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/zAddress.inline.hpp"
  26 #include "gc/z/zBarrier.inline.hpp"
  27 #include "gc/z/zHeap.hpp"
  28 #include "gc/z/zOopClosures.inline.hpp"
  29 #include "gc/z/zPage.hpp"
  30 #include "gc/z/zRelocate.hpp"
  31 #include "gc/z/zRelocationSet.inline.hpp"
  32 #include "gc/z/zRootsIterator.hpp"
  33 #include "gc/z/zTask.hpp"
  34 #include "gc/z/zWorkers.hpp"
  35 
  36 ZRelocate::ZRelocate(ZWorkers* workers) :
  37     _workers(workers) {}
  38 
  39 class ZRelocateRootsIteratorClosure : public ZRootsIteratorClosure {
  40 private:
  41   static void remap_address(HeapWord** p) {
  42     *p = (HeapWord*)ZAddress::good_or_null((uintptr_t)*p);
  43   }
  44 
  45 public:
  46   virtual void do_thread(Thread* thread) {
  47     ZRootsIteratorClosure::do_thread(thread);
  48 
  49     // Update thread local address bad mask
  50     ZThreadLocalData::set_address_bad_mask(thread, ZAddressBadMask);
  51 
  52     // Remap TLAB
  53     if (UseTLAB && thread->is_Java_thread()) {
  54       thread->tlab().addresses_do(remap_address);
  55     }
  56   }
  57 
  58   virtual void do_oop(oop* p) {
  59     ZBarrier::relocate_barrier_on_root_oop_field(p);
  60   }
  61 
  62   virtual void do_oop(narrowOop* p) {
  63     ShouldNotReachHere();
  64   }
  65 };
  66 
  67 class ZRelocateRootsTask : public ZTask {
  68 private:
  69   ZRootsIterator                _roots;
  70   ZRelocateRootsIteratorClosure _cl;
  71 
  72 public:
  73   ZRelocateRootsTask() :
  74       ZTask("ZRelocateRootsTask"),
  75       _roots() {}
  76 
  77   virtual void work() {
  78     // During relocation we need to visit the JVMTI
  79     // export weak roots to rehash the JVMTI tag map
  80     _roots.oops_do(&_cl, true /* visit_jvmti_weak_export */);
  81   }
  82 };
  83 
  84 void ZRelocate::start() {
  85   ZRelocateRootsTask task;
  86   _workers->run_parallel(&task);
  87 }
  88 
  89 class ZRelocateObjectClosure : public ObjectClosure {
  90 private:
  91   ZPage* const _page;
  92 
  93 public:
  94   ZRelocateObjectClosure(ZPage* page) :
  95       _page(page) {}
  96 
  97   virtual void do_object(oop o) {
  98     _page->relocate_object(ZOop::to_address(o));
  99   }
 100 };
 101 
 102 bool ZRelocate::work(ZRelocationSetParallelIterator* iter) {
 103   bool success = true;
 104 
 105   // Relocate pages in the relocation set
 106   for (ZPage* page; iter->next(&page);) {
 107     // Relocate objects in page
 108     ZRelocateObjectClosure cl(page);
 109     page->object_iterate(&cl);
 110 
 111     if (ZVerifyForwarding) {
 112       page->verify_forwarding();
 113     }
 114 
 115     if (page->is_pinned()) {
 116       // Relocation failed, page is now pinned
 117       success = false;
 118     } else {
 119       // Relocation succeeded, release page
 120       ZHeap::heap()->release_page(page, true /* reclaimed */);
 121     }
 122   }
 123 
 124   return success;
 125 }
 126 
 127 class ZRelocateTask : public ZTask {
 128 private:
 129   ZRelocate* const               _relocate;
 130   ZRelocationSetParallelIterator _iter;
 131   bool                           _failed;
 132 
 133 public:
 134   ZRelocateTask(ZRelocate* relocate, ZRelocationSet* relocation_set) :
 135       ZTask("ZRelocateTask"),
 136       _relocate(relocate),
 137       _iter(relocation_set),
 138       _failed(false) {}
 139 
 140   virtual void work() {
 141     if (!_relocate->work(&_iter)) {
 142       _failed = true;
 143     }
 144   }
 145 
 146   bool failed() const {
 147     return _failed;
 148   }
 149 };
 150 
 151 bool ZRelocate::relocate(ZRelocationSet* relocation_set) {
 152   ZRelocateTask task(this, relocation_set);
 153   _workers->run_concurrent(&task);
 154   return !task.failed();
 155 }