What if... java BindExceptions would actually tell you *which* address is already in use?

jdk8binderror.patch

diff -r d3b0a91b15b3 make/mapfiles/libjava/mapfile-vers
--- a/make/mapfiles/libjava/mapfile-vers	Tue Oct 06 12:54:22 2015 +0300
+++ b/make/mapfiles/libjava/mapfile-vers	Fri Oct 09 22:15:40 2015 +0200
@@ -56,6 +56,7 @@
 		JNU_ThrowArrayIndexOutOfBoundsException;
 		JNU_ThrowByName;
 		JNU_ThrowByNameWithLastError;
+		JNU_ThrowByNameWithLastErrorAndMsg;
 		JNU_ThrowClassNotFoundException;
 		JNU_ThrowIllegalAccessError;
 		JNU_ThrowIllegalAccessException;
diff -r d3b0a91b15b3 src/share/native/common/jni_util.c
--- a/src/share/native/common/jni_util.c	Tue Oct 06 12:54:22 2015 +0300
+++ b/src/share/native/common/jni_util.c	Fri Oct 09 22:15:40 2015 +0200
@@ -149,7 +149,7 @@
 
 
 /* Throw an exception by name, using the string returned by
- * JVM_LastErrorString for the detail string.  If the last-error
+ * JVM_GetLastErrorString for the detail string.  If the last-error
  * string is NULL, use the given default detail string.
  */
 JNIEXPORT void JNICALL
@@ -174,6 +174,47 @@
     }
 }
 
+/* Throw an exception by name, using the string returned by
+ * JVM_GetLastErrorString along with a given message. If the
+ * msg is NULL, only the last error is added. If the last-error
+ * string is NULL, use the given default detail string.
+ */
+JNIEXPORT void JNICALL
+JNU_ThrowByNameWithLastErrorAndMsg(JNIEnv *env, const char *name,
+                                   const char *msg,
+                                   const char *defaultError)
+{
+    char buf[1024];
+    size_t n = 0;
+    if (msg != NULL) {
+        n = strlen(msg);
+        if (n >= sizeof(buf))
+            n = sizeof(buf) - 1;
+        strncpy(buf, msg, n);
+        buf[n] = '\0';
+    }
+
+    if (n < sizeof(buf)-1) {
+        size_t j = JVM_GetLastErrorString(buf + n, sizeof(buf) - n);
+        n = n + j;
+    }
+
+    if (n > 0) {
+        jstring s = JNU_NewStringPlatform(env, buf);
+        if (s != NULL) {
+            jobject x = JNU_NewObjectByName(env, name,
+                                            "(Ljava/lang/String;)V", s);
+            if (x != NULL) {
+                (*env)->Throw(env, x);
+            }
+        }
+    }
+    if (!(*env)->ExceptionOccurred(env)) {
+        JNU_ThrowByName(env, name, defaultError);
+    }
+}
+
+
 /* Throw an IOException, using the last-error string for the detail
  * string.  If the last-error string is NULL, use the given default
  * detail string.
diff -r d3b0a91b15b3 src/share/native/common/jni_util.h
--- a/src/share/native/common/jni_util.h	Tue Oct 06 12:54:22 2015 +0300
+++ b/src/share/native/common/jni_util.h	Fri Oct 09 22:15:40 2015 +0200
@@ -98,13 +98,23 @@
 JNU_ThrowInstantiationException(JNIEnv *env, const char *msg);
 
 /* Throw an exception by name, using the string returned by
- * JVM_LastErrorString for the detail string.  If the last-error
+ * JVM_GetLastErrorString for the detail string.  If the last-error
  * string is NULL, use the given default detail string.
  */
 JNIEXPORT void JNICALL
 JNU_ThrowByNameWithLastError(JNIEnv *env, const char *name,
                              const char *defaultMessage);
 
+/* Throw an exception by name, using the string returned by
+ * JVM_GetLastErrorString along with a given message. If the
+ * msg is NULL, only the last error is added. If the last-error
+ * string is NULL, use the given default detail string.
+ */
+JNIEXPORT void JNICALL
+JNU_ThrowByNameWithLastErrorAndMsg(JNIEnv *env, const char *name,
+                                   const char *msg,
+                                   const char *defaultError);
+
 /* Throw an IOException, using the last-error string for the detail
  * string.  If the last-error string is NULL, use the given default
  * detail string.
diff -r d3b0a91b15b3 src/solaris/native/sun/nio/ch/Net.c
--- a/src/solaris/native/sun/nio/ch/Net.c	Tue Oct 06 12:54:22 2015 +0300
+++ b/src/solaris/native/sun/nio/ch/Net.c	Fri Oct 09 22:15:40 2015 +0200
@@ -27,8 +27,10 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <string.h>
+#include <stdio.h>
 #include <netinet/in.h>
 #include <netinet/tcp.h>
+#include <arpa/inet.h>
 
 #include "jni.h"
 #include "jni_util.h"
@@ -319,7 +321,23 @@
 
     rv = NET_Bind(fdval(env, fdo), (struct sockaddr *)&sa, sa_len);
     if (rv != 0) {
-        handleSocketError(env, errno);
+        char msg[256];
+        char addr[256];
+        switch (((struct sockaddr *)&sa)->sa_family) {
+            case AF_INET: {
+                struct sockaddr_in *sin = (struct sockaddr_in*)&sa;
+                snprintf(msg, sizeof(msg), "%s:%d: ", inet_ntop(sin->sin_family, &(sin->sin_addr), addr, sizeof(addr)), port);
+                break;
+            }
+            case AF_INET6: {
+                struct sockaddr_in6 *sin = (struct sockaddr_in6*)&sa;
+                snprintf(msg, sizeof(msg), "%s:%d: ", inet_ntop(sin->sin6_family, &(sin->sin6_addr), addr, sizeof(addr)), port);
+                break;
+            }
+            default:
+                snprintf(msg, sizeof(msg), ":%d: ", port);
+        }
+        handleSocketErrorWithMsg(env, msg, errno);
     }
 }
 
@@ -806,10 +824,8 @@
 }
 
 
-/* Declared in nio_util.h */
-
 jint
-handleSocketError(JNIEnv *env, jint errorValue)
+handleSocketErrorWithMsg(JNIEnv *env, const char *msg, jint errorValue)
 {
     char *xn;
     switch (errorValue) {
@@ -838,6 +854,12 @@
             break;
     }
     errno = errorValue;
-    JNU_ThrowByNameWithLastError(env, xn, "NioSocketError");
+    JNU_ThrowByNameWithLastErrorAndMsg(env, xn, msg, "NioSocketError");
     return IOS_THROWN;
 }
+
+jint
+handleSocketError(JNIEnv *env, jint errorValue)
+{
+    return handleSocketErrorWithMsg(env, NULL, errorValue);
+}
diff -r d3b0a91b15b3 src/solaris/native/sun/nio/ch/nio_util.h
--- a/src/solaris/native/sun/nio/ch/nio_util.h	Tue Oct 06 12:54:22 2015 +0300
+++ b/src/solaris/native/sun/nio/ch/nio_util.h	Fri Oct 09 22:15:40 2015 +0200
@@ -50,4 +50,5 @@
 
 /* Defined in Net.c */
 
+jint handleSocketErrorWithMsg(JNIEnv *env, const char *msg, jint errorValue);
 jint handleSocketError(JNIEnv *env, jint errorValue);