8013136: NPG: Parallel class loading tests fail after fix for JDK-8011802
Summary: Move initialization of dependencies to before allocation of CLD
Reviewed-by: stefank, coleenp
--- a/hotspot/src/share/vm/classfile/classLoaderData.cpp Tue Feb 12 14:15:45 2013 -0800
+++ b/hotspot/src/share/vm/classfile/classLoaderData.cpp Wed Apr 24 19:55:02 2013 +0200
@@ -66,17 +66,19 @@
ClassLoaderData * ClassLoaderData::_the_null_class_loader_data = NULL;
-ClassLoaderData::ClassLoaderData(Handle h_class_loader, bool is_anonymous) :
+ClassLoaderData::ClassLoaderData(Handle h_class_loader, bool is_anonymous, Dependencies dependencies) :
_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(),
+ _next(NULL), _dependencies(dependencies),
_metaspace_lock(new Mutex(Monitor::leaf+1, "Metaspace allocation lock", true)) {
// empty
}
void ClassLoaderData::init_dependencies(TRAPS) {
+ assert(!Universe::is_fully_initialized(), "should only be called when initializing");
+ assert(is_the_null_class_loader_data(), "should only call this for the null class loader");
_dependencies.init(CHECK);
}
@@ -499,29 +501,25 @@
// Add a new class loader data node to the list. Assign the newly created
// ClassLoaderData into the java/lang/ClassLoader object as a hidden field
ClassLoaderData* ClassLoaderDataGraph::add(Handle loader, bool is_anonymous, TRAPS) {
- // Not assigned a class loader data yet.
- // Create one.
- ClassLoaderData* cld = new ClassLoaderData(loader, is_anonymous);
- cld->init_dependencies(THREAD);
- if (HAS_PENDING_EXCEPTION) {
- delete cld;
- return NULL;
- }
+ // We need to allocate all the oops for the ClassLoaderData before allocating the
+ // actual ClassLoaderData object.
+ ClassLoaderData::Dependencies dependencies(CHECK_NULL);
- No_Safepoint_Verifier no_safepoints; // nothing is keeping the dependencies array in cld alive
- // make sure we don't encounter a GC until we've inserted
- // cld into the CLDG
+ No_Safepoint_Verifier no_safepoints; // we mustn't GC until we've installed the
+ // ClassLoaderData in the graph since the CLD
+ // contains unhandled oops
+
+ ClassLoaderData* cld = new ClassLoaderData(loader, is_anonymous, dependencies);
+
if (!is_anonymous) {
ClassLoaderData** cld_addr = java_lang_ClassLoader::loader_data_addr(loader());
- if (cld_addr != NULL) {
- // First, Atomically set it
- ClassLoaderData* old = (ClassLoaderData*) Atomic::cmpxchg_ptr(cld, cld_addr, NULL);
- if (old != NULL) {
- delete cld;
- // Returns the data.
- return old;
- }
+ // First, Atomically set it
+ ClassLoaderData* old = (ClassLoaderData*) Atomic::cmpxchg_ptr(cld, cld_addr, NULL);
+ if (old != NULL) {
+ delete cld;
+ // Returns the data.
+ return old;
}
}
--- a/hotspot/src/share/vm/classfile/classLoaderData.hpp Tue Feb 12 14:15:45 2013 -0800
+++ b/hotspot/src/share/vm/classfile/classLoaderData.hpp Wed Apr 24 19:55:02 2013 +0200
@@ -100,6 +100,9 @@
Thread* THREAD);
public:
Dependencies() : _list_head(NULL) {}
+ Dependencies(TRAPS) : _list_head(NULL) {
+ init(CHECK);
+ }
void add(Handle dependency, TRAPS);
void init(TRAPS);
void oops_do(OopClosure* f);
@@ -150,7 +153,7 @@
void set_next(ClassLoaderData* next) { _next = next; }
ClassLoaderData* next() const { return _next; }
- ClassLoaderData(Handle h_class_loader, bool is_anonymous);
+ ClassLoaderData(Handle h_class_loader, bool is_anonymous, Dependencies dependencies);
~ClassLoaderData();
void set_metaspace(Metaspace* m) { _metaspace = m; }
@@ -190,7 +193,9 @@
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, false);
+
+ // We explicitly initialize the Dependencies object at a later phase in the initialization
+ _the_null_class_loader_data = new ClassLoaderData((oop)NULL, false, Dependencies());
ClassLoaderDataGraph::_head = _the_null_class_loader_data;
assert(_the_null_class_loader_data->is_the_null_class_loader_data(), "Must be");
if (DumpSharedSpaces) {