src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/gc/z/ZPageTable.java

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2019, 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
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.

@@ -22,10 +22,12 @@
  *
  */
 
 package sun.jvm.hotspot.gc.z;
 
+import java.util.Iterator;
+
 import sun.jvm.hotspot.debugger.Address;
 import sun.jvm.hotspot.runtime.VM;
 import sun.jvm.hotspot.runtime.VMObject;
 import sun.jvm.hotspot.runtime.VMObjectFactory;
 import sun.jvm.hotspot.types.Type;

@@ -61,6 +63,114 @@
     }
 
     boolean is_relocating(Address o) {
         return getEntry(o).relocating();
     }
+
+    private class ZPagesIterator implements Iterator<ZPage> {
+        private ZAddressRangeMapForPageTable.Iterator mapIter;
+        private ZPage next;
+
+        ZPagesIterator() {
+            mapIter = map().new Iterator();
+            positionToNext();
+        }
+
+        private ZPage positionToNext() {
+            ZPage current = next;
+
+            // Find next
+            ZPage found = null;
+            while (mapIter.hasNext()) {
+                ZPageTableEntry entry = new ZPageTableEntry(mapIter.next());
+                if (!entry.isEmpty()) {
+                    ZPage page = entry.page();
+                    // Medium pages have repeated entries for all covered slots,
+                    // therefore we need to compare against the current page.
+                    if (page != null && !page.equals(current)) {
+                        found = page;
+                        break;
+                    }
+                }
+            }
+
+            next = found;
+
+            return current;
+        }
+
+        @Override
+        public boolean hasNext() {
+            return next != null;
+        }
+
+        @Override
+        public ZPage next() {
+            return positionToNext();
+        }
+
+        @Override
+        public void remove() {
+            /* not supported */
+        }
+    }
+
+    abstract class ZPageFilter {
+        public abstract boolean accept(ZPage page);
+    }
+
+    class ZPagesFilteredIterator implements Iterator<ZPage> {
+        private ZPage next;
+        private ZPagesIterator iter = new ZPagesIterator();
+        private ZPageFilter filter;
+
+        ZPagesFilteredIterator(ZPageFilter filter) {
+            this.filter = filter;
+            positionToNext();
+        }
+
+        public ZPage positionToNext() {
+            ZPage current = next;
+
+            // Find next
+            ZPage found = null;
+            while (iter.hasNext()) {
+                ZPage page = iter.next();
+                if (filter.accept(page)) {
+                    found = page;
+                    break;
+                }
+            }
+
+            next = found;
+
+            return current;
+        }
+
+        @Override
+        public boolean hasNext() {
+            return next != null;
+        }
+
+        @Override
+        public ZPage next() {
+            return positionToNext();
+        }
+
+        @Override
+        public void remove() {
+            /* not supported */
+        }
+    }
+
+    public Iterator<ZPage> iterator() {
+        return new ZPagesIterator();
+    }
+
+    public Iterator<ZPage> activePagesIterator() {
+        return new ZPagesFilteredIterator(new ZPageFilter() {
+            public boolean accept(ZPage page) {
+                return page.is_active();
+            }
+        });
+    }
 }