1 files changed, 49 insertions, 1 deletions
diff --git a/src/windows/native/java/net/DualStackPlainDatagramSocketImpl.c b/src/windows/native/java/net/DualStackPlainDatagramSocketImpl.c
index 108f0de16c..23d7ce2a65 100644
--- a/src/windows/native/java/net/DualStackPlainDatagramSocketImpl.c
+++ b/src/windows/native/java/net/DualStackPlainDatagramSocketImpl.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2007, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -70,6 +70,25 @@ static jboolean purgeOutstandingICMP(JNIEnv *env, jint fd)
     return got_icmp;
 }
 
+static jfieldID IO_fd_fdID = NULL;
+static jfieldID pdsi_fdID = NULL;
+
+/*
+ * Class:     java_net_DualStackPlainDatagramSocketImpl
+ * Method:    initIDs
+ * Signature: ()V
+ */
+JNIEXPORT void JNICALL Java_java_net_DualStackPlainDatagramSocketImpl_initIDs
+  (JNIEnv *env, jclass clazz)
+{
+    pdsi_fdID = (*env)->GetFieldID(env, clazz, "fd",
+                                   "Ljava/io/FileDescriptor;");
+    CHECK_NULL(pdsi_fdID);
+    IO_fd_fdID = NET_GetFileDescriptorID(env);
+    CHECK_NULL(IO_fd_fdID);
+    JNU_CHECK_EXCEPTION(env);
+}
+
 /*
  * Class:     java_net_DualStackPlainDatagramSocketImpl
  * Method:    socketCreate
@@ -498,3 +517,32 @@ JNIEXPORT jint JNICALL Java_java_net_DualStackPlainDatagramSocketImpl_socketGetI
 
     return result;
 }
+
+/*
+ * Class:     java_net_DualStackPlainDatagramSocketImpl
+ * Method:    dataAvailable
+ * Signature: ()I
+ */
+JNIEXPORT jint JNICALL Java_java_net_DualStackPlainDatagramSocketImpl_dataAvailable
+(JNIEnv *env, jobject this) {
+    SOCKET fd;
+    int  rv = -1;
+    jobject fdObj = (*env)->GetObjectField(env, this, pdsi_fdID);
+
+    if (!IS_NULL(fdObj)) {
+        int retval = 0;
+        fd = (SOCKET)(*env)->GetIntField(env, fdObj, IO_fd_fdID);
+        rv = ioctlsocket(fd, FIONREAD, &retval);
+        if (retval > 0) {
+            return retval;
+        }
+    }
+
+    if (rv < 0) {
+        JNU_ThrowByName(env, JNU_JAVANETPKG "SocketException",
+                        "Socket closed");
+        return -1;
+    }
+
+    return 0;
+}