HADOOP-10406. TestIPC.testIpcWithReaderQueuing may fail. Contributed by Xiao Chen.

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -897,6 +897,8 @@ Release 2.8.0 - UNRELEASED
     HADOOP-12460. Add overwrite option for 'get' shell command
     (Jagadesh Kiran N via vinayakumarb)
 
+    HADOOP-10406. TestIPC.testIpcWithReaderQueuing may fail. (Xiao Chen via wang)
+
   OPTIMIZATIONS
 
     HADOOP-11785. Reduce the number of listStatus operation in distcp

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/ipc/TestIPC.java

@@ -47,11 +47,13 @@ import java.util.Random;
 import java.util.concurrent.BrokenBarrierException;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.CyclicBarrier;
+import java.util.concurrent.TimeoutException;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import javax.net.SocketFactory;
 
+import com.google.common.base.Supplier;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.commons.logging.impl.Log4JLogger;
@@ -73,6 +75,7 @@ import org.apache.hadoop.ipc.Server.Connection;
 import org.apache.hadoop.ipc.protobuf.RpcHeaderProtos.RpcResponseHeaderProto;
 import org.apache.hadoop.net.ConnectTimeoutException;
 import org.apache.hadoop.net.NetUtils;
+import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.hadoop.util.StringUtils;
 import org.apache.hadoop.security.token.SecretManager.InvalidToken;
 import org.apache.log4j.Level;
@@ -707,9 +710,9 @@ public class TestIPC {
     conf.setInt(CommonConfigurationKeys.IPC_SERVER_RPC_READ_CONNECTION_QUEUE_SIZE_KEY, readerQ);
 
     // send in enough clients to block up the handlers, callq, and readers
-    int initialClients = readers + callQ + handlers;
+    final int initialClients = readers + callQ + handlers;
     // max connections we should ever end up accepting at once
-    int maxAccept = initialClients + readers*readerQ + 1; // 1 = listener
+    final int maxAccept = initialClients + readers*readerQ + 1; // 1 = listener
     // stress it with 2X the max
     int clients = maxAccept*2;
     
@@ -762,12 +765,18 @@ public class TestIPC {
       } // additional threads block the readers trying to add to the callq
     }
 
-    // wait till everything is slotted, should happen immediately
-    Thread.sleep(10);
-    if (server.getNumOpenConnections() < initialClients) {
-      LOG.info("(initial clients) need:"+initialClients+" connections have:"+server.getNumOpenConnections());
-      Thread.sleep(100);
+    try {
+      // wait till everything is slotted, should happen immediately
+      GenericTestUtils.waitFor(new Supplier<Boolean>() {
+        @Override public Boolean get() {
+          return server.getNumOpenConnections() >= initialClients;
+        }
+      }, 100, 3000);
+    } catch (TimeoutException e) {
+      fail("timed out while waiting for connections to open.");
     }
+    LOG.info("(initial clients) need:"+initialClients
+        +" connections have:"+server.getNumOpenConnections());
     LOG.info("ipc layer should be blocked");
     assertEquals(callQ, server.getCallQueueLen());
     assertEquals(initialClients, server.getNumOpenConnections());
@@ -778,10 +787,18 @@ public class TestIPC {
       threads[i].start();
     }
     Thread.sleep(10);
-    if (server.getNumOpenConnections() < maxAccept) {
-      LOG.info("(max clients) need:"+maxAccept+" connections have:"+server.getNumOpenConnections());
-      Thread.sleep(100);
+
+    try {
+      GenericTestUtils.waitFor(new Supplier<Boolean>() {
+        @Override public Boolean get() {
+          return server.getNumOpenConnections() >= maxAccept;
+        }
+      }, 100, 3000);
+    } catch (TimeoutException e) {
+      fail("timed out while waiting for connections to open until maxAccept.");
     }
+    LOG.info("(max clients) need:"+maxAccept
+        +" connections have:"+server.getNumOpenConnections());
     // check a few times to make sure we didn't go over
     for (int i=0; i<4; i++) {
       assertEquals(maxAccept, server.getNumOpenConnections());