2 * This file is part of the Palacios Virtual Machine Monitor developed
3 * by the V3VEE Project with funding from the United States National
4 * Science Foundation and the Department of Energy.
6 * The V3VEE Project is a joint project between Northwestern University
7 * and the University of New Mexico. You can find out more at
10 * Copyright (c) 2008, Jack Lange <jarusl@cs.northwestern.edu>
11 * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org>
12 * All rights reserved.
14 * Author: Jack Lange <jarusl@cs.northwestern.edu>
16 * This is free software. You are permitted to use,
17 * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
20 #include <palacios/vmm_ringbuffer.h>
21 #include <palacios/vmm.h>
24 void v3_init_ringbuf(struct v3_ringbuf * ring, uint_t size) {
25 ring->buf = V3_Malloc(size);
30 ring->current_len = 0;
34 struct v3_ringbuf * v3_create_ringbuf(uint_t size) {
35 struct v3_ringbuf * ring = (struct v3_ringbuf *)V3_Malloc(sizeof(struct v3_ringbuf));
37 v3_init_ringbuf(ring, size);
42 void v3_free_ringbuf(struct v3_ringbuf * ring) {
51 static inline uchar_t * get_read_ptr(struct v3_ringbuf * ring) {
52 return (uchar_t *)(ring->buf + ring->start);
55 static inline uchar_t * get_write_ptr(struct v3_ringbuf * ring) {
56 return (uchar_t *)(ring->buf + ring->end);
60 static inline int get_read_section_size(struct v3_ringbuf * ring) {
61 return ring->size - ring->start;
64 static inline int get_write_section_size(struct v3_ringbuf * ring) {
65 return ring->size - ring->end;
68 static inline int is_read_loop(struct v3_ringbuf * ring, uint_t len) {
69 if ((ring->start >= ring->end) && (ring->current_len > 0)) {
70 // end is past the end of the buffer
71 if (get_read_section_size(ring) < len) {
79 static inline int is_write_loop(struct v3_ringbuf * ring, uint_t len) {
80 if ((ring->end >= ring->start) && (ring->current_len < ring->size)) {
81 // end is past the end of the buffer
82 if (get_write_section_size(ring) < len) {
90 int v3_ringbuf_data_len(struct v3_ringbuf * ring) {
91 return ring->current_len;
94 int v3_ringbuf_capacity(struct v3_ringbuf * ring) {
98 int v3_ringbuf_read(struct v3_ringbuf * ring, uchar_t * dst, uint_t len) {
100 int ring_data_len = ring->current_len;
102 read_len = (len > ring_data_len) ? ring_data_len : len;
104 if (is_read_loop(ring, read_len)) {
105 int section_len = get_read_section_size(ring);
107 memcpy(dst, get_read_ptr(ring), section_len);
108 memcpy(dst + section_len, ring->buf, read_len - section_len);
110 ring->start = read_len - section_len;
112 memcpy(dst, get_read_ptr(ring), read_len);
114 ring->start += read_len;
117 ring->current_len -= read_len;
125 int v3_ringbuf_peek(struct v3_ringbuf * ring, uchar_t * dst, uint_t len) {
127 int ring_data_len = ring->current_len;
129 read_len = (len > ring_data_len) ? ring_data_len : len;
131 if (is_read_loop(ring, read_len)) {
132 int section_len = get_read_section_size(ring);
134 memcpy(dst, get_read_ptr(ring), section_len);
135 memcpy(dst + section_len, ring->buf, read_len - section_len);
137 memcpy(dst, get_read_ptr(ring), read_len);
144 int v3_ringbuf_delete(struct v3_ringbuf * ring, uint_t len) {
146 int ring_data_len = ring->current_len;
148 del_len = (len > ring_data_len) ? ring_data_len : len;
150 if (is_read_loop(ring, del_len)) {
151 int section_len = get_read_section_size(ring);
152 ring->start = del_len - section_len;
154 ring->start += del_len;
157 ring->current_len -= del_len;
162 int v3_ringbuf_write(struct v3_ringbuf * ring, uchar_t * src, uint_t len) {
164 int ring_avail_space = ring->size - ring->current_len;
166 write_len = (len > ring_avail_space) ? ring_avail_space : len;
169 if (is_write_loop(ring, write_len)) {
170 int section_len = get_write_section_size(ring);
172 memcpy(get_write_ptr(ring), src, section_len);
175 memcpy(get_write_ptr(ring), src + section_len, write_len - section_len);
177 ring->end += write_len - section_len;
179 memcpy(get_write_ptr(ring), src, write_len);
181 ring->end += write_len;
184 ring->current_len += write_len;
190 void v3_print_ringbuf(struct v3_ringbuf * ring) {
193 for (ctr = 0; ctr < ring->current_len; ctr++) {
194 int index = (ctr + ring->start) % ring->size;
196 PrintDebug("Entry %d (index=%d): %c\n", ctr, index, ring->buf[index]);