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

 /*

  * Copyright 2001-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

  * CA 95054 USA or visit www.sun.com if you need additional information or

  * have any questions.

  *

  */

 # include "incls/_precompiled.incl"

 # include "incls/_collectedHeap.cpp.incl"

 #ifdef ASSERT

 int CollectedHeap::_fire_out_of_memory_count = 0;

 #endif

 size_t CollectedHeap::_filler_array_max_size = 0;

 // Memory state functions.

 CollectedHeap::CollectedHeap()

 {

   const size_t max_len = size_t(arrayOopDesc::max_array_length(T_INT));

   const size_t elements_per_word = HeapWordSize / sizeof(jint);

   _filler_array_max_size = align_object_size(filler_array_hdr_size() +

                                              max_len * elements_per_word);

   _barrier_set = NULL;

   _is_gc_active = false;

   _total_collections = _total_full_collections = 0;

   _gc_cause = _gc_lastcause = GCCause::_no_gc;

   NOT_PRODUCT(_promotion_failure_alot_count = 0;)

   NOT_PRODUCT(_promotion_failure_alot_gc_number = 0;)

   if (UsePerfData) {

     EXCEPTION_MARK;

     // create the gc cause jvmstat counters

     _perf_gc_cause = PerfDataManager::create_string_variable(SUN_GC, "cause",

                              80, GCCause::to_string(_gc_cause), CHECK);

     _perf_gc_lastcause =

                 PerfDataManager::create_string_variable(SUN_GC, "lastCause",

                              80, GCCause::to_string(_gc_lastcause), CHECK);

   }

 }

 #ifndef PRODUCT

 void CollectedHeap::check_for_bad_heap_word_value(HeapWord* addr, size_t size) {

   if (CheckMemoryInitialization && ZapUnusedHeapArea) {

     for (size_t slot = 0; slot < size; slot += 1) {

       assert((*(intptr_t*) (addr + slot)) != ((intptr_t) badHeapWordVal),

              "Found badHeapWordValue in post-allocation check");

     }

   }

 }

 void CollectedHeap::check_for_non_bad_heap_word_value(HeapWord* addr, size_t size)

  {

   if (CheckMemoryInitialization && ZapUnusedHeapArea) {

     for (size_t slot = 0; slot < size; slot += 1) {

       assert((*(intptr_t*) (addr + slot)) == ((intptr_t) badHeapWordVal),

              "Found non badHeapWordValue in pre-allocation check");

     }

   }

 }

 #endif // PRODUCT

 #ifdef ASSERT

 void CollectedHeap::check_for_valid_allocation_state() {

   Thread *thread = Thread::current();

   // How to choose between a pending exception and a potential

   // OutOfMemoryError?  Don't allow pending exceptions.

   // This is a VM policy failure, so how do we exhaustively test it?

   assert(!thread->has_pending_exception(),

          "shouldn't be allocating with pending exception");

   if (StrictSafepointChecks) {

     assert(thread->allow_allocation(),

            "Allocation done by thread for which allocation is blocked "

            "by No_Allocation_Verifier!");

     // Allocation of an oop can always invoke a safepoint,

     // hence, the true argument

     thread->check_for_valid_safepoint_state(true);

   }

 }

 #endif

 HeapWord* CollectedHeap::allocate_from_tlab_slow(Thread* thread, size_t size) {

   // Retain tlab and allocate object in shared space if

   // the amount free in the tlab is too large to discard.

   if (thread->tlab().free() > thread->tlab().refill_waste_limit()) {

     thread->tlab().record_slow_allocation(size);

     return NULL;

   }

   // Discard tlab and allocate a new one.

   // To minimize fragmentation, the last TLAB may be smaller than the rest.

   size_t new_tlab_size = thread->tlab().compute_size(size);

   thread->tlab().clear_before_allocation();

   if (new_tlab_size == 0) {

     return NULL;

   }

   // Allocate a new TLAB...

   HeapWord* obj = Universe::heap()->allocate_new_tlab(new_tlab_size);

   if (obj == NULL) {

     return NULL;

   }

   if (ZeroTLAB) {

     // ..and clear it.

     Copy::zero_to_words(obj, new_tlab_size);

   } else {

     // ...and clear just the allocated object.

     Copy::zero_to_words(obj, size);

   }

   thread->tlab().fill(obj, obj + size, new_tlab_size);

   return obj;

 }

 size_t CollectedHeap::filler_array_hdr_size() {

   return size_t(arrayOopDesc::header_size(T_INT));

 }

 size_t CollectedHeap::filler_array_min_size() {

   return align_object_size(filler_array_hdr_size());

 }

 size_t CollectedHeap::filler_array_max_size() {

   return _filler_array_max_size;

 }

 #ifdef ASSERT

 void CollectedHeap::fill_args_check(HeapWord* start, size_t words)

 {

   assert(words >= min_fill_size(), "too small to fill");

   assert(words % MinObjAlignment == 0, "unaligned size");

   assert(Universe::heap()->is_in_reserved(start), "not in heap");

   assert(Universe::heap()->is_in_reserved(start + words - 1), "not in heap");

 }

 void CollectedHeap::zap_filler_array(HeapWord* start, size_t words)

 {

   if (ZapFillerObjects) {

     Copy::fill_to_words(start + filler_array_hdr_size(),

                         words - filler_array_hdr_size(), 0XDEAFBABE);

   }

 }

 #endif // ASSERT

 void

 CollectedHeap::fill_with_array(HeapWord* start, size_t words)

 {

   assert(words >= filler_array_min_size(), "too small for an array");

   assert(words <= filler_array_max_size(), "too big for a single object");

   const size_t payload_size = words - filler_array_hdr_size();

   const size_t len = payload_size * HeapWordSize / sizeof(jint);

   // Set the length first for concurrent GC.

   ((arrayOop)start)->set_length((int)len);

   post_allocation_setup_common(Universe::intArrayKlassObj(), start, words);

   DEBUG_ONLY(zap_filler_array(start, words);)

 }

 void

 CollectedHeap::fill_with_object_impl(HeapWord* start, size_t words)

 {

   assert(words <= filler_array_max_size(), "too big for a single object");

   if (words >= filler_array_min_size()) {

     fill_with_array(start, words);

   } else if (words > 0) {

     assert(words == min_fill_size(), "unaligned size");

     post_allocation_setup_common(SystemDictionary::object_klass(), start,

                                  words);

   }

 }

 void CollectedHeap::fill_with_object(HeapWord* start, size_t words)

 {

   DEBUG_ONLY(fill_args_check(start, words);)

   HandleMark hm;  // Free handles before leaving.

   fill_with_object_impl(start, words);

 }

 void CollectedHeap::fill_with_objects(HeapWord* start, size_t words)

 {

   DEBUG_ONLY(fill_args_check(start, words);)

   HandleMark hm;  // Free handles before leaving.

 #ifdef LP64

   // A single array can fill ~8G, so multiple objects are needed only in 64-bit.

   // First fill with arrays, ensuring that any remaining space is big enough to

   // fill.  The remainder is filled with a single object.

   const size_t min = min_fill_size();

   const size_t max = filler_array_max_size();

   while (words > max) {

     const size_t cur = words - max >= min ? max : max - min;

     fill_with_array(start, cur);

     start += cur;

     words -= cur;

   }

 #endif

   fill_with_object_impl(start, words);

 }

 oop CollectedHeap::new_store_barrier(oop new_obj) {

   // %%% This needs refactoring.  (It was imported from the server compiler.)

   guarantee(can_elide_tlab_store_barriers(), "store barrier elision not supported");

   BarrierSet* bs = this->barrier_set();

   assert(bs->has_write_region_opt(), "Barrier set does not have write_region");

   int new_size = new_obj->size();

   bs->write_region(MemRegion((HeapWord*)new_obj, new_size));

   return new_obj;

 }

 HeapWord* CollectedHeap::allocate_new_tlab(size_t size) {

   guarantee(false, "thread-local allocation buffers not supported");

   return NULL;

 }

 void CollectedHeap::fill_all_tlabs(bool retire) {

   assert(UseTLAB, "should not reach here");

   // See note in ensure_parsability() below.

   assert(SafepointSynchronize::is_at_safepoint() ||

          !is_init_completed(),

          "should only fill tlabs at safepoint");

   // The main thread starts allocating via a TLAB even before it

   // has added itself to the threads list at vm boot-up.

   assert(Threads::first() != NULL,

          "Attempt to fill tlabs before main thread has been added"

          " to threads list is doomed to failure!");

   for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {

      thread->tlab().make_parsable(retire);

   }

 }

 void CollectedHeap::ensure_parsability(bool retire_tlabs) {

   // The second disjunct in the assertion below makes a concession

   // for the start-up verification done while the VM is being

   // created. Callers be careful that you know that mutators

   // aren't going to interfere -- for instance, this is permissible

   // if we are still single-threaded and have either not yet

   // started allocating (nothing much to verify) or we have

   // started allocating but are now a full-fledged JavaThread

   // (and have thus made our TLAB's) available for filling.

   assert(SafepointSynchronize::is_at_safepoint() ||

          !is_init_completed(),

          "Should only be called at a safepoint or at start-up"

          " otherwise concurrent mutator activity may make heap "

          " unparsable again");

   if (UseTLAB) {

     fill_all_tlabs(retire_tlabs);

   }

 }

 void CollectedHeap::accumulate_statistics_all_tlabs() {

   if (UseTLAB) {

     assert(SafepointSynchronize::is_at_safepoint() ||

          !is_init_completed(),

          "should only accumulate statistics on tlabs at safepoint");

     ThreadLocalAllocBuffer::accumulate_statistics_before_gc();

   }

 }

 void CollectedHeap::resize_all_tlabs() {

   if (UseTLAB) {

     assert(SafepointSynchronize::is_at_safepoint() ||

          !is_init_completed(),

          "should only resize tlabs at safepoint");

     ThreadLocalAllocBuffer::resize_all_tlabs();

   }

 }