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asterisk/include/asterisk/linkedlists.h

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/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 1999 - 2006, Digium, Inc.
*
* Mark Spencer <markster@digium.com>
* Kevin P. Fleming <kpfleming@digium.com>
*
* 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.
*/
#ifndef ASTERISK_LINKEDLISTS_H
#define ASTERISK_LINKEDLISTS_H
#include "asterisk/lock.h"
/*!
* \file linkedlists.h
* \brief A set of macros to manage forward-linked lists.
*/
/*!
* \brief Locks a list.
* \param head This is a pointer to the list head structure
*
* This macro attempts to place an exclusive lock in the
* list head structure pointed to by head.
* \retval 0 on success
* \retval non-zero on failure
*/
#define AST_LIST_LOCK(head) \
ast_mutex_lock(&(head)->lock)
/*!
* \brief Write locks a list.
* \param head This is a pointer to the list head structure
*
* This macro attempts to place an exclusive write lock in the
* list head structure pointed to by head.
* \retval 0 on success
* \retval non-zero on failure
*/
#define AST_RWLIST_WRLOCK(head) \
ast_rwlock_wrlock(&(head)->lock)
/*!
* \brief Write locks a list, with timeout.
* \param head This is a pointer to the list head structure
* \param ts Pointer to a timespec structure
*
* This macro attempts to place an exclusive write lock in the
* list head structure pointed to by head.
* \retval 0 on success
* \retval non-zero on failure
*
* \since 1.6.1
*/
#define AST_RWLIST_TIMEDWRLOCK(head, ts) ast_rwlock_timedwrlock(&(head)->lock, ts)
/*!
* \brief Read locks a list.
* \param head This is a pointer to the list head structure
*
* This macro attempts to place a read lock in the
* list head structure pointed to by head.
* \retval 0 on success
* \retval non-zero on failure
*/
#define AST_RWLIST_RDLOCK(head) \
ast_rwlock_rdlock(&(head)->lock)
/*!
* \brief Read locks a list, with timeout.
* \param head This is a pointer to the list head structure
* \param ts Pointer to a timespec structure
*
* This macro attempts to place a read lock in the
* list head structure pointed to by head.
* \retval 0 on success
* \retval non-zero on failure
*
* \since 1.6.1
*/
#define AST_RWLIST_TIMEDRDLOCK(head, ts) \
ast_rwlock_timedrdlock(&(head)->lock, ts)
/*!
* \brief Locks a list, without blocking if the list is locked.
* \param head This is a pointer to the list head structure
*
* This macro attempts to place an exclusive lock in the
* list head structure pointed to by head.
* \retval 0 on success
* \retval non-zero on failure
*/
#define AST_LIST_TRYLOCK(head) \
ast_mutex_trylock(&(head)->lock)
/*!
* \brief Write locks a list, without blocking if the list is locked.
* \param head This is a pointer to the list head structure
*
* This macro attempts to place an exclusive write lock in the
* list head structure pointed to by head.
* \retval 0 on success
* \retval non-zero on failure
*/
#define AST_RWLIST_TRYWRLOCK(head) \
ast_rwlock_trywrlock(&(head)->lock)
/*!
* \brief Read locks a list, without blocking if the list is locked.
* \param head This is a pointer to the list head structure
*
* This macro attempts to place a read lock in the
* list head structure pointed to by head.
* \retval 0 on success
* \retval non-zero on failure
*/
#define AST_RWLIST_TRYRDLOCK(head) \
ast_rwlock_tryrdlock(&(head)->lock)
/*!
* \brief Attempts to unlock a list.
* \param head This is a pointer to the list head structure
*
* This macro attempts to remove an exclusive lock from the
* list head structure pointed to by head. If the list
* was not locked by this thread, this macro has no effect.
*/
#define AST_LIST_UNLOCK(head) \
ast_mutex_unlock(&(head)->lock)
/*!
* \brief Attempts to unlock a read/write based list.
* \param head This is a pointer to the list head structure
*
* This macro attempts to remove a read or write lock from the
* list head structure pointed to by head. If the list
* was not locked by this thread, this macro has no effect.
*/
#define AST_RWLIST_UNLOCK(head) \
ast_rwlock_unlock(&(head)->lock)
/*!
* \brief Defines a structure to be used to hold a list of specified type.
* \param name This will be the name of the defined structure.
* \param type This is the type of each list entry.
*
* This macro creates a structure definition that can be used
* to hold a list of the entries of type \a type. It does not actually
* declare (allocate) a structure; to do that, either follow this
* macro with the desired name of the instance you wish to declare,
* or use the specified \a name to declare instances elsewhere.
*
* Example usage:
* \code
* static AST_LIST_HEAD(entry_list, entry) entries;
* \endcode
*
* This would define \c struct \c entry_list, and declare an instance of it named
* \a entries, all intended to hold a list of type \c struct \c entry.
*/
#define AST_LIST_HEAD(name, type) \
struct name { \
struct type *first; \
struct type *last; \
ast_mutex_t lock; \
}
/*!
* \brief Defines a structure to be used to hold a read/write list of specified type.
* \param name This will be the name of the defined structure.
* \param type This is the type of each list entry.
*
* This macro creates a structure definition that can be used
* to hold a list of the entries of type \a type. It does not actually
* declare (allocate) a structure; to do that, either follow this
* macro with the desired name of the instance you wish to declare,
* or use the specified \a name to declare instances elsewhere.
*
* Example usage:
* \code
* static AST_RWLIST_HEAD(entry_list, entry) entries;
* \endcode
*
* This would define \c struct \c entry_list, and declare an instance of it named
* \a entries, all intended to hold a list of type \c struct \c entry.
*/
#define AST_RWLIST_HEAD(name, type) \
struct name { \
struct type *first; \
struct type *last; \
ast_rwlock_t lock; \
}
/*!
* \brief Defines a structure to be used to hold a list of specified type (with no lock).
* \param name This will be the name of the defined structure.
* \param type This is the type of each list entry.
*
* This macro creates a structure definition that can be used
* to hold a list of the entries of type \a type. It does not actually
* declare (allocate) a structure; to do that, either follow this
* macro with the desired name of the instance you wish to declare,
* or use the specified \a name to declare instances elsewhere.
*
* Example usage:
* \code
* static AST_LIST_HEAD_NOLOCK(entry_list, entry) entries;
* \endcode
*
* This would define \c struct \c entry_list, and declare an instance of it named
* \a entries, all intended to hold a list of type \c struct \c entry.
*/
#define AST_LIST_HEAD_NOLOCK(name, type) \
struct name { \
struct type *first; \
struct type *last; \
}
/*!
* \brief Defines initial values for a declaration of AST_LIST_HEAD
*/
#define AST_LIST_HEAD_INIT_VALUE { \
.first = NULL, \
.last = NULL, \
.lock = AST_MUTEX_INIT_VALUE, \
}
/*!
* \brief Defines initial values for a declaration of AST_RWLIST_HEAD
*/
#define AST_RWLIST_HEAD_INIT_VALUE { \
.first = NULL, \
.last = NULL, \
.lock = AST_RWLOCK_INIT_VALUE, \
}
/*!
* \brief Defines initial values for a declaration of AST_LIST_HEAD_NOLOCK
*/
#define AST_LIST_HEAD_NOLOCK_INIT_VALUE { \
.first = NULL, \
.last = NULL, \
}
/*!
* \brief Defines a structure to be used to hold a list of specified type, statically initialized.
* \param name This will be the name of the defined structure.
* \param type This is the type of each list entry.
*
* This macro creates a structure definition that can be used
* to hold a list of the entries of type \a type, and allocates an instance
* of it, initialized to be empty.
*
* Example usage:
* \code
* static AST_LIST_HEAD_STATIC(entry_list, entry);
* \endcode
*
* This would define \c struct \c entry_list, intended to hold a list of
* type \c struct \c entry.
*/
#if defined(AST_MUTEX_INIT_W_CONSTRUCTORS)
#define AST_LIST_HEAD_STATIC(name, type) \
struct name { \
struct type *first; \
struct type *last; \
ast_mutex_t lock; \
} name; \
static void __attribute__((constructor)) __init_##name(void) \
{ \
AST_LIST_HEAD_INIT(&name); \
} \
static void __attribute__((destructor)) __fini_##name(void) \
{ \
AST_LIST_HEAD_DESTROY(&name); \
} \
struct __dummy_##name
#else
#define AST_LIST_HEAD_STATIC(name, type) \
struct name { \
struct type *first; \
struct type *last; \
ast_mutex_t lock; \
} name = AST_LIST_HEAD_INIT_VALUE
#endif
/*!
* \brief Defines a structure to be used to hold a read/write list of specified type, statically initialized.
* \param name This will be the name of the defined structure.
* \param type This is the type of each list entry.
*
* This macro creates a structure definition that can be used
* to hold a list of the entries of type \a type, and allocates an instance
* of it, initialized to be empty.
*
* Example usage:
* \code
* static AST_RWLIST_HEAD_STATIC(entry_list, entry);
* \endcode
*
* This would define \c struct \c entry_list, intended to hold a list of
* type \c struct \c entry.
*/
#ifndef HAVE_PTHREAD_RWLOCK_INITIALIZER
#define AST_RWLIST_HEAD_STATIC(name, type) \
struct name { \
struct type *first; \
struct type *last; \
ast_rwlock_t lock; \
} name; \
static void __attribute__((constructor)) __init_##name(void) \
{ \
AST_RWLIST_HEAD_INIT(&name); \
} \
static void __attribute__((destructor)) __fini_##name(void) \
{ \
AST_RWLIST_HEAD_DESTROY(&name); \
} \
struct __dummy_##name
#else
#define AST_RWLIST_HEAD_STATIC(name, type) \
struct name { \
struct type *first; \
struct type *last; \
ast_rwlock_t lock; \
} name = AST_RWLIST_HEAD_INIT_VALUE
#endif
/*!
* \brief Defines a structure to be used to hold a list of specified type, statically initialized.
*
* This is the same as AST_LIST_HEAD_STATIC, except without the lock included.
*/
#define AST_LIST_HEAD_NOLOCK_STATIC(name, type) \
struct name { \
struct type *first; \
struct type *last; \
} name = AST_LIST_HEAD_NOLOCK_INIT_VALUE
/*!
* \brief Initializes a list head structure with a specified first entry.
* \param head This is a pointer to the list head structure
* \param entry pointer to the list entry that will become the head of the list
*
* This macro initializes a list head structure by setting the head
* entry to the supplied value and recreating the embedded lock.
*/
#define AST_LIST_HEAD_SET(head, entry) do { \
(head)->first = (entry); \
(head)->last = (entry); \
ast_mutex_init(&(head)->lock); \
} while (0)
/*!
* \brief Initializes an rwlist head structure with a specified first entry.
* \param head This is a pointer to the list head structure
* \param entry pointer to the list entry that will become the head of the list
*
* This macro initializes a list head structure by setting the head
* entry to the supplied value and recreating the embedded lock.
*/
#define AST_RWLIST_HEAD_SET(head, entry) do { \
(head)->first = (entry); \
(head)->last = (entry); \
ast_rwlock_init(&(head)->lock); \
} while (0)
/*!
* \brief Initializes a list head structure with a specified first entry.
* \param head This is a pointer to the list head structure
* \param entry pointer to the list entry that will become the head of the list
*
* This macro initializes a list head structure by setting the head
* entry to the supplied value.
*/
#define AST_LIST_HEAD_SET_NOLOCK(head, entry) do { \
(head)->first = (entry); \
(head)->last = (entry); \
} while (0)
/*!
* \brief Declare a forward link structure inside a list entry.
* \param type This is the type of each list entry.
*
* This macro declares a structure to be used to link list entries together.
* It must be used inside the definition of the structure named in
* \a type, as follows:
*
* \code
* struct list_entry {
...
AST_LIST_ENTRY(list_entry) list;
* }
* \endcode
*
* The field name \a list here is arbitrary, and can be anything you wish.
*/
#define AST_LIST_ENTRY(type) \
struct { \
struct type *next; \
}
#define AST_RWLIST_ENTRY AST_LIST_ENTRY
/*!
* \brief Returns the first entry contained in a list.
* \param head This is a pointer to the list head structure
*/
#define AST_LIST_FIRST(head) ((head)->first)
#define AST_RWLIST_FIRST AST_LIST_FIRST
/*!
* \brief Returns the last entry contained in a list.
* \param head This is a pointer to the list head structure
*/
#define AST_LIST_LAST(head) ((head)->last)
#define AST_RWLIST_LAST AST_LIST_LAST
/*!
* \brief Returns the next entry in the list after the given entry.
* \param elm This is a pointer to the current entry.
* \param field This is the name of the field (declared using AST_LIST_ENTRY())
* used to link entries of this list together.
*/
#define AST_LIST_NEXT(elm, field) ((elm)->field.next)
#define AST_RWLIST_NEXT AST_LIST_NEXT
/*!
* \brief Checks whether the specified list contains any entries.
* \param head This is a pointer to the list head structure
*
* \return zero if the list has entries
* \return non-zero if not.
*/
#define AST_LIST_EMPTY(head) (AST_LIST_FIRST(head) == NULL)
#define AST_RWLIST_EMPTY AST_LIST_EMPTY
/*!
* \brief Loops over (traverses) the entries in a list.
* \param head This is a pointer to the list head structure
* \param var This is the name of the variable that will hold a pointer to the
* current list entry on each iteration. It must be declared before calling
* this macro.
* \param field This is the name of the field (declared using AST_LIST_ENTRY())
* used to link entries of this list together.
*
* This macro is use to loop over (traverse) the entries in a list. It uses a
* \a for loop, and supplies the enclosed code with a pointer to each list
* entry as it loops. It is typically used as follows:
* \code
* static AST_LIST_HEAD(entry_list, list_entry) entries;
* ...
* struct list_entry {
...
AST_LIST_ENTRY(list_entry) list;
* }
* ...
* struct list_entry *current;
* ...
* AST_LIST_TRAVERSE(&entries, current, list) {
(do something with current here)
* }
* \endcode
* \warning If you modify the forward-link pointer contained in the \a current entry while
* inside the loop, the behavior will be unpredictable. At a minimum, the following
* macros will modify the forward-link pointer, and should not be used inside
* AST_LIST_TRAVERSE() against the entry pointed to by the \a current pointer without
* careful consideration of their consequences:
* \li AST_LIST_NEXT() (when used as an lvalue)
* \li AST_LIST_INSERT_AFTER()
* \li AST_LIST_INSERT_HEAD()
* \li AST_LIST_INSERT_TAIL()
* \li AST_LIST_INSERT_SORTALPHA()
*/
#define AST_LIST_TRAVERSE(head,var,field) \
for((var) = (head)->first; (var); (var) = (var)->field.next)
#define AST_RWLIST_TRAVERSE AST_LIST_TRAVERSE
/*!
* \brief Loops safely over (traverses) the entries in a list.
* \param head This is a pointer to the list head structure
* \param var This is the name of the variable that will hold a pointer to the
* current list entry on each iteration. It must be declared before calling
* this macro.
* \param field This is the name of the field (declared using AST_LIST_ENTRY())
* used to link entries of this list together.
*
* This macro is used to safely loop over (traverse) the entries in a list. It
* uses a \a for loop, and supplies the enclosed code with a pointer to each list
* entry as it loops. It is typically used as follows:
*
* \code
* static AST_LIST_HEAD(entry_list, list_entry) entries;
* ...
* struct list_entry {
...
AST_LIST_ENTRY(list_entry) list;
* }
* ...
* struct list_entry *current;
* ...
* AST_LIST_TRAVERSE_SAFE_BEGIN(&entries, current, list) {
(do something with current here)
* }
* AST_LIST_TRAVERSE_SAFE_END;
* \endcode
*
* It differs from AST_LIST_TRAVERSE() in that the code inside the loop can modify
* (or even free, after calling AST_LIST_REMOVE_CURRENT()) the entry pointed to by
* the \a current pointer without affecting the loop traversal.
*/
#define AST_LIST_TRAVERSE_SAFE_BEGIN(head, var, field) { \
typeof((head)) __list_head = head; \
typeof(__list_head->first) __list_next; \
typeof(__list_head->first) __list_prev = NULL; \
typeof(__list_head->first) __new_prev = NULL; \
for ((var) = __list_head->first, __new_prev = (var), \
__list_next = (var) ? (var)->field.next : NULL; \
(var); \
__list_prev = __new_prev, (var) = __list_next, \
__new_prev = (var), \
__list_next = (var) ? (var)->field.next : NULL, \
(void) __list_prev \
)
#define AST_RWLIST_TRAVERSE_SAFE_BEGIN AST_LIST_TRAVERSE_SAFE_BEGIN
/*!
* \brief Removes the \a current entry from a list during a traversal.
* \param field This is the name of the field (declared using AST_LIST_ENTRY())
* used to link entries of this list together.
*
* \note This macro can \b only be used inside an AST_LIST_TRAVERSE_SAFE_BEGIN()
* block; it is used to unlink the current entry from the list without affecting
* the list traversal (and without having to re-traverse the list to modify the
* previous entry, if any).
*/
#define AST_LIST_REMOVE_CURRENT(field) do { \
__new_prev->field.next = NULL; \
__new_prev = __list_prev; \
if (__list_prev) \
__list_prev->field.next = __list_next; \
else \
__list_head->first = __list_next; \
if (!__list_next) \
__list_head->last = __list_prev; \
} while (0)
#define AST_RWLIST_REMOVE_CURRENT AST_LIST_REMOVE_CURRENT
#define AST_LIST_MOVE_CURRENT(newhead, field) do { \
typeof ((newhead)->first) __list_cur = __new_prev; \
AST_LIST_REMOVE_CURRENT(field); \
AST_LIST_INSERT_TAIL((newhead), __list_cur, field); \
} while (0)
#define AST_RWLIST_MOVE_CURRENT AST_LIST_MOVE_CURRENT
/*!
* \brief Inserts a list entry before the current entry during a traversal.
* \param elm This is a pointer to the entry to be inserted.
* \param field This is the name of the field (declared using AST_LIST_ENTRY())
* used to link entries of this list together.
*
* \note This macro can \b only be used inside an AST_LIST_TRAVERSE_SAFE_BEGIN()
* block.
*/
#define AST_LIST_INSERT_BEFORE_CURRENT(elm, field) do { \
if (__list_prev) { \
(elm)->field.next = __list_prev->field.next; \
__list_prev->field.next = elm; \
} else { \
(elm)->field.next = __list_head->first; \
__list_head->first = (elm); \
} \
__new_prev = (elm); \
} while (0)
#define AST_RWLIST_INSERT_BEFORE_CURRENT AST_LIST_INSERT_BEFORE_CURRENT
/*!
* \brief Closes a safe loop traversal block.
*/
#define AST_LIST_TRAVERSE_SAFE_END }
#define AST_RWLIST_TRAVERSE_SAFE_END AST_LIST_TRAVERSE_SAFE_END
/*!
* \brief Initializes a list head structure.
* \param head This is a pointer to the list head structure
*
* This macro initializes a list head structure by setting the head
* entry to \a NULL (empty list) and recreating the embedded lock.
*/
#define AST_LIST_HEAD_INIT(head) { \
(head)->first = NULL; \
(head)->last = NULL; \
ast_mutex_init(&(head)->lock); \
}
/*!
* \brief Initializes an rwlist head structure.
* \param head This is a pointer to the list head structure
*
* This macro initializes a list head structure by setting the head
* entry to \a NULL (empty list) and recreating the embedded lock.
*/
#define AST_RWLIST_HEAD_INIT(head) { \
(head)->first = NULL; \
(head)->last = NULL; \
ast_rwlock_init(&(head)->lock); \
}
/*!
* \brief Destroys a list head structure.
* \param head This is a pointer to the list head structure
*
* This macro destroys a list head structure by setting the head
* entry to \a NULL (empty list) and destroying the embedded lock.
* It does not free the structure from memory.
*/
#define AST_LIST_HEAD_DESTROY(head) { \
(head)->first = NULL; \
(head)->last = NULL; \
ast_mutex_destroy(&(head)->lock); \
}
/*!
* \brief Destroys an rwlist head structure.
* \param head This is a pointer to the list head structure
*
* This macro destroys a list head structure by setting the head
* entry to \a NULL (empty list) and destroying the embedded lock.
* It does not free the structure from memory.
*/
#define AST_RWLIST_HEAD_DESTROY(head) { \
(head)->first = NULL; \
(head)->last = NULL; \
ast_rwlock_destroy(&(head)->lock); \
}
/*!
* \brief Initializes a list head structure.
* \param head This is a pointer to the list head structure
*
* This macro initializes a list head structure by setting the head
* entry to \a NULL (empty list). There is no embedded lock handling
* with this macro.
*/
#define AST_LIST_HEAD_INIT_NOLOCK(head) { \
(head)->first = NULL; \
(head)->last = NULL; \
}
/*!
* \brief Inserts a list entry after a given entry.
* \param head This is a pointer to the list head structure
* \param listelm This is a pointer to the entry after which the new entry should
* be inserted.
* \param elm This is a pointer to the entry to be inserted.
* \param field This is the name of the field (declared using AST_LIST_ENTRY())
* used to link entries of this list together.
*/
#define AST_LIST_INSERT_AFTER(head, listelm, elm, field) do { \
(elm)->field.next = (listelm)->field.next; \
(listelm)->field.next = (elm); \
if ((head)->last == (listelm)) \
(head)->last = (elm); \
} while (0)
#define AST_RWLIST_INSERT_AFTER AST_LIST_INSERT_AFTER
/*!
* \brief Inserts a list entry at the head of a list.
* \param head This is a pointer to the list head structure
* \param elm This is a pointer to the entry to be inserted.
* \param field This is the name of the field (declared using AST_LIST_ENTRY())
* used to link entries of this list together.
*/
#define AST_LIST_INSERT_HEAD(head, elm, field) do { \
(elm)->field.next = (head)->first; \
(head)->first = (elm); \
if (!(head)->last) \
(head)->last = (elm); \
} while (0)
#define AST_RWLIST_INSERT_HEAD AST_LIST_INSERT_HEAD
/*!
* \brief Appends a list entry to the tail of a list.
* \param head This is a pointer to the list head structure
* \param elm This is a pointer to the entry to be appended.
* \param field This is the name of the field (declared using AST_LIST_ENTRY())
* used to link entries of this list together.
*
* Note: The link field in the appended entry is \b not modified, so if it is
* actually the head of a list itself, the entire list will be appended
* temporarily (until the next AST_LIST_INSERT_TAIL is performed).
*/
#define AST_LIST_INSERT_TAIL(head, elm, field) do { \
if (!(head)->first) { \
(head)->first = (elm); \
(head)->last = (elm); \
} else { \
(head)->last->field.next = (elm); \
(head)->last = (elm); \
} \
} while (0)
#define AST_RWLIST_INSERT_TAIL AST_LIST_INSERT_TAIL
/*!
* \brief Inserts a list entry into a alphabetically sorted list
* \param head Pointer to the list head structure
* \param elm Pointer to the entry to be inserted
* \param field Name of the list entry field (declared using AST_LIST_ENTRY())
* \param sortfield Name of the field on which the list is sorted
* \since 1.6.1
*/
#define AST_LIST_INSERT_SORTALPHA(head, elm, field, sortfield) do { \
if (!(head)->first) { \
(head)->first = (elm); \
(head)->last = (elm); \
} else { \
typeof((head)->first) cur = (head)->first, prev = NULL; \
while (cur && strcmp(cur->sortfield, elm->sortfield) < 0) { \
prev = cur; \
cur = cur->field.next; \
} \
if (!prev) { \
AST_LIST_INSERT_HEAD(head, elm, field); \
} else if (!cur) { \
AST_LIST_INSERT_TAIL(head, elm, field); \
} else { \
AST_LIST_INSERT_AFTER(head, prev, elm, field); \
} \
} \
} while (0)
#define AST_RWLIST_INSERT_SORTALPHA AST_LIST_INSERT_SORTALPHA
/*!
* \brief Appends a whole list to the tail of a list.
* \param head This is a pointer to the list head structure
* \param list This is a pointer to the list to be appended.
* \param field This is the name of the field (declared using AST_LIST_ENTRY())
* used to link entries of this list together.
*
* Note: The source list (the \a list parameter) will be empty after
* calling this macro (the list entries are \b moved to the target list).
*/
#define AST_LIST_APPEND_LIST(head, list, field) do { \
if (!(list)->first) { \
break; \
} \
if (!(head)->first) { \
(head)->first = (list)->first; \
(head)->last = (list)->last; \
} else { \
(head)->last->field.next = (list)->first; \
(head)->last = (list)->last; \
} \
(list)->first = NULL; \
(list)->last = NULL; \
} while (0)
#define AST_RWLIST_APPEND_LIST AST_LIST_APPEND_LIST
/*!
\brief Inserts a whole list after a specific entry in a list
\param head This is a pointer to the list head structure
\param list This is a pointer to the list to be inserted.
\param elm This is a pointer to the entry after which the new list should
be inserted.
\param field This is the name of the field (declared using AST_LIST_ENTRY())
used to link entries of the lists together.
Note: The source list (the \a list parameter) will be empty after
calling this macro (the list entries are \b moved to the target list).
*/
#define AST_LIST_INSERT_LIST_AFTER(head, list, elm, field) do { \
(list)->last->field.next = (elm)->field.next; \
(elm)->field.next = (list)->first; \
if ((head)->last == elm) { \
(head)->last = (list)->last; \
} \
(list)->first = NULL; \
(list)->last = NULL; \
} while(0)
#define AST_RWLIST_INSERT_LIST_AFTER AST_LIST_INSERT_LIST_AFTER
/*!
* \brief Removes and returns the head entry from a list.
* \param head This is a pointer to the list head structure
* \param field This is the name of the field (declared using AST_LIST_ENTRY())
* used to link entries of this list together.
*
* Removes the head entry from the list, and returns a pointer to it.
* This macro is safe to call on an empty list.
*/
#define AST_LIST_REMOVE_HEAD(head, field) ({ \
typeof((head)->first) cur = (head)->first; \
if (cur) { \
(head)->first = cur->field.next; \
cur->field.next = NULL; \
if ((head)->last == cur) \
(head)->last = NULL; \
} \
cur; \
})
#define AST_RWLIST_REMOVE_HEAD AST_LIST_REMOVE_HEAD
/*!
* \brief Removes a specific entry from a list.
* \param head This is a pointer to the list head structure
* \param elm This is a pointer to the entry to be removed.
* \param field This is the name of the field (declared using AST_LIST_ENTRY())
* used to link entries of this list together.
* \warning The removed entry is \b not freed nor modified in any way.
*/
#define AST_LIST_REMOVE(head, elm, field) ({ \
__typeof(elm) __res = NULL; \
__typeof(elm) __tmp = elm; \
if (!__tmp) { \
__res = NULL; \
} else if ((head)->first == (elm)) { \
__res = (head)->first; \
(head)->first = (elm)->field.next; \
if ((head)->last == (elm)) \
(head)->last = NULL; \
} else { \
typeof(elm) curelm = (head)->first; \
while (curelm && (curelm->field.next != (elm))) \
curelm = curelm->field.next; \
if (curelm) { \
__res = (elm); \
curelm->field.next = (elm)->field.next; \
if ((head)->last == (elm)) \
(head)->last = curelm; \
} \
} \
if (__res) { \
(__res)->field.next = NULL; \
} \
(__res); \
})
#define AST_RWLIST_REMOVE AST_LIST_REMOVE
#endif /* _ASTERISK_LINKEDLISTS_H */
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