Mercurial > hg > graal-compiler
diff src/share/vm/classfile/classLoaderData.cpp @ 14190:ce86c36b8921
8029178: Parallel class loading test anonymous-simple gets SIGSEGV in Metaspace::contains
Summary: Metaspace::contains cannot look at purged metaspaces while CMS concurrently deallocates them.
Reviewed-by: mgerdin, sspitsyn, jmasa
author | coleenp |
---|---|
date | Tue, 07 Jan 2014 13:26:56 -0500 |
parents | 86e6d691f2e1 |
children | 48314d596a04 3cdda110bbb5 |
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--- a/src/share/vm/classfile/classLoaderData.cpp Tue Jan 07 12:32:57 2014 +0100 +++ b/src/share/vm/classfile/classLoaderData.cpp Tue Jan 07 13:26:56 2014 -0500 @@ -648,12 +648,12 @@ return array; } -#ifndef PRODUCT -// for debugging and hsfind(x) -bool ClassLoaderDataGraph::contains(address x) { - // I think we need the _metaspace_lock taken here because the class loader - // data graph could be changing while we are walking it (new entries added, - // new entries being unloaded, etc). +// For profiling and hsfind() only. Otherwise, this is unsafe (and slow). This +// is done lock free to avoid lock inversion problems. It is safe because +// new ClassLoaderData are added to the end of the CLDG, and only removed at +// safepoint. The _unloading list can be deallocated concurrently with CMS so +// this doesn't look in metaspace for classes that have been unloaded. +bool ClassLoaderDataGraph::contains(const void* x) { if (DumpSharedSpaces) { // There are only two metaspaces to worry about. ClassLoaderData* ncld = ClassLoaderData::the_null_class_loader_data(); @@ -670,16 +670,11 @@ } } - // Could also be on an unloading list which is okay, ie. still allocated - // for a little while. - for (ClassLoaderData* ucld = _unloading; ucld != NULL; ucld = ucld->next()) { - if (ucld->metaspace_or_null() != NULL && ucld->metaspace_or_null()->contains(x)) { - return true; - } - } + // Do not check unloading list because deallocation can be concurrent. return false; } +#ifndef PRODUCT bool ClassLoaderDataGraph::contains_loader_data(ClassLoaderData* loader_data) { for (ClassLoaderData* data = _head; data != NULL; data = data->next()) { if (loader_data == data) {