1.1 --- a/src/share/vm/classfile/classLoaderData.cpp Mon Feb 10 10:34:52 2014 +0100
1.2 +++ b/src/share/vm/classfile/classLoaderData.cpp Tue Jan 07 13:26:56 2014 -0500
1.3 @@ -648,12 +648,12 @@
1.4 return array;
1.5 }
1.6
1.7 -#ifndef PRODUCT
1.8 -// for debugging and hsfind(x)
1.9 -bool ClassLoaderDataGraph::contains(address x) {
1.10 - // I think we need the _metaspace_lock taken here because the class loader
1.11 - // data graph could be changing while we are walking it (new entries added,
1.12 - // new entries being unloaded, etc).
1.13 +// For profiling and hsfind() only. Otherwise, this is unsafe (and slow). This
1.14 +// is done lock free to avoid lock inversion problems. It is safe because
1.15 +// new ClassLoaderData are added to the end of the CLDG, and only removed at
1.16 +// safepoint. The _unloading list can be deallocated concurrently with CMS so
1.17 +// this doesn't look in metaspace for classes that have been unloaded.
1.18 +bool ClassLoaderDataGraph::contains(const void* x) {
1.19 if (DumpSharedSpaces) {
1.20 // There are only two metaspaces to worry about.
1.21 ClassLoaderData* ncld = ClassLoaderData::the_null_class_loader_data();
1.22 @@ -670,16 +670,11 @@
1.23 }
1.24 }
1.25
1.26 - // Could also be on an unloading list which is okay, ie. still allocated
1.27 - // for a little while.
1.28 - for (ClassLoaderData* ucld = _unloading; ucld != NULL; ucld = ucld->next()) {
1.29 - if (ucld->metaspace_or_null() != NULL && ucld->metaspace_or_null()->contains(x)) {
1.30 - return true;
1.31 - }
1.32 - }
1.33 + // Do not check unloading list because deallocation can be concurrent.
1.34 return false;
1.35 }
1.36
1.37 +#ifndef PRODUCT
1.38 bool ClassLoaderDataGraph::contains_loader_data(ClassLoaderData* loader_data) {
1.39 for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
1.40 if (loader_data == data) {
