src/java.base/share/classes/java/lang/ClassLoader.java

rev 10764 : 8060130: Simplify the synchronization of defining and getting java.lang.Package
Reviewed-by: mchung

*** 27,42 ****
  import java.io.InputStream;
  import java.io.IOException;
  import java.io.File;
  import java.lang.reflect.Constructor;
  import java.lang.reflect.InvocationTargetException;
- import java.net.MalformedURLException;
  import java.net.URL;
  import java.security.AccessController;
  import java.security.AccessControlContext;
  import java.security.CodeSource;
- import java.security.Policy;
  import java.security.PrivilegedAction;
  import java.security.PrivilegedActionException;
  import java.security.PrivilegedExceptionAction;
  import java.security.ProtectionDomain;
  import java.security.cert.Certificate;
--- 27,40 ----
*** 52,62 ****
  import java.util.WeakHashMap;
  import java.util.concurrent.ConcurrentHashMap;
  import sun.misc.CompoundEnumeration;
  import sun.misc.Resource;
  import sun.misc.URLClassPath;
- import sun.misc.VM;
  import sun.reflect.CallerSensitive;
  import sun.reflect.Reflection;
  import sun.reflect.misc.ReflectUtil;
  import sun.security.util.SecurityConstants;
  
--- 50,59 ----
*** 267,277 ****
      }
  
      // The packages defined in this class loader.  Each package name is mapped
      // to its corresponding Package object.
      // @GuardedBy("itself")
!     private final HashMap<String, Package> packages = new HashMap<>();
  
      private static Void checkCreateClassLoader() {
          SecurityManager security = System.getSecurityManager();
          if (security != null) {
              security.checkCreateClassLoader();
--- 264,275 ----
      }
  
      // The packages defined in this class loader.  Each package name is mapped
      // to its corresponding Package object.
      // @GuardedBy("itself")
!     private final ConcurrentHashMap<String, Package> packages
!             = new ConcurrentHashMap<>();
  
      private static Void checkCreateClassLoader() {
          SecurityManager security = System.getSecurityManager();
          if (security != null) {
              security.checkCreateClassLoader();
*** 1573,1593 ****
                                      String specVersion, String specVendor,
                                      String implTitle, String implVersion,
                                      String implVendor, URL sealBase)
          throws IllegalArgumentException
      {
-         synchronized (packages) {
              Package pkg = getPackage(name);
              if (pkg != null) {
                  throw new IllegalArgumentException(name);
              }
              pkg = new Package(name, specTitle, specVersion, specVendor,
                                implTitle, implVersion, implVendor,
                                sealBase, this);
!             packages.put(name, pkg);
!             return pkg;
!         }
      }
  
      /**
       * Returns a <tt>Package</tt> that has been defined by this class loader
       * or any of its ancestors.
--- 1571,1591 ----
                                      String specVersion, String specVendor,
                                      String implTitle, String implVersion,
                                      String implVendor, URL sealBase)
          throws IllegalArgumentException
      {
          Package pkg = getPackage(name);
          if (pkg != null) {
              throw new IllegalArgumentException(name);
          }
          pkg = new Package(name, specTitle, specVersion, specVendor,
                            implTitle, implVersion, implVendor,
                            sealBase, this);
!         // Races here can be safely dealt with by ensuring we always return
!         // the same package object
!         Package oldPkg = packages.putIfAbsent(name, pkg);
!         return (oldPkg != null ? oldPkg : pkg);
      }
  
      /**
       * Returns a <tt>Package</tt> that has been defined by this class loader
       * or any of its ancestors.
*** 1599,1628 ****
       *          <tt>null</tt> if not found
       *
       * @since  1.2
       */
      protected Package getPackage(String name) {
!         Package pkg;
!         synchronized (packages) {
!             pkg = packages.get(name);
!         }
          if (pkg == null) {
              if (parent != null) {
                  pkg = parent.getPackage(name);
              } else {
                  pkg = Package.getSystemPackage(name);
              }
-             if (pkg != null) {
-                 synchronized (packages) {
-                     Package pkg2 = packages.get(name);
-                     if (pkg2 == null) {
-                         packages.put(name, pkg);
-                     } else {
-                         pkg = pkg2;
-                     }
-                 }
-             }
          }
          return pkg;
      }
  
      /**
--- 1597,1613 ----
       *          <tt>null</tt> if not found
       *
       * @since  1.2
       */
      protected Package getPackage(String name) {
!         Package pkg = packages.get(name);
          if (pkg == null) {
              if (parent != null) {
                  pkg = parent.getPackage(name);
              } else {
                  pkg = Package.getSystemPackage(name);
              }
          }
          return pkg;
      }
  
      /**
*** 1634,1661 ****
       *
       * @since  1.2
       */
      protected Package[] getPackages() {
          Map<String, Package> map;
-         synchronized (packages) {
-             map = new HashMap<>(packages);
-         }
          Package[] pkgs;
          if (parent != null) {
              pkgs = parent.getPackages();
          } else {
              pkgs = Package.getSystemPackages();
          }
!         if (pkgs != null) {
              for (Package pkg : pkgs) {
                  String pkgName = pkg.getName();
!                 if (map.get(pkgName) == null) {
                      map.put(pkgName, pkg);
                  }
              }
          }
          return map.values().toArray(new Package[map.size()]);
      }
  
  
      // -- Native library access --
  
--- 1619,1648 ----
       *
       * @since  1.2
       */
      protected Package[] getPackages() {
          Map<String, Package> map;
          Package[] pkgs;
          if (parent != null) {
              pkgs = parent.getPackages();
          } else {
              pkgs = Package.getSystemPackages();
          }
! 
!         if (pkgs == null) {
!             map = packages;
!         } else {
!             map = new HashMap<>(packages);
              for (Package pkg : pkgs) {
                  String pkgName = pkg.getName();
!                 if (!map.containsKey(pkgName)) {
                      map.put(pkgName, pkg);
                  }
              }
          }
          return map.values().toArray(new Package[map.size()]);
+ 
      }
  
  
      // -- Native library access --