# HG changeset patch
# User redestad
# Date 1500033030 -7200
#      Fri Jul 14 13:50:30 2017 +0200
# Node ID 64e55fef647fcd1afd686a270939611bc90ca69d
# Parent  7bdb59123fe516a4a9170a43581047390c52e372
8184603: Create ObjectStreamField signature lazily when possible
Reviewed-by: rriggs

diff --git a/src/java.base/share/classes/java/io/ObjectStreamField.java b/src/java.base/share/classes/java/io/ObjectStreamField.java
--- a/src/java.base/share/classes/java/io/ObjectStreamField.java
+++ b/src/java.base/share/classes/java/io/ObjectStreamField.java
@@ -46,7 +46,7 @@
     /** field name */
     private final String name;
     /** canonical JVM signature of field type */
-    private final String signature;
+    private volatile String signature;
     /** field type (Object.class if unknown non-primitive type) */
     private final Class<?> type;
     /** whether or not to (de)serialize field values as unshared */
@@ -91,7 +91,7 @@
         this.name = name;
         this.type = type;
         this.unshared = unshared;
-        signature = getClassSignature(type).intern();
+        signature = null;
         field = null;
     }
 
@@ -242,7 +242,7 @@
      */
     // REMIND: deprecate?
     public char getTypeCode() {
-        return signature.charAt(0);
+        return getSignature().charAt(0);
     }
 
     /**
@@ -252,7 +252,7 @@
      */
     // REMIND: deprecate?
     public String getTypeString() {
-        return isPrimitive() ? null : signature;
+        return isPrimitive() ? null : getSignature();
     }
 
     /**
@@ -284,7 +284,7 @@
      */
     // REMIND: deprecate?
     public boolean isPrimitive() {
-        char tcode = signature.charAt(0);
+        char tcode = getTypeCode();
         return ((tcode != 'L') && (tcode != '['));
     }
 
@@ -336,6 +336,14 @@
      * that signature strings are returned for primitive fields as well).
      */
     String getSignature() {
-        return signature;
+        String sig = signature;
+
+        // This lazy calculation is safe since sig can be null iff one of the
+        // public constructors are used, in which case type is always
+        // initialized to the exact type we want the signature to represent.
+        if (sig == null) {
+            sig = signature = getClassSignature(type).intern();
+        }
+        return sig;
     }
 }