1 /*

     2  * Copyright (c) 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 #include "incls/_precompiled.incl"

    26 #include "incls/_cmsPermGen.cpp.incl"

    27 

    28 CMSPermGen::CMSPermGen(ReservedSpace rs, size_t initial_byte_size,

    29              CardTableRS* ct,

    30              FreeBlockDictionary::DictionaryChoice dictionaryChoice) {

    31   CMSPermGenGen* g =

    32     new CMSPermGenGen(rs, initial_byte_size, -1, ct);

    33   if (g == NULL) {

    34     vm_exit_during_initialization("Could not allocate a CompactingPermGen");

    35   }

    36 

    37   g->initialize_performance_counters();

    38 

    39   _gen = g;

    40 }

    41 

    42 HeapWord* CMSPermGen::mem_allocate(size_t size) {

    43   Mutex* lock = _gen->freelistLock();

    44   bool lock_owned = lock->owned_by_self();

    45   if (lock_owned) {

    46     MutexUnlocker mul(lock);

    47     return mem_allocate_work(size);

    48   } else {

    49     return mem_allocate_work(size);

    50   }

    51 }

    52 

    53 HeapWord* CMSPermGen::mem_allocate_work(size_t size) {

    54   assert(!_gen->freelistLock()->owned_by_self(), "Potetntial deadlock");

    55 

    56   MutexLocker ml(Heap_lock);

    57   HeapWord* obj = NULL;

    58 

    59   obj = _gen->allocate(size, false);

    60   // Since we want to minimize pause times, we will prefer

    61   // expanding the perm gen rather than doing a stop-world

    62   // collection to satisfy the allocation request.

    63   if (obj == NULL) {

    64     // Try to expand the perm gen and allocate space.

    65     obj = _gen->expand_and_allocate(size, false, false);

    66     if (obj == NULL) {

    67       // Let's see if a normal stop-world full collection will

    68       // free up enough space.

    69       SharedHeap::heap()->collect_locked(GCCause::_permanent_generation_full);

    70       obj = _gen->allocate(size, false);

    71       if (obj == NULL) {

    72         // The collection above may have shrunk the space, so try

    73         // to expand again and allocate space.

    74         obj = _gen->expand_and_allocate(size, false, false);

    75       }

    76       if (obj == NULL) {

    77         // We have not been able to allocate space despite a

    78         // full stop-world collection. We now make a last-ditch collection

    79         // attempt (in which soft refs are all aggressively freed)

    80         // that will try to reclaim as much space as possible.

    81         SharedHeap::heap()->collect_locked(GCCause::_last_ditch_collection);

    82         obj = _gen->allocate(size, false);

    83         if (obj == NULL) {

    84           // Expand generation in case it was shrunk following the collection.

    85           obj = _gen->expand_and_allocate(size, false, false);

    86         }

    87       }

    88     }

    89   }

    90   return obj;

    91 }

    92 

    93 void CMSPermGen::compute_new_size() {

    94   _gen->compute_new_size();

    95 }

    96 

    97 void CMSPermGenGen::initialize_performance_counters() {

    98 

    99   const char* gen_name = "perm";

   100 

   101   // Generation Counters - generation 2, 1 subspace

   102   _gen_counters = new GenerationCounters(gen_name, 2, 1, &_virtual_space);

   103 

   104   _gc_counters = NULL;

   105 

   106   _space_counters = new GSpaceCounters(gen_name, 0,

   107                                        _virtual_space.reserved_size(),

   108                                        this, _gen_counters);

   109 }