1 files changed, 28 insertions, 15 deletions

diff --git a/src/share/classes/java/lang/invoke/MethodTypeForm.java b/src/share/classes/java/lang/invoke/MethodTypeForm.java
index 6733e29ef9..bcf16dba9d 100644
--- a/src/share/classes/java/lang/invoke/MethodTypeForm.java
+++ b/src/share/classes/java/lang/invoke/MethodTypeForm.java
@@ -26,9 +26,8 @@
 package java.lang.invoke;
 
 import sun.invoke.util.Wrapper;
+import java.lang.ref.SoftReference;
 import static java.lang.invoke.MethodHandleStatics.*;
-import static java.lang.invoke.MethodHandleNatives.Constants.*;
- import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
 
 /**
  * Shared information for a group of method types, which differ
@@ -51,7 +50,7 @@ final class MethodTypeForm {
     final MethodType basicType;         // the canonical erasure, with primitives simplified
 
     // Cached adapter information:
-    @Stable final MethodHandle[] methodHandles;
+    @Stable final SoftReference<MethodHandle>[] methodHandles;
     // Indexes into methodHandles:
     static final int
             MH_BASIC_INV      =  0,  // cached instance of MH.invokeBasic
@@ -60,7 +59,7 @@ final class MethodTypeForm {
             MH_LIMIT          =  3;
 
     // Cached lambda form information, for basic types only:
-    final @Stable LambdaForm[] lambdaForms;
+    final @Stable SoftReference<LambdaForm>[] lambdaForms;
     // Indexes into lambdaForms:
     static final int
             LF_INVVIRTUAL              =  0,  // DMH invokeVirtual
@@ -108,26 +107,40 @@ final class MethodTypeForm {
 
     public MethodHandle cachedMethodHandle(int which) {
         assert(assertIsBasicType());
-        return methodHandles[which];
+        SoftReference<MethodHandle> entry = methodHandles[which];
+        return (entry != null) ? entry.get() : null;
     }
 
     synchronized public MethodHandle setCachedMethodHandle(int which, MethodHandle mh) {
         // Simulate a CAS, to avoid racy duplication of results.
-        MethodHandle prev = methodHandles[which];
-        if (prev != null)  return prev;
-        return methodHandles[which] = mh;
+        SoftReference<MethodHandle> entry = methodHandles[which];
+        if (entry != null) {
+            MethodHandle prev = entry.get();
+            if (prev != null) {
+                return prev;
+            }
+        }
+        methodHandles[which] = new SoftReference<>(mh);
+        return mh;
     }
 
     public LambdaForm cachedLambdaForm(int which) {
         assert(assertIsBasicType());
-        return lambdaForms[which];
+        SoftReference<LambdaForm> entry = lambdaForms[which];
+        return (entry != null) ? entry.get() : null;
     }
 
     synchronized public LambdaForm setCachedLambdaForm(int which, LambdaForm form) {
         // Simulate a CAS, to avoid racy duplication of results.
-        LambdaForm prev = lambdaForms[which];
-        if (prev != null) return prev;
-        return lambdaForms[which] = form;
+        SoftReference<LambdaForm> entry = lambdaForms[which];
+        if (entry != null) {
+            LambdaForm prev = entry.get();
+            if (prev != null) {
+                return prev;
+            }
+        }
+        lambdaForms[which] = new SoftReference<>(form);
+        return form;
     }
 
     /**
@@ -135,6 +148,7 @@ final class MethodTypeForm {
      * This MTF will stand for that type and all un-erased variations.
      * Eagerly compute some basic properties of the type, common to all variations.
      */
+    @SuppressWarnings({"rawtypes", "unchecked"})
     protected MethodTypeForm(MethodType erasedType) {
         this.erasedType = erasedType;
 
@@ -234,8 +248,8 @@ final class MethodTypeForm {
 
         // Initialize caches, but only for basic types
         assert(basicType == erasedType);
-        this.lambdaForms = new LambdaForm[LF_LIMIT];
-        this.methodHandles = new MethodHandle[MH_LIMIT];
+        this.lambdaForms   = new SoftReference[LF_LIMIT];
+        this.methodHandles = new SoftReference[MH_LIMIT];
     }
 
     private static long pack(int a, int b, int c, int d) {
@@ -409,5 +423,4 @@ final class MethodTypeForm {
     public String toString() {
         return "Form"+erasedType;
     }
-
 }