--- a/src/hotspot/share/classfile/systemDictionary.cpp Fri Nov 16 07:30:40 2018 -0500
+++ b/src/hotspot/share/classfile/systemDictionary.cpp Fri Nov 16 10:54:04 2018 -0500
@@ -1807,18 +1807,26 @@
bool SystemDictionary::do_unloading(GCTimer* gc_timer) {
bool unloading_occurred;
+ bool is_concurrent = !SafepointSynchronize::is_at_safepoint();
{
GCTraceTime(Debug, gc, phases) t("ClassLoaderData", gc_timer);
-
+ assert_locked_or_safepoint(ClassLoaderDataGraph_lock); // caller locks.
// First, mark for unload all ClassLoaderData referencing a dead class loader.
unloading_occurred = ClassLoaderDataGraph::do_unloading();
if (unloading_occurred) {
+ MutexLockerEx ml2(is_concurrent ? Module_lock : NULL);
JFR_ONLY(Jfr::on_unloading_classes();)
+ MutexLockerEx ml1(is_concurrent ? SystemDictionary_lock : NULL);
ClassLoaderDataGraph::clean_module_and_package_info();
}
}
- // TODO: just return if !unloading_occurred.
+ // Cleanup ResolvedMethodTable even if no unloading occurred.
+ {
+ GCTraceTime(Debug, gc, phases) t("ResolvedMethodTable", gc_timer);
+ ResolvedMethodTable::trigger_cleanup();
+ }
+
if (unloading_occurred) {
{
GCTraceTime(Debug, gc, phases) t("SymbolTable", gc_timer);
@@ -1827,23 +1835,21 @@
}
{
+ MutexLockerEx ml(is_concurrent ? SystemDictionary_lock : NULL);
GCTraceTime(Debug, gc, phases) t("Dictionary", gc_timer);
constraints()->purge_loader_constraints();
resolution_errors()->purge_resolution_errors();
}
- }
-
- {
- GCTraceTime(Debug, gc, phases) t("ProtectionDomainCacheTable", gc_timer);
- // Oops referenced by the protection domain cache table may get unreachable independently
- // of the class loader (eg. cached protection domain oops). So we need to
- // explicitly unlink them here.
- _pd_cache_table->trigger_cleanup();
- }
-
- {
- GCTraceTime(Debug, gc, phases) t("ResolvedMethodTable", gc_timer);
- ResolvedMethodTable::trigger_cleanup();
+
+ {
+ GCTraceTime(Debug, gc, phases) t("ResolvedMethodTable", gc_timer);
+ // Oops referenced by the protection domain cache table may get unreachable independently
+ // of the class loader (eg. cached protection domain oops). So we need to
+ // explicitly unlink them here.
+ // All protection domain oops are linked to the caller class, so if nothing
+ // unloads, this is not needed.
+ _pd_cache_table->trigger_cleanup();
+ }
}
return unloading_occurred;