- /* General queue data structure for GDB, the GNU debugger.
- Copyright (C) 2012-2015 Free Software Foundation, Inc.
- This file is part of GDB.
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
- #ifndef QUEUE_H
- #define QUEUE_H
- /* These macros implement functions and structs for a general queue.
- Macro 'DEFINE_QUEUE_P(TYPEDEF)' is to define the new queue type for
- TYPEDEF', and macro 'DECLARE_QUEUE_P' is to declare external queue
- APIs. The character P indicates TYPEDEF is a pointer (P). The
- counterpart on object (O) and integer (I) are not implemented.
- An example of their use would be,
- typedef struct foo
- {} *foo_p;
- DEFINE_QUEUE_P (foo_p);
- // A pointer to a queue of foo pointers. FOO_XFREE is a destructor
- // function for foo instances in queue.
- QUEUE(foo_p) *foo_queue = QUEUE_alloc (foo_p, foo_xfree);
- foo_p foo_var_p;
- // Enqueue and Dequeue
- QUEUE_enque (foo_p, foo_queue, foo_var_p);
- foo_var_p = QUEUE_deque (foo_p, foo_queue);
- static int visit_foo (QUEUE (foo_p) *q, QUEUE_ITER (foo_p) *iter,
- foo_p f, void *data)
- {
- return 1;
- }
- // Iterate over queue.
- QUEUE_iterate (foo_p, foo_queue, visit_foo, ¶m);
- QUEUE_free (foo_p, foo_queue); // Free queue. */
- /* Typical enqueue operation. Put V into queue Q. */
- #define QUEUE_enque(TYPE, Q, V) queue_ ## TYPE ## _enque ((Q), (V))
- /* Typical dequeue operation. Return head element of queue Q and
- remove it. Q must not be empty. */
- #define QUEUE_deque(TYPE, Q) queue_ ## TYPE ## _deque (Q)
- /* Return the head element, but don't remove it from the queue.
- Q must not be empty. */
- #define QUEUE_peek(TYPE, Q) queue_ ## TYPE ## _peek (Q)
- /* Return true if queue Q is empty. */
- #define QUEUE_is_empty(TYPE, Q) queue_ ## TYPE ## _is_empty (Q)
- /* Allocate memory for queue. FREE_FUNC is a function to release the
- data put in each queue element. */
- #define QUEUE_alloc(TYPE, FREE_FUNC) queue_ ## TYPE ## _alloc (FREE_FUNC)
- /* Length of queue Q. */
- #define QUEUE_length(TYPE, Q) queue_ ## TYPE ## _length (Q)
- /* Free queue Q. Q's free_func is called once for each element. */
- #define QUEUE_free(TYPE, Q) queue_ ## TYPE ## _free (Q)
- /* Iterate over elements in the queue Q and call function OPERATE on
- each element. It is allowed to remove element by OPERATE. OPERATE
- returns false to terminate the iteration and true to continue the
- iteration. Return false if iteration is terminated by function
- OPERATE, otherwise return true. */
- #define QUEUE_iterate(TYPE, Q, OPERATE, PARAM) \
- queue_ ## TYPE ## _iterate ((Q), (OPERATE), (PARAM))
- /* Remove the element per the state of iterator ITER from queue Q.
- Leave the caller to release the data in the queue element. */
- #define QUEUE_remove_elem(TYPE, Q, ITER) \
- queue_ ## TYPE ## _remove_elem ((Q), (ITER))
- /* Define a new queue implementation. */
- #define QUEUE(TYPE) struct queue_ ## TYPE
- #define QUEUE_ELEM(TYPE) struct queue_elem_ ## TYPE
- #define QUEUE_ITER(TYPE) struct queue_iter_ ## TYPE
- #define QUEUE_ITER_FUNC(TYPE) queue_ ## TYPE ## _operate_func
- #define DEFINE_QUEUE_P(TYPE) \
- QUEUE_ELEM (TYPE) \
- { \
- QUEUE_ELEM (TYPE) *next; \
- \
- TYPE data; \
- }; \
- \
- /* Queue iterator. */ \
- QUEUE_ITER (TYPE) \
- { \
- /* The current element during traverse. */ \
- QUEUE_ELEM (TYPE) *p; \
- /* The previous element of P. */ \
- QUEUE_ELEM (TYPE) *prev; \
- }; \
- \
- QUEUE(TYPE) \
- { \
- /* The head and tail of the queue. */ \
- QUEUE_ELEM (TYPE) *head; \
- QUEUE_ELEM (TYPE) *tail; \
- /* Function to release the data put in each \
- queue element. */ \
- void (*free_func) (TYPE); \
- }; \
- \
- void \
- queue_ ## TYPE ## _enque (QUEUE (TYPE) *q, TYPE v) \
- { \
- QUEUE_ELEM (TYPE) *p \
- = xmalloc (sizeof (QUEUE_ELEM (TYPE))); \
- \
- gdb_assert (q != NULL); \
- p->data = v; \
- p->next = NULL; \
- if (q->tail == NULL) \
- { \
- q->tail = p; \
- q->head = p; \
- } \
- else \
- { \
- q->tail->next = p; \
- q->tail = p; \
- } \
- } \
- \
- TYPE \
- queue_ ## TYPE ## _deque (QUEUE (TYPE) *q) \
- { \
- QUEUE_ELEM (TYPE) *p; \
- TYPE v; \
- \
- gdb_assert (q != NULL); \
- p = q->head; \
- gdb_assert (p != NULL); \
- \
- if (q->head == q->tail) \
- { \
- q->head = NULL; \
- q->tail = NULL; \
- } \
- else \
- q->head = q->head->next; \
- \
- v = p->data; \
- \
- xfree (p); \
- return v; \
- } \
- \
- TYPE \
- queue_ ## TYPE ## _peek (QUEUE (TYPE) *q) \
- { \
- gdb_assert (q != NULL); \
- gdb_assert (q->head != NULL); \
- return q->head->data; \
- } \
- \
- int \
- queue_ ## TYPE ## _is_empty (QUEUE (TYPE) *q) \
- { \
- gdb_assert (q != NULL); \
- return q->head == NULL; \
- } \
- \
- void \
- queue_ ## TYPE ## _remove_elem (QUEUE (TYPE) *q, \
- QUEUE_ITER (TYPE) *iter) \
- { \
- gdb_assert (q != NULL); \
- gdb_assert (iter != NULL && iter->p != NULL); \
- \
- if (iter->p == q->head || iter->p == q->tail) \
- { \
- if (iter->p == q->head) \
- q->head = iter->p->next; \
- if (iter->p == q->tail) \
- q->tail = iter->prev; \
- } \
- else \
- iter->prev->next = iter->p->next; \
- \
- xfree (iter->p); \
- /* Indicate that ITER->p has been deleted from QUEUE q. */ \
- iter->p = NULL; \
- } \
- \
- int \
- queue_ ## TYPE ## _iterate (QUEUE (TYPE) *q, \
- QUEUE_ITER_FUNC (TYPE) operate, \
- void *data) \
- { \
- QUEUE_ELEM (TYPE) *next = NULL; \
- QUEUE_ITER (TYPE) iter = { NULL, NULL }; \
- \
- gdb_assert (q != NULL); \
- \
- for (iter.p = q->head; iter.p != NULL; iter.p = next) \
- { \
- next = iter.p->next; \
- if (!operate (q, &iter, iter.p->data, data)) \
- return 0; \
- /* ITER.P was not deleted by function OPERATE. */ \
- if (iter.p != NULL) \
- iter.prev = iter.p; \
- } \
- return 1; \
- } \
- \
- QUEUE (TYPE) * \
- queue_ ## TYPE ## _alloc (void (*free_func) (TYPE)) \
- { \
- QUEUE (TYPE) *q; \
- \
- q = (QUEUE (TYPE) *) xmalloc (sizeof (QUEUE (TYPE))); \
- q->head = NULL; \
- q->tail = NULL; \
- q->free_func = free_func; \
- return q; \
- } \
- \
- int \
- queue_ ## TYPE ## _length (QUEUE (TYPE) *q) \
- { \
- QUEUE_ELEM (TYPE) *p; \
- int len = 0; \
- \
- gdb_assert (q != NULL); \
- \
- for (p = q->head; p != NULL; p = p->next) \
- len++; \
- \
- return len; \
- } \
- \
- void \
- queue_ ## TYPE ## _free (QUEUE (TYPE) *q) \
- { \
- QUEUE_ELEM (TYPE) *p, *next; \
- \
- gdb_assert (q != NULL); \
- \
- for (p = q->head; p != NULL; p = next) \
- { \
- next = p->next; \
- if (q->free_func) \
- q->free_func (p->data); \
- xfree (p); \
- } \
- xfree (q); \
- } \
- /* External declarations for queue functions. */
- #define DECLARE_QUEUE_P(TYPE) \
- QUEUE (TYPE); \
- QUEUE_ELEM (TYPE); \
- QUEUE_ITER (TYPE); \
- extern void \
- queue_ ## TYPE ## _enque (QUEUE (TYPE) *q, TYPE v); \
- extern TYPE \
- queue_ ## TYPE ## _deque (QUEUE (TYPE) *q); \
- extern int queue_ ## TYPE ## _is_empty (QUEUE (TYPE) *q); \
- extern QUEUE (TYPE) * \
- queue_ ## TYPE ## _alloc (void (*free_func) (TYPE)); \
- extern int queue_ ## TYPE ## _length (QUEUE (TYPE) *q); \
- extern TYPE \
- queue_ ## TYPE ## _peek (QUEUE (TYPE) *q); \
- extern void queue_ ## TYPE ## _free (QUEUE (TYPE) *q); \
- typedef int QUEUE_ITER_FUNC(TYPE) (QUEUE (TYPE) *, \
- QUEUE_ITER (TYPE) *, \
- TYPE, \
- void *); \
- extern int \
- queue_ ## TYPE ## _iterate (QUEUE (TYPE) *q, \
- QUEUE_ITER_FUNC (TYPE) operate, \
- void *); \
- extern void \
- queue_ ## TYPE ## _remove_elem (QUEUE (TYPE) *q, \
- QUEUE_ITER (TYPE) *iter); \
- #endif /* QUEUE_H */