src/share/vm/gc_implementation/concurrentMarkSweep/cmsPermGen.cpp

Sat, 01 Dec 2007 00:00:00 +0000

author
duke
date
Sat, 01 Dec 2007 00:00:00 +0000
changeset 435
a61af66fc99e
child 574
c0492d52d55b
permissions
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     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  */
    25 #include "incls/_precompiled.incl"
    26 #include "incls/_cmsPermGen.cpp.incl"
    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   }
    37   g->initialize_performance_counters();
    39   _gen = g;
    40 }
    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 }
    53 HeapWord* CMSPermGen::mem_allocate_work(size_t size) {
    54   assert(!_gen->freelistLock()->owned_by_self(), "Potetntial deadlock");
    56   MutexLocker ml(Heap_lock);
    57   HeapWord* obj = NULL;
    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 }
    93 void CMSPermGen::compute_new_size() {
    94   _gen->compute_new_size();
    95 }
    97 void CMSPermGenGen::initialize_performance_counters() {
    99   const char* gen_name = "perm";
   101   // Generation Counters - generation 2, 1 subspace
   102   _gen_counters = new GenerationCounters(gen_name, 2, 1, &_virtual_space);
   104   _gc_counters = NULL;
   106   _space_counters = new GSpaceCounters(gen_name, 0,
   107                                        _virtual_space.reserved_size(),
   108                                        this, _gen_counters);
   109 }

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