--- old/src/share/vm/gc/parallel/psPromotionManager.cpp 2016-10-05 00:16:12.000000000 +0900 +++ new/src/share/vm/gc/parallel/psPromotionManager.cpp 2016-10-05 00:16:11.000000000 +0900 @@ -489,7 +489,7 @@ // this started. If it is the same (i.e., no forwarding // pointer has been installed), then this thread owns // it. - if (obj->cas_forward_to(obj, obj_mark)) { + if (obj->cas_forward_to(obj, obj_mark, memory_order_relaxed)) { // We won any races, we "own" this object. assert(obj == obj->forwardee(), "Sanity"); @@ -498,15 +498,18 @@ push_contents(obj); _preserved_marks->push_if_necessary(obj, obj_mark); + + log_develop_trace(gc, scavenge)("{promotion-failure %s " PTR_FORMAT " (%d)}", obj->klass()->internal_name(), p2i(obj), obj->size()); + } else { // We lost, someone else "owns" this object guarantee(obj->is_forwarded(), "Object must be forwarded if the cas failed."); + log_develop_trace(gc, scavenge)("{promotion-failure %s " PTR_FORMAT "}", obj->klass()->internal_name(), p2i(obj)); + // No unallocation to worry about. obj = obj->forwardee(); } - log_develop_trace(gc, scavenge)("{promotion-failure %s " PTR_FORMAT " (%d)}", obj->klass()->internal_name(), p2i(obj), obj->size()); - return obj; } --- old/src/share/vm/gc/parallel/psPromotionManager.inline.hpp 2016-10-05 00:16:12.000000000 +0900 +++ new/src/share/vm/gc/parallel/psPromotionManager.inline.hpp 2016-10-05 00:16:12.000000000 +0900 @@ -211,7 +211,7 @@ Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size); // Now we have to CAS in the header. - if (o->cas_forward_to(new_obj, test_mark)) { + if (o->cas_forward_to(new_obj, test_mark, memory_order_relaxed)) { // We won any races, we "own" this object. assert(new_obj == o->forwardee(), "Sanity"); @@ -238,6 +238,15 @@ // we'll just push its contents push_contents(new_obj); } + + // This code must come after the CAS test, or it will print incorrect + // information. + if (log_develop_is_enabled(Trace, gc, scavenge)) { + log_develop_trace(gc, scavenge)("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}", + should_scavenge(&new_obj) ? "copying" : "tenuring", + new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), + new_obj->size()) + } } else { // We lost, someone else "owns" this object guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed."); @@ -255,18 +264,25 @@ // don't update this before the unallocation! new_obj = o->forwardee(); + + // fields in new_obj may not be synchronized. + if (log_develop_is_enabled(Trace, gc, scavenge)) { + log_develop_trace(gc, scavenge)("{%s %s " PTR_FORMAT " -> " PTR_FORMAT "}", + should_scavenge(&new_obj) ? "copying" : "tenuring", + o->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj)); + } } } else { assert(o->is_forwarded(), "Sanity"); new_obj = o->forwardee(); + // fields in new_obj may not be synchronized. + if (log_develop_is_enabled(Trace, gc, scavenge)) { + log_develop_trace(gc, scavenge)("{%s %s " PTR_FORMAT " -> " PTR_FORMAT "}", + should_scavenge(&new_obj) ? "copying" : "tenuring", + o->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj)); + } } - // This code must come after the CAS test, or it will print incorrect - // information. - log_develop_trace(gc, scavenge)("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}", - should_scavenge(&new_obj) ? "copying" : "tenuring", - new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size()); - return new_obj; } @@ -278,16 +294,16 @@ assert(should_scavenge(p, true), "revisiting object?"); oop o = oopDesc::load_decode_heap_oop_not_null(p); - oop new_obj = o->is_forwarded() - ? o->forwardee() - : copy_to_survivor_space(o); - - // This code must come after the CAS test, or it will print incorrect - // information. - if (log_develop_is_enabled(Trace, gc, scavenge) && o->is_forwarded()) { - log_develop_trace(gc, scavenge)("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}", - "forwarding", - new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size()); + + if (!o->is_forwarded()) { + copy_to_survivor_space(o); + } + oop new_obj = o->forwardee(); + assert(forwardee != NULL, "forwardee should not be NULL"); + // This code must come after the CAS test, or it will print incorrect information. + if (log_develop_is_enabled(Trace, gc, scavenge)) { + log_develop_trace(gc, scavenge)("{forwarding %s " PTR_FORMAT " -> " PTR_FORMAT "}", + o->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj)); } oopDesc::encode_store_heap_oop_not_null(p, new_obj); --- old/src/share/vm/gc/parallel/psScavenge.inline.hpp 2016-10-05 00:16:13.000000000 +0900 +++ new/src/share/vm/gc/parallel/psScavenge.inline.hpp 2016-10-05 00:16:13.000000000 +0900 @@ -102,12 +102,10 @@ assert(PSScavenge::should_scavenge(p, true), "revisiting object?"); oop o = *p; - oop new_obj; - if (o->is_forwarded()) { - new_obj = o->forwardee(); - } else { - new_obj = _pm->copy_to_survivor_space(o); + if (!o->is_forwarded()) { + _pm->copy_to_survivor_space(o); } + oop new_obj = o->forwardee(); oopDesc::encode_store_heap_oop_not_null(p, new_obj); if (PSScavenge::is_obj_in_young(new_obj)) { --- old/src/share/vm/oops/oop.hpp 2016-10-05 00:16:13.000000000 +0900 +++ new/src/share/vm/oops/oop.hpp 2016-10-05 00:16:13.000000000 +0900 @@ -30,6 +30,7 @@ #include "memory/memRegion.hpp" #include "oops/metadata.hpp" #include "utilities/macros.hpp" +#include "runtime/atomic.hpp" // oopDesc is the top baseclass for objects classes. The {name}Desc classes describe // the format of Java objects so the fields can be accessed from C++. @@ -75,7 +76,7 @@ void set_mark(volatile markOop m) { _mark = m; } inline void release_set_mark(markOop m); - inline markOop cas_set_mark(markOop new_mark, markOop old_mark); + inline markOop cas_set_mark(markOop new_mark, markOop old_mark, cmpxchg_memory_order order = memory_order_conservative); // Used only to re-initialize the mark word (e.g., of promoted // objects during a GC) -- requires a valid klass pointer @@ -298,7 +299,7 @@ inline bool is_forwarded() const; inline void forward_to(oop p); - inline bool cas_forward_to(oop p, markOop compare); + inline bool cas_forward_to(oop p, markOop compare, cmpxchg_memory_order order = memory_order_conservative); #if INCLUDE_ALL_GCS // Like "forward_to", but inserts the forwarding pointer atomically. --- old/src/share/vm/oops/oop.inline.hpp 2016-10-05 00:16:14.000000000 +0900 +++ new/src/share/vm/oops/oop.inline.hpp 2016-10-05 00:16:14.000000000 +0900 @@ -92,8 +92,8 @@ OrderAccess::release_store_ptr(&_mark, m); } -markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark) { - return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark); +markOop oopDesc::cas_set_mark(markOop new_mark, markOop old_mark, cmpxchg_memory_order order) { + return (markOop) Atomic::cmpxchg_ptr(new_mark, &_mark, old_mark, order); } void oopDesc::init_mark() { @@ -578,14 +578,14 @@ } // Used by parallel scavengers -bool oopDesc::cas_forward_to(oop p, markOop compare) { +bool oopDesc::cas_forward_to(oop p, markOop compare, cmpxchg_memory_order order) { assert(check_obj_alignment(p), "forwarding to something not aligned"); assert(Universe::heap()->is_in_reserved(p), "forwarding to something not in heap"); markOop m = markOopDesc::encode_pointer_as_mark(p); assert(m->decode_pointer() == p, "encoding must be reversable"); - return cas_set_mark(m, compare) == compare; + return cas_set_mark(m, compare, order) == compare; } #if INCLUDE_ALL_GCS