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_VM_GC_SHENANDOAH_SHENANDOAHCODEROOTS_HPP
  25 #define SHARE_VM_GC_SHENANDOAH_SHENANDOAHCODEROOTS_HPP
  26 
  27 #include "code/codeCache.hpp"
  28 #include "gc/shenandoah/shenandoahSharedVariables.hpp"
  29 #include "gc/shenandoah/shenandoahLock.hpp"
  30 #include "memory/allocation.hpp"
  31 #include "memory/iterator.hpp"
  32 
  33 class ShenandoahHeap;
  34 class ShenandoahHeapRegion;
  35 
  36 class ShenandoahParallelCodeHeapIterator {
  37   friend class CodeCache;
  38 private:
  39   CodeHeap*     _heap;
  40   DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile int));
  41   volatile int  _claimed_idx;
  42   volatile bool _finished;
  43   DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
  44 public:
  45   ShenandoahParallelCodeHeapIterator(CodeHeap* heap);
  46   void parallel_blobs_do(CodeBlobClosure* f);
  47 };
  48 
  49 class ShenandoahParallelCodeCacheIterator {
  50   friend class CodeCache;
  51 private:
  52   ShenandoahParallelCodeHeapIterator* _iters;
  53   int                       _length;
  54 
  55 private:
  56   // Noncopyable.
  57   ShenandoahParallelCodeCacheIterator(const ShenandoahParallelCodeCacheIterator& o);
  58   ShenandoahParallelCodeCacheIterator& operator=(const ShenandoahParallelCodeCacheIterator& o);
  59 public:
  60   ShenandoahParallelCodeCacheIterator(const GrowableArray<CodeHeap*>* heaps);
  61   ~ShenandoahParallelCodeCacheIterator();
  62   void parallel_blobs_do(CodeBlobClosure* f);
  63 };
  64 
  65 // ShenandoahNMethod tuple records the internal locations of oop slots within the nmethod.
  66 // This allows us to quickly scan the oops without doing the nmethod-internal scans, that
  67 // sometimes involves parsing the machine code. Note it does not record the oops themselves,
  68 // because it would then require handling these tuples as the new class of roots.
  69 class ShenandoahNMethod : public CHeapObj<mtGC> {
  70 private:
  71   nmethod* _nm;
  72   oop**    _oops;
  73   int      _oops_count;
  74 
  75 public:
  76   ShenandoahNMethod(nmethod *nm, GrowableArray<oop*>* oops);
  77   ~ShenandoahNMethod();
  78 
  79   nmethod* nm() {
  80     return _nm;
  81   }
  82 
  83   bool has_cset_oops(ShenandoahHeap* heap);
  84 
  85   void assert_alive_and_correct() NOT_DEBUG_RETURN;
  86   void assert_same_oops(GrowableArray<oop*>* oops) NOT_DEBUG_RETURN;
  87 
  88   static bool find_with_nmethod(void* nm, ShenandoahNMethod* other) {
  89     return other->_nm == nm;
  90   }
  91 };
  92 
  93 class ShenandoahCodeRootsIterator {
  94   friend class ShenandoahCodeRoots;
  95 protected:
  96   ShenandoahHeap* _heap;
  97   ShenandoahParallelCodeCacheIterator _par_iterator;
  98   ShenandoahSharedFlag _seq_claimed;
  99   DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
 100   volatile size_t _claimed;
 101   DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
 102 protected:
 103   ShenandoahCodeRootsIterator();
 104   ~ShenandoahCodeRootsIterator();
 105 
 106   template<bool CSET_FILTER>
 107   void dispatch_parallel_blobs_do(CodeBlobClosure *f);
 108 
 109   template<bool CSET_FILTER>
 110   void fast_parallel_blobs_do(CodeBlobClosure *f);
 111 };
 112 
 113 class ShenandoahAllCodeRootsIterator : public ShenandoahCodeRootsIterator {
 114 public:
 115   ShenandoahAllCodeRootsIterator() : ShenandoahCodeRootsIterator() {};
 116   void possibly_parallel_blobs_do(CodeBlobClosure *f);
 117 };
 118 
 119 class ShenandoahCsetCodeRootsIterator : public ShenandoahCodeRootsIterator {
 120 public:
 121   ShenandoahCsetCodeRootsIterator() : ShenandoahCodeRootsIterator() {};
 122   void possibly_parallel_blobs_do(CodeBlobClosure* f);
 123 };
 124 
 125 class ShenandoahCodeRoots : public AllStatic {
 126   friend class ShenandoahHeap;
 127   friend class ShenandoahCodeRootsIterator;
 128 
 129 public:
 130   static void initialize();
 131   static void add_nmethod(nmethod* nm);
 132   static void remove_nmethod(nmethod* nm);
 133 
 134 private:
 135   static GrowableArray<ShenandoahNMethod*>* _recorded_nms;
 136   static ShenandoahLock                     _recorded_nms_lock;
 137 };
 138 
 139 #endif //SHARE_VM_GC_SHENANDOAH_SHENANDOAHCODEROOTS_HPP