duke@435: /*
xdono@1014:  * Copyright 2001-2009 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/_collectedHeap.cpp.incl"
duke@435: 
duke@435: 
duke@435: #ifdef ASSERT
duke@435: int CollectedHeap::_fire_out_of_memory_count = 0;
duke@435: #endif
duke@435: 
jcoomes@916: size_t CollectedHeap::_filler_array_max_size = 0;
jcoomes@916: 
duke@435: // Memory state functions.
duke@435: 
jcoomes@916: CollectedHeap::CollectedHeap()
jcoomes@916: {
jcoomes@916:   const size_t max_len = size_t(arrayOopDesc::max_array_length(T_INT));
jcoomes@916:   const size_t elements_per_word = HeapWordSize / sizeof(jint);
jcoomes@916:   _filler_array_max_size = align_object_size(filler_array_hdr_size() +
jcoomes@916:                                              max_len * elements_per_word);
jcoomes@916: 
jcoomes@916:   _barrier_set = NULL;
jcoomes@916:   _is_gc_active = false;
jcoomes@916:   _total_collections = _total_full_collections = 0;
jcoomes@916:   _gc_cause = _gc_lastcause = GCCause::_no_gc;
duke@435:   NOT_PRODUCT(_promotion_failure_alot_count = 0;)
duke@435:   NOT_PRODUCT(_promotion_failure_alot_gc_number = 0;)
duke@435: 
duke@435:   if (UsePerfData) {
duke@435:     EXCEPTION_MARK;
duke@435: 
duke@435:     // create the gc cause jvmstat counters
duke@435:     _perf_gc_cause = PerfDataManager::create_string_variable(SUN_GC, "cause",
duke@435:                              80, GCCause::to_string(_gc_cause), CHECK);
duke@435: 
duke@435:     _perf_gc_lastcause =
duke@435:                 PerfDataManager::create_string_variable(SUN_GC, "lastCause",
duke@435:                              80, GCCause::to_string(_gc_lastcause), CHECK);
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: #ifndef PRODUCT
duke@435: void CollectedHeap::check_for_bad_heap_word_value(HeapWord* addr, size_t size) {
duke@435:   if (CheckMemoryInitialization && ZapUnusedHeapArea) {
duke@435:     for (size_t slot = 0; slot < size; slot += 1) {
duke@435:       assert((*(intptr_t*) (addr + slot)) != ((intptr_t) badHeapWordVal),
duke@435:              "Found badHeapWordValue in post-allocation check");
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: void CollectedHeap::check_for_non_bad_heap_word_value(HeapWord* addr, size_t size)
duke@435:  {
duke@435:   if (CheckMemoryInitialization && ZapUnusedHeapArea) {
duke@435:     for (size_t slot = 0; slot < size; slot += 1) {
duke@435:       assert((*(intptr_t*) (addr + slot)) == ((intptr_t) badHeapWordVal),
duke@435:              "Found non badHeapWordValue in pre-allocation check");
duke@435:     }
duke@435:   }
duke@435: }
duke@435: #endif // PRODUCT
duke@435: 
duke@435: #ifdef ASSERT
duke@435: void CollectedHeap::check_for_valid_allocation_state() {
duke@435:   Thread *thread = Thread::current();
duke@435:   // How to choose between a pending exception and a potential
duke@435:   // OutOfMemoryError?  Don't allow pending exceptions.
duke@435:   // This is a VM policy failure, so how do we exhaustively test it?
duke@435:   assert(!thread->has_pending_exception(),
duke@435:          "shouldn't be allocating with pending exception");
duke@435:   if (StrictSafepointChecks) {
duke@435:     assert(thread->allow_allocation(),
duke@435:            "Allocation done by thread for which allocation is blocked "
duke@435:            "by No_Allocation_Verifier!");
duke@435:     // Allocation of an oop can always invoke a safepoint,
duke@435:     // hence, the true argument
duke@435:     thread->check_for_valid_safepoint_state(true);
duke@435:   }
duke@435: }
duke@435: #endif
duke@435: 
duke@435: HeapWord* CollectedHeap::allocate_from_tlab_slow(Thread* thread, size_t size) {
duke@435: 
duke@435:   // Retain tlab and allocate object in shared space if
duke@435:   // the amount free in the tlab is too large to discard.
duke@435:   if (thread->tlab().free() > thread->tlab().refill_waste_limit()) {
duke@435:     thread->tlab().record_slow_allocation(size);
duke@435:     return NULL;
duke@435:   }
duke@435: 
duke@435:   // Discard tlab and allocate a new one.
duke@435:   // To minimize fragmentation, the last TLAB may be smaller than the rest.
duke@435:   size_t new_tlab_size = thread->tlab().compute_size(size);
duke@435: 
duke@435:   thread->tlab().clear_before_allocation();
duke@435: 
duke@435:   if (new_tlab_size == 0) {
duke@435:     return NULL;
duke@435:   }
duke@435: 
duke@435:   // Allocate a new TLAB...
duke@435:   HeapWord* obj = Universe::heap()->allocate_new_tlab(new_tlab_size);
duke@435:   if (obj == NULL) {
duke@435:     return NULL;
duke@435:   }
duke@435:   if (ZeroTLAB) {
duke@435:     // ..and clear it.
duke@435:     Copy::zero_to_words(obj, new_tlab_size);
duke@435:   } else {
duke@435:     // ...and clear just the allocated object.
duke@435:     Copy::zero_to_words(obj, size);
duke@435:   }
duke@435:   thread->tlab().fill(obj, obj + size, new_tlab_size);
duke@435:   return obj;
duke@435: }
duke@435: 
jcoomes@916: size_t CollectedHeap::filler_array_hdr_size() {
jcoomes@916:   return size_t(arrayOopDesc::header_size(T_INT));
jcoomes@916: }
jcoomes@916: 
jcoomes@916: size_t CollectedHeap::filler_array_min_size() {
jcoomes@916:   return align_object_size(filler_array_hdr_size());
jcoomes@916: }
jcoomes@916: 
jcoomes@916: size_t CollectedHeap::filler_array_max_size() {
jcoomes@916:   return _filler_array_max_size;
jcoomes@916: }
jcoomes@916: 
jcoomes@916: #ifdef ASSERT
jcoomes@916: void CollectedHeap::fill_args_check(HeapWord* start, size_t words)
jcoomes@916: {
jcoomes@916:   assert(words >= min_fill_size(), "too small to fill");
jcoomes@916:   assert(words % MinObjAlignment == 0, "unaligned size");
jcoomes@916:   assert(Universe::heap()->is_in_reserved(start), "not in heap");
jcoomes@916:   assert(Universe::heap()->is_in_reserved(start + words - 1), "not in heap");
jcoomes@916: }
jcoomes@916: 
jcoomes@916: void CollectedHeap::zap_filler_array(HeapWord* start, size_t words)
jcoomes@916: {
jcoomes@916:   if (ZapFillerObjects) {
jcoomes@916:     Copy::fill_to_words(start + filler_array_hdr_size(),
jcoomes@916:                         words - filler_array_hdr_size(), 0XDEAFBABE);
jcoomes@916:   }
jcoomes@916: }
jcoomes@916: #endif // ASSERT
jcoomes@916: 
jcoomes@916: void
jcoomes@916: CollectedHeap::fill_with_array(HeapWord* start, size_t words)
jcoomes@916: {
jcoomes@916:   assert(words >= filler_array_min_size(), "too small for an array");
jcoomes@916:   assert(words <= filler_array_max_size(), "too big for a single object");
jcoomes@916: 
jcoomes@916:   const size_t payload_size = words - filler_array_hdr_size();
jcoomes@916:   const size_t len = payload_size * HeapWordSize / sizeof(jint);
jcoomes@916: 
jcoomes@916:   // Set the length first for concurrent GC.
jcoomes@916:   ((arrayOop)start)->set_length((int)len);
jcoomes@929:   post_allocation_setup_common(Universe::intArrayKlassObj(), start, words);
jcoomes@916:   DEBUG_ONLY(zap_filler_array(start, words);)
jcoomes@916: }
jcoomes@916: 
jcoomes@916: void
jcoomes@916: CollectedHeap::fill_with_object_impl(HeapWord* start, size_t words)
jcoomes@916: {
jcoomes@916:   assert(words <= filler_array_max_size(), "too big for a single object");
jcoomes@916: 
jcoomes@916:   if (words >= filler_array_min_size()) {
jcoomes@916:     fill_with_array(start, words);
jcoomes@916:   } else if (words > 0) {
jcoomes@916:     assert(words == min_fill_size(), "unaligned size");
jcoomes@916:     post_allocation_setup_common(SystemDictionary::object_klass(), start,
jcoomes@916:                                  words);
jcoomes@916:   }
jcoomes@916: }
jcoomes@916: 
jcoomes@916: void CollectedHeap::fill_with_object(HeapWord* start, size_t words)
jcoomes@916: {
jcoomes@916:   DEBUG_ONLY(fill_args_check(start, words);)
jcoomes@916:   HandleMark hm;  // Free handles before leaving.
jcoomes@916:   fill_with_object_impl(start, words);
jcoomes@916: }
jcoomes@916: 
jcoomes@916: void CollectedHeap::fill_with_objects(HeapWord* start, size_t words)
jcoomes@916: {
jcoomes@916:   DEBUG_ONLY(fill_args_check(start, words);)
jcoomes@916:   HandleMark hm;  // Free handles before leaving.
jcoomes@916: 
jcoomes@916: #ifdef LP64
jcoomes@916:   // A single array can fill ~8G, so multiple objects are needed only in 64-bit.
jcoomes@916:   // First fill with arrays, ensuring that any remaining space is big enough to
jcoomes@916:   // fill.  The remainder is filled with a single object.
jcoomes@916:   const size_t min = min_fill_size();
jcoomes@916:   const size_t max = filler_array_max_size();
jcoomes@916:   while (words > max) {
jcoomes@916:     const size_t cur = words - max >= min ? max : max - min;
jcoomes@916:     fill_with_array(start, cur);
jcoomes@916:     start += cur;
jcoomes@916:     words -= cur;
jcoomes@916:   }
jcoomes@916: #endif
jcoomes@916: 
jcoomes@916:   fill_with_object_impl(start, words);
jcoomes@916: }
jcoomes@916: 
duke@435: oop CollectedHeap::new_store_barrier(oop new_obj) {
duke@435:   // %%% This needs refactoring.  (It was imported from the server compiler.)
duke@435:   guarantee(can_elide_tlab_store_barriers(), "store barrier elision not supported");
duke@435:   BarrierSet* bs = this->barrier_set();
duke@435:   assert(bs->has_write_region_opt(), "Barrier set does not have write_region");
duke@435:   int new_size = new_obj->size();
duke@435:   bs->write_region(MemRegion((HeapWord*)new_obj, new_size));
duke@435:   return new_obj;
duke@435: }
duke@435: 
duke@435: HeapWord* CollectedHeap::allocate_new_tlab(size_t size) {
duke@435:   guarantee(false, "thread-local allocation buffers not supported");
duke@435:   return NULL;
duke@435: }
duke@435: 
duke@435: void CollectedHeap::fill_all_tlabs(bool retire) {
duke@435:   assert(UseTLAB, "should not reach here");
duke@435:   // See note in ensure_parsability() below.
duke@435:   assert(SafepointSynchronize::is_at_safepoint() ||
duke@435:          !is_init_completed(),
duke@435:          "should only fill tlabs at safepoint");
duke@435:   // The main thread starts allocating via a TLAB even before it
duke@435:   // has added itself to the threads list at vm boot-up.
duke@435:   assert(Threads::first() != NULL,
duke@435:          "Attempt to fill tlabs before main thread has been added"
duke@435:          " to threads list is doomed to failure!");
duke@435:   for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
duke@435:      thread->tlab().make_parsable(retire);
duke@435:   }
duke@435: }
duke@435: 
duke@435: void CollectedHeap::ensure_parsability(bool retire_tlabs) {
duke@435:   // The second disjunct in the assertion below makes a concession
duke@435:   // for the start-up verification done while the VM is being
duke@435:   // created. Callers be careful that you know that mutators
duke@435:   // aren't going to interfere -- for instance, this is permissible
duke@435:   // if we are still single-threaded and have either not yet
duke@435:   // started allocating (nothing much to verify) or we have
duke@435:   // started allocating but are now a full-fledged JavaThread
duke@435:   // (and have thus made our TLAB's) available for filling.
duke@435:   assert(SafepointSynchronize::is_at_safepoint() ||
duke@435:          !is_init_completed(),
duke@435:          "Should only be called at a safepoint or at start-up"
duke@435:          " otherwise concurrent mutator activity may make heap "
duke@435:          " unparsable again");
duke@435:   if (UseTLAB) {
duke@435:     fill_all_tlabs(retire_tlabs);
duke@435:   }
duke@435: }
duke@435: 
duke@435: void CollectedHeap::accumulate_statistics_all_tlabs() {
duke@435:   if (UseTLAB) {
duke@435:     assert(SafepointSynchronize::is_at_safepoint() ||
duke@435:          !is_init_completed(),
duke@435:          "should only accumulate statistics on tlabs at safepoint");
duke@435: 
duke@435:     ThreadLocalAllocBuffer::accumulate_statistics_before_gc();
duke@435:   }
duke@435: }
duke@435: 
duke@435: void CollectedHeap::resize_all_tlabs() {
duke@435:   if (UseTLAB) {
duke@435:     assert(SafepointSynchronize::is_at_safepoint() ||
duke@435:          !is_init_completed(),
duke@435:          "should only resize tlabs at safepoint");
duke@435: 
duke@435:     ThreadLocalAllocBuffer::resize_all_tlabs();
duke@435:   }
duke@435: }
ysr@1050: 
ysr@1050: void CollectedHeap::pre_full_gc_dump() {
ysr@1050:   if (HeapDumpBeforeFullGC) {
ysr@1050:     TraceTime tt("Heap Dump: ", PrintGCDetails, false, gclog_or_tty);
ysr@1050:     // We are doing a "major" collection and a heap dump before
ysr@1050:     // major collection has been requested.
ysr@1050:     HeapDumper::dump_heap();
ysr@1050:   }
ysr@1050:   if (PrintClassHistogramBeforeFullGC) {
ysr@1050:     TraceTime tt("Class Histogram: ", PrintGCDetails, true, gclog_or_tty);
ysr@1050:     VM_GC_HeapInspection inspector(gclog_or_tty, false /* ! full gc */, false /* ! prologue */);
ysr@1050:     inspector.doit();
ysr@1050:   }
ysr@1050: }
ysr@1050: 
ysr@1050: void CollectedHeap::post_full_gc_dump() {
ysr@1050:   if (HeapDumpAfterFullGC) {
ysr@1050:     TraceTime tt("Heap Dump", PrintGCDetails, false, gclog_or_tty);
ysr@1050:     HeapDumper::dump_heap();
ysr@1050:   }
ysr@1050:   if (PrintClassHistogramAfterFullGC) {
ysr@1050:     TraceTime tt("Class Histogram", PrintGCDetails, true, gclog_or_tty);
ysr@1050:     VM_GC_HeapInspection inspector(gclog_or_tty, false /* ! full gc */, false /* ! prologue */);
ysr@1050:     inspector.doit();
ysr@1050:   }
ysr@1050: }