8075249: Cleanup forward_to_atomic and ClaimedForwardPtr
Reviewed-by: kbarrett, brutisso
--- a/hotspot/src/share/vm/gc_implementation/g1/g1ParScanThreadState.cpp Tue Mar 17 14:18:52 2015 +0100
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1ParScanThreadState.cpp Tue Mar 17 15:53:55 2015 +0100
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2015, 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
@@ -226,6 +226,8 @@
}
assert(obj_ptr != NULL, "when we get here, allocation should have succeeded");
+ assert(_g1h->is_in_reserved(obj_ptr), "Allocated memory should be in the heap");
+
#ifndef PRODUCT
// Should this evacuation fail?
if (_g1h->evacuation_should_fail()) {
--- a/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp Tue Mar 17 14:18:52 2015 +0100
+++ b/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp Tue Mar 17 15:53:55 2015 +0100
@@ -1122,14 +1122,6 @@
return forward_ptr;
}
-#ifdef ASSERT
-bool ParNewGeneration::is_legal_forward_ptr(oop p) {
- return
- (p == ClaimedForwardPtr)
- || Universe::heap()->is_in_reserved(p);
-}
-#endif
-
void ParNewGeneration::preserve_mark_if_necessary(oop obj, markOop m) {
if (m->must_be_preserved_for_promotion_failure(obj)) {
// We should really have separate per-worker stacks, rather
@@ -1204,6 +1196,7 @@
} else {
// Is in to-space; do copying ourselves.
Copy::aligned_disjoint_words((HeapWord*)old, (HeapWord*)new_obj, sz);
+ assert(Universe::heap()->is_in_reserved(new_obj), "illegal forwarding pointer value.");
forward_ptr = old->forward_to_atomic(new_obj);
// Restore the mark word copied above.
new_obj->set_mark(m);
--- a/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.hpp Tue Mar 17 14:18:52 2015 +0100
+++ b/hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.hpp Tue Mar 17 15:53:55 2015 +0100
@@ -419,8 +419,6 @@
}
static oop real_forwardee(oop obj);
-
- DEBUG_ONLY(static bool is_legal_forward_ptr(oop p);)
};
#endif // SHARE_VM_GC_IMPLEMENTATION_PARNEW_PARNEWGENERATION_HPP
--- a/hotspot/src/share/vm/oops/oop.inline.hpp Tue Mar 17 14:18:52 2015 +0100
+++ b/hotspot/src/share/vm/oops/oop.inline.hpp Tue Mar 17 15:53:55 2015 +0100
@@ -630,6 +630,30 @@
return cas_set_mark(m, compare) == compare;
}
+#if INCLUDE_ALL_GCS
+inline oop oopDesc::forward_to_atomic(oop p) {
+ markOop oldMark = mark();
+ markOop forwardPtrMark = markOopDesc::encode_pointer_as_mark(p);
+ markOop curMark;
+
+ assert(forwardPtrMark->decode_pointer() == p, "encoding must be reversable");
+ assert(sizeof(markOop) == sizeof(intptr_t), "CAS below requires this.");
+
+ while (!oldMark->is_marked()) {
+ curMark = (markOop)Atomic::cmpxchg_ptr(forwardPtrMark, &_mark, oldMark);
+ assert(is_forwarded(), "object should have been forwarded");
+ if (curMark == oldMark) {
+ return NULL;
+ }
+ // If the CAS was unsuccessful then curMark->is_marked()
+ // should return true as another thread has CAS'd in another
+ // forwarding pointer.
+ oldMark = curMark;
+ }
+ return forwardee();
+}
+#endif
+
// Note that the forwardee is not the same thing as the displaced_mark.
// The forwardee is used when copying during scavenge and mark-sweep.
// It does need to clear the low two locking- and GC-related bits.
--- a/hotspot/src/share/vm/oops/oop.pcgc.inline.hpp Tue Mar 17 14:18:52 2015 +0100
+++ b/hotspot/src/share/vm/oops/oop.pcgc.inline.hpp Tue Mar 17 15:53:55 2015 +0100
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2015, 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
@@ -54,28 +54,4 @@
klass()->oop_follow_contents(cm, this);
}
-inline oop oopDesc::forward_to_atomic(oop p) {
- assert(ParNewGeneration::is_legal_forward_ptr(p),
- "illegal forwarding pointer value.");
- markOop oldMark = mark();
- markOop forwardPtrMark = markOopDesc::encode_pointer_as_mark(p);
- markOop curMark;
-
- assert(forwardPtrMark->decode_pointer() == p, "encoding must be reversable");
- assert(sizeof(markOop) == sizeof(intptr_t), "CAS below requires this.");
-
- while (!oldMark->is_marked()) {
- curMark = (markOop)Atomic::cmpxchg_ptr(forwardPtrMark, &_mark, oldMark);
- assert(is_forwarded(), "object should have been forwarded");
- if (curMark == oldMark) {
- return NULL;
- }
- // If the CAS was unsuccessful then curMark->is_marked()
- // should return true as another thread has CAS'd in another
- // forwarding pointer.
- oldMark = curMark;
- }
- return forwardee();
-}
-
#endif // SHARE_VM_OOPS_OOP_PCGC_INLINE_HPP