Mercurial > hg > graal-compiler
view src/share/vm/gc_implementation/g1/g1AllocRegion.cpp @ 14692:8504393de66b
8037043: put Method flag bits in predictable positions
Reviewed-by: kvn, coleenp
author | twisti |
---|---|
date | Tue, 11 Mar 2014 14:54:47 -0700 |
parents | 720b6a76dd9d |
children | 78bbf4d43a14 |
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/* * Copyright (c) 2011, 2012, 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/g1/g1AllocRegion.inline.hpp" #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" G1CollectedHeap* G1AllocRegion::_g1h = NULL; HeapRegion* G1AllocRegion::_dummy_region = NULL; void G1AllocRegion::setup(G1CollectedHeap* g1h, HeapRegion* dummy_region) { assert(_dummy_region == NULL, "should be set once"); assert(dummy_region != NULL, "pre-condition"); assert(dummy_region->free() == 0, "pre-condition"); // Make sure that any allocation attempt on this region will fail // and will not trigger any asserts. assert(allocate(dummy_region, 1, false) == NULL, "should fail"); assert(par_allocate(dummy_region, 1, false) == NULL, "should fail"); assert(allocate(dummy_region, 1, true) == NULL, "should fail"); assert(par_allocate(dummy_region, 1, true) == NULL, "should fail"); _g1h = g1h; _dummy_region = dummy_region; } void G1AllocRegion::fill_up_remaining_space(HeapRegion* alloc_region, bool bot_updates) { assert(alloc_region != NULL && alloc_region != _dummy_region, "pre-condition"); // Other threads might still be trying to allocate using a CAS out // of the region we are trying to retire, as they can do so without // holding the lock. So, we first have to make sure that noone else // can allocate out of it by doing a maximal allocation. Even if our // CAS attempt fails a few times, we'll succeed sooner or later // given that failed CAS attempts mean that the region is getting // closed to being full. size_t free_word_size = alloc_region->free() / HeapWordSize; // This is the minimum free chunk we can turn into a dummy // object. If the free space falls below this, then noone can // allocate in this region anyway (all allocation requests will be // of a size larger than this) so we won't have to perform the dummy // allocation. size_t min_word_size_to_fill = CollectedHeap::min_fill_size(); while (free_word_size >= min_word_size_to_fill) { HeapWord* dummy = par_allocate(alloc_region, free_word_size, bot_updates); if (dummy != NULL) { // If the allocation was successful we should fill in the space. CollectedHeap::fill_with_object(dummy, free_word_size); alloc_region->set_pre_dummy_top(dummy); break; } free_word_size = alloc_region->free() / HeapWordSize; // It's also possible that someone else beats us to the // allocation and they fill up the region. In that case, we can // just get out of the loop. } assert(alloc_region->free() / HeapWordSize < min_word_size_to_fill, "post-condition"); } void G1AllocRegion::retire(bool fill_up) { assert(_alloc_region != NULL, ar_ext_msg(this, "not initialized properly")); trace("retiring"); HeapRegion* alloc_region = _alloc_region; if (alloc_region != _dummy_region) { // We never have to check whether the active region is empty or not, // and potentially free it if it is, given that it's guaranteed that // it will never be empty. assert(!alloc_region->is_empty(), ar_ext_msg(this, "the alloc region should never be empty")); if (fill_up) { fill_up_remaining_space(alloc_region, _bot_updates); } assert(alloc_region->used() >= _used_bytes_before, ar_ext_msg(this, "invariant")); size_t allocated_bytes = alloc_region->used() - _used_bytes_before; retire_region(alloc_region, allocated_bytes); _used_bytes_before = 0; _alloc_region = _dummy_region; } trace("retired"); } HeapWord* G1AllocRegion::new_alloc_region_and_allocate(size_t word_size, bool force) { assert(_alloc_region == _dummy_region, ar_ext_msg(this, "pre-condition")); assert(_used_bytes_before == 0, ar_ext_msg(this, "pre-condition")); trace("attempting region allocation"); HeapRegion* new_alloc_region = allocate_new_region(word_size, force); if (new_alloc_region != NULL) { new_alloc_region->reset_pre_dummy_top(); // Need to do this before the allocation _used_bytes_before = new_alloc_region->used(); HeapWord* result = allocate(new_alloc_region, word_size, _bot_updates); assert(result != NULL, ar_ext_msg(this, "the allocation should succeeded")); OrderAccess::storestore(); // Note that we first perform the allocation and then we store the // region in _alloc_region. This is the reason why an active region // can never be empty. _alloc_region = new_alloc_region; _count += 1; trace("region allocation successful"); return result; } else { trace("region allocation failed"); return NULL; } ShouldNotReachHere(); } void G1AllocRegion::fill_in_ext_msg(ar_ext_msg* msg, const char* message) { msg->append("[%s] %s c: %u b: %s r: "PTR_FORMAT" u: "SIZE_FORMAT, _name, message, _count, BOOL_TO_STR(_bot_updates), _alloc_region, _used_bytes_before); } void G1AllocRegion::init() { trace("initializing"); assert(_alloc_region == NULL && _used_bytes_before == 0, ar_ext_msg(this, "pre-condition")); assert(_dummy_region != NULL, ar_ext_msg(this, "should have been set")); _alloc_region = _dummy_region; _count = 0; trace("initialized"); } void G1AllocRegion::set(HeapRegion* alloc_region) { trace("setting"); // We explicitly check that the region is not empty to make sure we // maintain the "the alloc region cannot be empty" invariant. assert(alloc_region != NULL && !alloc_region->is_empty(), ar_ext_msg(this, "pre-condition")); assert(_alloc_region == _dummy_region && _used_bytes_before == 0 && _count == 0, ar_ext_msg(this, "pre-condition")); _used_bytes_before = alloc_region->used(); _alloc_region = alloc_region; _count += 1; trace("set"); } HeapRegion* G1AllocRegion::release() { trace("releasing"); HeapRegion* alloc_region = _alloc_region; retire(false /* fill_up */); assert(_alloc_region == _dummy_region, ar_ext_msg(this, "post-condition of retire()")); _alloc_region = NULL; trace("released"); return (alloc_region == _dummy_region) ? NULL : alloc_region; } #if G1_ALLOC_REGION_TRACING void G1AllocRegion::trace(const char* str, size_t word_size, HeapWord* result) { // All the calls to trace that set either just the size or the size // and the result are considered part of level 2 tracing and are // skipped during level 1 tracing. if ((word_size == 0 && result == NULL) || (G1_ALLOC_REGION_TRACING > 1)) { const size_t buffer_length = 128; char hr_buffer[buffer_length]; char rest_buffer[buffer_length]; HeapRegion* alloc_region = _alloc_region; if (alloc_region == NULL) { jio_snprintf(hr_buffer, buffer_length, "NULL"); } else if (alloc_region == _dummy_region) { jio_snprintf(hr_buffer, buffer_length, "DUMMY"); } else { jio_snprintf(hr_buffer, buffer_length, HR_FORMAT, HR_FORMAT_PARAMS(alloc_region)); } if (G1_ALLOC_REGION_TRACING > 1) { if (result != NULL) { jio_snprintf(rest_buffer, buffer_length, SIZE_FORMAT" "PTR_FORMAT, word_size, result); } else if (word_size != 0) { jio_snprintf(rest_buffer, buffer_length, SIZE_FORMAT, word_size); } else { jio_snprintf(rest_buffer, buffer_length, ""); } } else { jio_snprintf(rest_buffer, buffer_length, ""); } tty->print_cr("[%s] %u %s : %s %s", _name, _count, hr_buffer, str, rest_buffer); } } #endif // G1_ALLOC_REGION_TRACING G1AllocRegion::G1AllocRegion(const char* name, bool bot_updates) : _name(name), _bot_updates(bot_updates), _alloc_region(NULL), _count(0), _used_bytes_before(0) { }