acrn-hypervisor/misc/debug_tools/acrn_trace/sbuf.c

83 lines
1.5 KiB
C

/*
* Copyright (C) 2018-2022 Intel Corporation.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <asm/errno.h>
#include <string.h>
#include <unistd.h>
#include <stdio.h>
#include <stdbool.h>
#include "sbuf.h"
#include <errno.h>
static inline bool sbuf_is_empty(shared_buf_t *sbuf)
{
return (sbuf->head == sbuf->tail);
}
static inline uint32_t sbuf_next_ptr(uint32_t pos,
uint32_t span, uint32_t scope)
{
pos += span;
pos = (pos >= scope) ? (pos - scope) : pos;
return pos;
}
int sbuf_get(shared_buf_t *sbuf, uint8_t *data)
{
const void *from;
if ((sbuf == NULL) || (data == NULL))
return -EINVAL;
if (sbuf_is_empty(sbuf)) {
/* no data available */
return 0;
}
from = (void *)sbuf + SBUF_HEAD_SIZE + sbuf->head;
memcpy(data, from, sbuf->ele_size);
sbuf->head = sbuf_next_ptr(sbuf->head, sbuf->ele_size, sbuf->size);
return sbuf->ele_size;
}
int sbuf_write(int fd, shared_buf_t *sbuf)
{
const void *start;
int written;
if (sbuf == NULL)
return -EINVAL;
if (sbuf_is_empty(sbuf)) {
return 0;
}
start = (void *)sbuf + SBUF_HEAD_SIZE + sbuf->head;
written = write(fd, start, sbuf->ele_size);
if (written != sbuf->ele_size) {
printf("Failed to write: ret %d (ele_size %d), errno %d\n",
written, sbuf->ele_size, (written == -1) ? errno : 0);
return -1;
}
sbuf->head = sbuf_next_ptr(sbuf->head, sbuf->ele_size, sbuf->size);
return sbuf->ele_size;
}
int sbuf_clear_buffered(shared_buf_t *sbuf)
{
if (sbuf == NULL)
return -EINVAL;
sbuf->head = sbuf->tail;
return 0;
}