8004883: NPG: clean up anonymous class fix
Summary: Add klass_holder() to return either mirror or class_loader depending on if the class is anonymous or not.
Reviewed-by: stefank, jrose
--- a/hotspot/src/share/vm/asm/codeBuffer.cpp Fri Dec 07 10:55:16 2012 -0800
+++ b/hotspot/src/share/vm/asm/codeBuffer.cpp Wed Dec 12 11:39:29 2012 -0500
@@ -496,21 +496,9 @@
dest->verify_section_allocation();
}
-// Anonymous classes need mirror to keep the metadata alive but
-// for regular classes, the class_loader is sufficient.
+// Append an oop reference that keeps the class alive.
static void append_oop_references(GrowableArray<oop>* oops, Klass* k) {
- if (k->oop_is_instance()) {
- InstanceKlass* ik = InstanceKlass::cast(k);
- if (ik->is_anonymous()) {
- oop o = ik->java_mirror();
- assert (o != NULL, "should have a mirror");
- if (!oops->contains(o)) {
- oops->append(o);
- }
- return; // only need the mirror
- }
- }
- oop cl = k->class_loader();
+ oop cl = k->klass_holder();
if (cl != NULL && !oops->contains(cl)) {
oops->append(cl);
}
--- a/hotspot/src/share/vm/classfile/classLoaderData.cpp Fri Dec 07 10:55:16 2012 -0800
+++ b/hotspot/src/share/vm/classfile/classLoaderData.cpp Wed Dec 12 11:39:29 2012 -0500
@@ -64,8 +64,10 @@
ClassLoaderData * ClassLoaderData::_the_null_class_loader_data = NULL;
-ClassLoaderData::ClassLoaderData(Handle h_class_loader) : _class_loader(h_class_loader()),
- _metaspace(NULL), _unloading(false), _keep_alive(false), _klasses(NULL),
+ClassLoaderData::ClassLoaderData(Handle h_class_loader, bool is_anonymous) :
+ _class_loader(h_class_loader()),
+ _is_anonymous(is_anonymous), _keep_alive(is_anonymous), // initially
+ _metaspace(NULL), _unloading(false), _klasses(NULL),
_claimed(0), _jmethod_ids(NULL), _handles(NULL), _deallocate_list(NULL),
_next(NULL), _dependencies(NULL),
_metaspace_lock(new Mutex(Monitor::leaf+1, "Metaspace allocation lock", true)) {
@@ -257,13 +259,6 @@
ShouldNotReachHere(); // should have found this class!!
}
-
-bool ClassLoaderData::is_anonymous() const {
- Klass* k = _klasses;
- return (_keep_alive || (k != NULL && k->oop_is_instance() &&
- InstanceKlass::cast(k)->is_anonymous()));
-}
-
void ClassLoaderData::unload() {
_unloading = true;
@@ -396,8 +391,7 @@
// These anonymous class loaders are to contain classes used for JSR292
ClassLoaderData* ClassLoaderData::anonymous_class_loader_data(oop loader, TRAPS) {
// Add a new class loader data to the graph.
- ClassLoaderData* cld = ClassLoaderDataGraph::add(NULL, loader, CHECK_NULL);
- return cld;
+ return ClassLoaderDataGraph::add(NULL, loader, CHECK_NULL);
}
const char* ClassLoaderData::loader_name() {
@@ -475,7 +469,9 @@
// Create one.
ClassLoaderData* *list_head = &_head;
ClassLoaderData* next = _head;
- ClassLoaderData* cld = new ClassLoaderData(loader);
+
+ bool is_anonymous = (cld_addr == NULL);
+ ClassLoaderData* cld = new ClassLoaderData(loader, is_anonymous);
if (cld_addr != NULL) {
// First, Atomically set it
@@ -485,10 +481,6 @@
// Returns the data.
return old;
}
- } else {
- // Disallow unloading for this CLD during initialization if there is no
- // class_loader oop to link this to.
- cld->set_keep_alive(true);
}
// We won the race, and therefore the task of adding the data to the list of
--- a/hotspot/src/share/vm/classfile/classLoaderData.hpp Fri Dec 07 10:55:16 2012 -0800
+++ b/hotspot/src/share/vm/classfile/classLoaderData.hpp Wed Dec 12 11:39:29 2012 -0500
@@ -109,6 +109,7 @@
Mutex* _metaspace_lock; // Locks the metaspace for allocations and setup.
bool _unloading; // true if this class loader goes away
bool _keep_alive; // if this CLD can be unloaded for anonymous loaders
+ bool _is_anonymous; // if this CLD is for an anonymous class
volatile int _claimed; // true if claimed, for example during GC traces.
// To avoid applying oop closure more than once.
// Has to be an int because we cas it.
@@ -139,7 +140,7 @@
void set_next(ClassLoaderData* next) { _next = next; }
ClassLoaderData* next() const { return _next; }
- ClassLoaderData(Handle h_class_loader);
+ ClassLoaderData(Handle h_class_loader, bool is_anonymous);
~ClassLoaderData();
void set_metaspace(Metaspace* m) { _metaspace = m; }
@@ -174,12 +175,12 @@
return _the_null_class_loader_data;
}
- bool is_anonymous() const;
+ bool is_anonymous() const { return _is_anonymous; }
static void init_null_class_loader_data() {
assert(_the_null_class_loader_data == NULL, "cannot initialize twice");
assert(ClassLoaderDataGraph::_head == NULL, "cannot initialize twice");
- _the_null_class_loader_data = new ClassLoaderData((oop)NULL);
+ _the_null_class_loader_data = new ClassLoaderData((oop)NULL, false);
ClassLoaderDataGraph::_head = _the_null_class_loader_data;
assert(_the_null_class_loader_data->is_the_null_class_loader_data(), "Must be");
if (DumpSharedSpaces) {
--- a/hotspot/src/share/vm/compiler/compileBroker.cpp Fri Dec 07 10:55:16 2012 -0800
+++ b/hotspot/src/share/vm/compiler/compileBroker.cpp Wed Dec 12 11:39:29 2012 -0500
@@ -269,12 +269,10 @@
const char* comment,
bool is_blocking) {
assert(!_lock->is_locked(), "bad locking");
- InstanceKlass* holder = method->method_holder();
_compile_id = compile_id;
_method = method();
- _method_holder = JNIHandles::make_global(
- holder->is_anonymous() ? holder->java_mirror(): holder->class_loader());
+ _method_holder = JNIHandles::make_global(method->method_holder()->klass_holder());
_osr_bci = osr_bci;
_is_blocking = is_blocking;
_comp_level = comp_level;
@@ -298,10 +296,7 @@
} else {
_hot_method = hot_method();
// only add loader or mirror if different from _method_holder
- InstanceKlass* hot_holder = hot_method->method_holder();
- _hot_method_holder = JNIHandles::make_global(
- hot_holder->is_anonymous() ? hot_holder->java_mirror() :
- hot_holder->class_loader());
+ _hot_method_holder = JNIHandles::make_global(hot_method->method_holder()->klass_holder());
}
}
}
--- a/hotspot/src/share/vm/oops/instanceKlass.hpp Fri Dec 07 10:55:16 2012 -0800
+++ b/hotspot/src/share/vm/oops/instanceKlass.hpp Wed Dec 12 11:39:29 2012 -0500
@@ -538,6 +538,12 @@
}
}
+ // Oop that keeps the metadata for this class from being unloaded
+ // in places where the metadata is stored in other places, like nmethods
+ oop klass_holder() const {
+ return is_anonymous() ? java_mirror() : class_loader();
+ }
+
// signers
objArrayOop signers() const { return _signers; }
void set_signers(objArrayOop s) { klass_oop_store((oop*)&_signers, s); }
--- a/hotspot/src/share/vm/oops/klass.hpp Fri Dec 07 10:55:16 2012 -0800
+++ b/hotspot/src/share/vm/oops/klass.hpp Wed Dec 12 11:39:29 2012 -0500
@@ -451,6 +451,8 @@
oop class_loader() const;
+ virtual oop klass_holder() const { return class_loader(); }
+
protected:
virtual Klass* array_klass_impl(bool or_null, int rank, TRAPS);
virtual Klass* array_klass_impl(bool or_null, TRAPS);