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src/share/vm/classfile/dictionary.hpp
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@@ -27,10 +27,11 @@
#include "classfile/protectionDomainCache.hpp"
#include "classfile/systemDictionary.hpp"
#include "oops/instanceKlass.hpp"
#include "oops/oop.hpp"
+#include "runtime/orderAccess.hpp"
#include "utilities/hashtable.hpp"
#include "utilities/ostream.hpp"
class DictionaryEntry;
class BoolObjectClosure;
@@ -132,11 +133,27 @@
//
// The usage of the PD set can be seen in SystemDictionary::validate_protection_domain()
// It is essentially a cache to avoid repeated Java up-calls to
// ClassLoader.checkPackageAccess().
//
- ProtectionDomainEntry* _pd_set;
+ class ProtectionDomainSet {
+ // Do not access without synchronization
+ ProtectionDomainEntry* volatile _pd_set;
+ public:
+ ProtectionDomainEntry* pd_set() const {
+ return (ProtectionDomainEntry*)OrderAccess::load_ptr_acquire(&_pd_set);
+ }
+ void set_pd_set(ProtectionDomainEntry* new_head) {
+ // Warning: Preserve store ordering. The SystemDictionary is read
+ // without locks. The new ProtectionDomainEntry must be
+ // complete before other threads can be allowed to see it
+ // via a store to _pd_set.
+ OrderAccess::release_store_ptr(&_pd_set, new_head);
+ }
+ };
+
+ ProtectionDomainSet _inner;
public:
// Tells whether a protection is in the approved set.
bool contains_protection_domain(oop protection_domain) const;
// Adds a protection domain to the approved set.
@@ -151,12 +168,12 @@
DictionaryEntry** next_addr() {
return (DictionaryEntry**)HashtableEntry<InstanceKlass*, mtClass>::next_addr();
}
- ProtectionDomainEntry* pd_set() const { return _pd_set; }
- void set_pd_set(ProtectionDomainEntry* pd_set) { _pd_set = pd_set; }
+ ProtectionDomainEntry* pd_set() const { return _inner.pd_set(); }
+ void set_pd_set(ProtectionDomainEntry* new_head) { _inner.set_pd_set(new_head); }
// Tells whether the initiating class' protection domain can access the klass in this entry
bool is_valid_protection_domain(Handle protection_domain) {
if (!ProtectionDomainVerification) return true;
if (!SystemDictionary::has_checkPackageAccess()) return true;
@@ -165,11 +182,11 @@
? true
: contains_protection_domain(protection_domain());
}
void verify_protection_domain_set() {
- for (ProtectionDomainEntry* current = _pd_set;
+ for (ProtectionDomainEntry* current = pd_set();
current != NULL;
current = current->_next) {
current->_pd_cache->protection_domain()->verify();
}
}
@@ -179,11 +196,11 @@
return (klass->name() == class_name);
}
void print_count(outputStream *st) {
int count = 0;
- for (ProtectionDomainEntry* current = _pd_set;
+ for (ProtectionDomainEntry* current = pd_set();
current != NULL;
current = current->_next) {
count++;
}
st->print_cr("pd set count = #%d", count);
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