1 /*
   2  * Copyright (c) 2017, 2020, Red Hat, Inc. 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 
  25 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHCODEROOTS_HPP
  26 #define SHARE_GC_SHENANDOAH_SHENANDOAHCODEROOTS_HPP
  27 
  28 #include "code/codeCache.hpp"
  29 #include "gc/shenandoah/shenandoahSharedVariables.hpp"
  30 #include "gc/shenandoah/shenandoahLock.hpp"
  31 #include "gc/shenandoah/shenandoahNMethod.hpp"
  32 #include "memory/allocation.hpp"
  33 #include "memory/iterator.hpp"
  34 #include "utilities/globalDefinitions.hpp"
  35 
  36 class ShenandoahHeap;
  37 class ShenandoahHeapRegion;
  38 
  39 class ShenandoahParallelCodeHeapIterator {
  40   friend class CodeCache;
  41 private:
  42   CodeHeap*     _heap;
  43   DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile int));
  44   volatile int  _claimed_idx;
  45   volatile bool _finished;
  46   DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
  47 public:
  48   ShenandoahParallelCodeHeapIterator(CodeHeap* heap);
  49   void parallel_blobs_do(CodeBlobClosure* f);
  50 };
  51 
  52 class ShenandoahParallelCodeCacheIterator {
  53   friend class CodeCache;
  54 private:
  55   ShenandoahParallelCodeHeapIterator* _iters;
  56   int                       _length;
  57 
  58   NONCOPYABLE(ShenandoahParallelCodeCacheIterator);
  59 
  60 public:
  61   ShenandoahParallelCodeCacheIterator(const GrowableArray<CodeHeap*>* heaps);
  62   ~ShenandoahParallelCodeCacheIterator();
  63   void parallel_blobs_do(CodeBlobClosure* f);
  64 };
  65 
  66 class ShenandoahCodeRootsIterator {
  67   friend class ShenandoahCodeRoots;
  68 protected:
  69   ShenandoahParallelCodeCacheIterator _par_iterator;
  70   ShenandoahSharedFlag _seq_claimed;
  71   ShenandoahNMethodTableSnapshot* _table_snapshot;
  72 
  73 protected:
  74   ShenandoahCodeRootsIterator();
  75   ~ShenandoahCodeRootsIterator();
  76 
  77   template<bool CSET_FILTER>
  78   void dispatch_parallel_blobs_do(CodeBlobClosure *f);
  79 
  80   template<bool CSET_FILTER>
  81   void fast_parallel_blobs_do(CodeBlobClosure *f);
  82 };
  83 
  84 class ShenandoahAllCodeRootsIterator : public ShenandoahCodeRootsIterator {
  85 public:
  86   ShenandoahAllCodeRootsIterator() : ShenandoahCodeRootsIterator() {};
  87   void possibly_parallel_blobs_do(CodeBlobClosure *f);
  88 };
  89 
  90 class ShenandoahCsetCodeRootsIterator : public ShenandoahCodeRootsIterator {
  91 public:
  92   ShenandoahCsetCodeRootsIterator() : ShenandoahCodeRootsIterator() {};
  93   void possibly_parallel_blobs_do(CodeBlobClosure* f);
  94 };
  95 
  96 class ShenandoahCodeRoots : public AllStatic {
  97   friend class ShenandoahHeap;
  98   friend class ShenandoahCodeRootsIterator;
  99 
 100 public:
 101   static void initialize();
 102   static void register_nmethod(nmethod* nm);
 103   static void unregister_nmethod(nmethod* nm);
 104   static void flush_nmethod(nmethod* nm);
 105 
 106   static ShenandoahNMethodTable* table() {
 107     return _nmethod_table;
 108   }
 109 
 110   // Concurrent nmethod unloading support
 111   static void unlink(WorkGang* workers, bool unloading_occurred);
 112   static void purge(WorkGang* workers);
 113   static void arm_nmethods();
 114   static void disarm_nmethods();
 115   static int  disarmed_value()         { return _disarmed_value; }
 116   static int* disarmed_value_address() { return &_disarmed_value; }
 117 
 118 private:
 119   static ShenandoahNMethodTable* _nmethod_table;
 120   static int                     _disarmed_value;
 121 };
 122 
 123 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHCODEROOTS_HPP