int index = indexSeq.incrementAndGet() % length;
-                int currentWeight;
-                if (index == 0) {
-                    currentWeight = sequence.incrementAndGet() % maxWeight;
-                } else {
-                    currentWeight = sequence.get() % maxWeight;
-                }
-                if (getWeight(nonZeroWeightedInvokers.get(index), invocation) > currentWeight) {
-                    return nonZeroWeightedInvokers.get(index);
+            if (weightedRoundRobin == null) {
+                weightedRoundRobin = new WeightedRoundRobin();
+                weightedRoundRobin.setWeight(weight);
+                map.putIfAbsent(identifyString, weightedRoundRobin);
+                weightedRoundRobin = map.get(identifyString);
+            }
+            if (weight != weightedRoundRobin.getWeight()) {
+                //weight changed
+                weightedRoundRobin.setWeight(weight);
+            }
+            long cur = weightedRoundRobin.increaseCurrent();
+            weightedRoundRobin.setLastUpdate(now);
+            if (cur > maxCurrent) {
+                maxCurrent = cur;
+                selectedInvoker = invoker;
+                selectedWRR = weightedRoundRobin;
+            }
+            totalWeight += weight;
+        }
+        if (!updateLock.get() && invokers.size() != map.size()) {
+            if (updateLock.compareAndSet(false, true)) {
+                try {
+                    // copy -> modify -> update reference
+                    ConcurrentMap<String, WeightedRoundRobin> newMap = new ConcurrentHashMap<String, WeightedRoundRobin>();
+                    newMap.putAll(map);
+                    Iterator<Entry<String, WeightedRoundRobin>> it = newMap.entrySet().iterator();
+                    while (it.hasNext()) {
+                        Entry<String, WeightedRoundRobin> item = it.next();
+                        if (now - item.getValue().getLastUpdate() > RECYCLE_PERIOD) {
+                            it.remove();
+                        }
+                    }
+                    methodWeightMap.put(key, newMap);
+                } finally {
+                    updateLock.set(false);
                 }
             }
         }
-        // Round robin
-        return invokers.get(sequence.getAndIncrement() % length);
+        if (selectedInvoker != null) {
+            selectedWRR.sel(totalWeight);
+            return selectedInvoker;
+        }
+        // should not happen here
+        return invokers.get(0);
     }
+
 }

dubbo-cluster/src/main/java/org/apache/dubbo/rpc/cluster/router/condition/ConditionRouter.java

@@ -42,7 +42,7 @@
  * ConditionRouter
  *
  */
-public class ConditionRouter implements Router, Comparable<Router> {
+public class ConditionRouter implements Router {
 
     private static final Logger logger = LoggerFactory.getLogger(ConditionRouter.class);
     private static Pattern ROUTE_PATTERN = Pattern.compile("([&!=,]*)\\s*([^&!=,\\s]+)");