home *** CD-ROM | disk | FTP | other *** search
- /* Copyright 2000-2005 The Apache Software Foundation or its licensors, as
- * applicable.
- *
- * Licensed 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.
- */
-
- #ifndef APR_ATOMIC_H
- #define APR_ATOMIC_H
-
- /**
- * @file apr_atomic.h
- * @brief APR Atomic Operations
- */
-
- #include "apr.h"
- #include "apr_pools.h"
-
- #ifdef __cplusplus
- extern "C" {
- #endif
-
- /**
- * @defgroup apr_atomic Atomic Operations
- * @ingroup APR
- * @{
- */
-
- /**
- * this function is required on some platforms to initialize the
- * atomic operation's internal structures
- * @param p pool
- * @return APR_SUCCESS on successful completion
- */
- APR_DECLARE(apr_status_t) apr_atomic_init(apr_pool_t *p);
-
- /*
- * Atomic operations on 32-bit values
- * Note: Each of these functions internally implements a memory barrier
- * on platforms that require it
- */
-
- /**
- * atomically read an apr_uint32_t from memory
- * @param mem the pointer
- */
- APR_DECLARE(apr_uint32_t) apr_atomic_read32(volatile apr_uint32_t *mem);
-
- /**
- * atomically set an apr_uint32_t in memory
- * @param mem pointer to the object
- * @param val value that the object will assume
- */
- APR_DECLARE(void) apr_atomic_set32(volatile apr_uint32_t *mem, apr_uint32_t val);
-
- /**
- * atomically add 'val' to an apr_uint32_t
- * @param mem pointer to the object
- * @param val amount to add
- * @return old value pointed to by mem
- */
- APR_DECLARE(apr_uint32_t) apr_atomic_add32(volatile apr_uint32_t *mem, apr_uint32_t val);
-
- /**
- * atomically subtract 'val' from an apr_uint32_t
- * @param mem pointer to the object
- * @param val amount to subtract
- */
- APR_DECLARE(void) apr_atomic_sub32(volatile apr_uint32_t *mem, apr_uint32_t val);
-
- /**
- * atomically increment an apr_uint32_t by 1
- * @param mem pointer to the object
- * @return old value pointed to by mem
- */
- APR_DECLARE(apr_uint32_t) apr_atomic_inc32(volatile apr_uint32_t *mem);
-
- /**
- * atomically decrement an apr_uint32_t by 1
- * @param mem pointer to the atomic value
- * @return zero if the value becomes zero on decrement, otherwise non-zero
- */
- APR_DECLARE(int) apr_atomic_dec32(volatile apr_uint32_t *mem);
-
- /**
- * compare an apr_uint32_t's value with 'cmp'.
- * If they are the same swap the value with 'with'
- * @param mem pointer to the value
- * @param with what to swap it with
- * @param cmp the value to compare it to
- * @return the old value of *mem
- */
- APR_DECLARE(apr_uint32_t) apr_atomic_cas32(volatile apr_uint32_t *mem, apr_uint32_t with,
- apr_uint32_t cmp);
-
- /**
- * exchange an apr_uint32_t's value with 'val'.
- * @param mem pointer to the value
- * @param val what to swap it with
- * @return the old value of *mem
- */
- APR_DECLARE(apr_uint32_t) apr_atomic_xchg32(volatile apr_uint32_t *mem, apr_uint32_t val);
-
- /**
- * compare the pointer's value with cmp.
- * If they are the same swap the value with 'with'
- * @param mem pointer to the pointer
- * @param with what to swap it with
- * @param cmp the value to compare it to
- * @return the old value of the pointer
- */
- APR_DECLARE(void*) apr_atomic_casptr(volatile void **mem, void *with, const void *cmp);
-
- /** @} */
-
- #ifdef __cplusplus
- }
- #endif
-
- #endif /* !APR_ATOMIC_H */
-