--- a/hotspot/src/share/vm/classfile/packageEntry.hpp Thu Jan 19 21:52:51 2017 -0800
+++ b/hotspot/src/share/vm/classfile/packageEntry.hpp Fri Jan 20 16:09:56 2017 -0500
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2017, 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
@@ -34,8 +34,8 @@
// 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 unqualifiedly
-// - a flag indicating if this package is exported to all unnamed modules.
+// - a field indicating if the package is exported unqualifiedly or to all
+// unnamed modules.
// - a growable array containing other module entries that this
// package is exported to.
//
@@ -44,9 +44,9 @@
// - qualified exports: the package has been explicitly qualified to at least
// one particular module or has been qualifiedly exported
// to all unnamed modules.
-// Note: _is_exported_allUnnamed is a form of a qualified
-// export. It is equivalent to the package being
-// explicitly exported to all current and future unnamed modules.
+// Note: being exported to all unnamed is a form of a qualified
+// export. It is equivalent to the package being explicitly
+// exported to all current and future unnamed modules.
// - unqualified exports: the package is exported to all modules.
//
// A package can transition from:
@@ -56,21 +56,53 @@
// A package cannot transition from:
// - being unqualifiedly exported, to exported qualifiedly to a specific module.
// This transition attempt is silently ignored in set_exported.
+// - being qualifiedly exported to not exported.
+// Because transitions are only allowed from less exposure to greater exposure,
+// the transition from qualifiedly exported to not exported would be considered
+// a backward direction. Therefore the implementation considers a package as
+// qualifiedly exported even if its export-list exists but is empty.
//
// The Mutex Module_lock is shared between ModuleEntry and PackageEntry, to lock either
// data structure.
+
+// PKG_EXP_UNQUALIFIED and PKG_EXP_ALLUNNAMED indicate whether the package is
+// exported unqualifiedly or exported to all unnamed modules. They are used to
+// set the value of _export_flags. Field _export_flags and the _qualified_exports
+// list are used to determine a package's export state.
+// Valid states are:
+//
+// 1. Package is not exported
+// _export_flags is zero and _qualified_exports is null
+// 2. Package is unqualifiedly exported
+// _export_flags is set to PKG_EXP_UNQUALIFIED
+// _qualified_exports may or may not be null depending on whether the package
+// transitioned from qualifiedly exported to unqualifiedly exported.
+// 3. Package is qualifiedly exported
+// _export_flags may be set to PKG_EXP_ALLUNNAMED if the package is also
+// exported to all unnamed modules
+// _qualified_exports will be non-null
+// 4. Package is exported to all unnamed modules
+// _export_flags is set to PKG_EXP_ALLUNNAMED
+// _qualified_exports may or may not be null depending on whether the package
+// is also qualifiedly exported to one or more named modules.
+#define PKG_EXP_UNQUALIFIED 0x0001
+#define PKG_EXP_ALLUNNAMED 0x0002
+#define PKG_EXP_UNQUALIFIED_OR_ALL_UNAMED (PKG_EXP_UNQUALIFIED | PKG_EXP_ALLUNNAMED)
+
class PackageEntry : public HashtableEntry<Symbol*, mtModule> {
private:
ModuleEntry* _module;
+ // Indicates if package is exported unqualifiedly or to all unnamed. Access to
+ // this field is protected by the Module_lock.
+ int _export_flags;
// 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_unqualified;
- bool _is_exported_allUnnamed;
bool _must_walk_exports;
- GrowableArray<ModuleEntry*>* _exported_pending_delete; // transitioned from qualified to unqualified, delete at safepoint
+ // Contains list of modules this package is qualifiedly exported to. Access
+ // to this list is protected by the Module_lock.
GrowableArray<ModuleEntry*>* _qualified_exports;
TRACE_DEFINE_TRACE_ID_FIELD;
@@ -80,17 +112,14 @@
public:
void init() {
_module = NULL;
+ _export_flags = 0;
_classpath_index = -1;
- _is_exported_unqualified = false;
- _is_exported_allUnnamed = false;
_must_walk_exports = 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; }
@@ -98,37 +127,39 @@
// package's export state
bool is_exported() const { // qualifiedly or unqualifiedly exported
- return (is_unqual_exported() || has_qual_exports_list() || is_exported_allUnnamed());
+ assert_locked_or_safepoint(Module_lock);
+ return ((_export_flags & PKG_EXP_UNQUALIFIED_OR_ALL_UNAMED) != 0) || has_qual_exports_list();
}
// Returns true if the package has any explicit qualified exports or is exported to all unnamed
bool is_qual_exported() const {
+ assert_locked_or_safepoint(Module_lock);
return (has_qual_exports_list() || is_exported_allUnnamed());
}
- // Returns true if there are any explicit qualified exports
+ // Returns true if there are any explicit qualified exports. Note that even
+ // if the _qualified_exports list is now empty (because the modules that were
+ // on the list got gc-ed and deleted from the list) this method may still
+ // return true.
bool has_qual_exports_list() const {
- assert(!(_qualified_exports != NULL && _is_exported_unqualified),
- "_qualified_exports set at same time as _is_exported_unqualified");
- return (_qualified_exports != NULL);
+ assert_locked_or_safepoint(Module_lock);
+ return (!is_unqual_exported() && _qualified_exports != NULL);
}
bool is_exported_allUnnamed() const {
- assert(!(_is_exported_allUnnamed && _is_exported_unqualified),
- "_is_exported_allUnnamed set at same time as _is_exported_unqualified");
- return _is_exported_allUnnamed;
+ assert_locked_or_safepoint(Module_lock);
+ return (_export_flags == PKG_EXP_ALLUNNAMED);
}
bool is_unqual_exported() const {
- assert(!(_qualified_exports != NULL && _is_exported_unqualified),
- "_qualified_exports set at same time as _is_exported_unqualified");
- assert(!(_is_exported_allUnnamed && _is_exported_unqualified),
- "_is_exported_allUnnamed set at same time as _is_exported_unqualified");
- return _is_exported_unqualified;
+ assert_locked_or_safepoint(Module_lock);
+ return (_export_flags == PKG_EXP_UNQUALIFIED);
}
+
+ // Explicitly set _export_flags to PKG_EXP_UNQUALIFIED and clear
+ // PKG_EXP_ALLUNNAMED, if it was set.
void set_unqual_exported() {
assert(Module_lock->owned_by_self(), "should have the Module_lock");
- _is_exported_unqualified = true;
- _is_exported_allUnnamed = false;
- _qualified_exports = NULL;
+ _export_flags = PKG_EXP_UNQUALIFIED;
}
- bool exported_pending_delete() const { return (_exported_pending_delete != NULL); }
+
+ bool exported_pending_delete() const;
void set_exported(ModuleEntry* m);