Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  *

  */

 #include "precompiled.hpp"

 #include "gc_implementation/shared/cSpaceCounters.hpp"

 #include "gc_implementation/shared/vmGCOperations.hpp"

 #include "gc_interface/collectedHeap.inline.hpp"

 #include "memory/blockOffsetTable.inline.hpp"

 #include "memory/compactPermGen.hpp"

 #include "memory/gcLocker.hpp"

 #include "memory/gcLocker.inline.hpp"

 #include "memory/genCollectedHeap.hpp"

 #include "memory/generation.inline.hpp"

 #include "memory/permGen.hpp"

 #include "memory/universe.hpp"

 #include "oops/oop.inline.hpp"

 #include "runtime/java.hpp"

 #include "runtime/vmThread.hpp"

 HeapWord* PermGen::request_expand_and_allocate(Generation* gen, size_t size,

                                                GCCause::Cause prev_cause) {

   if (gen->capacity() < _capacity_expansion_limit ||

       prev_cause != GCCause::_no_gc || UseG1GC) {  // last disjunct is a temporary hack for G1

     return gen->expand_and_allocate(size, false);

   }

   // We have reached the limit of capacity expansion where

   // we will not expand further until a GC is done; request denied.

   return NULL;

 }

 HeapWord* PermGen::mem_allocate_in_gen(size_t size, Generation* gen) {

   GCCause::Cause next_cause = GCCause::_permanent_generation_full;

   GCCause::Cause prev_cause = GCCause::_no_gc;

   unsigned int gc_count_before, full_gc_count_before;

   HeapWord* obj;

   for (;;) {

     {

       MutexLocker ml(Heap_lock);

       if ((obj = gen->allocate(size, false)) != NULL) {

         return obj;

       }

       // Attempt to expand and allocate the requested space:

       // specific subtypes may use specific policy to either expand

       // or not. The default policy (see above) is to expand until

       // _capacity_expansion_limit, and no further unless a GC is done.

       // Concurrent collectors may decide to kick off a concurrent

       // collection under appropriate conditions.

       obj = request_expand_and_allocate(gen, size, prev_cause);

       if (obj != NULL || prev_cause == GCCause::_last_ditch_collection) {

         return obj;

       }

       if (GC_locker::is_active_and_needs_gc()) {

         // If this thread is not in a jni critical section, we stall

         // the requestor until the critical section has cleared and

         // GC allowed. When the critical section clears, a GC is

         // initiated by the last thread exiting the critical section; so

         // we retry the allocation sequence from the beginning of the loop,

         // rather than causing more, now probably unnecessary, GC attempts.

         JavaThread* jthr = JavaThread::current();

         if (!jthr->in_critical()) {

           MutexUnlocker mul(Heap_lock);

           // Wait for JNI critical section to be exited

           GC_locker::stall_until_clear();

           continue;

         } else {

           if (CheckJNICalls) {

             fatal("Possible deadlock due to allocating while"

                   " in jni critical section");

           }

           return NULL;

         }

       }

       // Read the GC count while holding the Heap_lock

       gc_count_before      = SharedHeap::heap()->total_collections();

       full_gc_count_before = SharedHeap::heap()->total_full_collections();

     }

     // Give up heap lock above, VMThread::execute below gets it back

     VM_GenCollectForPermanentAllocation op(size, gc_count_before, full_gc_count_before,

                                            next_cause);

     VMThread::execute(&op);

     if (!op.prologue_succeeded() || op.gc_locked()) {

       assert(op.result() == NULL, "must be NULL if gc_locked() is true");

       continue;  // retry and/or stall as necessary

     }

     obj = op.result();

     assert(obj == NULL || SharedHeap::heap()->is_in_reserved(obj),

            "result not in heap");

     if (obj != NULL) {

       return obj;

     }

     prev_cause = next_cause;

     next_cause = GCCause::_last_ditch_collection;

   }

 }

 CompactingPermGen::CompactingPermGen(ReservedSpace rs,

                                      ReservedSpace shared_rs,

                                      size_t initial_byte_size,

                                      GenRemSet* remset,

                                      PermanentGenerationSpec* perm_spec)

 {

   CompactingPermGenGen* g =

     new CompactingPermGenGen(rs, shared_rs, initial_byte_size, -1, remset,

                              NULL, perm_spec);

   if (g == NULL)

     vm_exit_during_initialization("Could not allocate a CompactingPermGen");

   _gen = g;

   g->initialize_performance_counters();

   _capacity_expansion_limit = g->capacity() + MaxPermHeapExpansion;

 }

 HeapWord* CompactingPermGen::mem_allocate(size_t size) {

   return mem_allocate_in_gen(size, _gen);

 }

 void CompactingPermGen::compute_new_size() {

   size_t desired_capacity = align_size_up(_gen->used(), MinPermHeapExpansion);

   if (desired_capacity < PermSize) {

     desired_capacity = PermSize;

   }

   if (_gen->capacity() > desired_capacity) {

     _gen->shrink(_gen->capacity() - desired_capacity);

   }

   set_capacity_expansion_limit(_gen->capacity() + MaxPermHeapExpansion);

 }