1 /*

     2  * Copyright (c) 2011, 2015, 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 

    25 #ifndef SHARE_VM_GC_G1_HEAPREGIONSET_HPP

    26 #define SHARE_VM_GC_G1_HEAPREGIONSET_HPP

    27 

    28 #include "gc/g1/heapRegion.hpp"

    29 

    30 #define assert_heap_region_set(p, message) \

    31   do {                                     \

    32     assert((p), "[%s] %s ln: %u",          \

    33            name(), message, length());     \

    34   } while (0)

    35 

    36 #define guarantee_heap_region_set(p, message) \

    37   do {                                        \

    38     guarantee((p), "[%s] %s ln: %u",          \

    39               name(), message, length());     \

    40   } while (0)

    41 

    42 #define assert_free_region_list(p, message)                          \

    43   do {                                                               \

    44     assert((p), "[%s] %s ln: %u hd: " PTR_FORMAT " tl: " PTR_FORMAT, \

    45            name(), message, length(), p2i(_head), p2i(_tail));       \

    46   } while (0)

    47 

    48 

    49 // Set verification will be forced either if someone defines

    50 // HEAP_REGION_SET_FORCE_VERIFY to be 1, or in builds in which

    51 // asserts are compiled in.

    52 #ifndef HEAP_REGION_SET_FORCE_VERIFY

    53 #define HEAP_REGION_SET_FORCE_VERIFY defined(ASSERT)

    54 #endif // HEAP_REGION_SET_FORCE_VERIFY

    55 

    56 class HRSMtSafeChecker : public CHeapObj<mtGC> {

    57 public:

    58   virtual void check() = 0;

    59 };

    60 

    61 class MasterFreeRegionListMtSafeChecker    : public HRSMtSafeChecker { public: void check(); };

    62 class SecondaryFreeRegionListMtSafeChecker : public HRSMtSafeChecker { public: void check(); };

    63 class HumongousRegionSetMtSafeChecker      : public HRSMtSafeChecker { public: void check(); };

    64 class OldRegionSetMtSafeChecker            : public HRSMtSafeChecker { public: void check(); };

    65 

    66 // Base class for all the classes that represent heap region sets. It

    67 // contains the basic attributes that each set needs to maintain

    68 // (e.g., length, region num, used bytes sum) plus any shared

    69 // functionality (e.g., verification).

    70 

    71 class HeapRegionSetBase VALUE_OBJ_CLASS_SPEC {

    72   friend class VMStructs;

    73 private:

    74   bool _is_humongous;

    75   bool _is_free;

    76   HRSMtSafeChecker* _mt_safety_checker;

    77 

    78 protected:

    79   // The number of regions in to the set.

    80   uint _length;

    81 

    82   const char* _name;

    83 

    84   bool _verify_in_progress;

    85 

    86   // verify_region() is used to ensure that the contents of a region

    87   // added to / removed from a set are consistent.

    88   void verify_region(HeapRegion* hr) PRODUCT_RETURN;

    89 

    90   // Indicates whether all regions in the set should be humongous or

    91   // not. Only used during verification.

    92   bool regions_humongous() { return _is_humongous; }

    93 

    94   // Indicates whether all regions in the set should be free or

    95   // not. Only used during verification.

    96   bool regions_free() { return _is_free; }

    97 

    98   void check_mt_safety() {

    99     if (_mt_safety_checker != NULL) {

   100       _mt_safety_checker->check();

   101     }

   102   }

   103 

   104   HeapRegionSetBase(const char* name, bool humongous, bool free, HRSMtSafeChecker* mt_safety_checker);

   105 

   106 public:

   107   const char* name() { return _name; }

   108 

   109   uint length() const { return _length; }

   110 

   111   bool is_empty() { return _length == 0; }

   112 

   113   // It updates the fields of the set to reflect hr being added to

   114   // the set and tags the region appropriately.

   115   inline void add(HeapRegion* hr);

   116 

   117   // It updates the fields of the set to reflect hr being removed

   118   // from the set and tags the region appropriately.

   119   inline void remove(HeapRegion* hr);

   120 

   121   virtual void verify();

   122   void verify_start();

   123   void verify_next_region(HeapRegion* hr);

   124   void verify_end();

   125 

   126 #if HEAP_REGION_SET_FORCE_VERIFY

   127   void verify_optional() {

   128     verify();

   129   }

   130 #else // HEAP_REGION_SET_FORCE_VERIFY

   131   void verify_optional() { }

   132 #endif // HEAP_REGION_SET_FORCE_VERIFY

   133 

   134   virtual void print_on(outputStream* out, bool print_contents = false);

   135 };

   136 

   137 #define hrs_assert_sets_match(_set1_, _set2_)                                  \

   138   do {                                                                         \

   139     assert(((_set1_)->regions_humongous() == (_set2_)->regions_humongous()) && \

   140            ((_set1_)->regions_free() == (_set2_)->regions_free()),             \

   141            "the contents of set %s and set %s should match",                   \

   142            (_set1_)->name(),                                                   \

   143            (_set2_)->name());                                                  \

   144   } while (0)

   145 

   146 // This class represents heap region sets whose members are not

   147 // explicitly tracked. It's helpful to group regions using such sets

   148 // so that we can reason about all the region groups in the heap using

   149 // the same interface (namely, the HeapRegionSetBase API).

   150 

   151 class HeapRegionSet : public HeapRegionSetBase {

   152 public:

   153   HeapRegionSet(const char* name, bool humongous, HRSMtSafeChecker* mt_safety_checker):

   154     HeapRegionSetBase(name, humongous, false /* free */, mt_safety_checker) { }

   155 

   156   void bulk_remove(const uint removed) {

   157     _length -= removed;

   158   }

   159 };

   160 

   161 // A set that links all the regions added to it in a doubly-linked

   162 // sorted list. We should try to avoid doing operations that iterate over

   163 // such lists in performance critical paths. Typically we should

   164 // add / remove one region at a time or concatenate two lists.

   165 

   166 class FreeRegionListIterator;

   167 

   168 class FreeRegionList : public HeapRegionSetBase {

   169   friend class FreeRegionListIterator;

   170 

   171 private:

   172   HeapRegion* _head;

   173   HeapRegion* _tail;

   174 

   175   // _last is used to keep track of where we added an element the last

   176   // time. It helps to improve performance when adding several ordered items in a row.

   177   HeapRegion* _last;

   178 

   179   static uint _unrealistically_long_length;

   180 

   181   inline HeapRegion* remove_from_head_impl();

   182   inline HeapRegion* remove_from_tail_impl();

   183 

   184 protected:

   185   // See the comment for HeapRegionSetBase::clear()

   186   virtual void clear();

   187 

   188 public:

   189   FreeRegionList(const char* name, HRSMtSafeChecker* mt_safety_checker = NULL):

   190     HeapRegionSetBase(name, false /* humongous */, true /* empty */, mt_safety_checker) {

   191     clear();

   192   }

   193 

   194   void verify_list();

   195 

   196 #ifdef ASSERT

   197   bool contains(HeapRegion* hr) const {

   198     return hr->containing_set() == this;

   199   }

   200 #endif

   201 

   202   static void set_unrealistically_long_length(uint len);

   203 

   204   // Add hr to the list. The region should not be a member of another set.

   205   // Assumes that the list is ordered and will preserve that order. The order

   206   // is determined by hrm_index.

   207   inline void add_ordered(HeapRegion* hr);

   208 

   209   // Removes from head or tail based on the given argument.

   210   HeapRegion* remove_region(bool from_head);

   211 

   212   // Merge two ordered lists. The result is also ordered. The order is

   213   // determined by hrm_index.

   214   void add_ordered(FreeRegionList* from_list);

   215 

   216   // It empties the list by removing all regions from it.

   217   void remove_all();

   218 

   219   // Remove all (contiguous) regions from first to first + num_regions -1 from

   220   // this list.

   221   // Num_regions must be > 1.

   222   void remove_starting_at(HeapRegion* first, uint num_regions);

   223 

   224   virtual void verify();

   225 };

   226 

   227 // Iterator class that provides a convenient way to iterate over the

   228 // regions of a FreeRegionList.

   229 

   230 class FreeRegionListIterator : public StackObj {

   231 private:

   232   FreeRegionList* _list;

   233   HeapRegion*     _curr;

   234 

   235 public:

   236   bool more_available() {

   237     return _curr != NULL;

   238   }

   239 

   240   HeapRegion* get_next() {

   241     assert(more_available(),

   242            "get_next() should be called when more regions are available");

   243 

   244     // If we are going to introduce a count in the iterator we should

   245     // do the "cycle" check.

   246 

   247     HeapRegion* hr = _curr;

   248     _list->verify_region(hr);

   249     _curr = hr->next();

   250     return hr;

   251   }

   252 

   253   FreeRegionListIterator(FreeRegionList* list) : _curr(NULL), _list(list) {

   254     _curr = list->_head;

   255   }

   256 };

   257 

   258 #endif // SHARE_VM_GC_G1_HEAPREGIONSET_HPP