duke@435: /*
xdono@631:  * Copyright 2001-2008 Sun Microsystems, Inc.  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:  *
duke@435:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435:  * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435:  * have any questions.
duke@435:  *
duke@435:  */
duke@435: 
duke@435: # include "incls/_precompiled.incl"
duke@435: # include "incls/_parallelScavengeHeap.cpp.incl"
duke@435: 
duke@435: PSYoungGen*  ParallelScavengeHeap::_young_gen = NULL;
duke@435: PSOldGen*    ParallelScavengeHeap::_old_gen = NULL;
duke@435: PSPermGen*   ParallelScavengeHeap::_perm_gen = NULL;
duke@435: PSAdaptiveSizePolicy* ParallelScavengeHeap::_size_policy = NULL;
duke@435: PSGCAdaptivePolicyCounters* ParallelScavengeHeap::_gc_policy_counters = NULL;
duke@435: ParallelScavengeHeap* ParallelScavengeHeap::_psh = NULL;
duke@435: GCTaskManager* ParallelScavengeHeap::_gc_task_manager = NULL;
duke@435: 
duke@435: static void trace_gen_sizes(const char* const str,
duke@435:                             size_t pg_min, size_t pg_max,
duke@435:                             size_t og_min, size_t og_max,
duke@435:                             size_t yg_min, size_t yg_max)
duke@435: {
duke@435:   if (TracePageSizes) {
duke@435:     tty->print_cr("%s:  " SIZE_FORMAT "," SIZE_FORMAT " "
duke@435:                   SIZE_FORMAT "," SIZE_FORMAT " "
duke@435:                   SIZE_FORMAT "," SIZE_FORMAT " "
duke@435:                   SIZE_FORMAT,
duke@435:                   str, pg_min / K, pg_max / K,
duke@435:                   og_min / K, og_max / K,
duke@435:                   yg_min / K, yg_max / K,
duke@435:                   (pg_max + og_max + yg_max) / K);
duke@435:   }
duke@435: }
duke@435: 
duke@435: jint ParallelScavengeHeap::initialize() {
duke@435:   // Cannot be initialized until after the flags are parsed
duke@435:   GenerationSizer flag_parser;
duke@435: 
duke@435:   size_t yg_min_size = flag_parser.min_young_gen_size();
duke@435:   size_t yg_max_size = flag_parser.max_young_gen_size();
duke@435:   size_t og_min_size = flag_parser.min_old_gen_size();
duke@435:   size_t og_max_size = flag_parser.max_old_gen_size();
duke@435:   // Why isn't there a min_perm_gen_size()?
duke@435:   size_t pg_min_size = flag_parser.perm_gen_size();
duke@435:   size_t pg_max_size = flag_parser.max_perm_gen_size();
duke@435: 
duke@435:   trace_gen_sizes("ps heap raw",
duke@435:                   pg_min_size, pg_max_size,
duke@435:                   og_min_size, og_max_size,
duke@435:                   yg_min_size, yg_max_size);
duke@435: 
duke@435:   // The ReservedSpace ctor used below requires that the page size for the perm
duke@435:   // gen is <= the page size for the rest of the heap (young + old gens).
duke@435:   const size_t og_page_sz = os::page_size_for_region(yg_min_size + og_min_size,
duke@435:                                                      yg_max_size + og_max_size,
duke@435:                                                      8);
duke@435:   const size_t pg_page_sz = MIN2(os::page_size_for_region(pg_min_size,
duke@435:                                                           pg_max_size, 16),
duke@435:                                  og_page_sz);
duke@435: 
duke@435:   const size_t pg_align = set_alignment(_perm_gen_alignment,  pg_page_sz);
duke@435:   const size_t og_align = set_alignment(_old_gen_alignment,   og_page_sz);
duke@435:   const size_t yg_align = set_alignment(_young_gen_alignment, og_page_sz);
duke@435: 
duke@435:   // Update sizes to reflect the selected page size(s).
duke@435:   //
duke@435:   // NEEDS_CLEANUP.  The default TwoGenerationCollectorPolicy uses NewRatio; it
duke@435:   // should check UseAdaptiveSizePolicy.  Changes from generationSizer could
duke@435:   // move to the common code.
duke@435:   yg_min_size = align_size_up(yg_min_size, yg_align);
duke@435:   yg_max_size = align_size_up(yg_max_size, yg_align);
duke@435:   size_t yg_cur_size = align_size_up(flag_parser.young_gen_size(), yg_align);
duke@435:   yg_cur_size = MAX2(yg_cur_size, yg_min_size);
duke@435: 
duke@435:   og_min_size = align_size_up(og_min_size, og_align);
duke@435:   og_max_size = align_size_up(og_max_size, og_align);
duke@435:   size_t og_cur_size = align_size_up(flag_parser.old_gen_size(), og_align);
duke@435:   og_cur_size = MAX2(og_cur_size, og_min_size);
duke@435: 
duke@435:   pg_min_size = align_size_up(pg_min_size, pg_align);
duke@435:   pg_max_size = align_size_up(pg_max_size, pg_align);
duke@435:   size_t pg_cur_size = pg_min_size;
duke@435: 
duke@435:   trace_gen_sizes("ps heap rnd",
duke@435:                   pg_min_size, pg_max_size,
duke@435:                   og_min_size, og_max_size,
duke@435:                   yg_min_size, yg_max_size);
duke@435: 
kvn@1077:   const size_t total_reserved = pg_max_size + og_max_size + yg_max_size;
kvn@1077:   char* addr = Universe::preferred_heap_base(total_reserved, Universe::UnscaledNarrowOop);
kvn@1077: 
duke@435:   // The main part of the heap (old gen + young gen) can often use a larger page
duke@435:   // size than is needed or wanted for the perm gen.  Use the "compound
duke@435:   // alignment" ReservedSpace ctor to avoid having to use the same page size for
duke@435:   // all gens.
kvn@1077: 
coleenp@672:   ReservedHeapSpace heap_rs(pg_max_size, pg_align, og_max_size + yg_max_size,
kvn@1077:                             og_align, addr);
kvn@1077: 
kvn@1077:   if (UseCompressedOops) {
kvn@1077:     if (addr != NULL && !heap_rs.is_reserved()) {
kvn@1077:       // Failed to reserve at specified address - the requested memory
kvn@1077:       // region is taken already, for example, by 'java' launcher.
kvn@1077:       // Try again to reserver heap higher.
kvn@1077:       addr = Universe::preferred_heap_base(total_reserved, Universe::ZeroBasedNarrowOop);
kvn@1077:       ReservedHeapSpace heap_rs0(pg_max_size, pg_align, og_max_size + yg_max_size,
kvn@1077:                                  og_align, addr);
kvn@1077:       if (addr != NULL && !heap_rs0.is_reserved()) {
kvn@1077:         // Failed to reserve at specified address again - give up.
kvn@1077:         addr = Universe::preferred_heap_base(total_reserved, Universe::HeapBasedNarrowOop);
kvn@1077:         assert(addr == NULL, "");
kvn@1077:         ReservedHeapSpace heap_rs1(pg_max_size, pg_align, og_max_size + yg_max_size,
kvn@1077:                                    og_align, addr);
kvn@1077:         heap_rs = heap_rs1;
kvn@1077:       } else {
kvn@1077:         heap_rs = heap_rs0;
kvn@1077:       }
kvn@1077:     }
kvn@1077:   }
kvn@1077: 
duke@435:   os::trace_page_sizes("ps perm", pg_min_size, pg_max_size, pg_page_sz,
duke@435:                        heap_rs.base(), pg_max_size);
duke@435:   os::trace_page_sizes("ps main", og_min_size + yg_min_size,
duke@435:                        og_max_size + yg_max_size, og_page_sz,
duke@435:                        heap_rs.base() + pg_max_size,
duke@435:                        heap_rs.size() - pg_max_size);
duke@435:   if (!heap_rs.is_reserved()) {
duke@435:     vm_shutdown_during_initialization(
duke@435:       "Could not reserve enough space for object heap");
duke@435:     return JNI_ENOMEM;
duke@435:   }
duke@435: 
duke@435:   _reserved = MemRegion((HeapWord*)heap_rs.base(),
duke@435:                         (HeapWord*)(heap_rs.base() + heap_rs.size()));
duke@435: 
duke@435:   CardTableExtension* const barrier_set = new CardTableExtension(_reserved, 3);
duke@435:   _barrier_set = barrier_set;
duke@435:   oopDesc::set_bs(_barrier_set);
duke@435:   if (_barrier_set == NULL) {
duke@435:     vm_shutdown_during_initialization(
duke@435:       "Could not reserve enough space for barrier set");
duke@435:     return JNI_ENOMEM;
duke@435:   }
duke@435: 
duke@435:   // Initial young gen size is 4 Mb
duke@435:   //
duke@435:   // XXX - what about flag_parser.young_gen_size()?
duke@435:   const size_t init_young_size = align_size_up(4 * M, yg_align);
duke@435:   yg_cur_size = MAX2(MIN2(init_young_size, yg_max_size), yg_cur_size);
duke@435: 
duke@435:   // Split the reserved space into perm gen and the main heap (everything else).
duke@435:   // The main heap uses a different alignment.
duke@435:   ReservedSpace perm_rs = heap_rs.first_part(pg_max_size);
duke@435:   ReservedSpace main_rs = heap_rs.last_part(pg_max_size, og_align);
duke@435: 
duke@435:   // Make up the generations
duke@435:   // Calculate the maximum size that a generation can grow.  This
duke@435:   // includes growth into the other generation.  Note that the
duke@435:   // parameter _max_gen_size is kept as the maximum
duke@435:   // size of the generation as the boundaries currently stand.
duke@435:   // _max_gen_size is still used as that value.
duke@435:   double max_gc_pause_sec = ((double) MaxGCPauseMillis)/1000.0;
duke@435:   double max_gc_minor_pause_sec = ((double) MaxGCMinorPauseMillis)/1000.0;
duke@435: 
duke@435:   _gens = new AdjoiningGenerations(main_rs,
duke@435:                                    og_cur_size,
duke@435:                                    og_min_size,
duke@435:                                    og_max_size,
duke@435:                                    yg_cur_size,
duke@435:                                    yg_min_size,
duke@435:                                    yg_max_size,
duke@435:                                    yg_align);
duke@435: 
duke@435:   _old_gen = _gens->old_gen();
duke@435:   _young_gen = _gens->young_gen();
duke@435: 
duke@435:   const size_t eden_capacity = _young_gen->eden_space()->capacity_in_bytes();
duke@435:   const size_t old_capacity = _old_gen->capacity_in_bytes();
duke@435:   const size_t initial_promo_size = MIN2(eden_capacity, old_capacity);
duke@435:   _size_policy =
duke@435:     new PSAdaptiveSizePolicy(eden_capacity,
duke@435:                              initial_promo_size,
duke@435:                              young_gen()->to_space()->capacity_in_bytes(),
jmasa@448:                              intra_heap_alignment(),
duke@435:                              max_gc_pause_sec,
duke@435:                              max_gc_minor_pause_sec,
duke@435:                              GCTimeRatio
duke@435:                              );
duke@435: 
duke@435:   _perm_gen = new PSPermGen(perm_rs,
duke@435:                             pg_align,
duke@435:                             pg_cur_size,
duke@435:                             pg_cur_size,
duke@435:                             pg_max_size,
duke@435:                             "perm", 2);
duke@435: 
duke@435:   assert(!UseAdaptiveGCBoundary ||
duke@435:     (old_gen()->virtual_space()->high_boundary() ==
duke@435:      young_gen()->virtual_space()->low_boundary()),
duke@435:     "Boundaries must meet");
duke@435:   // initialize the policy counters - 2 collectors, 3 generations
duke@435:   _gc_policy_counters =
duke@435:     new PSGCAdaptivePolicyCounters("ParScav:MSC", 2, 3, _size_policy);
duke@435:   _psh = this;
duke@435: 
duke@435:   // Set up the GCTaskManager
duke@435:   _gc_task_manager = GCTaskManager::create(ParallelGCThreads);
duke@435: 
duke@435:   if (UseParallelOldGC && !PSParallelCompact::initialize()) {
duke@435:     return JNI_ENOMEM;
duke@435:   }
duke@435: 
duke@435:   return JNI_OK;
duke@435: }
duke@435: 
duke@435: void ParallelScavengeHeap::post_initialize() {
duke@435:   // Need to init the tenuring threshold
duke@435:   PSScavenge::initialize();
duke@435:   if (UseParallelOldGC) {
duke@435:     PSParallelCompact::post_initialize();
duke@435:   } else {
duke@435:     PSMarkSweep::initialize();
duke@435:   }
duke@435:   PSPromotionManager::initialize();
duke@435: }
duke@435: 
duke@435: void ParallelScavengeHeap::update_counters() {
duke@435:   young_gen()->update_counters();
duke@435:   old_gen()->update_counters();
duke@435:   perm_gen()->update_counters();
duke@435: }
duke@435: 
duke@435: size_t ParallelScavengeHeap::capacity() const {
duke@435:   size_t value = young_gen()->capacity_in_bytes() + old_gen()->capacity_in_bytes();
duke@435:   return value;
duke@435: }
duke@435: 
duke@435: size_t ParallelScavengeHeap::used() const {
duke@435:   size_t value = young_gen()->used_in_bytes() + old_gen()->used_in_bytes();
duke@435:   return value;
duke@435: }
duke@435: 
duke@435: bool ParallelScavengeHeap::is_maximal_no_gc() const {
duke@435:   return old_gen()->is_maximal_no_gc() && young_gen()->is_maximal_no_gc();
duke@435: }
duke@435: 
duke@435: 
duke@435: size_t ParallelScavengeHeap::permanent_capacity() const {
duke@435:   return perm_gen()->capacity_in_bytes();
duke@435: }
duke@435: 
duke@435: size_t ParallelScavengeHeap::permanent_used() const {
duke@435:   return perm_gen()->used_in_bytes();
duke@435: }
duke@435: 
duke@435: size_t ParallelScavengeHeap::max_capacity() const {
duke@435:   size_t estimated = reserved_region().byte_size();
duke@435:   estimated -= perm_gen()->reserved().byte_size();
duke@435:   if (UseAdaptiveSizePolicy) {
duke@435:     estimated -= _size_policy->max_survivor_size(young_gen()->max_size());
duke@435:   } else {
duke@435:     estimated -= young_gen()->to_space()->capacity_in_bytes();
duke@435:   }
duke@435:   return MAX2(estimated, capacity());
duke@435: }
duke@435: 
duke@435: bool ParallelScavengeHeap::is_in(const void* p) const {
duke@435:   if (young_gen()->is_in(p)) {
duke@435:     return true;
duke@435:   }
duke@435: 
duke@435:   if (old_gen()->is_in(p)) {
duke@435:     return true;
duke@435:   }
duke@435: 
duke@435:   if (perm_gen()->is_in(p)) {
duke@435:     return true;
duke@435:   }
duke@435: 
duke@435:   return false;
duke@435: }
duke@435: 
duke@435: bool ParallelScavengeHeap::is_in_reserved(const void* p) const {
duke@435:   if (young_gen()->is_in_reserved(p)) {
duke@435:     return true;
duke@435:   }
duke@435: 
duke@435:   if (old_gen()->is_in_reserved(p)) {
duke@435:     return true;
duke@435:   }
duke@435: 
duke@435:   if (perm_gen()->is_in_reserved(p)) {
duke@435:     return true;
duke@435:   }
duke@435: 
duke@435:   return false;
duke@435: }
duke@435: 
duke@435: // Static method
duke@435: bool ParallelScavengeHeap::is_in_young(oop* p) {
duke@435:   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
duke@435:   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap,
duke@435:                                             "Must be ParallelScavengeHeap");
duke@435: 
duke@435:   PSYoungGen* young_gen = heap->young_gen();
duke@435: 
duke@435:   if (young_gen->is_in_reserved(p)) {
duke@435:     return true;
duke@435:   }
duke@435: 
duke@435:   return false;
duke@435: }
duke@435: 
duke@435: // Static method
duke@435: bool ParallelScavengeHeap::is_in_old_or_perm(oop* p) {
duke@435:   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
duke@435:   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap,
duke@435:                                             "Must be ParallelScavengeHeap");
duke@435: 
duke@435:   PSOldGen* old_gen = heap->old_gen();
duke@435:   PSPermGen* perm_gen = heap->perm_gen();
duke@435: 
duke@435:   if (old_gen->is_in_reserved(p)) {
duke@435:     return true;
duke@435:   }
duke@435: 
duke@435:   if (perm_gen->is_in_reserved(p)) {
duke@435:     return true;
duke@435:   }
duke@435: 
duke@435:   return false;
duke@435: }
duke@435: 
duke@435: // There are two levels of allocation policy here.
duke@435: //
duke@435: // When an allocation request fails, the requesting thread must invoke a VM
duke@435: // operation, transfer control to the VM thread, and await the results of a
duke@435: // garbage collection. That is quite expensive, and we should avoid doing it
duke@435: // multiple times if possible.
duke@435: //
duke@435: // To accomplish this, we have a basic allocation policy, and also a
duke@435: // failed allocation policy.
duke@435: //
duke@435: // The basic allocation policy controls how you allocate memory without
duke@435: // attempting garbage collection. It is okay to grab locks and
duke@435: // expand the heap, if that can be done without coming to a safepoint.
duke@435: // It is likely that the basic allocation policy will not be very
duke@435: // aggressive.
duke@435: //
duke@435: // The failed allocation policy is invoked from the VM thread after
duke@435: // the basic allocation policy is unable to satisfy a mem_allocate
duke@435: // request. This policy needs to cover the entire range of collection,
duke@435: // heap expansion, and out-of-memory conditions. It should make every
duke@435: // attempt to allocate the requested memory.
duke@435: 
duke@435: // Basic allocation policy. Should never be called at a safepoint, or
duke@435: // from the VM thread.
duke@435: //
duke@435: // This method must handle cases where many mem_allocate requests fail
duke@435: // simultaneously. When that happens, only one VM operation will succeed,
duke@435: // and the rest will not be executed. For that reason, this method loops
duke@435: // during failed allocation attempts. If the java heap becomes exhausted,
duke@435: // we rely on the size_policy object to force a bail out.
duke@435: HeapWord* ParallelScavengeHeap::mem_allocate(
duke@435:                                      size_t size,
duke@435:                                      bool is_noref,
duke@435:                                      bool is_tlab,
duke@435:                                      bool* gc_overhead_limit_was_exceeded) {
duke@435:   assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint");
duke@435:   assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
duke@435:   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
duke@435: 
duke@435:   HeapWord* result = young_gen()->allocate(size, is_tlab);
duke@435: 
duke@435:   uint loop_count = 0;
duke@435:   uint gc_count = 0;
duke@435: 
duke@435:   while (result == NULL) {
duke@435:     // We don't want to have multiple collections for a single filled generation.
duke@435:     // To prevent this, each thread tracks the total_collections() value, and if
duke@435:     // the count has changed, does not do a new collection.
duke@435:     //
duke@435:     // The collection count must be read only while holding the heap lock. VM
duke@435:     // operations also hold the heap lock during collections. There is a lock
duke@435:     // contention case where thread A blocks waiting on the Heap_lock, while
duke@435:     // thread B is holding it doing a collection. When thread A gets the lock,
duke@435:     // the collection count has already changed. To prevent duplicate collections,
duke@435:     // The policy MUST attempt allocations during the same period it reads the
duke@435:     // total_collections() value!
duke@435:     {
duke@435:       MutexLocker ml(Heap_lock);
duke@435:       gc_count = Universe::heap()->total_collections();
duke@435: 
duke@435:       result = young_gen()->allocate(size, is_tlab);
duke@435: 
duke@435:       // (1) If the requested object is too large to easily fit in the
duke@435:       //     young_gen, or
duke@435:       // (2) If GC is locked out via GCLocker, young gen is full and
duke@435:       //     the need for a GC already signalled to GCLocker (done
duke@435:       //     at a safepoint),
duke@435:       // ... then, rather than force a safepoint and (a potentially futile)
duke@435:       // collection (attempt) for each allocation, try allocation directly
duke@435:       // in old_gen. For case (2) above, we may in the future allow
duke@435:       // TLAB allocation directly in the old gen.
duke@435:       if (result != NULL) {
duke@435:         return result;
duke@435:       }
duke@435:       if (!is_tlab &&
iveresov@808:           size >= (young_gen()->eden_space()->capacity_in_words(Thread::current()) / 2)) {
duke@435:         result = old_gen()->allocate(size, is_tlab);
duke@435:         if (result != NULL) {
duke@435:           return result;
duke@435:         }
duke@435:       }
duke@435:       if (GC_locker::is_active_and_needs_gc()) {
duke@435:         // GC is locked out. If this is a TLAB allocation,
duke@435:         // return NULL; the requestor will retry allocation
duke@435:         // of an idividual object at a time.
duke@435:         if (is_tlab) {
duke@435:           return NULL;
duke@435:         }
duke@435: 
duke@435:         // If this thread is not in a jni critical section, we stall
duke@435:         // the requestor until the critical section has cleared and
duke@435:         // GC allowed. When the critical section clears, a GC is
duke@435:         // initiated by the last thread exiting the critical section; so
duke@435:         // we retry the allocation sequence from the beginning of the loop,
duke@435:         // rather than causing more, now probably unnecessary, GC attempts.
duke@435:         JavaThread* jthr = JavaThread::current();
duke@435:         if (!jthr->in_critical()) {
duke@435:           MutexUnlocker mul(Heap_lock);
duke@435:           GC_locker::stall_until_clear();
duke@435:           continue;
duke@435:         } else {
duke@435:           if (CheckJNICalls) {
duke@435:             fatal("Possible deadlock due to allocating while"
duke@435:                   " in jni critical section");
duke@435:           }
duke@435:           return NULL;
duke@435:         }
duke@435:       }
duke@435:     }
duke@435: 
duke@435:     if (result == NULL) {
duke@435: 
duke@435:       // Exit the loop if if the gc time limit has been exceeded.
duke@435:       // The allocation must have failed above (result must be NULL),
duke@435:       // and the most recent collection must have exceeded the
duke@435:       // gc time limit.  Exit the loop so that an out-of-memory
duke@435:       // will be thrown (returning a NULL will do that), but
duke@435:       // clear gc_time_limit_exceeded so that the next collection
duke@435:       // will succeeded if the applications decides to handle the
duke@435:       // out-of-memory and tries to go on.
duke@435:       *gc_overhead_limit_was_exceeded = size_policy()->gc_time_limit_exceeded();
duke@435:       if (size_policy()->gc_time_limit_exceeded()) {
duke@435:         size_policy()->set_gc_time_limit_exceeded(false);
duke@435:         if (PrintGCDetails && Verbose) {
duke@435:         gclog_or_tty->print_cr("ParallelScavengeHeap::mem_allocate: "
duke@435:           "return NULL because gc_time_limit_exceeded is set");
duke@435:         }
duke@435:         return NULL;
duke@435:       }
duke@435: 
duke@435:       // Generate a VM operation
duke@435:       VM_ParallelGCFailedAllocation op(size, is_tlab, gc_count);
duke@435:       VMThread::execute(&op);
duke@435: 
duke@435:       // Did the VM operation execute? If so, return the result directly.
duke@435:       // This prevents us from looping until time out on requests that can
duke@435:       // not be satisfied.
duke@435:       if (op.prologue_succeeded()) {
duke@435:         assert(Universe::heap()->is_in_or_null(op.result()),
duke@435:           "result not in heap");
duke@435: 
duke@435:         // If GC was locked out during VM operation then retry allocation
duke@435:         // and/or stall as necessary.
duke@435:         if (op.gc_locked()) {
duke@435:           assert(op.result() == NULL, "must be NULL if gc_locked() is true");
duke@435:           continue;  // retry and/or stall as necessary
duke@435:         }
duke@435:         // If a NULL result is being returned, an out-of-memory
duke@435:         // will be thrown now.  Clear the gc_time_limit_exceeded
duke@435:         // flag to avoid the following situation.
duke@435:         //      gc_time_limit_exceeded is set during a collection
duke@435:         //      the collection fails to return enough space and an OOM is thrown
duke@435:         //      the next GC is skipped because the gc_time_limit_exceeded
duke@435:         //        flag is set and another OOM is thrown
duke@435:         if (op.result() == NULL) {
duke@435:           size_policy()->set_gc_time_limit_exceeded(false);
duke@435:         }
duke@435:         return op.result();
duke@435:       }
duke@435:     }
duke@435: 
duke@435:     // The policy object will prevent us from looping forever. If the
duke@435:     // time spent in gc crosses a threshold, we will bail out.
duke@435:     loop_count++;
duke@435:     if ((result == NULL) && (QueuedAllocationWarningCount > 0) &&
duke@435:         (loop_count % QueuedAllocationWarningCount == 0)) {
duke@435:       warning("ParallelScavengeHeap::mem_allocate retries %d times \n\t"
duke@435:               " size=%d %s", loop_count, size, is_tlab ? "(TLAB)" : "");
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   return result;
duke@435: }
duke@435: 
duke@435: // Failed allocation policy. Must be called from the VM thread, and
duke@435: // only at a safepoint! Note that this method has policy for allocation
duke@435: // flow, and NOT collection policy. So we do not check for gc collection
duke@435: // time over limit here, that is the responsibility of the heap specific
duke@435: // collection methods. This method decides where to attempt allocations,
duke@435: // and when to attempt collections, but no collection specific policy.
duke@435: HeapWord* ParallelScavengeHeap::failed_mem_allocate(size_t size, bool is_tlab) {
duke@435:   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
duke@435:   assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
duke@435:   assert(!Universe::heap()->is_gc_active(), "not reentrant");
duke@435:   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
duke@435: 
duke@435:   size_t mark_sweep_invocation_count = total_invocations();
duke@435: 
duke@435:   // We assume (and assert!) that an allocation at this point will fail
duke@435:   // unless we collect.
duke@435: 
duke@435:   // First level allocation failure, scavenge and allocate in young gen.
duke@435:   GCCauseSetter gccs(this, GCCause::_allocation_failure);
duke@435:   PSScavenge::invoke();
duke@435:   HeapWord* result = young_gen()->allocate(size, is_tlab);
duke@435: 
duke@435:   // Second level allocation failure.
duke@435:   //   Mark sweep and allocate in young generation.
duke@435:   if (result == NULL) {
duke@435:     // There is some chance the scavenge method decided to invoke mark_sweep.
duke@435:     // Don't mark sweep twice if so.
duke@435:     if (mark_sweep_invocation_count == total_invocations()) {
duke@435:       invoke_full_gc(false);
duke@435:       result = young_gen()->allocate(size, is_tlab);
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   // Third level allocation failure.
duke@435:   //   After mark sweep and young generation allocation failure,
duke@435:   //   allocate in old generation.
duke@435:   if (result == NULL && !is_tlab) {
duke@435:     result = old_gen()->allocate(size, is_tlab);
duke@435:   }
duke@435: 
duke@435:   // Fourth level allocation failure. We're running out of memory.
duke@435:   //   More complete mark sweep and allocate in young generation.
duke@435:   if (result == NULL) {
duke@435:     invoke_full_gc(true);
duke@435:     result = young_gen()->allocate(size, is_tlab);
duke@435:   }
duke@435: 
duke@435:   // Fifth level allocation failure.
duke@435:   //   After more complete mark sweep, allocate in old generation.
duke@435:   if (result == NULL && !is_tlab) {
duke@435:     result = old_gen()->allocate(size, is_tlab);
duke@435:   }
duke@435: 
duke@435:   return result;
duke@435: }
duke@435: 
duke@435: //
duke@435: // This is the policy loop for allocating in the permanent generation.
duke@435: // If the initial allocation fails, we create a vm operation which will
duke@435: // cause a collection.
duke@435: HeapWord* ParallelScavengeHeap::permanent_mem_allocate(size_t size) {
duke@435:   assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint");
duke@435:   assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
duke@435:   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
duke@435: 
duke@435:   HeapWord* result;
duke@435: 
duke@435:   uint loop_count = 0;
duke@435:   uint gc_count = 0;
duke@435:   uint full_gc_count = 0;
duke@435: 
duke@435:   do {
duke@435:     // We don't want to have multiple collections for a single filled generation.
duke@435:     // To prevent this, each thread tracks the total_collections() value, and if
duke@435:     // the count has changed, does not do a new collection.
duke@435:     //
duke@435:     // The collection count must be read only while holding the heap lock. VM
duke@435:     // operations also hold the heap lock during collections. There is a lock
duke@435:     // contention case where thread A blocks waiting on the Heap_lock, while
duke@435:     // thread B is holding it doing a collection. When thread A gets the lock,
duke@435:     // the collection count has already changed. To prevent duplicate collections,
duke@435:     // The policy MUST attempt allocations during the same period it reads the
duke@435:     // total_collections() value!
duke@435:     {
duke@435:       MutexLocker ml(Heap_lock);
duke@435:       gc_count      = Universe::heap()->total_collections();
duke@435:       full_gc_count = Universe::heap()->total_full_collections();
duke@435: 
duke@435:       result = perm_gen()->allocate_permanent(size);
apetrusenko@574: 
apetrusenko@574:       if (result != NULL) {
apetrusenko@574:         return result;
apetrusenko@574:       }
apetrusenko@574: 
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:           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:       }
duke@435:     }
duke@435: 
duke@435:     if (result == NULL) {
duke@435: 
duke@435:       // Exit the loop if the gc time limit has been exceeded.
duke@435:       // The allocation must have failed above (result must be NULL),
duke@435:       // and the most recent collection must have exceeded the
duke@435:       // gc time limit.  Exit the loop so that an out-of-memory
duke@435:       // will be thrown (returning a NULL will do that), but
duke@435:       // clear gc_time_limit_exceeded so that the next collection
duke@435:       // will succeeded if the applications decides to handle the
duke@435:       // out-of-memory and tries to go on.
duke@435:       if (size_policy()->gc_time_limit_exceeded()) {
duke@435:         size_policy()->set_gc_time_limit_exceeded(false);
duke@435:         if (PrintGCDetails && Verbose) {
duke@435:         gclog_or_tty->print_cr("ParallelScavengeHeap::permanent_mem_allocate: "
duke@435:           "return NULL because gc_time_limit_exceeded is set");
duke@435:         }
duke@435:         assert(result == NULL, "Allocation did not fail");
duke@435:         return NULL;
duke@435:       }
duke@435: 
duke@435:       // Generate a VM operation
duke@435:       VM_ParallelGCFailedPermanentAllocation op(size, gc_count, full_gc_count);
duke@435:       VMThread::execute(&op);
duke@435: 
duke@435:       // Did the VM operation execute? If so, return the result directly.
duke@435:       // This prevents us from looping until time out on requests that can
duke@435:       // not be satisfied.
duke@435:       if (op.prologue_succeeded()) {
duke@435:         assert(Universe::heap()->is_in_permanent_or_null(op.result()),
duke@435:           "result not in heap");
apetrusenko@574:         // If GC was locked out during VM operation then retry allocation
apetrusenko@574:         // and/or stall as necessary.
apetrusenko@574:         if (op.gc_locked()) {
apetrusenko@574:           assert(op.result() == NULL, "must be NULL if gc_locked() is true");
apetrusenko@574:           continue;  // retry and/or stall as necessary
apetrusenko@574:         }
duke@435:         // If a NULL results is being returned, an out-of-memory
duke@435:         // will be thrown now.  Clear the gc_time_limit_exceeded
duke@435:         // flag to avoid the following situation.
duke@435:         //      gc_time_limit_exceeded is set during a collection
duke@435:         //      the collection fails to return enough space and an OOM is thrown
duke@435:         //      the next GC is skipped because the gc_time_limit_exceeded
duke@435:         //        flag is set and another OOM is thrown
duke@435:         if (op.result() == NULL) {
duke@435:           size_policy()->set_gc_time_limit_exceeded(false);
duke@435:         }
duke@435:         return op.result();
duke@435:       }
duke@435:     }
duke@435: 
duke@435:     // The policy object will prevent us from looping forever. If the
duke@435:     // time spent in gc crosses a threshold, we will bail out.
duke@435:     loop_count++;
duke@435:     if ((QueuedAllocationWarningCount > 0) &&
duke@435:         (loop_count % QueuedAllocationWarningCount == 0)) {
duke@435:       warning("ParallelScavengeHeap::permanent_mem_allocate retries %d times \n\t"
duke@435:               " size=%d", loop_count, size);
duke@435:     }
duke@435:   } while (result == NULL);
duke@435: 
duke@435:   return result;
duke@435: }
duke@435: 
duke@435: //
duke@435: // This is the policy code for permanent allocations which have failed
duke@435: // and require a collection. Note that just as in failed_mem_allocate,
duke@435: // we do not set collection policy, only where & when to allocate and
duke@435: // collect.
duke@435: HeapWord* ParallelScavengeHeap::failed_permanent_mem_allocate(size_t size) {
duke@435:   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
duke@435:   assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
duke@435:   assert(!Universe::heap()->is_gc_active(), "not reentrant");
duke@435:   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
duke@435:   assert(size > perm_gen()->free_in_words(), "Allocation should fail");
duke@435: 
duke@435:   // We assume (and assert!) that an allocation at this point will fail
duke@435:   // unless we collect.
duke@435: 
duke@435:   // First level allocation failure.  Mark-sweep and allocate in perm gen.
duke@435:   GCCauseSetter gccs(this, GCCause::_allocation_failure);
duke@435:   invoke_full_gc(false);
duke@435:   HeapWord* result = perm_gen()->allocate_permanent(size);
duke@435: 
duke@435:   // Second level allocation failure. We're running out of memory.
duke@435:   if (result == NULL) {
duke@435:     invoke_full_gc(true);
duke@435:     result = perm_gen()->allocate_permanent(size);
duke@435:   }
duke@435: 
duke@435:   return result;
duke@435: }
duke@435: 
duke@435: void ParallelScavengeHeap::ensure_parsability(bool retire_tlabs) {
duke@435:   CollectedHeap::ensure_parsability(retire_tlabs);
duke@435:   young_gen()->eden_space()->ensure_parsability();
duke@435: }
duke@435: 
duke@435: size_t ParallelScavengeHeap::unsafe_max_alloc() {
duke@435:   return young_gen()->eden_space()->free_in_bytes();
duke@435: }
duke@435: 
duke@435: size_t ParallelScavengeHeap::tlab_capacity(Thread* thr) const {
duke@435:   return young_gen()->eden_space()->tlab_capacity(thr);
duke@435: }
duke@435: 
duke@435: size_t ParallelScavengeHeap::unsafe_max_tlab_alloc(Thread* thr) const {
duke@435:   return young_gen()->eden_space()->unsafe_max_tlab_alloc(thr);
duke@435: }
duke@435: 
duke@435: HeapWord* ParallelScavengeHeap::allocate_new_tlab(size_t size) {
duke@435:   return young_gen()->allocate(size, true);
duke@435: }
duke@435: 
duke@435: void ParallelScavengeHeap::fill_all_tlabs(bool retire) {
duke@435:   CollectedHeap::fill_all_tlabs(retire);
duke@435: }
duke@435: 
duke@435: void ParallelScavengeHeap::accumulate_statistics_all_tlabs() {
duke@435:   CollectedHeap::accumulate_statistics_all_tlabs();
duke@435: }
duke@435: 
duke@435: void ParallelScavengeHeap::resize_all_tlabs() {
duke@435:   CollectedHeap::resize_all_tlabs();
duke@435: }
duke@435: 
duke@435: // This method is used by System.gc() and JVMTI.
duke@435: void ParallelScavengeHeap::collect(GCCause::Cause cause) {
duke@435:   assert(!Heap_lock->owned_by_self(),
duke@435:     "this thread should not own the Heap_lock");
duke@435: 
duke@435:   unsigned int gc_count      = 0;
duke@435:   unsigned int full_gc_count = 0;
duke@435:   {
duke@435:     MutexLocker ml(Heap_lock);
duke@435:     // This value is guarded by the Heap_lock
duke@435:     gc_count      = Universe::heap()->total_collections();
duke@435:     full_gc_count = Universe::heap()->total_full_collections();
duke@435:   }
duke@435: 
duke@435:   VM_ParallelGCSystemGC op(gc_count, full_gc_count, cause);
duke@435:   VMThread::execute(&op);
duke@435: }
duke@435: 
duke@435: // This interface assumes that it's being called by the
duke@435: // vm thread. It collects the heap assuming that the
duke@435: // heap lock is already held and that we are executing in
duke@435: // the context of the vm thread.
duke@435: void ParallelScavengeHeap::collect_as_vm_thread(GCCause::Cause cause) {
duke@435:   assert(Thread::current()->is_VM_thread(), "Precondition#1");
duke@435:   assert(Heap_lock->is_locked(), "Precondition#2");
duke@435:   GCCauseSetter gcs(this, cause);
duke@435:   switch (cause) {
duke@435:     case GCCause::_heap_inspection:
duke@435:     case GCCause::_heap_dump: {
duke@435:       HandleMark hm;
duke@435:       invoke_full_gc(false);
duke@435:       break;
duke@435:     }
duke@435:     default: // XXX FIX ME
duke@435:       ShouldNotReachHere();
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: void ParallelScavengeHeap::oop_iterate(OopClosure* cl) {
duke@435:   Unimplemented();
duke@435: }
duke@435: 
duke@435: void ParallelScavengeHeap::object_iterate(ObjectClosure* cl) {
duke@435:   young_gen()->object_iterate(cl);
duke@435:   old_gen()->object_iterate(cl);
duke@435:   perm_gen()->object_iterate(cl);
duke@435: }
duke@435: 
duke@435: void ParallelScavengeHeap::permanent_oop_iterate(OopClosure* cl) {
duke@435:   Unimplemented();
duke@435: }
duke@435: 
duke@435: void ParallelScavengeHeap::permanent_object_iterate(ObjectClosure* cl) {
duke@435:   perm_gen()->object_iterate(cl);
duke@435: }
duke@435: 
duke@435: HeapWord* ParallelScavengeHeap::block_start(const void* addr) const {
duke@435:   if (young_gen()->is_in_reserved(addr)) {
duke@435:     assert(young_gen()->is_in(addr),
duke@435:            "addr should be in allocated part of young gen");
duke@435:     Unimplemented();
duke@435:   } else if (old_gen()->is_in_reserved(addr)) {
duke@435:     assert(old_gen()->is_in(addr),
duke@435:            "addr should be in allocated part of old gen");
duke@435:     return old_gen()->start_array()->object_start((HeapWord*)addr);
duke@435:   } else if (perm_gen()->is_in_reserved(addr)) {
duke@435:     assert(perm_gen()->is_in(addr),
duke@435:            "addr should be in allocated part of perm gen");
duke@435:     return perm_gen()->start_array()->object_start((HeapWord*)addr);
duke@435:   }
duke@435:   return 0;
duke@435: }
duke@435: 
duke@435: size_t ParallelScavengeHeap::block_size(const HeapWord* addr) const {
duke@435:   return oop(addr)->size();
duke@435: }
duke@435: 
duke@435: bool ParallelScavengeHeap::block_is_obj(const HeapWord* addr) const {
duke@435:   return block_start(addr) == addr;
duke@435: }
duke@435: 
duke@435: jlong ParallelScavengeHeap::millis_since_last_gc() {
duke@435:   return UseParallelOldGC ?
duke@435:     PSParallelCompact::millis_since_last_gc() :
duke@435:     PSMarkSweep::millis_since_last_gc();
duke@435: }
duke@435: 
duke@435: void ParallelScavengeHeap::prepare_for_verify() {
duke@435:   ensure_parsability(false);  // no need to retire TLABs for verification
duke@435: }
duke@435: 
duke@435: void ParallelScavengeHeap::print() const { print_on(tty); }
duke@435: 
duke@435: void ParallelScavengeHeap::print_on(outputStream* st) const {
duke@435:   young_gen()->print_on(st);
duke@435:   old_gen()->print_on(st);
duke@435:   perm_gen()->print_on(st);
duke@435: }
duke@435: 
duke@435: void ParallelScavengeHeap::gc_threads_do(ThreadClosure* tc) const {
duke@435:   PSScavenge::gc_task_manager()->threads_do(tc);
duke@435: }
duke@435: 
duke@435: void ParallelScavengeHeap::print_gc_threads_on(outputStream* st) const {
duke@435:   PSScavenge::gc_task_manager()->print_threads_on(st);
duke@435: }
duke@435: 
duke@435: void ParallelScavengeHeap::print_tracing_info() const {
duke@435:   if (TraceGen0Time) {
duke@435:     double time = PSScavenge::accumulated_time()->seconds();
duke@435:     tty->print_cr("[Accumulated GC generation 0 time %3.7f secs]", time);
duke@435:   }
duke@435:   if (TraceGen1Time) {
duke@435:     double time = PSMarkSweep::accumulated_time()->seconds();
duke@435:     tty->print_cr("[Accumulated GC generation 1 time %3.7f secs]", time);
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: void ParallelScavengeHeap::verify(bool allow_dirty, bool silent) {
duke@435:   // Why do we need the total_collections()-filter below?
duke@435:   if (total_collections() > 0) {
duke@435:     if (!silent) {
duke@435:       gclog_or_tty->print("permanent ");
duke@435:     }
duke@435:     perm_gen()->verify(allow_dirty);
duke@435: 
duke@435:     if (!silent) {
duke@435:       gclog_or_tty->print("tenured ");
duke@435:     }
duke@435:     old_gen()->verify(allow_dirty);
duke@435: 
duke@435:     if (!silent) {
duke@435:       gclog_or_tty->print("eden ");
duke@435:     }
duke@435:     young_gen()->verify(allow_dirty);
duke@435:   }
duke@435:   if (!silent) {
duke@435:     gclog_or_tty->print("ref_proc ");
duke@435:   }
duke@435:   ReferenceProcessor::verify();
duke@435: }
duke@435: 
duke@435: void ParallelScavengeHeap::print_heap_change(size_t prev_used) {
duke@435:   if (PrintGCDetails && Verbose) {
duke@435:     gclog_or_tty->print(" "  SIZE_FORMAT
duke@435:                         "->" SIZE_FORMAT
duke@435:                         "("  SIZE_FORMAT ")",
duke@435:                         prev_used, used(), capacity());
duke@435:   } else {
duke@435:     gclog_or_tty->print(" "  SIZE_FORMAT "K"
duke@435:                         "->" SIZE_FORMAT "K"
duke@435:                         "("  SIZE_FORMAT "K)",
duke@435:                         prev_used / K, used() / K, capacity() / K);
duke@435:   }
duke@435: }
duke@435: 
duke@435: ParallelScavengeHeap* ParallelScavengeHeap::heap() {
duke@435:   assert(_psh != NULL, "Uninitialized access to ParallelScavengeHeap::heap()");
duke@435:   assert(_psh->kind() == CollectedHeap::ParallelScavengeHeap, "not a parallel scavenge heap");
duke@435:   return _psh;
duke@435: }
duke@435: 
duke@435: // Before delegating the resize to the young generation,
duke@435: // the reserved space for the young and old generations
duke@435: // may be changed to accomodate the desired resize.
duke@435: void ParallelScavengeHeap::resize_young_gen(size_t eden_size,
duke@435:     size_t survivor_size) {
duke@435:   if (UseAdaptiveGCBoundary) {
duke@435:     if (size_policy()->bytes_absorbed_from_eden() != 0) {
duke@435:       size_policy()->reset_bytes_absorbed_from_eden();
duke@435:       return;  // The generation changed size already.
duke@435:     }
duke@435:     gens()->adjust_boundary_for_young_gen_needs(eden_size, survivor_size);
duke@435:   }
duke@435: 
duke@435:   // Delegate the resize to the generation.
duke@435:   _young_gen->resize(eden_size, survivor_size);
duke@435: }
duke@435: 
duke@435: // Before delegating the resize to the old generation,
duke@435: // the reserved space for the young and old generations
duke@435: // may be changed to accomodate the desired resize.
duke@435: void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) {
duke@435:   if (UseAdaptiveGCBoundary) {
duke@435:     if (size_policy()->bytes_absorbed_from_eden() != 0) {
duke@435:       size_policy()->reset_bytes_absorbed_from_eden();
duke@435:       return;  // The generation changed size already.
duke@435:     }
duke@435:     gens()->adjust_boundary_for_old_gen_needs(desired_free_space);
duke@435:   }
duke@435: 
duke@435:   // Delegate the resize to the generation.
duke@435:   _old_gen->resize(desired_free_space);
duke@435: }
jmasa@698: 
jmasa@698: #ifndef PRODUCT
jmasa@698: void ParallelScavengeHeap::record_gen_tops_before_GC() {
jmasa@698:   if (ZapUnusedHeapArea) {
jmasa@698:     young_gen()->record_spaces_top();
jmasa@698:     old_gen()->record_spaces_top();
jmasa@698:     perm_gen()->record_spaces_top();
jmasa@698:   }
jmasa@698: }
jmasa@698: 
jmasa@698: void ParallelScavengeHeap::gen_mangle_unused_area() {
jmasa@698:   if (ZapUnusedHeapArea) {
jmasa@698:     young_gen()->eden_space()->mangle_unused_area();
jmasa@698:     young_gen()->to_space()->mangle_unused_area();
jmasa@698:     young_gen()->from_space()->mangle_unused_area();
jmasa@698:     old_gen()->object_space()->mangle_unused_area();
jmasa@698:     perm_gen()->object_space()->mangle_unused_area();
jmasa@698:   }
jmasa@698: }
jmasa@698: #endif