archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-08-28 15:24:43 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

8171971: Fix timing bug in JVM management of package export lists

Browse source 
Reduce the number of fields that maintain export state and use Module_lock to access these fields

Reviewed-by: acorn, sspitsyn, lfoltan
This commit is contained in:
Harold Seigel 2017-01-20 16:09:56 -05:00
parent 5796b2e174
commit c199f4eac2
4 changed files with 105 additions and 75 deletions
Download patch file Download diff file Expand all files Collapse all files

44
hotspot/src/share/vm/classfile/packageEntry.cpp
View file

@ -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
@ -37,8 +37,8 @@
// Returns true if this package specifies m as a qualified export, including through an unnamed export
bool PackageEntry::is_qexported_to(ModuleEntry* m) const {
assert(Module_lock->owned_by_self(), "should have the Module_lock");
assert(m != NULL, "No module to lookup in this package's qualified exports list");
MutexLocker m1(Module_lock);
if (is_exported_allUnnamed() && !m->is_named()) {
return true;
} else if (!has_qual_exports_list()) {
@ -98,15 +98,8 @@ void PackageEntry::set_exported(ModuleEntry* m) {
}
if (m == NULL) {
// NULL indicates the package is being unqualifiedly exported
if (has_qual_exports_list()) {
// Legit to transition a package from being qualifiedly exported
// to unqualified. Clean up the qualified lists at the next
// safepoint.
_exported_pending_delete = _qualified_exports;
}
// Mark package as unqualifiedly exported
// NULL indicates the package is being unqualifiedly exported. Clean up
// the qualified list at the next safepoint.
set_unqual_exported();
} else {
@ -115,14 +108,19 @@ void PackageEntry::set_exported(ModuleEntry* m) {
}
}
// Set the package as exported to all unnamed modules unless the package is
// already unqualifiedly exported.
void PackageEntry::set_is_exported_allUnnamed() {
MutexLocker m1(Module_lock);
if (!is_unqual_exported()) {
_is_exported_allUnnamed = true;
_export_flags = PKG_EXP_ALLUNNAMED;
}
}
// Remove dead module entries within the package's exported list.
// Remove dead module entries within the package's exported list. Note that
// if all of the modules on the _qualified_exports get purged the list does not
// get deleted. This prevents the package from illegally transitioning from
// exported to non-exported.
void PackageEntry::purge_qualified_exports() {
assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
if (_must_walk_exports &&
@ -160,18 +158,9 @@ void PackageEntry::purge_qualified_exports() {
void PackageEntry::delete_qualified_exports() {
assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
if (_exported_pending_delete != NULL) {
// If a transition occurred from qualified to unqualified, the _qualified_exports
// field should have been NULL'ed out.
assert(_qualified_exports == NULL, "Package's exported pending delete, exported list should not be active");
delete _exported_pending_delete;
}
if (_qualified_exports != NULL) {
delete _qualified_exports;
}
_exported_pending_delete = NULL;
_qualified_exports = NULL;
}
@ -314,6 +303,11 @@ void PackageEntry::package_exports_do(ModuleClosure* const f) {
}
}
bool PackageEntry::exported_pending_delete() const {
assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
return (is_unqual_exported() && _qualified_exports != NULL);
}
// Remove dead entries from all packages' exported list
void PackageEntryTable::purge_all_package_exports() {
assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
@ -344,13 +338,17 @@ void PackageEntryTable::print(outputStream* st) {
}
}
// This function may be called from debuggers so access private fields directly
// to prevent triggering locking-related asserts that could result from calling
// getter methods.
void PackageEntry::print(outputStream* st) {
ResourceMark rm;
st->print_cr("package entry " PTR_FORMAT " name %s module %s classpath_index "
INT32_FORMAT " is_exported_unqualified %d is_exported_allUnnamed %d " "next " PTR_FORMAT,
p2i(this), name()->as_C_string(),
(module()->is_named() ? module()->name()->as_C_string() : UNNAMED_MODULE),
_classpath_index, _is_exported_unqualified, _is_exported_allUnnamed, p2i(next()));
_classpath_index, _export_flags == PKG_EXP_UNQUALIFIED,
_export_flags == PKG_EXP_ALLUNNAMED, p2i(next()));
}
void PackageEntryTable::verify() {