1 /*
   2  * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 #include "precompiled.hpp"
  25 #include "gc/z/zHeap.hpp"
  26 #include "gc/z/zOopClosures.inline.hpp"
  27 #include "gc/z/zPage.hpp"
  28 #include "gc/z/zRelocate.hpp"
  29 #include "gc/z/zRelocationSet.inline.hpp"
  30 #include "gc/z/zRootsIterator.hpp"
  31 #include "gc/z/zTask.hpp"
  32 #include "gc/z/zWorkers.hpp"
  33 
  34 ZRelocate::ZRelocate(ZWorkers* workers) :
  35     _workers(workers) {}
  36 
  37 class ZRelocateRootsIteratorClosure : public ZRootsIteratorClosure {
  38 public:
  39   virtual void do_thread(Thread* thread) {
  40     ZRootsIteratorClosure::do_thread(thread);
  41 
  42     // Update thread local address bad mask
  43     ZThreadLocalData::set_address_bad_mask(thread, ZAddressBadMask);
  44   }
  45 
  46   virtual void do_oop(oop* p) {
  47     ZBarrier::relocate_barrier_on_root_oop_field(p);
  48   }
  49 
  50   virtual void do_oop(narrowOop* p) {
  51     ShouldNotReachHere();
  52   }
  53 };
  54 
  55 class ZRelocateRootsTask : public ZTask {
  56 private:
  57   ZRootsIterator _roots;
  58 
  59 public:
  60   ZRelocateRootsTask() :
  61       ZTask("ZRelocateRootsTask"),
  62       _roots() {}
  63 
  64   virtual void work() {
  65     // During relocation we need to visit the JVMTI
  66     // export weak roots to rehash the JVMTI tag map
  67     ZRelocateRootsIteratorClosure cl;
  68     _roots.oops_do(&cl, true /* visit_jvmti_weak_export */);
  69   }
  70 };
  71 
  72 void ZRelocate::start() {
  73   ZRelocateRootsTask task;
  74   _workers->run_parallel(&task);
  75 }
  76 
  77 class ZRelocateObjectClosure : public ObjectClosure {
  78 private:
  79   ZPage* const _page;
  80 
  81 public:
  82   ZRelocateObjectClosure(ZPage* page) :
  83       _page(page) {}
  84 
  85   virtual void do_object(oop o) {
  86     _page->relocate_object(ZOop::to_address(o));
  87   }
  88 };
  89 
  90 bool ZRelocate::work(ZRelocationSetParallelIterator* iter) {
  91   bool success = true;
  92 
  93   // Relocate pages in the relocation set
  94   for (ZPage* page; iter->next(&page);) {
  95     // Relocate objects in page
  96     ZRelocateObjectClosure cl(page);
  97     page->object_iterate(&cl);
  98 
  99     if (ZVerifyForwarding) {
 100       page->verify_forwarding();
 101     }
 102 
 103     if (page->is_pinned()) {
 104       // Relocation failed, page is now pinned
 105       success = false;
 106     } else {
 107       // Relocation succeeded, release page
 108       ZHeap::heap()->release_page(page, true /* reclaimed */);
 109     }
 110   }
 111 
 112   return success;
 113 }
 114 
 115 class ZRelocateTask : public ZTask {
 116 private:
 117   ZRelocate* const               _relocate;
 118   ZRelocationSetParallelIterator _iter;
 119   bool                           _failed;
 120 
 121 public:
 122   ZRelocateTask(ZRelocate* relocate, ZRelocationSet* relocation_set) :
 123       ZTask("ZRelocateTask"),
 124       _relocate(relocate),
 125       _iter(relocation_set),
 126       _failed(false) {}
 127 
 128   virtual void work() {
 129     if (!_relocate->work(&_iter)) {
 130       _failed = true;
 131     }
 132   }
 133 
 134   bool failed() const {
 135     return _failed;
 136   }
 137 };
 138 
 139 bool ZRelocate::relocate(ZRelocationSet* relocation_set) {
 140   ZRelocateTask task(this, relocation_set);
 141   _workers->run_concurrent(&task);
 142   return !task.failed();
 143 }