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Diffstat (limited to 'subversion/include/private/svn_named_atomic.h')
| -rw-r--r-- | subversion/include/private/svn_named_atomic.h | 162 |
1 files changed, 0 insertions, 162 deletions
diff --git a/subversion/include/private/svn_named_atomic.h b/subversion/include/private/svn_named_atomic.h deleted file mode 100644 index 4efa255..0000000 --- a/subversion/include/private/svn_named_atomic.h +++ /dev/null @@ -1,162 +0,0 @@ -/** - * @copyright - * ==================================================================== - * 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. - * ==================================================================== - * @endcopyright - * - * @file svn_named_atomics.h - * @brief Structures and functions for machine-wide named atomics. - * These atomics store 64 bit signed integer values and provide - * a number of basic operations on them. Instead of an address, - * these atomics are identified by strings / names. We also support - * namespaces - mainly to separate debug from production data. - */ - -#ifndef SVN_NAMED_ATOMICS_H -#define SVN_NAMED_ATOMICS_H - -#include "svn_error.h" - -#ifdef __cplusplus -extern "C" { -#endif /* __cplusplus */ - -/** An opaque structure that represents a namespace, i.e. a container - * for named atomics. - */ -typedef struct svn_atomic_namespace__t svn_atomic_namespace__t; - -/** An opaque structure that represents a named, system-wide visible - * 64 bit integer with atomic access routines. - */ -typedef struct svn_named_atomic__t svn_named_atomic__t; - -/** Maximum length of the name of any atomic (excluding the terminal NUL). - */ -#define SVN_NAMED_ATOMIC__MAX_NAME_LENGTH 30 - -/** Returns #FALSE when named atomics are not available to our process - * and svn_atomic_namespace__create is likely to fail. - * - * @note The actual check will be performed only once and later - * changes in process privileges will not reflect in the outcome of future - * calls to this function. - */ -svn_boolean_t -svn_named_atomic__is_supported(void); - -/** Returns #TRUE on platforms that don't need expensive synchronization - * objects to serialize access to named atomics. If this returns #FALSE, - * reading from or modifying a #svn_named_atomic__t may be as expensive - * as a file system operation. - */ -svn_boolean_t -svn_named_atomic__is_efficient(void); - -/** Create a namespace (i.e. access object) with the given @a name and - * return it in @a *ns. - * - * Multiple access objects with the same name may be created. They access - * the same shared memory region but have independent lifetimes. - * - * The access object will be allocated in @a result_pool and atomics gotten - * from this object will become invalid when the pool is being cleared. - */ -svn_error_t * -svn_atomic_namespace__create(svn_atomic_namespace__t **ns, - const char *name, - apr_pool_t *result_pool); - -/** Removes persistent data structures (files in particular) that got - * created for the namespace given by @a name. Use @a pool for temporary - * allocations. - * - * @note You must not call this while the respective namespace is still - * in use. Calling this multiple times for the same namespace is safe. - */ -svn_error_t * -svn_atomic_namespace__cleanup(const char *name, - apr_pool_t *pool); - -/** Find the atomic with the specified @a name in namespace @a ns and - * return it in @a *atomic. If no object with that name can be found, the - * behavior depends on @a auto_create. If it is @c FALSE, @a *atomic will - * be set to @c NULL. Otherwise, a new atomic will be created, its value - * set to 0 and the access structure be returned in @a *atomic. - * - * Note that @a name must not exceed #SVN_NAMED_ATOMIC__MAX_NAME_LENGTH - * characters and an error will be returned if the specified name is longer - * than supported. - * - * @note The lifetime of the atomic object is bound to the lifetime - * of the @a ns object, i.e. the pool the latter was created in. - * The data in the namespace persists as long as at least one process - * holds an #svn_atomic_namespace__t object corresponding to it. - */ -svn_error_t * -svn_named_atomic__get(svn_named_atomic__t **atomic, - svn_atomic_namespace__t *ns, - const char *name, - svn_boolean_t auto_create); - -/** Read the @a atomic and return its current @a *value. - * An error will be returned if @a atomic is @c NULL. - */ -svn_error_t * -svn_named_atomic__read(apr_int64_t *value, - svn_named_atomic__t *atomic); - -/** Set the data in @a atomic to @a new_value and return its old content - * in @a *old_value. @a old_value may be NULL. - * - * An error will be returned if @a atomic is @c NULL. - */ -svn_error_t * -svn_named_atomic__write(apr_int64_t *old_value, - apr_int64_t new_value, - svn_named_atomic__t *atomic); - -/** Add @a delta to the data in @a atomic and return its new value in - * @a *new_value. @a new_value may be null. - * - * An error will be returned if @a atomic is @c NULL. - */ -svn_error_t * -svn_named_atomic__add(apr_int64_t *new_value, - apr_int64_t delta, - svn_named_atomic__t *atomic); - -/** If the current data in @a atomic equals @a comperand, set it to - * @a new_value. Return the initial value in @a *old_value. - * @a old_value may be NULL. - * - * An error will be returned if @a atomic is @c NULL. - */ -svn_error_t * -svn_named_atomic__cmpxchg(apr_int64_t *old_value, - apr_int64_t new_value, - apr_int64_t comperand, - svn_named_atomic__t *atomic); - - -#ifdef __cplusplus -} -#endif /* __cplusplus */ - -#endif /* SVN_NAMED_ATOMICS_H */ |