--- a/src/hotspot/share/classfile/classLoaderData.cpp Wed Apr 18 10:30:57 2018 -0700
+++ b/src/hotspot/share/classfile/classLoaderData.cpp Wed Apr 18 18:43:04 2018 -0400
@@ -54,6 +54,7 @@
#include "classfile/metadataOnStackMark.hpp"
#include "classfile/moduleEntry.hpp"
#include "classfile/packageEntry.hpp"
+#include "classfile/symbolTable.hpp"
#include "classfile/systemDictionary.hpp"
#include "logging/log.hpp"
#include "logging/logStream.hpp"
@@ -102,8 +103,25 @@
}
}
+// JFR and logging support so that the name and klass are available after the
+// class_loader oop is no longer alive, during unloading.
+void ClassLoaderData::initialize_name_and_klass(Handle class_loader) {
+ _class_loader_klass = class_loader->klass();
+ oop class_loader_name = java_lang_ClassLoader::name(class_loader());
+ if (class_loader_name != NULL) {
+ Thread* THREAD = Thread::current();
+ ResourceMark rm(THREAD);
+ const char* class_loader_instance_name =
+ java_lang_String::as_utf8_string(class_loader_name);
+
+ if (class_loader_instance_name != NULL && class_loader_instance_name[0] != '\0') {
+ // Can't throw InternalError and SymbolTable doesn't throw OOM anymore.
+ _class_loader_name = SymbolTable::new_symbol(class_loader_instance_name, CATCH);
+ }
+ }
+}
+
ClassLoaderData::ClassLoaderData(Handle h_class_loader, bool is_anonymous) :
- _class_loader(h_class_loader()),
_is_anonymous(is_anonymous),
// An anonymous class loader data doesn't have anything to keep
// it from being unloaded during parsing of the anonymous class.
@@ -114,9 +132,14 @@
_claimed(0), _modified_oops(true), _accumulated_modified_oops(false),
_jmethod_ids(NULL), _handles(), _deallocate_list(NULL),
_next(NULL),
+ _class_loader_klass(NULL), _class_loader_name(NULL),
_metaspace_lock(new Mutex(Monitor::leaf+1, "Metaspace allocation lock", true,
Monitor::_safepoint_check_never)) {
+ if (!h_class_loader.is_null()) {
+ _class_loader = _handles.add(h_class_loader());
+ }
+
if (!is_anonymous) {
// The holder is initialized later for anonymous classes, and before calling anything
// that call class_loader().
@@ -269,7 +292,6 @@
clear_modified_oops();
}
- f->do_oop(&_class_loader);
_handles.oops_do(f);
}
@@ -556,7 +578,7 @@
if (lt.is_enabled()) {
ResourceMark rm;
LogStream ls(lt);
- ls.print("unload ");
+ ls.print("unload");
print_value_on(&ls);
ls.cr();
}
@@ -631,7 +653,7 @@
// Unloading support
bool ClassLoaderData::is_alive() const {
bool alive = keep_alive() // null class loader and incomplete anonymous klasses.
- || (_holder.peek() != NULL); // not cleaned by weak reference processing
+ || (_holder.peek() != NULL); // and not cleaned by the GC weak handle processing.
return alive;
}
@@ -887,13 +909,23 @@
}
const char* ClassLoaderData::loader_name() const {
- // Handles null class loader
- return SystemDictionary::loader_name(class_loader());
+ if (is_unloading()) {
+ if (_class_loader_klass == NULL) {
+ return "<bootloader>";
+ } else if (_class_loader_name != NULL) {
+ return _class_loader_name->as_C_string();
+ } else {
+ return _class_loader_klass->name()->as_C_string();
+ }
+ } else {
+ // Handles null class loader
+ return SystemDictionary::loader_name(class_loader());
+ }
}
void ClassLoaderData::print_value_on(outputStream* out) const {
- if (class_loader() != NULL) {
+ if (!is_unloading() && class_loader() != NULL) {
out->print("loader data: " INTPTR_FORMAT " for instance ", p2i(this));
class_loader()->print_value_on(out); // includes loader_name() and address of class loader instance
} else {
@@ -908,7 +940,7 @@
#ifndef PRODUCT
void ClassLoaderData::print_on(outputStream* out) const {
out->print("ClassLoaderData CLD: " PTR_FORMAT ", loader: " PTR_FORMAT ", loader_klass: %s {",
- p2i(this), p2i((void *)class_loader()), loader_name());
+ p2i(this), p2i(_class_loader.ptr_raw()), loader_name());
if (is_anonymous()) out->print(" anonymous");
if (claimed()) out->print(" claimed");
if (is_unloading()) out->print(" unloading");
@@ -962,10 +994,10 @@
// 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) {
+ClassLoaderData* ClassLoaderDataGraph::add_to_graph(Handle loader, bool is_anonymous) {
NoSafepointVerifier no_safepoints; // we mustn't GC until we've installed the
// ClassLoaderData in the graph since the CLD
- // contains unhandled oops
+ // contains oops in _handles that must be walked.
ClassLoaderData* cld = new ClassLoaderData(loader, is_anonymous);
@@ -1002,6 +1034,16 @@
} while (true);
}
+ClassLoaderData* ClassLoaderDataGraph::add(Handle loader, bool is_anonymous) {
+ ClassLoaderData* loader_data = add_to_graph(loader, is_anonymous);
+ // Initialize name and class after the loader data is added to the CLDG
+ // because adding the Symbol for the name might safepoint.
+ if (loader.not_null()) {
+ loader_data->initialize_name_and_klass(loader);
+ }
+ return loader_data;
+}
+
void ClassLoaderDataGraph::oops_do(OopClosure* f, bool must_claim) {
for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
cld->oops_do(f, must_claim);