| /* Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "apr_arch_atomic.h" |
| |
| #ifdef USE_ATOMICS_GENERIC |
| |
| #include <stdlib.h> |
| |
| #if APR_HAS_THREADS |
| # define DECLARE_MUTEX_LOCKED(name, mem) \ |
| apr_thread_mutex_t *name = mutex_hash(mem) |
| # define MUTEX_UNLOCK(name) \ |
| do { \ |
| if (apr_thread_mutex_unlock(name) != APR_SUCCESS) \ |
| abort(); \ |
| } while (0) |
| #else |
| # define DECLARE_MUTEX_LOCKED(name, mem) |
| # define MUTEX_UNLOCK(name) |
| # warning Be warned: using stubs for all atomic operations |
| #endif |
| |
| #if APR_HAS_THREADS |
| |
| static apr_thread_mutex_t **hash_mutex; |
| |
| #define NUM_ATOMIC_HASH 7 |
| /* shift by 2 to get rid of alignment issues */ |
| #define ATOMIC_HASH(x) (unsigned int)(((unsigned long)(x)>>2)%(unsigned int)NUM_ATOMIC_HASH) |
| |
| static apr_status_t atomic_cleanup(void *data) |
| { |
| if (hash_mutex == data) |
| hash_mutex = NULL; |
| |
| return APR_SUCCESS; |
| } |
| |
| APR_DECLARE(apr_status_t) apr_atomic_init(apr_pool_t *p) |
| { |
| int i; |
| apr_status_t rv; |
| |
| if (hash_mutex != NULL) |
| return APR_SUCCESS; |
| |
| hash_mutex = apr_palloc(p, sizeof(apr_thread_mutex_t*) * NUM_ATOMIC_HASH); |
| apr_pool_cleanup_register(p, hash_mutex, atomic_cleanup, |
| apr_pool_cleanup_null); |
| |
| for (i = 0; i < NUM_ATOMIC_HASH; i++) { |
| rv = apr_thread_mutex_create(&(hash_mutex[i]), |
| APR_THREAD_MUTEX_DEFAULT, p); |
| if (rv != APR_SUCCESS) { |
| return rv; |
| } |
| } |
| |
| return APR_SUCCESS; |
| } |
| |
| static APR_INLINE apr_thread_mutex_t *mutex_hash(volatile apr_uint32_t *mem) |
| { |
| apr_thread_mutex_t *mutex = hash_mutex[ATOMIC_HASH(mem)]; |
| |
| if (apr_thread_mutex_lock(mutex) != APR_SUCCESS) { |
| abort(); |
| } |
| |
| return mutex; |
| } |
| |
| #else |
| |
| APR_DECLARE(apr_status_t) apr_atomic_init(apr_pool_t *p) |
| { |
| return APR_SUCCESS; |
| } |
| |
| #endif /* APR_HAS_THREADS */ |
| |
| APR_DECLARE(apr_uint32_t) apr_atomic_read32(volatile apr_uint32_t *mem) |
| { |
| return *mem; |
| } |
| |
| APR_DECLARE(void) apr_atomic_set32(volatile apr_uint32_t *mem, apr_uint32_t val) |
| { |
| DECLARE_MUTEX_LOCKED(mutex, mem); |
| |
| *mem = val; |
| |
| MUTEX_UNLOCK(mutex); |
| } |
| |
| APR_DECLARE(apr_uint32_t) apr_atomic_add32(volatile apr_uint32_t *mem, apr_uint32_t val) |
| { |
| apr_uint32_t old_value; |
| DECLARE_MUTEX_LOCKED(mutex, mem); |
| |
| old_value = *mem; |
| *mem += val; |
| |
| MUTEX_UNLOCK(mutex); |
| |
| return old_value; |
| } |
| |
| APR_DECLARE(void) apr_atomic_sub32(volatile apr_uint32_t *mem, apr_uint32_t val) |
| { |
| DECLARE_MUTEX_LOCKED(mutex, mem); |
| *mem -= val; |
| MUTEX_UNLOCK(mutex); |
| } |
| |
| APR_DECLARE(apr_uint32_t) apr_atomic_inc32(volatile apr_uint32_t *mem) |
| { |
| return apr_atomic_add32(mem, 1); |
| } |
| |
| APR_DECLARE(int) apr_atomic_dec32(volatile apr_uint32_t *mem) |
| { |
| apr_uint32_t new; |
| DECLARE_MUTEX_LOCKED(mutex, mem); |
| |
| (*mem)--; |
| new = *mem; |
| |
| MUTEX_UNLOCK(mutex); |
| |
| return new; |
| } |
| |
| APR_DECLARE(apr_uint32_t) apr_atomic_cas32(volatile apr_uint32_t *mem, apr_uint32_t with, |
| apr_uint32_t cmp) |
| { |
| apr_uint32_t prev; |
| DECLARE_MUTEX_LOCKED(mutex, mem); |
| |
| prev = *mem; |
| if (prev == cmp) { |
| *mem = with; |
| } |
| |
| MUTEX_UNLOCK(mutex); |
| |
| return prev; |
| } |
| |
| APR_DECLARE(apr_uint32_t) apr_atomic_xchg32(volatile apr_uint32_t *mem, apr_uint32_t val) |
| { |
| apr_uint32_t prev; |
| DECLARE_MUTEX_LOCKED(mutex, mem); |
| |
| prev = *mem; |
| *mem = val; |
| |
| MUTEX_UNLOCK(mutex); |
| |
| return prev; |
| } |
| |
| APR_DECLARE(void*) apr_atomic_casptr(volatile void **mem, void *with, const void *cmp) |
| { |
| void *prev; |
| DECLARE_MUTEX_LOCKED(mutex, *mem); |
| |
| prev = *(void **)mem; |
| if (prev == cmp) { |
| *mem = with; |
| } |
| |
| MUTEX_UNLOCK(mutex); |
| |
| return prev; |
| } |
| |
| APR_DECLARE(void*) apr_atomic_xchgptr(volatile void **mem, void *with) |
| { |
| void *prev; |
| DECLARE_MUTEX_LOCKED(mutex, *mem); |
| |
| prev = *(void **)mem; |
| *mem = with; |
| |
| MUTEX_UNLOCK(mutex); |
| |
| return prev; |
| } |
| |
| #endif /* USE_ATOMICS_GENERIC */ |