Code Review Request JDK-8146725 Issues with SignatureAndHashAlgorithm.getSupportedAlgorithms

[Xuelei Fan]

Hi,

Please review this simple fix for JDK-8146725.

In the SignatureAndHashAlgorithm.getSupportedAlgorithms() method, there
is a synchronization block on a static final collection, priorityMap.
The priorityMap would not get update any more after the instantiation.
The synchronization is not actually necessary.

See the attack diff for the fix.  No new regression test.

Thanks,
Xuelei

--- 
a/src/java.base/share/classes/sun/security/ssl/SignatureAndHashAlgorithm.java
+++ 
b/src/java.base/share/classes/sun/security/ssl/SignatureAndHashAlgorithm.java
@@ -153,13 +153,11 @@
             getSupportedAlgorithms(AlgorithmConstraints constraints) {

         Collection<SignatureAndHashAlgorithm> supported = new ArrayList<>();
-        synchronized (priorityMap) {
-            for (SignatureAndHashAlgorithm sigAlg : priorityMap.values()) {
-                if (sigAlg.priority <= SUPPORTED_ALG_PRIORITY_MAX_NUM &&
-                        constraints.permits(SIGNATURE_PRIMITIVE_SET,
-                                sigAlg.algorithm, null)) {
-                    supported.add(sigAlg);
-                }
+        for (SignatureAndHashAlgorithm sigAlg : priorityMap.values()) {
+            if (sigAlg.priority <= SUPPORTED_ALG_PRIORITY_MAX_NUM &&
+                    constraints.permits(SIGNATURE_PRIMITIVE_SET,
+                            sigAlg.algorithm, null)) {
+                supported.add(sigAlg);
             }
         }