duke@435: /*
ysr@2194:  * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
stefank@2314: #include "precompiled.hpp"
stefank@2314: #include "gc_implementation/shared/cSpaceCounters.hpp"
stefank@2314: #include "gc_implementation/shared/vmGCOperations.hpp"
stefank@2314: #include "gc_interface/collectedHeap.inline.hpp"
stefank@2314: #include "memory/blockOffsetTable.inline.hpp"
stefank@2314: #include "memory/compactPermGen.hpp"
stefank@2314: #include "memory/gcLocker.hpp"
stefank@2314: #include "memory/gcLocker.inline.hpp"
stefank@2314: #include "memory/genCollectedHeap.hpp"
stefank@2314: #include "memory/generation.inline.hpp"
stefank@2314: #include "memory/permGen.hpp"
stefank@2314: #include "memory/universe.hpp"
stefank@2314: #include "oops/oop.inline.hpp"
stefank@2314: #include "runtime/java.hpp"
stefank@2314: #include "runtime/vmThread.hpp"
duke@435: 
ysr@2194: HeapWord* PermGen::request_expand_and_allocate(Generation* gen, size_t size,
ysr@2194:                                                GCCause::Cause prev_cause) {
ysr@2194:   if (gen->capacity() < _capacity_expansion_limit ||
ysr@2194:       prev_cause != GCCause::_no_gc || UseG1GC) {  // last disjunct is a temporary hack for G1
ysr@2194:     return gen->expand_and_allocate(size, false);
ysr@2194:   }
ysr@2194:   // We have reached the limit of capacity expansion where
ysr@2194:   // we will not expand further until a GC is done; request denied.
ysr@2194:   return NULL;
ysr@2194: }
ysr@2194: 
apetrusenko@574: HeapWord* PermGen::mem_allocate_in_gen(size_t size, Generation* gen) {
apetrusenko@574:   GCCause::Cause next_cause = GCCause::_permanent_generation_full;
apetrusenko@574:   GCCause::Cause prev_cause = GCCause::_no_gc;
ysr@915:   unsigned int gc_count_before, full_gc_count_before;
ysr@915:   HeapWord* obj;
apetrusenko@574: 
apetrusenko@574:   for (;;) {
ysr@915:     {
ysr@915:       MutexLocker ml(Heap_lock);
ysr@915:       if ((obj = gen->allocate(size, false)) != NULL) {
ysr@915:         return obj;
ysr@915:       }
ysr@2194:       // Attempt to expand and allocate the requested space:
ysr@2194:       // specific subtypes may use specific policy to either expand
ysr@2194:       // or not. The default policy (see above) is to expand until
ysr@2194:       // _capacity_expansion_limit, and no further unless a GC is done.
ysr@2194:       // Concurrent collectors may decide to kick off a concurrent
ysr@2194:       // collection under appropriate conditions.
ysr@2194:       obj = request_expand_and_allocate(gen, size, prev_cause);
ysr@2194: 
ysr@915:       if (obj != NULL || prev_cause == GCCause::_last_ditch_collection) {
ysr@915:         return obj;
ysr@915:       }
apetrusenko@574:       if (GC_locker::is_active_and_needs_gc()) {
apetrusenko@574:         // If this thread is not in a jni critical section, we stall
apetrusenko@574:         // the requestor until the critical section has cleared and
apetrusenko@574:         // GC allowed. When the critical section clears, a GC is
apetrusenko@574:         // initiated by the last thread exiting the critical section; so
apetrusenko@574:         // we retry the allocation sequence from the beginning of the loop,
apetrusenko@574:         // rather than causing more, now probably unnecessary, GC attempts.
apetrusenko@574:         JavaThread* jthr = JavaThread::current();
apetrusenko@574:         if (!jthr->in_critical()) {
apetrusenko@574:           MutexUnlocker mul(Heap_lock);
apetrusenko@574:           // Wait for JNI critical section to be exited
apetrusenko@574:           GC_locker::stall_until_clear();
apetrusenko@574:           continue;
apetrusenko@574:         } else {
apetrusenko@574:           if (CheckJNICalls) {
apetrusenko@574:             fatal("Possible deadlock due to allocating while"
apetrusenko@574:                   " in jni critical section");
apetrusenko@574:           }
apetrusenko@574:           return NULL;
apetrusenko@574:         }
apetrusenko@574:       }
ysr@915:       // Read the GC count while holding the Heap_lock
ysr@915:       gc_count_before      = SharedHeap::heap()->total_collections();
ysr@915:       full_gc_count_before = SharedHeap::heap()->total_full_collections();
ysr@915:     }
apetrusenko@574: 
ysr@915:     // Give up heap lock above, VMThread::execute below gets it back
ysr@915:     VM_GenCollectForPermanentAllocation op(size, gc_count_before, full_gc_count_before,
ysr@915:                                            next_cause);
ysr@915:     VMThread::execute(&op);
ysr@915:     if (!op.prologue_succeeded() || op.gc_locked()) {
ysr@915:       assert(op.result() == NULL, "must be NULL if gc_locked() is true");
ysr@915:       continue;  // retry and/or stall as necessary
ysr@915:     }
ysr@915:     obj = op.result();
ysr@915:     assert(obj == NULL || SharedHeap::heap()->is_in_reserved(obj),
ysr@915:            "result not in heap");
ysr@915:     if (obj != NULL) {
apetrusenko@574:       return obj;
apetrusenko@574:     }
ysr@915:     prev_cause = next_cause;
ysr@915:     next_cause = GCCause::_last_ditch_collection;
apetrusenko@574:   }
apetrusenko@574: }
apetrusenko@574: 
duke@435: CompactingPermGen::CompactingPermGen(ReservedSpace rs,
duke@435:                                      ReservedSpace shared_rs,
duke@435:                                      size_t initial_byte_size,
duke@435:                                      GenRemSet* remset,
duke@435:                                      PermanentGenerationSpec* perm_spec)
duke@435: {
duke@435:   CompactingPermGenGen* g =
duke@435:     new CompactingPermGenGen(rs, shared_rs, initial_byte_size, -1, remset,
duke@435:                              NULL, perm_spec);
duke@435:   if (g == NULL)
duke@435:     vm_exit_during_initialization("Could not allocate a CompactingPermGen");
duke@435:   _gen = g;
duke@435: 
duke@435:   g->initialize_performance_counters();
duke@435: 
duke@435:   _capacity_expansion_limit = g->capacity() + MaxPermHeapExpansion;
duke@435: }
duke@435: 
duke@435: HeapWord* CompactingPermGen::mem_allocate(size_t size) {
apetrusenko@574:   return mem_allocate_in_gen(size, _gen);
duke@435: }
duke@435: 
duke@435: void CompactingPermGen::compute_new_size() {
duke@435:   size_t desired_capacity = align_size_up(_gen->used(), MinPermHeapExpansion);
duke@435:   if (desired_capacity < PermSize) {
duke@435:     desired_capacity = PermSize;
duke@435:   }
duke@435:   if (_gen->capacity() > desired_capacity) {
duke@435:     _gen->shrink(_gen->capacity() - desired_capacity);
duke@435:   }
ysr@2194:   set_capacity_expansion_limit(_gen->capacity() + MaxPermHeapExpansion);
duke@435: }