jdk/src/java.base/share/classes/java/security/Permissions.java
changeset 31080 00a25f4c4d44
parent 30033 b9c86c17164a
child 31538 0981099a3e54
--- a/jdk/src/java.base/share/classes/java/security/Permissions.java	Mon Jun 08 16:17:37 2015 +0300
+++ b/jdk/src/java.base/share/classes/java/security/Permissions.java	Tue Jun 09 09:18:07 2015 -0400
@@ -33,6 +33,7 @@
 import java.util.List;
 import java.util.Iterator;
 import java.util.Collections;
+import java.util.concurrent.ConcurrentHashMap;
 import java.io.Serializable;
 import java.io.ObjectStreamField;
 import java.io.ObjectOutputStream;
@@ -85,7 +86,7 @@
      * Key is permissions Class, value is PermissionCollection for that class.
      * Not serialized; see serialization section at end of class.
      */
-    private transient Map<Class<?>, PermissionCollection> permsMap;
+    private transient ConcurrentHashMap<Class<?>, PermissionCollection> permsMap;
 
     // optimization. keep track of whether unresolved permissions need to be
     // checked
@@ -99,7 +100,7 @@
      * Creates a new Permissions object containing no PermissionCollections.
      */
     public Permissions() {
-        permsMap = new HashMap<>(11);
+        permsMap = new ConcurrentHashMap<>(11);
         allPermission = null;
     }
 
@@ -120,18 +121,14 @@
      *
      * @see PermissionCollection#isReadOnly()
      */
-
+    @Override
     public void add(Permission permission) {
         if (isReadOnly())
             throw new SecurityException(
               "attempt to add a Permission to a readonly Permissions object");
 
-        PermissionCollection pc;
-
-        synchronized (this) {
-            pc = getPermissionCollection(permission, true);
-            pc.add(permission);
-        }
+        PermissionCollection pc = getPermissionCollection(permission, true);
+        pc.add(permission);
 
         // No sync; staleness -> optimizations delayed, which is OK
         if (permission instanceof AllPermission) {
@@ -169,21 +166,19 @@
      * PermissionCollection it
      * belongs to, false if not.
      */
-
+    @Override
     public boolean implies(Permission permission) {
         // No sync; staleness -> skip optimization, which is OK
         if (allPermission != null) {
             return true; // AllPermission has already been added
         } else {
-            synchronized (this) {
-                PermissionCollection pc = getPermissionCollection(permission,
-                    false);
-                if (pc != null) {
-                    return pc.implies(permission);
-                } else {
-                    // none found
-                    return false;
-                }
+            PermissionCollection pc = getPermissionCollection(permission,
+                false);
+            if (pc != null) {
+                return pc.implies(permission);
+            } else {
+                // none found
+                return false;
             }
         }
     }
@@ -194,14 +189,12 @@
      *
      * @return an enumeration of all the Permissions.
      */
-
+    @Override
     public Enumeration<Permission> elements() {
         // go through each Permissions in the hash table
         // and call their elements() function.
 
-        synchronized (this) {
-            return new PermissionsEnumerator(permsMap.values().iterator());
-        }
+        return new PermissionsEnumerator(permsMap.values().iterator());
     }
 
     /**
@@ -236,34 +229,39 @@
      * It should be set to true when invoked from add().
      */
     private PermissionCollection getPermissionCollection(Permission p,
-        boolean createEmpty) {
+                                                         boolean createEmpty) {
         Class<?> c = p.getClass();
 
-        PermissionCollection pc = permsMap.get(c);
-
         if (!hasUnresolved && !createEmpty) {
-            return pc;
-        } else if (pc == null) {
+            return permsMap.get(c);
+        }
 
-            // Check for unresolved permissions
-            pc = (hasUnresolved ? getUnresolvedPermissions(p) : null);
-
-            // if still null, create a new collection
-            if (pc == null && createEmpty) {
-
-                pc = p.newPermissionCollection();
+        // Create and add permission collection to map if it is absent.
+        // NOTE: cannot use lambda for mappingFunction parameter until
+        // JDK-8076596 is fixed.
+        return permsMap.computeIfAbsent(c,
+            new java.util.function.Function<>() {
+                @Override
+                public PermissionCollection apply(Class<?> k) {
+                    // Check for unresolved permissions
+                    PermissionCollection pc =
+                        (hasUnresolved ? getUnresolvedPermissions(p) : null);
 
-                // still no PermissionCollection?
-                // We'll give them a PermissionsHash.
-                if (pc == null)
-                    pc = new PermissionsHash();
-            }
+                    // if still null, create a new collection
+                    if (pc == null && createEmpty) {
+
+                        pc = p.newPermissionCollection();
 
-            if (pc != null) {
-                permsMap.put(c, pc);
+                        // still no PermissionCollection?
+                        // We'll give them a PermissionsHash.
+                        if (pc == null) {
+                            pc = new PermissionsHash();
+                        }
+                    }
+                    return pc;
+                }
             }
-        }
-        return pc;
+        );
     }
 
     /**
@@ -277,8 +275,6 @@
      */
     private PermissionCollection getUnresolvedPermissions(Permission p)
     {
-        // Called from within synchronized method so permsMap doesn't need lock
-
         UnresolvedPermissionCollection uc =
         (UnresolvedPermissionCollection) permsMap.get(UnresolvedPermission.class);
 
@@ -362,9 +358,7 @@
         // Copy perms into a Hashtable
         Hashtable<Class<?>, PermissionCollection> perms =
             new Hashtable<>(permsMap.size()*2); // no sync; estimate
-        synchronized (this) {
-            perms.putAll(permsMap);
-        }
+        perms.putAll(permsMap);
 
         // Write out serializable fields
         ObjectOutputStream.PutField pfields = out.putFields();
@@ -394,7 +388,7 @@
         @SuppressWarnings("unchecked")
         Hashtable<Class<?>, PermissionCollection> perms =
             (Hashtable<Class<?>, PermissionCollection>)gfields.get("perms", null);
-        permsMap = new HashMap<>(perms.size()*2);
+        permsMap = new ConcurrentHashMap<>(perms.size()*2);
         permsMap.putAll(perms);
 
         // Set hasUnresolved
@@ -481,14 +475,13 @@
      * Key and value are (same) permissions objects.
      * Not serialized; see serialization section at end of class.
      */
-    private transient Map<Permission, Permission> permsMap;
+    private transient ConcurrentHashMap<Permission, Permission> permsMap;
 
     /**
      * Create an empty PermissionsHash object.
      */
-
     PermissionsHash() {
-        permsMap = new HashMap<>(11);
+        permsMap = new ConcurrentHashMap<>(11);
     }
 
     /**
@@ -496,11 +489,9 @@
      *
      * @param permission the Permission object to add.
      */
-
+    @Override
     public void add(Permission permission) {
-        synchronized (this) {
-            permsMap.put(permission, permission);
-        }
+        permsMap.put(permission, permission);
     }
 
     /**
@@ -512,23 +503,21 @@
      * @return true if "permission" is a proper subset of a permission in
      * the set, false if not.
      */
-
+    @Override
     public boolean implies(Permission permission) {
         // attempt a fast lookup and implies. If that fails
         // then enumerate through all the permissions.
-        synchronized (this) {
-            Permission p = permsMap.get(permission);
+        Permission p = permsMap.get(permission);
 
-            // If permission is found, then p.equals(permission)
-            if (p == null) {
-                for (Permission p_ : permsMap.values()) {
-                    if (p_.implies(permission))
-                        return true;
-                }
-                return false;
-            } else {
-                return true;
+        // If permission is found, then p.equals(permission)
+        if (p == null) {
+            for (Permission p_ : permsMap.values()) {
+                if (p_.implies(permission))
+                    return true;
             }
+            return false;
+        } else {
+            return true;
         }
     }
 
@@ -537,12 +526,9 @@
      *
      * @return an enumeration of all the Permissions.
      */
-
+    @Override
     public Enumeration<Permission> elements() {
-        // Convert Iterator of Map values into an Enumeration
-        synchronized (this) {
-            return Collections.enumeration(permsMap.values());
-        }
+        return permsMap.elements();
     }
 
     private static final long serialVersionUID = -8491988220802933440L;
@@ -570,9 +556,7 @@
         // Copy perms into a Hashtable
         Hashtable<Permission, Permission> perms =
                 new Hashtable<>(permsMap.size()*2);
-        synchronized (this) {
-            perms.putAll(permsMap);
-        }
+        perms.putAll(permsMap);
 
         // Write out serializable fields
         ObjectOutputStream.PutField pfields = out.putFields();
@@ -597,7 +581,7 @@
         @SuppressWarnings("unchecked")
         Hashtable<Permission, Permission> perms =
                 (Hashtable<Permission, Permission>)gfields.get("perms", null);
-        permsMap = new HashMap<>(perms.size()*2);
+        permsMap = new ConcurrentHashMap<>(perms.size()*2);
         permsMap.putAll(perms);
     }
 }