RFR: 8061472 String.format in DeferredAttr.DeferredTypeMap constructor leads to excessive object creation

[Joel Borggrén-Franck]

Hi Maurizio,

> On 18 dec 2014, at 23:08, Maurizio Cimadamore <maurizio.cimadamore at oracle.com> wrote:
> 
> The fix looks ok - but it feels a bit odd for the AttrMode (which is a general enum) to be returning the name including the 'deferredTypeMap' string - as that's another class. Maybe a static 'EnumMap<AttrMode, String>' inside the DeferredAttrMap class would more encapsulated?
> 

You are right, new patch inline.

cheers
/Joel

diff -r 47926c290355 src/jdk.compiler/share/classes/com/sun/tools/javac/comp/DeferredAttr.java
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/DeferredAttr.java	Wed Dec 17 12:48:04 2014 -0800
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/DeferredAttr.java	Fri Dec 19 12:11:56 2014 +0100
@@ -41,6 +41,7 @@

 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.EnumMap;
 import java.util.EnumSet;
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
@@ -838,6 +839,14 @@
     /** an empty deferred attribution context - all methods throw exceptions */
     final DeferredAttrContext emptyDeferredAttrContext;

+    /** The AttrMode to descriptive name mapping */
+    private static final EnumMap<AttrMode, String> deferredTypeMapDescriptions;
+    static {
+        deferredTypeMapDescriptions = new EnumMap<>(AttrMode.class);
+        deferredTypeMapDescriptions.put(AttrMode.CHECK, "deferredTypeMap[CHECK]");
+        deferredTypeMapDescriptions.put(AttrMode.SPECULATIVE, "deferredTypeMap[SPECULATIVE]");
+    }
+
     /**
      * Map a list of types possibly containing one or more deferred types
      * into a list of ordinary types. Each deferred type D is mapped into a type T,
@@ -845,11 +854,10 @@
      * computed for D during a previous deferred attribution round of the given kind.
      */
     class DeferredTypeMap extends Type.Mapping {
-
         DeferredAttrContext deferredAttrContext;

         protected DeferredTypeMap(AttrMode mode, Symbol msym, MethodResolutionPhase phase) {
-            super(String.format("deferredTypeMap[%s]", mode));
+            super(deferredTypeMapDescriptions.get(mode));
             this.deferredAttrContext = new DeferredAttrContext(mode, msym, phase,
                     infer.emptyContext, emptyDeferredAttrContext, types.noWarnings);
         }