hotspot/src/share/vm/classfile/packageEntry.hpp
changeset 36508 5f9eee6b383b
child 37503 77531df4dad3
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/classfile/packageEntry.hpp	Thu Mar 17 19:04:01 2016 +0000
@@ -0,0 +1,202 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_CLASSFILE_PACKAGEENTRY_HPP
+#define SHARE_VM_CLASSFILE_PACKAGEENTRY_HPP
+
+#include "classfile/moduleEntry.hpp"
+#include "oops/symbol.hpp"
+#include "utilities/growableArray.hpp"
+#include "utilities/hashtable.hpp"
+
+// A PackageEntry basically represents a Java package.  It contains:
+//   - Symbol* containing the package's name.
+//   - ModuleEntry* for this package's containing module.
+//   - a flag indicating if package is exported, either qualifiedly or
+//     unqualifiedly.
+//   - a flag indicating if this package is exported to all unnamed modules.
+//   - a growable array containing other module entries that this
+//     package is exported to.
+//
+// Packages that are:
+//   - not exported:        _qualified_exports = NULL  && _is_exported is false
+//   - qualified exports:   (_qualified_exports != NULL || _is_exported_allUnnamed is true) && _is_exported is true
+//   - unqualified exports: (_qualified_exports = NULL && _is_exported_allUnnamed is false) && _is_exported is true
+//
+// The Mutex Module_lock is shared between ModuleEntry and PackageEntry, to lock either
+// data structure.
+class PackageEntry : public HashtableEntry<Symbol*, mtClass> {
+private:
+  ModuleEntry* _module;
+  // Used to indicate for packages with classes loaded by the boot loader that
+  // a class in that package has been loaded.  And, for packages with classes
+  // loaded by the boot loader from -Xbootclasspath/a in an unnamed module, it
+  // indicates from which class path entry.
+  s2 _classpath_index;
+  bool _is_exported;
+  bool _is_exported_allUnnamed;
+  GrowableArray<ModuleEntry*>* _exported_pending_delete; // transitioned from qualified to unqualified, delete at safepoint
+  GrowableArray<ModuleEntry*>* _qualified_exports;
+  TRACE_DEFINE_TRACE_ID_FIELD;
+
+  // Initial size of a package entry's list of qualified exports.
+  enum {QUAL_EXP_SIZE = 43};
+
+public:
+  void init() {
+    _module = NULL;
+    _classpath_index = -1;
+    _is_exported = false;
+    _is_exported_allUnnamed = false;
+    _exported_pending_delete = NULL;
+    _qualified_exports = NULL;
+  }
+
+  // package name
+  Symbol*            name() const               { return literal(); }
+  void               set_name(Symbol* n)        { set_literal(n); }
+
+  // the module containing the package definition
+  ModuleEntry*       module() const             { return _module; }
+  void               set_module(ModuleEntry* m) { _module = m; }
+
+  // package's export state
+  bool is_exported() const { return _is_exported; } // qualifiedly or unqualifiedly exported
+  bool is_qual_exported() const {
+    return (_is_exported && (_qualified_exports != NULL || _is_exported_allUnnamed));
+  }
+  bool is_unqual_exported() const {
+    return (_is_exported && (_qualified_exports == NULL && !_is_exported_allUnnamed));
+  }
+  void set_unqual_exported() {
+    _is_exported = true;
+    _is_exported_allUnnamed = false;
+    _qualified_exports = NULL;
+  }
+  bool exported_pending_delete() const     { return (_exported_pending_delete != NULL); }
+
+  void set_exported(bool e)                { _is_exported = e; }
+  void set_exported(ModuleEntry* m);
+
+  void set_is_exported_allUnnamed() {
+    if (!is_unqual_exported()) {
+     _is_exported_allUnnamed = true;
+     _is_exported = true;
+    }
+  }
+  bool is_exported_allUnnamed() const {
+    assert(_is_exported || !_is_exported_allUnnamed,
+           "is_allUnnamed set without is_exported being set");
+    return _is_exported_allUnnamed;
+  }
+
+  void set_classpath_index(s2 classpath_index) {
+    _classpath_index = classpath_index;
+  }
+  s2 classpath_index() const { return _classpath_index; }
+
+  bool has_loaded_class() const { return _classpath_index != -1; }
+
+  // returns true if the package is defined in the unnamed module
+  bool in_unnamed_module() const  { return !_module->is_named(); }
+
+  // returns true if the package specifies m as a qualified export
+  bool is_qexported_to(ModuleEntry* m) const;
+
+  // add the module to the package's qualified exports
+  void add_qexport(ModuleEntry* m);
+
+  PackageEntry* next() const {
+    return (PackageEntry*)HashtableEntry<Symbol*, mtClass>::next();
+  }
+
+  PackageEntry** next_addr() {
+    return (PackageEntry**)HashtableEntry<Symbol*, mtClass>::next_addr();
+  }
+
+  // iteration of qualified exports
+  void package_exports_do(ModuleClosure* const f);
+
+  TRACE_DEFINE_TRACE_ID_METHODS;
+
+  // Purge dead weak references out of exported list when any given class loader is unloaded.
+  void purge_qualified_exports();
+  void delete_qualified_exports();
+
+  void print() PRODUCT_RETURN;
+  void verify();
+};
+
+// The PackageEntryTable is a Hashtable containing a list of all packages defined
+// by a particular class loader.  Each package is represented as a PackageEntry node.
+// The PackageEntryTable's lookup is lock free.
+//
+class PackageEntryTable : public Hashtable<Symbol*, mtClass> {
+  friend class VMStructs;
+public:
+  enum Constants {
+    _packagetable_entry_size = 1009  // number of entries in package entry table
+  };
+
+private:
+  PackageEntry* new_entry(unsigned int hash, Symbol* name, ModuleEntry* module);
+  void add_entry(int index, PackageEntry* new_entry);
+
+  int entry_size() const { return BasicHashtable<mtClass>::entry_size(); }
+
+  PackageEntry** bucket_addr(int i) {
+    return (PackageEntry**)Hashtable<Symbol*, mtClass>::bucket_addr(i);
+  }
+
+  static unsigned int compute_hash(Symbol* name) { return (unsigned int)(name->identity_hash()); }
+  int index_for(Symbol* name) const { return hash_to_index(compute_hash(name)); }
+
+public:
+  PackageEntryTable(int table_size);
+  ~PackageEntryTable();
+
+  PackageEntry* bucket(int i) {
+    return (PackageEntry*)Hashtable<Symbol*, mtClass>::bucket(i);
+  }
+
+  // Create package in loader's package entry table and return the entry.
+  // If entry already exists, return null.  Assume Module lock was taken by caller.
+  PackageEntry* locked_create_entry_or_null(Symbol* name, ModuleEntry* module);
+
+  // lookup Package with loader's package entry table, if not found add
+  PackageEntry* lookup(Symbol* name, ModuleEntry* module);
+
+  // Only lookup Package within loader's package entry table.  The table read is lock-free.
+  PackageEntry* lookup_only(Symbol* Package);
+
+  void verify_javabase_packages(GrowableArray<Symbol*> *pkg_list);
+
+  // purge dead weak references out of exported list
+  void purge_all_package_exports();
+
+  void print() PRODUCT_RETURN;
+  void verify();
+};
+
+#endif // SHARE_VM_CLASSFILE_PACKAGEENTRY_HPP