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/* 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"
#include "apr_thread_mutex.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__atomic_generic64_init(p);
}
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__atomic_generic64_init(p);
}
#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 */
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