add libbpf.

1 files changed, 329 insertions, 0 deletions

diff --git a/libbpf/queue.h b/libbpf/queue.h
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+++ b/libbpf/queue.h
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+/*
+ * Mach Operating System
+ * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
+ * All Rights Reserved.
+ *
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ *
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * Carnegie Mellon requests users of this software to return to
+ *
+ *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ *
+ * any improvements or extensions that they make and grant Carnegie Mellon rights
+ * to redistribute these changes.
+ */
+/*
+ *	File:	queue.h
+ *	Author:	Avadis Tevanian, Jr.
+ *	Date:	1985
+ *
+ *	Type definitions for generic queues.
+ *
+ */
+
+#ifndef	_KERN_QUEUE_H_
+#define	_KERN_QUEUE_H_
+
+/*
+ *	Queue of abstract objects.  Queue is maintained
+ *	within that object.
+ *
+ *	Supports fast removal from within the queue.
+ *
+ *	How to declare a queue of elements of type "foo_t":
+ *		In the "*foo_t" type, you must have a field of
+ *		type "queue_chain_t" to hold together this queue.
+ *		There may be more than one chain through a
+ *		"foo_t", for use by different queues.
+ *
+ *		Declare the queue as a "queue_t" type.
+ *
+ *		Elements of the queue (of type "foo_t", that is)
+ *		are referred to by reference, and cast to type
+ *		"queue_entry_t" within this module.
+ */
+
+/*
+ *	A generic doubly-linked list (queue).
+ */
+
+struct queue_entry {
+	struct queue_entry	*next;		/* next element */
+	struct queue_entry	*prev;		/* previous element */
+};
+
+typedef struct queue_entry	*queue_t;
+typedef	struct queue_entry	queue_head_t;
+typedef	struct queue_entry	queue_chain_t;
+typedef	struct queue_entry	*queue_entry_t;
+
+/*
+ *	enqueue puts "elt" on the "queue".
+ *	dequeue returns the first element in the "queue".
+ *	remqueue removes the specified "elt" from the specified "queue".
+ */
+
+#define enqueue(queue,elt)	enqueue_tail(queue, elt)
+#define	dequeue(queue)		dequeue_head(queue)
+
+void		enqueue_head(queue_t, queue_entry_t);
+void		enqueue_tail(queue_t, queue_entry_t);
+queue_entry_t	dequeue_head(queue_t);
+queue_entry_t	dequeue_tail(queue_t);
+void		remqueue(queue_t, queue_entry_t);
+
+/*
+ *	Macro:		queue_init
+ *	Function:
+ *		Initialize the given queue.
+ *	Header:
+ *		void queue_init(q)
+ *			queue_t		q;	*MODIFIED*
+ */
+#define	queue_init(q)	((q)->next = (q)->prev = q)
+
+/*
+ *	Macro:		queue_first
+ *	Function:
+ *		Returns the first entry in the queue,
+ *	Header:
+ *		queue_entry_t queue_first(q)
+ *			queue_t	q;		*IN*
+ */
+#define	queue_first(q)	((q)->next)
+
+/*
+ *	Macro:		queue_next
+ *	Function:
+ *		Returns the entry after an item in the queue.
+ *	Header:
+ *		queue_entry_t queue_next(qc)
+ *			queue_t qc;
+ */
+#define	queue_next(qc)	((qc)->next)
+
+/*
+ *	Macro:		queue_last
+ *	Function:
+ *		Returns the last entry in the queue.
+ *	Header:
+ *		queue_entry_t queue_last(q)
+ *			queue_t	q;		 *IN*
+ */
+#define	queue_last(q)	((q)->prev)
+
+/*
+ *	Macro:		queue_prev
+ *	Function:
+ *		Returns the entry before an item in the queue.
+ *	Header:
+ *		queue_entry_t queue_prev(qc)
+ *			queue_t qc;
+ */
+#define	queue_prev(qc)	((qc)->prev)
+
+/*
+ *	Macro:		queue_end
+ *	Function:
+ *		Tests whether a new entry is really the end of
+ *		the queue.
+ *	Header:
+ *		boolean_t queue_end(q, qe)
+ *			queue_t q;
+ *			queue_entry_t qe;
+ */
+#define	queue_end(q, qe)	((q) == (qe))
+
+/*
+ *	Macro:		queue_empty
+ *	Function:
+ *		Tests whether a queue is empty.
+ *	Header:
+ *		boolean_t queue_empty(q)
+ *			queue_t q;
+ */
+#define	queue_empty(q)		queue_end((q), queue_first(q))
+
+
+/*----------------------------------------------------------------*/
+/*
+ * Macros that operate on generic structures.  The queue
+ * chain may be at any location within the structure, and there
+ * may be more than one chain.
+ */
+
+/*
+ *	Macro:		queue_enter
+ *	Function:
+ *		Insert a new element at the tail of the queue.
+ *	Header:
+ *		void queue_enter(q, elt, type, field)
+ *			queue_t q;
+ *			<type> elt;
+ *			<type> is what's in our queue
+ *			<field> is the chain field in (*<type>)
+ */
+#define queue_enter(head, elt, type, field)			\
+{ 								\
+	register queue_entry_t prev;				\
+								\
+	prev = (head)->prev;					\
+	if ((head) == prev) {					\
+		(head)->next = (queue_entry_t) (elt);		\
+	}							\
+	else {							\
+		((type)prev)->field.next = (queue_entry_t)(elt);\
+	}							\
+	(elt)->field.prev = prev;				\
+	(elt)->field.next = head;				\
+	(head)->prev = (queue_entry_t) elt;			\
+}
+
+/*
+ *	Macro:		queue_enter_first
+ *	Function:
+ *		Insert a new element at the head of the queue.
+ *	Header:
+ *		void queue_enter_first(q, elt, type, field)
+ *			queue_t q;
+ *			<type> elt;
+ *			<type> is what's in our queue
+ *			<field> is the chain field in (*<type>)
+ */
+#define queue_enter_first(head, elt, type, field)		\
+{ 								\
+	register queue_entry_t next;				\
+								\
+	next = (head)->next;					\
+	if ((head) == next) {					\
+		(head)->prev = (queue_entry_t) (elt);		\
+	}							\
+	else {							\
+		((type)next)->field.prev = (queue_entry_t)(elt);\
+	}							\
+	(elt)->field.next = next;				\
+	(elt)->field.prev = head;				\
+	(head)->next = (queue_entry_t) elt;			\
+}
+
+/*
+ *	Macro:		queue_field [internal use only]
+ *	Function:
+ *		Find the queue_chain_t (or queue_t) for the
+ *		given element (thing) in the given queue (head)
+ */
+#define	queue_field(head, thing, type, field)			\
+		(((head) == (thing)) ? (head) : &((type)(thing))->field)
+
+/*
+ *	Macro:		queue_remove
+ *	Function:
+ *		Remove an arbitrary item from the queue.
+ *	Header:
+ *		void queue_remove(q, qe, type, field)
+ *			arguments as in queue_enter
+ */
+#define	queue_remove(head, elt, type, field)			\
+{								\
+	register queue_entry_t	next, prev;			\
+								\
+	next = (elt)->field.next;				\
+	prev = (elt)->field.prev;				\
+								\
+	if ((head) == next)					\
+		(head)->prev = prev;				\
+	else							\
+		((type)next)->field.prev = prev;		\
+								\
+	if ((head) == prev)					\
+		(head)->next = next;				\
+	else							\
+		((type)prev)->field.next = next;		\
+}
+
+/*
+ *	Macro:		queue_remove_first
+ *	Function:
+ *		Remove and return the entry at the head of
+ *		the queue.
+ *	Header:
+ *		queue_remove_first(head, entry, type, field)
+ *		entry is returned by reference
+ */
+#define	queue_remove_first(head, entry, type, field)		\
+{								\
+	register queue_entry_t	next;				\
+								\
+	(entry) = (type) ((head)->next);			\
+	next = (entry)->field.next;				\
+								\
+	if ((head) == next)					\
+		(head)->prev = (head);				\
+	else							\
+		((type)(next))->field.prev = (head);		\
+	(head)->next = next;					\
+}
+
+/*
+ *	Macro:		queue_remove_last
+ *	Function:
+ *		Remove and return the entry at the tail of
+ *		the queue.
+ *	Header:
+ *		queue_remove_last(head, entry, type, field)
+ *		entry is returned by reference
+ */
+#define	queue_remove_last(head, entry, type, field)		\
+{								\
+	register queue_entry_t	prev;				\
+								\
+	(entry) = (type) ((head)->prev);			\
+	prev = (entry)->field.prev;				\
+								\
+	if ((head) == prev)					\
+		(head)->next = (head);				\
+	else							\
+		((type)(prev))->field.next = (head);		\
+	(head)->prev = prev;					\
+}
+
+/*
+ *	Macro:		queue_assign
+ */
+#define	queue_assign(to, from, type, field)			\
+{								\
+	((type)((from)->prev))->field.next = (to);		\
+	((type)((from)->next))->field.prev = (to);		\
+	*to = *from;						\
+}
+
+/*
+ *	Macro:		queue_iterate
+ *	Function:
+ *		iterate over each item in the queue.
+ *		Generates a 'for' loop, setting elt to
+ *		each item in turn (by reference).
+ *	Header:
+ *		queue_iterate(q, elt, type, field)
+ *			queue_t q;
+ *			<type> elt;
+ *			<type> is what's in our queue
+ *			<field> is the chain field in (*<type>)
+ */
+#define queue_iterate(head, elt, type, field)			\
+	for ((elt) = (type) queue_first(head);			\
+	     !queue_end((head), (queue_entry_t)(elt));		\
+	     (elt) = (type) queue_next(&(elt)->field))
+
+#endif	/* _KERN_QUEUE_H_ */