# HG changeset patch
# User rkennke
# Date 1494424049 -7200
#      Wed May 10 15:47:29 2017 +0200
# Node ID aea4d9f53c58d6f9ebafd72b96c5e02d4eeb6179
# Parent  4ee5b7c8a8ac716f5e7de3ce4fc3d547fae37e47
Simplify parallel synchronizer roots iterator.

diff --git a/src/share/vm/gc/shenandoah/shenandoahHeap.cpp b/src/share/vm/gc/shenandoah/shenandoahHeap.cpp
--- a/src/share/vm/gc/shenandoah/shenandoahHeap.cpp
+++ b/src/share/vm/gc/shenandoah/shenandoahHeap.cpp
@@ -2406,6 +2406,9 @@
   partial_gc()->do_partial_collection();
 }
 
+ShenandoahUpdateHeapRefsSuperClosure::ShenandoahUpdateHeapRefsSuperClosure() :
+  _heap(ShenandoahHeap::heap()) {}
+
 template<class T>
 class ShenandoahUpdateHeapRefsTask : public AbstractGangTask {
 private:
diff --git a/src/share/vm/gc/shenandoah/shenandoahOopClosures.hpp b/src/share/vm/gc/shenandoah/shenandoahOopClosures.hpp
--- a/src/share/vm/gc/shenandoah/shenandoahOopClosures.hpp
+++ b/src/share/vm/gc/shenandoah/shenandoahOopClosures.hpp
@@ -169,8 +169,7 @@
 private:
   ShenandoahHeap* _heap;
 public:
-  ShenandoahUpdateHeapRefsSuperClosure() :
-    _heap(ShenandoahHeap::heap()) {}
+  ShenandoahUpdateHeapRefsSuperClosure();
 
   template <class T, bool UPDATE_MATRIX>
   void work(T *p);
diff --git a/src/share/vm/runtime/objectMonitor.cpp b/src/share/vm/runtime/objectMonitor.cpp
--- a/src/share/vm/runtime/objectMonitor.cpp
+++ b/src/share/vm/runtime/objectMonitor.cpp
@@ -2444,10 +2444,6 @@
             "Fatal error(s) found in ObjectMonitor::sanity_checks()");
 }
 
-void* ObjectMonitor::cas_set_object(void* obj, void* expected) {
-  return Atomic::cmpxchg_ptr(obj, (volatile void*)&_object, expected);
-}
-
 #ifndef PRODUCT
 void ObjectMonitor::verify() {
 }
diff --git a/src/share/vm/runtime/objectMonitor.hpp b/src/share/vm/runtime/objectMonitor.hpp
--- a/src/share/vm/runtime/objectMonitor.hpp
+++ b/src/share/vm/runtime/objectMonitor.hpp
@@ -307,7 +307,6 @@
   void*     object() const;
   void*     object_addr();
   void      set_object(void* obj);
-  void*     cas_set_object(void* obj, void* expected_obj);
 
   bool      check(TRAPS);       // true if the thread owns the monitor.
   void      check_slow(TRAPS);
diff --git a/src/share/vm/runtime/synchronizer.cpp b/src/share/vm/runtime/synchronizer.cpp
--- a/src/share/vm/runtime/synchronizer.cpp
+++ b/src/share/vm/runtime/synchronizer.cpp
@@ -130,7 +130,6 @@
                                        const ObjectSynchronizer::InflateCause);
 
 #define CHAINMARKER   (cast_to_oop<intptr_t>(-1))
-#define CLAIMEDMARKER (cast_to_oop<intptr_t>(-2))
 
 
 // =====================> Quick functions
@@ -1948,17 +1947,15 @@
 
   while (true) {
     if (my_cur == NULL) return NULL;
-
-    if (my_cur->object() == CHAINMARKER) {
-      if (my_cur->cas_set_object(CLAIMEDMARKER, CHAINMARKER) == CHAINMARKER) {
-        return (void*)my_cur;
-      }
+    next_block =  (PaddedEnd<ObjectMonitor> *)next(my_cur);
+    void* cas_result = Atomic::cmpxchg_ptr(next_block, &_cur, my_cur);
+    if (my_cur == cas_result) {
+      // We succeeded.
+      return (void*) my_cur;
     } else {
-      assert(my_cur->object() == CLAIMEDMARKER, "Must be");
+      // We failed. Retry with offending CAS result.
+      my_cur = (PaddedEnd<ObjectMonitor>*) cas_result;
     }
-
-    next_block =  (PaddedEnd<ObjectMonitor> *)next(my_cur);
-    my_cur = (PaddedEnd<ObjectMonitor> *)Atomic::cmpxchg_ptr(next_block, &_cur, my_cur);
   }
 }
 
@@ -1975,4 +1972,4 @@
     return true;
   }
   return false;
-}
\ No newline at end of file
+}