1/* Licensed to the Apache Software Foundation (ASF) under one or more 2 * contributor license agreements. See the NOTICE file distributed with 3 * this work for additional information regarding copyright ownership. 4 * The ASF licenses this file to You under the Apache License, Version 2.0 5 * (the "License"); you may not use this file except in compliance with 6 * the License. You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include "apr_arch_atomic.h" 18 19#ifdef USE_ATOMICS_IA32 20 21APR_DECLARE(apr_status_t) apr_atomic_init(apr_pool_t *p) 22{ 23#if defined (NEED_ATOMICS_GENERIC64) 24 return apr__atomic_generic64_init(p); 25#else 26 return APR_SUCCESS; 27#endif 28} 29 30APR_DECLARE(apr_uint32_t) apr_atomic_read32(volatile apr_uint32_t *mem) 31{ 32 return *mem; 33} 34 35APR_DECLARE(void) apr_atomic_set32(volatile apr_uint32_t *mem, apr_uint32_t val) 36{ 37 *mem = val; 38} 39 40APR_DECLARE(apr_uint32_t) apr_atomic_add32(volatile apr_uint32_t *mem, apr_uint32_t val) 41{ 42 asm volatile ("lock; xaddl %0,%1" 43 : "=r" (val), "=m" (*mem) 44 : "0" (val), "m" (*mem) 45 : "memory", "cc"); 46 return val; 47} 48 49APR_DECLARE(void) apr_atomic_sub32(volatile apr_uint32_t *mem, apr_uint32_t val) 50{ 51 asm volatile ("lock; subl %1, %0" 52 : /* no output */ 53 : "m" (*(mem)), "r" (val) 54 : "memory", "cc"); 55} 56 57APR_DECLARE(apr_uint32_t) apr_atomic_inc32(volatile apr_uint32_t *mem) 58{ 59 return apr_atomic_add32(mem, 1); 60} 61 62APR_DECLARE(int) apr_atomic_dec32(volatile apr_uint32_t *mem) 63{ 64 unsigned char prev; 65 66 asm volatile ("lock; decl %0; setnz %1" 67 : "=m" (*mem), "=qm" (prev) 68 : "m" (*mem) 69 : "memory"); 70 71 return prev; 72} 73 74APR_DECLARE(apr_uint32_t) apr_atomic_cas32(volatile apr_uint32_t *mem, apr_uint32_t with, 75 apr_uint32_t cmp) 76{ 77 apr_uint32_t prev; 78 79 asm volatile ("lock; cmpxchgl %1, %2" 80 : "=a" (prev) 81 : "r" (with), "m" (*(mem)), "0"(cmp) 82 : "memory", "cc"); 83 return prev; 84} 85 86APR_DECLARE(apr_uint32_t) apr_atomic_xchg32(volatile apr_uint32_t *mem, apr_uint32_t val) 87{ 88 apr_uint32_t prev = val; 89 90 asm volatile ("xchgl %0, %1" 91 : "=r" (prev), "+m" (*mem) 92 : "0" (prev)); 93 return prev; 94} 95 96APR_DECLARE(void*) apr_atomic_casptr(volatile void **mem, void *with, const void *cmp) 97{ 98 void *prev; 99#if APR_SIZEOF_VOIDP == 4 100 asm volatile ("lock; cmpxchgl %2, %1" 101 : "=a" (prev), "=m" (*mem) 102 : "r" (with), "m" (*mem), "0" (cmp)); 103#elif APR_SIZEOF_VOIDP == 8 104 asm volatile ("lock; cmpxchgq %q2, %1" 105 : "=a" (prev), "=m" (*mem) 106 : "r" ((unsigned long)with), "m" (*mem), 107 "0" ((unsigned long)cmp)); 108#else 109#error APR_SIZEOF_VOIDP value not supported 110#endif 111 return prev; 112} 113 114APR_DECLARE(void*) apr_atomic_xchgptr(volatile void **mem, void *with) 115{ 116 void *prev; 117#if APR_SIZEOF_VOIDP == 4 118 asm volatile ("xchgl %2, %1" 119 : "=a" (prev), "+m" (*mem) 120 : "0" (with)); 121#elif APR_SIZEOF_VOIDP == 8 122 asm volatile ("xchgq %q2, %1" 123 : "=a" (prev), "+m" (*mem) 124 : "0" (with)); 125#else 126#error APR_SIZEOF_VOIDP value not supported 127#endif 128 return prev; 129} 130 131#endif /* USE_ATOMICS_IA32 */ 132