Mercurial > hg > truffle
diff src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.cpp @ 3249:e1162778c1c8
7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error
Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer.
Reviewed-by: kvn, iveresov, never, tonyp, dholmes
author | johnc |
---|---|
date | Thu, 07 Apr 2011 09:53:20 -0700 |
parents | f95d63e2154a |
children | f08d439fab8c |
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--- a/src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.cpp Tue Apr 05 19:14:03 2011 -0700 +++ b/src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.cpp Thu Apr 07 09:53:20 2011 -0700 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it @@ -47,7 +47,9 @@ void G1SATBCardTableModRefBS::enqueue(oop pre_val) { - assert(pre_val->is_oop_or_null(true), "Error"); + // Nulls should have been already filtered. + assert(pre_val->is_oop(true), "Error"); + if (!JavaThread::satb_mark_queue_set().is_active()) return; Thread* thr = Thread::current(); if (thr->is_Java_thread()) { @@ -59,20 +61,6 @@ } } -// When we know the current java thread: -template <class T> void -G1SATBCardTableModRefBS::write_ref_field_pre_static(T* field, - oop new_val, - JavaThread* jt) { - if (!JavaThread::satb_mark_queue_set().is_active()) return; - T heap_oop = oopDesc::load_heap_oop(field); - if (!oopDesc::is_null(heap_oop)) { - oop pre_val = oopDesc::decode_heap_oop_not_null(heap_oop); - assert(pre_val->is_oop(true /* ignore mark word */), "Error"); - jt->satb_mark_queue().enqueue(pre_val); - } -} - template <class T> void G1SATBCardTableModRefBS::write_ref_array_pre_work(T* dst, int count) { if (!JavaThread::satb_mark_queue_set().is_active()) return;