1 /* 2 * Copyright (c) 2016, 2018, Oracle and/or its affiliates. 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_VM_JFR_CHECKPOINT_TYPES_TRACEID_JFRTRACEIDBITS_INLINE_HPP 26 #define SHARE_VM_JFR_CHECKPOINT_TYPES_TRACEID_JFRTRACEIDBITS_INLINE_HPP 27 28 #include "jfr/utilities/jfrTypes.hpp" 29 #include "runtime/atomic.hpp" 30 #include "runtime/orderAccess.hpp" 31 #include "utilities/macros.hpp" 32 33 #ifdef VM_LITTLE_ENDIAN 34 static const int low_offset = 0; 35 static const int leakp_offset = low_offset + 1; 36 #else 37 static const int low_offset = 7; 38 static const int leakp_offset = low_offset - 1; 39 #endif 40 41 inline void set_bits(jbyte bits, jbyte* const dest) { 42 assert(dest != NULL, "invariant"); 43 const jbyte current = OrderAccess::load_acquire(dest); 44 if (bits != (current & bits)) { 45 *dest |= bits; 46 } 47 } 48 49 inline void set_mask(jbyte mask, jbyte* const dest) { 50 assert(dest != NULL, "invariant"); 51 const jbyte current = OrderAccess::load_acquire(dest); 52 if (mask != (current & mask)) { 53 *dest &= mask; 54 } 55 } 56 57 inline void set_bits_cas(jbyte bits, jbyte* const dest) { 58 assert(dest != NULL, "invariant"); 59 do { 60 const jbyte current = OrderAccess::load_acquire(dest); 61 if (bits == (current & bits)) { 62 return; 63 } 64 const jbyte new_value = current | bits; 65 if (Atomic::cmpxchg(new_value, dest, current) == current) { 66 return; 67 } 68 } while (true); 69 } 70 71 inline void clear_bits_cas(jbyte bits, jbyte* const dest) { 72 assert(dest != NULL, "invariant"); 73 do { 74 const jbyte current = OrderAccess::load_acquire(dest); 75 if (bits != (current & bits)) { 76 return; 77 } 78 const jbyte new_value = current ^ bits; 79 if (Atomic::cmpxchg(new_value, dest, current) == current) { 80 return; 81 } 82 } while (true); 83 } 84 85 inline void set_traceid_bits(jbyte bits, traceid* dest) { 86 set_bits(bits, ((jbyte*)dest) + low_offset); 87 } 88 89 inline void set_traceid_bits_cas(jbyte bits, traceid* dest) { 90 set_bits_cas(bits, ((jbyte*)dest) + low_offset); 91 } 92 93 inline void set_traceid_mask(jbyte mask, traceid* dest) { 94 set_mask(mask, ((jbyte*)dest) + low_offset); 95 } 96 97 inline void set_leakp_traceid_bits(jbyte bits, traceid* dest) { 98 set_bits(bits, ((jbyte*)dest) + leakp_offset); 99 } 100 101 inline void set_leakp_traceid_bits_cas(jbyte bits, traceid* dest) { 102 set_bits_cas(bits, ((jbyte*)dest) + leakp_offset); 103 } 104 105 inline void set_leakp_traceid_mask(jbyte mask, traceid* dest) { 106 set_mask(mask, ((jbyte*)dest) + leakp_offset); 107 } 108 109 #endif // SHARE_VM_JFR_CHECKPOINT_TYPES_TRACEID_JFRTRACEIDBITS_INLINE_HPP 110