/* * Asterisk -- An open source telephony toolkit. * * Copyright (C) 1999 - 2005, Digium, Inc. * * Mark Spencer * * See http://www.asterisk.org for more information about * the Asterisk project. Please do not directly contact * any of the maintainers of this project for assistance; * the project provides a web site, mailing lists and IRC * channels for your use. * * This program is free software, distributed under the terms of * the GNU General Public License Version 2. See the LICENSE file * at the top of the source tree. */ /* * Object Model for Asterisk */ #ifndef _ASTERISK_ASTOBJ_H #define _ASTERISK_ASTOBJ_H #include #include "asterisk/lock.h" #include "asterisk/compiler.h" /*! \file * \brief A set of macros implementing objects and containers. * Macros are used for maximum performance, to support multiple inheritance, * and to be easily integrated into existing structures without additional * malloc calls, etc. * * These macros expect to operate on two different object types, ASTOBJs and * ASTOBJ_CONTAINERs. These are not actual types, as any struct can be * converted into an ASTOBJ compatible object or container using the supplied * macros. * * Sample Usage: * \code * struct sample_object { * ASTOBJ_COMPONENTS(struct sample_object); * }; * * struct sample_container { * ASTOBJ_CONTAINER_COMPONENTS(struct sample_object); * } super_container; * * void sample_object_destroy(struct sample_object *obj) * { * free(obj); * } * * int init_stuff() * { * struct sample_object *obj1; * struct sample_object *found_obj; * * obj1 = malloc(sizeof(struct sample_object)); * * ASTOBJ_CONTAINER_INIT(&super_container); * * ASTOBJ_INIT(obj1); * ASTOBJ_WRLOCK(obj1); * ast_copy_string(obj1->name, "obj1", sizeof(obj1->name)); * ASTOBJ_UNLOCK(obj1); * * ASTOBJ_CONTAINER_LINK(&super_container, obj1); * * found_obj = ASTOBJ_CONTAINER_FIND(&super_container, "obj1"); * * if(found_obj) { * printf("Found object: %s", found_obj->name); * ASTOBJ_UNREF(found_obj,sample_object_destroy); * } * * ASTOBJ_CONTAINER_DESTROYALL(&super_container,sample_object_destroy); * ASTOBJ_CONTAINER_DESTROY(&super_container); * * return 0; * } * \endcode */ #if defined(__cplusplus) || defined(c_plusplus) extern "C" { #endif #define ASTOBJ_DEFAULT_NAMELEN 80 #define ASTOBJ_DEFAULT_BUCKETS 256 #define ASTOBJ_DEFAULT_HASH ast_strhash #define ASTOBJ_FLAG_MARKED (1 << 0) /* Object has been marked for future operation */ /* C++ is simply a syntactic crutch for those who cannot think for themselves in an object oriented way. */ /*! \brief Lock an ASTOBJ for reading. */ #define ASTOBJ_RDLOCK(object) ast_mutex_lock(&(object)->_lock) /*! \brief Lock an ASTOBJ for writing. */ #define ASTOBJ_WRLOCK(object) ast_mutex_lock(&(object)->_lock) /*! \brief Unlock a locked object. */ #define ASTOBJ_UNLOCK(object) ast_mutex_unlock(&(object)->_lock) #ifdef ASTOBJ_CONTAINER_HASHMODEL #define __ASTOBJ_HASH(type,hashes) \ type *next[hashes] #else #define __ASTOBJ_HASH(type,hashes) \ type *next[1] #endif /*! \brief Add ASTOBJ components to a struct (without locking support). * * \param type The datatype of the object. * \param namelen The length to make the name char array. * \param hashes The number of containers the object can be present in. * * This macro adds components to a struct to make it an ASTOBJ. This macro * differs from ASTOBJ_COMPONENTS_FULL in that it does not create a mutex for * locking. * * Sample Usage: * \code * struct sample_struct { * ASTOBJ_COMPONENTS_NOLOCK_FULL(struct sample_struct,1,1); * }; * \endcode */ #define ASTOBJ_COMPONENTS_NOLOCK_FULL(type,namelen,hashes) \ char name[namelen]; \ unsigned int refcount; \ unsigned int objflags; \ __ASTOBJ_HASH(type,hashes) /*! \brief Add ASTOBJ components to a struct (without locking support). * * \param type The datatype of the object. * * This macro works like #ASTOBJ_COMPONENTS_NOLOCK_FULL() except it only accepts a * type and uses default values for namelen and hashes. * * Sample Usage: * \code * struct sample_struct_componets { * ASTOBJ_COMPONENTS_NOLOCK(struct sample_struct); * }; * \endcode */ #define ASTOBJ_COMPONENTS_NOLOCK(type) \ ASTOBJ_COMPONENTS_NOLOCK_FULL(type,ASTOBJ_DEFAULT_NAMELEN,1) /*! \brief Add ASTOBJ components to a struct (with locking support). * * \param type The datatype of the object. * * This macro works like #ASTOBJ_COMPONENTS_NOLOCK() except it includes locking * support. * * Sample Usage: * \code * struct sample_struct { * ASTOBJ_COMPONENTS(struct sample_struct); * }; * \endcode */ #define ASTOBJ_COMPONENTS(type) \ ASTOBJ_COMPONENTS_NOLOCK(type); \ ast_mutex_t _lock; /*! \brief Add ASTOBJ components to a struct (with locking support). * * \param type The datatype of the object. * \param namelen The length to make the name char array. * \param hashes The number of containers the object can be present in. * * This macro adds components to a struct to make it an ASTOBJ and includes * support for locking. * * Sample Usage: * \code * struct sample_struct { * ASTOBJ_COMPONENTS_FULL(struct sample_struct,1,1); * }; * \endcode */ #define ASTOBJ_COMPONENTS_FULL(type,namelen,hashes) \ ASTOBJ_COMPONENTS_NOLOCK_FULL(type,namelen,hashes); \ ast_mutex_t _lock; /*! \brief Increment an object reference count. * \param object A pointer to the object to operate on. * \return The object. */ #define ASTOBJ_REF(object) \ ({ \ ASTOBJ_WRLOCK(object); \ (object)->refcount++; \ ASTOBJ_UNLOCK(object); \ (object); \ }) /*! \brief Decrement the reference count on an object. * * \param object A pointer the object to operate on. * \param destructor The destructor to call if the object is no longer referenced. It will be passed the pointer as an argument. * * This macro unreferences an object and calls the specfied destructor if the * object is no longer referenced. The destructor should free the object if it * was dynamically allocated. */ #define ASTOBJ_UNREF(object,destructor) \ do { \ int newcount = 0; \ ASTOBJ_WRLOCK(object); \ if (__builtin_expect((object)->refcount > 0, 1)) \ newcount = --((object)->refcount); \ else \ ast_log(LOG_WARNING, "Unreferencing unreferenced (object)!\n"); \ ASTOBJ_UNLOCK(object); \ if (newcount == 0) { \ ast_mutex_destroy(&(object)->_lock); \ destructor((object)); \ } \ (object) = NULL; \ } while(0) /*! \brief Mark an ASTOBJ by adding the #ASTOBJ_FLAG_MARKED flag to its objflags mask. * \param object A pointer to the object to operate on. * * This macro "marks" an object. Marked objects can later be unlinked from a container using * #ASTOBJ_CONTAINER_PRUNE_MARKED(). * */ #define ASTOBJ_MARK(object) \ do { \ ASTOBJ_WRLOCK(object); \ (object)->objflags |= ASTOBJ_FLAG_MARKED; \ ASTOBJ_UNLOCK(object); \ } while(0) /*! \brief Unmark an ASTOBJ by subtracting the #ASTOBJ_FLAG_MARKED flag from its objflags mask. * \param object A pointer to the object to operate on. */ #define ASTOBJ_UNMARK(object) \ do { \ ASTOBJ_WRLOCK(object); \ (object)->objflags &= ~ASTOBJ_FLAG_MARKED; \ ASTOBJ_UNLOCK(object); \ } while(0) /*! \brief Initialize an object. * \param object A pointer to the object to operate on. * * \note This should only be used on objects that support locking (objects * created with #ASTOBJ_COMPONENTS() or #ASTOBJ_COMPONENTS_FULL()) */ #define ASTOBJ_INIT(object) \ do { \ ast_mutex_init(&(object)->_lock); \ object->name[0] = '\0'; \ object->refcount = 1; \ } while(0) /* Containers for objects -- current implementation is linked lists, but should be able to be converted to hashes relatively easily */ /*! \brief Lock an ASTOBJ_CONTAINER for reading. */ #define ASTOBJ_CONTAINER_RDLOCK(container) ast_mutex_lock(&(container)->_lock) /*! \brief Lock an ASTOBJ_CONTAINER for writing. */ #define ASTOBJ_CONTAINER_WRLOCK(container) ast_mutex_lock(&(container)->_lock) /*! \brief Unlock an ASTOBJ_CONTAINER. */ #define ASTOBJ_CONTAINER_UNLOCK(container) ast_mutex_unlock(&(container)->_lock) #ifdef ASTOBJ_CONTAINER_HASHMODEL #error "Hash model for object containers not yet implemented!" #else /* Linked lists */ /*! \brief Create a container for ASTOBJs (without locking support). * * \param type The type of objects the container will hold. * \param hashes Currently unused. * \param buckets Currently unused. * * This macro is used to create a container for ASTOBJs without locking * support. * * Sample Usage: * \code * struct sample_struct_nolock_container { * ASTOBJ_CONTAINER_COMPONENTS_NOLOCK_FULL(struct sample_struct,1,1); * }; * \endcode */ #define ASTOBJ_CONTAINER_COMPONENTS_NOLOCK_FULL(type,hashes,buckets) \ type *head /*! \brief Initialize a container. * * \param container A pointer to the container to initialize. * \param hashes Currently unused. * \param buckets Currently unused. * * This macro initializes a container. It should only be used on containers * that support locking. * * Sample Usage: * \code * struct sample_struct_container { * ASTOBJ_CONTAINER_COMPONENTS_FULL(struct sample_struct,1,1); * } container; * * int func() * { * ASTOBJ_CONTAINER_INIT_FULL(&container,1,1); * } * \endcode */ #define ASTOBJ_CONTAINER_INIT_FULL(container,hashes,buckets) \ do { \ ast_mutex_init(&(container)->_lock); \ } while(0) /*! \brief Destroy a container. * * \param container A pointer to the container to destroy. * \param hashes Currently unused. * \param buckets Currently unused. * * This macro frees up resources used by a container. It does not operate on * the objects in the container. To unlink the objects from the container use * #ASTOBJ_CONTAINER_DESTROYALL(). * * \note This macro should only be used on containers with locking support. */ #define ASTOBJ_CONTAINER_DESTROY_FULL(container,hashes,buckets) \ do { \ ast_mutex_destroy(&(container)->_lock); \ } while(0) /*! \brief Iterate through the objects in a container. * * \param container A pointer to the container to traverse. * \param continue A condition to allow the traversal to continue. * \param eval A statement to evaluate in the iteration loop. * * This is macro is a little complicated, but it may help to think of it as a * loop. Basically it iterates through the specfied containter as long as the * condition is met. Two variables, iterator and next, are provided for use in * your \p eval statement. See the sample code for an example. * * Sample Usage: * \code * ASTOBJ_CONTAINER_TRAVERSE(&sample_container,1, { * ASTOBJ_RDLOCK(iterator); * printf("Currently iterating over '%s'\n", iterator->name); * ASTOBJ_UNLOCK(iterator); * } ); * \endcode * * \code * ASTOBJ_CONTAINER_TRAVERSE(&sample_container,1, sample_func(iterator)); * \endcode */ #define ASTOBJ_CONTAINER_TRAVERSE(container,continue,eval) \ do { \ typeof((container)->head) iterator; \ typeof((container)->head) next; \ ASTOBJ_CONTAINER_RDLOCK(container); \ next = (container)->head; \ while((continue) && (iterator = next)) { \ next = iterator->next[0]; \ eval; \ } \ ASTOBJ_CONTAINER_UNLOCK(container); \ } while(0) /*! \brief Find an object in a container. * * \param container A pointer to the container to search. * \param namestr The name to search for. * * Use this function to find an object with the specfied name in a container. * * \note When the returned object is no longer in use, #ASTOBJ_UNREF() should * be used to free the additional reference created by this macro. * * \return A new reference to the object located or NULL if nothing is found. */ #define ASTOBJ_CONTAINER_FIND(container,namestr) \ ({ \ typeof((container)->head) found = NULL; \ ASTOBJ_CONTAINER_TRAVERSE(container, !found, do { \ if (!(strcasecmp(iterator->name, (namestr)))) \ found = ASTOBJ_REF(iterator); \ } while (0)); \ found; \ }) /*! \brief Find an object in a container. * * \param container A pointer to the container to search. * \param data The data to search for. * \param field The field/member of the container's objects to search. * \param hashfunc The hash function to use, currently not implemented. * \param hashoffset The hash offset to use, currently not implemented. * \param comparefunc The function used to compare the field and data values. * * This macro iterates through a container passing the specified field and data * elements to the specified comparefunc. The function should return 0 when a match is found. * * \note When the returned object is no longer in use, #ASTOBJ_UNREF() should * be used to free the additional reference created by this macro. * * \return A pointer to the object located or NULL if nothing is found. */ #define ASTOBJ_CONTAINER_FIND_FULL(container,data,field,hashfunc,hashoffset,comparefunc) \ ({ \ typeof((container)->head) found = NULL; \ ASTOBJ_CONTAINER_TRAVERSE(container, !found, do { \ ASTOBJ_RDLOCK(iterator); \ if (!(comparefunc(iterator->field, (data)))) { \ found = ASTOBJ_REF(iterator); \ } \ ASTOBJ_UNLOCK(iterator); \ } while (0)); \ found; \ }) /*! \brief Empty a container. * * \param container A pointer to the container to operate on. * \param destructor A destructor function to call on each object. * * This macro loops through a container removing all the items from it using * #ASTOBJ_UNREF(). This does not destroy the container itself, use * #ASTOBJ_CONTAINER_DESTROY() for that. * * \note If any object in the container is only referenced by the container, * the destructor will be called for that object once it has been removed. */ #define ASTOBJ_CONTAINER_DESTROYALL(container,destructor) \ do { \ typeof((container)->head) iterator; \ ASTOBJ_CONTAINER_WRLOCK(container); \ while((iterator = (container)->head)) { \ (container)->head = (iterator)->next[0]; \ ASTOBJ_UNREF(iterator,destructor); \ } \ ASTOBJ_CONTAINER_UNLOCK(container); \ } while(0) /*! \brief Remove an object from a container. * * \param container A pointer to the container to operate on. * \param obj A pointer to the object to remove. * * This macro iterates through a container and removes the specfied object if * it exists in the container. * * \note This macro does not destroy any objects, it simply unlinks * them from the list. No destructors are called. * * \return The container's reference to the removed object or NULL if no * matching object was found. */ #define ASTOBJ_CONTAINER_UNLINK(container,obj) \ ({ \ typeof((container)->head) found = NULL; \ typeof((container)->head) prev = NULL; \ ASTOBJ_CONTAINER_TRAVERSE(container, !found, do { \ if (iterator == obj) { \ found = iterator; \ found->next[0] = NULL; \ ASTOBJ_CONTAINER_WRLOCK(container); \ if (prev) \ prev->next[0] = next; \ else \ (container)->head = next; \ ASTOBJ_CONTAINER_UNLOCK(container); \ } \ prev = iterator; \ } while (0)); \ found; \ }) /*! \brief Find and remove an object from a container. * * \param container A pointer to the container to operate on. * \param namestr The name of the object to remove. * * This macro iterates through a container and removes the first object with * the specfied name from the container. * * \note This macro does not destroy any objects, it simply unlinks * them. No destructors are called. * * \return The container's reference to the removed object or NULL if no * matching object was found. */ #define ASTOBJ_CONTAINER_FIND_UNLINK(container,namestr) \ ({ \ typeof((container)->head) found = NULL; \ typeof((container)->head) prev = NULL; \ ASTOBJ_CONTAINER_TRAVERSE(container, !found, do { \ if (!(strcasecmp(iterator->name, (namestr)))) { \ found = iterator; \ found->next[0] = NULL; \ ASTOBJ_CONTAINER_WRLOCK(container); \ if (prev) \ prev->next[0] = next; \ else \ (container)->head = next; \ ASTOBJ_CONTAINER_UNLOCK(container); \ } \ prev = iterator; \ } while (0)); \ found; \ }) /*! \brief Find and remove an object in a container. * * \param container A pointer to the container to search. * \param data The data to search for. * \param field The field/member of the container's objects to search. * \param hashfunc The hash function to use, currently not implemented. * \param hashoffset The hash offset to use, currently not implemented. * \param comparefunc The function used to compare the field and data values. * * This macro iterates through a container passing the specified field and data * elements to the specified comparefunc. The function should return 0 when a match is found. * If a match is found it is removed from the list. * * \note This macro does not destroy any objects, it simply unlinks * them. No destructors are called. * * \return The container's reference to the removed object or NULL if no match * was found. */ #define ASTOBJ_CONTAINER_FIND_UNLINK_FULL(container,data,field,hashfunc,hashoffset,comparefunc) \ ({ \ typeof((container)->head) found = NULL; \ typeof((container)->head) prev = NULL; \ ASTOBJ_CONTAINER_TRAVERSE(container, !found, do { \ ASTOBJ_RDLOCK(iterator); \ if (!(comparefunc(iterator->field, (data)))) { \ found = iterator; \ found->next[0] = NULL; \ ASTOBJ_CONTAINER_WRLOCK(container); \ if (prev) \ prev->next[0] = next; \ else \ (container)->head = next; \ ASTOBJ_CONTAINER_UNLOCK(container); \ } \ ASTOBJ_UNLOCK(iterator); \ prev = iterator; \ } while (0)); \ found; \ }) /*! \brief Prune marked objects from a container. * * \param container A pointer to the container to prune. * \param destructor A destructor function to call on each marked object. * * This macro iterates through the specfied container and prunes any marked * objects executing the specfied destructor if necessary. */ #define ASTOBJ_CONTAINER_PRUNE_MARKED(container,destructor) \ do { \ typeof((container)->head) prev = NULL; \ ASTOBJ_CONTAINER_TRAVERSE(container, 1, do { \ ASTOBJ_RDLOCK(iterator); \ if (iterator->objflags & ASTOBJ_FLAG_MARKED) { \ ASTOBJ_CONTAINER_WRLOCK(container); \ if (prev) \ prev->next[0] = next; \ else \ (container)->head = next; \ ASTOBJ_CONTAINER_UNLOCK(container); \ ASTOBJ_UNLOCK(iterator); \ ASTOBJ_UNREF(iterator,destructor); \ continue; \ } \ ASTOBJ_UNLOCK(iterator); \ prev = iterator; \ } while (0)); \ } while(0) /*! \brief Add an object to a container. * * \param container A pointer to the container to operate on. * \param newobj A pointer to the object to be added. * \param data Currently unused. * \param field Currently unused. * \param hashfunc Currently unused. * \param hashoffset Currently unused. * \param comparefunc Currently unused. * * Currently this function adds an object to the head of the list. One day it * will support adding objects atthe position specified using the various * options this macro offers. */ #define ASTOBJ_CONTAINER_LINK_FULL(container,newobj,data,field,hashfunc,hashoffset,comparefunc) \ do { \ ASTOBJ_CONTAINER_WRLOCK(container); \ (newobj)->next[0] = (container)->head; \ (container)->head = ASTOBJ_REF(newobj); \ ASTOBJ_CONTAINER_UNLOCK(container); \ } while(0) #endif /* List model */ /* Common to hash and linked list models */ /*! \brief Create a container for ASTOBJs (without locking support). * * \param type The type of objects the container will hold. * * This macro is used to create a container for ASTOBJs without locking * support. * * Sample Usage: * \code * struct sample_struct_nolock_container { * ASTOBJ_CONTAINER_COMPONENTS_NOLOCK(struct sample_struct); * }; * \endcode */ #define ASTOBJ_CONTAINER_COMPONENTS_NOLOCK(type) \ ASTOBJ_CONTAINER_COMPONENTS_NOLOCK_FULL(type,1,ASTOBJ_DEFAULT_BUCKETS) /*! \brief Create a container for ASTOBJs (with locking support). * * \param type The type of objects the container will hold. * * This macro is used to create a container for ASTOBJs with locking support. * * Sample Usage: * \code * struct sample_struct_container { * ASTOBJ_CONTAINER_COMPONENTS(struct sample_struct); * }; * \endcode */ #define ASTOBJ_CONTAINER_COMPONENTS(type) \ ast_mutex_t _lock; \ ASTOBJ_CONTAINER_COMPONENTS_NOLOCK(type) /*! \brief Initialize a container. * * \param container A pointer to the container to initialize. * * This macro initializes a container. It should only be used on containers * that support locking. * * Sample Usage: * \code * struct sample_struct_container { * ASTOBJ_CONTAINER_COMPONENTS(struct sample_struct); * } container; * * int func() * { * ASTOBJ_CONTAINER_INIT(&container); * } * \endcode */ #define ASTOBJ_CONTAINER_INIT(container) \ ASTOBJ_CONTAINER_INIT_FULL(container,1,ASTOBJ_DEFAULT_BUCKETS) /*! \brief Destroy a container. * * \param container A pointer to the container to destory. * * This macro frees up resources used by a container. It does not operate on * the objects in the container. To unlink the objects from the container use * #ASTOBJ_CONTAINER_DESTROYALL(). * * \note This macro should only be used on containers with locking support. */ #define ASTOBJ_CONTAINER_DESTROY(container) \ ASTOBJ_CONTAINER_DESTROY_FULL(container,1,ASTOBJ_DEFAULT_BUCKETS) /*! \brief Add an object to a container. * * \param container A pointer to the container to operate on. * \param newobj A pointer to the object to be added. * * Currently this macro adds an object to the head of a container. One day it * should add an object in alphabetical order. */ #define ASTOBJ_CONTAINER_LINK(container,newobj) \ ASTOBJ_CONTAINER_LINK_FULL(container,newobj,(newobj)->name,name,ASTOBJ_DEFAULT_HASH,0,strcasecmp) /*! \brief Mark all the objects in a container. * \param container A pointer to the container to operate on. */ #define ASTOBJ_CONTAINER_MARKALL(container) \ ASTOBJ_CONTAINER_TRAVERSE(container, 1, ASTOBJ_MARK(iterator)) /*! \brief Unmark all the objects in a container. * \param container A pointer to the container to operate on. */ #define ASTOBJ_CONTAINER_UNMARKALL(container) \ ASTOBJ_CONTAINER_TRAVERSE(container, 1, ASTOBJ_UNMARK(iterator)) /*! \brief Dump information about an object into a string. * * \param s A pointer to the string buffer to use. * \param slen The length of s. * \param obj A pointer to the object to dump. * * This macro dumps a text representation of the name, objectflags, and * refcount fields of an object to the specfied string buffer. */ #define ASTOBJ_DUMP(s,slen,obj) \ snprintf((s),(slen),"name: %s\nobjflags: %d\nrefcount: %d\n\n", (obj)->name, (obj)->objflags, (obj)->refcount); /*! \brief Dump information about all the objects in a container to a file descriptor. * * \param fd The file descriptor to write to. * \param s A string buffer, same as #ASTOBJ_DUMP(). * \param slen The length of s, same as #ASTOBJ_DUMP(). * \param container A pointer to the container to dump. * * This macro dumps a text representation of the name, objectflags, and * refcount fields of all the objects in a container to the specified file * descriptor. */ #define ASTOBJ_CONTAINER_DUMP(fd,s,slen,container) \ ASTOBJ_CONTAINER_TRAVERSE(container, 1, do { ASTOBJ_DUMP(s,slen,iterator); ast_cli(fd, s); } while(0)) #if defined(__cplusplus) || defined(c_plusplus) } #endif #endif /* _ASTERISK_ASTOBJ_H */