1 /* 2 * Copyright (c) 2020, Red Hat, Inc. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHEVACLOCKINGBITMAP_INLINE_HPP 26 #define SHARE_GC_SHENANDOAH_SHENANDOAHEVACLOCKINGBITMAP_INLINE_HPP 27 28 #include "gc/shenandoah/shenandoahEvacLockingBitmap.hpp" 29 #include "memory/memRegion.hpp" 30 #include "oops/oopsHierarchy.hpp" 31 #include "utilities/bitMap.hpp" 32 33 inline size_t ShenandoahEvacLockingBitmap::addr_to_offset(const HeapWord* addr) const { 34 return pointer_delta(addr, _covered.start()) >> _shifter; 35 } 36 37 inline void ShenandoahEvacLockingBitmap::acquire(oop obj) { 38 size_t offset = addr_to_offset(cast_from_oop<HeapWord*>(obj)); 39 int ctr = 0; 40 int yields = 0; 41 while (!_bm.par_set_bit(offset)) { 42 // Spin/yield/sleep-strategy inspired by Thread::SpinAcquire() 43 ++ctr; 44 if ((ctr & 0xFFF) == 0 || !os::is_MP()) { 45 if (yields > 5) { 46 os::naked_short_sleep(1); 47 } else { 48 os::naked_yield(); 49 ++yields; 50 } 51 } else { 52 SpinPause(); 53 } 54 55 } 56 } 57 58 inline void ShenandoahEvacLockingBitmap::release(oop obj) { 59 size_t offset = addr_to_offset(cast_from_oop<HeapWord*>(obj)); 60 assert(_bm.at(offset), ""); 61 bool success = _bm.par_clear_bit(offset); 62 assert(success, ""); 63 } 64 65 inline ShenandoahEvacLocker::ShenandoahEvacLocker(ShenandoahEvacLockingBitmap* bitmap, oop obj): 66 _bitmap(bitmap), _obj(obj) { 67 _bitmap->acquire(_obj); 68 } 69 70 inline ShenandoahEvacLocker::~ShenandoahEvacLocker() { 71 _bitmap->release(_obj); 72 } 73 74 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHEVACLOCKINGBITMAP_INLINE_HPP