1 /*
   2  * Copyright (c) 2017, 2019, Red Hat, Inc. All rights reserved.
   3  *
   4  * This code is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This code is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  11  * version 2 for more details (a copy is included in the LICENSE file that
  12  * accompanied this code).
  13  *
  14  * You should have received a copy of the GNU General Public License version
  15  * 2 along with this work; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  19  * or visit www.oracle.com if you need additional information or have any
  20  * questions.
  21  *
  22  */
  23 
  24 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHCODEROOTS_HPP
  25 #define SHARE_GC_SHENANDOAH_SHENANDOAHCODEROOTS_HPP
  26 
  27 #include "code/codeCache.hpp"
  28 #include "gc/shenandoah/shenandoahSharedVariables.hpp"
  29 #include "gc/shenandoah/shenandoahLock.hpp"
  30 #include "gc/shenandoah/shenandoahNMethod.hpp"
  31 #include "memory/allocation.hpp"
  32 #include "memory/iterator.hpp"
  33 
  34 class ShenandoahHeap;
  35 class ShenandoahHeapRegion;
  36 
  37 class ShenandoahParallelCodeHeapIterator {
  38   friend class CodeCache;
  39 private:
  40   CodeHeap*     _heap;
  41   DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile int));
  42   volatile int  _claimed_idx;
  43   volatile bool _finished;
  44   DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
  45 public:
  46   ShenandoahParallelCodeHeapIterator(CodeHeap* heap);
  47   void parallel_blobs_do(CodeBlobClosure* f);
  48 };
  49 
  50 class ShenandoahParallelCodeCacheIterator {
  51   friend class CodeCache;
  52 private:
  53   ShenandoahParallelCodeHeapIterator* _iters;
  54   int                       _length;
  55 
  56 private:
  57   // Noncopyable.
  58   ShenandoahParallelCodeCacheIterator(const ShenandoahParallelCodeCacheIterator& o);
  59   ShenandoahParallelCodeCacheIterator& operator=(const ShenandoahParallelCodeCacheIterator& o);
  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 prepare_concurrent_unloading();
 114   static int  disarmed_value() { return _disarmed_value; }
 115 private:
 116   static ShenandoahNMethodTable* _nmethod_table;
 117   static int                     _disarmed_value;
 118 };
 119 
 120 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHCODEROOTS_HPP