1 /*

     2  * Copyright 2001-2007 Sun Microsystems, 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  *

    23  */

    24 

    25 class AdjoiningGenerations;

    26 class GCTaskManager;

    27 class PSAdaptiveSizePolicy;

    28 

    29 class ParallelScavengeHeap : public CollectedHeap {

    30   friend class VMStructs;

    31  private:

    32   static PSYoungGen* _young_gen;

    33   static PSOldGen*   _old_gen;

    34   static PSPermGen*  _perm_gen;

    35 

    36   // Sizing policy for entire heap

    37   static PSAdaptiveSizePolicy* _size_policy;

    38   static PSGCAdaptivePolicyCounters*   _gc_policy_counters;

    39 

    40   static ParallelScavengeHeap* _psh;

    41 

    42   size_t _perm_gen_alignment;

    43   size_t _young_gen_alignment;

    44   size_t _old_gen_alignment;

    45 

    46   inline size_t set_alignment(size_t& var, size_t val);

    47 

    48   // Collection of generations that are adjacent in the

    49   // space reserved for the heap.

    50   AdjoiningGenerations* _gens;

    51 

    52   static GCTaskManager*          _gc_task_manager;      // The task manager.

    53 

    54  protected:

    55   static inline size_t total_invocations();

    56   HeapWord* allocate_new_tlab(size_t size);

    57   void fill_all_tlabs(bool retire);

    58 

    59  public:

    60   ParallelScavengeHeap() : CollectedHeap() {

    61     set_alignment(_perm_gen_alignment, intra_generation_alignment());

    62     set_alignment(_young_gen_alignment, intra_generation_alignment());

    63     set_alignment(_old_gen_alignment, intra_generation_alignment());

    64   }

    65 

    66   // For use by VM operations

    67   enum CollectionType {

    68     Scavenge,

    69     MarkSweep

    70   };

    71 

    72   ParallelScavengeHeap::Name kind() const {

    73     return CollectedHeap::ParallelScavengeHeap;

    74   }

    75 

    76   static PSYoungGen* young_gen()     { return _young_gen; }

    77   static PSOldGen* old_gen()         { return _old_gen; }

    78   static PSPermGen* perm_gen()       { return _perm_gen; }

    79 

    80   virtual PSAdaptiveSizePolicy* size_policy() { return _size_policy; }

    81 

    82   static PSGCAdaptivePolicyCounters* gc_policy_counters() { return _gc_policy_counters; }

    83 

    84   static ParallelScavengeHeap* heap();

    85 

    86   static GCTaskManager* const gc_task_manager() { return _gc_task_manager; }

    87 

    88   AdjoiningGenerations* gens() { return _gens; }

    89 

    90   // Returns JNI_OK on success

    91   virtual jint initialize();

    92 

    93   void post_initialize();

    94   void update_counters();

    95 

    96   // The alignment used for the various generations.

    97   size_t perm_gen_alignment()  const { return _perm_gen_alignment; }

    98   size_t young_gen_alignment() const { return _young_gen_alignment; }

    99   size_t old_gen_alignment()  const { return _old_gen_alignment; }

   100 

   101   // The alignment used for eden and survivors within the young gen.

   102   size_t intra_generation_alignment() const { return 64 * K; }

   103 

   104   size_t capacity() const;

   105   size_t used() const;

   106 

   107   // Return "true" if all generations (but perm) have reached the

   108   // maximal committed limit that they can reach, without a garbage

   109   // collection.

   110   virtual bool is_maximal_no_gc() const;

   111 

   112   // Does this heap support heap inspection? (+PrintClassHistogram)

   113   bool supports_heap_inspection() const { return true; }

   114 

   115   size_t permanent_capacity() const;

   116   size_t permanent_used() const;

   117 

   118   size_t max_capacity() const;

   119 

   120   // Whether p is in the allocated part of the heap

   121   bool is_in(const void* p) const;

   122 

   123   bool is_in_reserved(const void* p) const;

   124   bool is_in_permanent(const void *p) const {    // reserved part

   125     return perm_gen()->reserved().contains(p);

   126   }

   127 

   128   bool is_permanent(const void *p) const {    // committed part

   129     return perm_gen()->is_in(p);

   130   }

   131 

   132   static bool is_in_young(oop *p);        // reserved part

   133   static bool is_in_old_or_perm(oop *p);  // reserved part

   134 

   135   // Memory allocation.   "gc_time_limit_was_exceeded" will

   136   // be set to true if the adaptive size policy determine that

   137   // an excessive amount of time is being spent doing collections

   138   // and caused a NULL to be returned.  If a NULL is not returned,

   139   // "gc_time_limit_was_exceeded" has an undefined meaning.

   140 

   141   HeapWord* mem_allocate(size_t size,

   142                          bool is_noref,

   143                          bool is_tlab,

   144                          bool* gc_overhead_limit_was_exceeded);

   145   HeapWord* failed_mem_allocate(size_t size, bool is_tlab);

   146 

   147   HeapWord* permanent_mem_allocate(size_t size);

   148   HeapWord* failed_permanent_mem_allocate(size_t size);

   149 

   150   // Support for System.gc()

   151   void collect(GCCause::Cause cause);

   152 

   153   // This interface assumes that it's being called by the

   154   // vm thread. It collects the heap assuming that the

   155   // heap lock is already held and that we are executing in

   156   // the context of the vm thread.

   157   void collect_as_vm_thread(GCCause::Cause cause);

   158 

   159   // These also should be called by the vm thread at a safepoint (e.g., from a

   160   // VM operation).

   161   //

   162   // The first collects the young generation only, unless the scavenge fails; it

   163   // will then attempt a full gc.  The second collects the entire heap; if

   164   // maximum_compaction is true, it will compact everything and clear all soft

   165   // references.

   166   inline void invoke_scavenge();

   167   inline void invoke_full_gc(bool maximum_compaction);

   168 

   169   size_t large_typearray_limit() { return FastAllocateSizeLimit; }

   170 

   171   bool supports_inline_contig_alloc() const { return !UseNUMA; }

   172   HeapWord** top_addr() const { return !UseNUMA ? young_gen()->top_addr() : NULL; }

   173   HeapWord** end_addr() const { return !UseNUMA ? young_gen()->end_addr() : NULL; }

   174 

   175   void ensure_parsability(bool retire_tlabs);

   176   void accumulate_statistics_all_tlabs();

   177   void resize_all_tlabs();

   178 

   179   size_t unsafe_max_alloc();

   180 

   181   bool supports_tlab_allocation() const { return true; }

   182 

   183   size_t tlab_capacity(Thread* thr) const;

   184   size_t unsafe_max_tlab_alloc(Thread* thr) const;

   185 

   186   void oop_iterate(OopClosure* cl);

   187   void object_iterate(ObjectClosure* cl);

   188   void permanent_oop_iterate(OopClosure* cl);

   189   void permanent_object_iterate(ObjectClosure* cl);

   190 

   191   HeapWord* block_start(const void* addr) const;

   192   size_t block_size(const HeapWord* addr) const;

   193   bool block_is_obj(const HeapWord* addr) const;

   194 

   195   jlong millis_since_last_gc();

   196 

   197   void prepare_for_verify();

   198   void print() const;

   199   void print_on(outputStream* st) const;

   200   virtual void print_gc_threads_on(outputStream* st) const;

   201   virtual void gc_threads_do(ThreadClosure* tc) const;

   202   virtual void print_tracing_info() const;

   203 

   204   void verify(bool allow_dirty, bool silent);

   205 

   206   void print_heap_change(size_t prev_used);

   207 

   208   // Resize the young generation.  The reserved space for the

   209   // generation may be expanded in preparation for the resize.

   210   void resize_young_gen(size_t eden_size, size_t survivor_size);

   211 

   212   // Resize the old generation.  The reserved space for the

   213   // generation may be expanded in preparation for the resize.

   214   void resize_old_gen(size_t desired_free_space);

   215 };

   216 

   217 inline size_t ParallelScavengeHeap::set_alignment(size_t& var, size_t val)

   218 {

   219   assert(is_power_of_2((intptr_t)val), "must be a power of 2");

   220   var = round_to(val, intra_generation_alignment());

   221   return var;

   222 }