src/hotspot/share/gc/z/zRelocate.cpp
changeset 50525 767cdb97f103
child 51803 a16777c0a6c5
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/z/zRelocate.cpp	Tue Jun 12 17:40:28 2018 +0200
@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2015, 2017, 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.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#include "precompiled.hpp"
+#include "gc/z/zHeap.hpp"
+#include "gc/z/zOopClosures.inline.hpp"
+#include "gc/z/zPage.hpp"
+#include "gc/z/zRelocate.hpp"
+#include "gc/z/zRelocationSet.inline.hpp"
+#include "gc/z/zRootsIterator.hpp"
+#include "gc/z/zTask.hpp"
+#include "gc/z/zWorkers.hpp"
+
+ZRelocate::ZRelocate(ZWorkers* workers) :
+    _workers(workers) {}
+
+class ZRelocateRootsTask : public ZTask {
+private:
+  ZRootsIterator _roots;
+
+public:
+  ZRelocateRootsTask() :
+      ZTask("ZRelocateRootsTask"),
+      _roots() {}
+
+  virtual void work() {
+    // During relocation we need to visit the JVMTI
+    // export weak roots to rehash the JVMTI tag map
+    ZRelocateRootOopClosure cl;
+    _roots.oops_do(&cl, true /* visit_jvmti_weak_export */);
+  }
+};
+
+void ZRelocate::start() {
+  ZRelocateRootsTask task;
+  _workers->run_parallel(&task);
+}
+
+class ZRelocateObjectClosure : public ObjectClosure {
+private:
+  ZPage* const _page;
+
+public:
+  ZRelocateObjectClosure(ZPage* page) :
+      _page(page) {}
+
+  virtual void do_object(oop o) {
+    _page->relocate_object(ZOop::to_address(o));
+  }
+};
+
+bool ZRelocate::work(ZRelocationSetParallelIterator* iter) {
+  bool success = true;
+
+  // Relocate pages in the relocation set
+  for (ZPage* page; iter->next(&page);) {
+    // Relocate objects in page
+    ZRelocateObjectClosure cl(page);
+    page->object_iterate(&cl);
+
+    if (ZVerifyForwarding) {
+      page->verify_forwarding();
+    }
+
+    if (page->is_pinned()) {
+      // Relocation failed, page is now pinned
+      success = false;
+    } else {
+      // Relocation succeeded, release page
+      ZHeap::heap()->release_page(page, true /* reclaimed */);
+    }
+  }
+
+  return success;
+}
+
+class ZRelocateTask : public ZTask {
+private:
+  ZRelocate* const               _relocate;
+  ZRelocationSetParallelIterator _iter;
+  bool                           _failed;
+
+public:
+  ZRelocateTask(ZRelocate* relocate, ZRelocationSet* relocation_set) :
+      ZTask("ZRelocateTask"),
+      _relocate(relocate),
+      _iter(relocation_set),
+      _failed(false) {}
+
+  virtual void work() {
+    if (!_relocate->work(&_iter)) {
+      _failed = true;
+    }
+  }
+
+  bool failed() const {
+    return _failed;
+  }
+};
+
+bool ZRelocate::relocate(ZRelocationSet* relocation_set) {
+  ZRelocateTask task(this, relocation_set);
+  _workers->run_concurrent(&task);
+  return !task.failed();
+}