Function sys_read

lib_acl/src/stdlib/acl_vstream.c:271–355

}

static int sys_read(ACL_VSTREAM *in, void *buf, size_t size)
{
	int read_cnt, nagain = 0;

	 /* clear the read_ready flag first: we shouldn't clear the flag
	  * after read() API such as read_fn called, because in some case,
	  * the read_ready flag maybe set 1 again in order to invoke the
	  * IO event in non-blocking mode.
	  */
	in->read_ready = 0;

	if (in->type == ACL_VSTREAM_TYPE_FILE) {
		if (ACL_VSTREAM_FILE(in) == ACL_FILE_INVALID) {
			/* in->read_ready = 0; */
			return -1;
		}
	} else if (ACL_VSTREAM_SOCK(in) == ACL_SOCKET_INVALID) {
		/* in->read_ready = 0; */
		return -1;
	}

#ifndef	SAFE_COPY
#define	SAFE_COPY(x, y) ACL_SAFE_STRNCPY((x), (y), sizeof((x)))
#endif

AGAIN:

	/* ���ϵͳ����� */
	acl_set_error(0);

	if (in->type == ACL_VSTREAM_TYPE_FILE) {
		read_cnt = in->fread_fn(ACL_VSTREAM_FILE(in), buf, size,
			in->rw_timeout, in, in->context);
		if (in->read_cnt > 0) {
			in->sys_offset += in->read_cnt;
		}
	} else {
		read_cnt = in->read_fn(ACL_VSTREAM_SOCK(in), buf, size,
			in->rw_timeout, in, in->context);
	}

	if (read_cnt > 0) {
		in->flag &= ~ACL_VSTREAM_FLAG_BAD;
		in->errnum = 0;
		in->total_read_cnt += read_cnt;

		return read_cnt;
	} else if (read_cnt == 0) {
		in->flag = ACL_VSTREAM_FLAG_EOF;
		in->errnum = 0;

		return 0;
	}

	in->errnum = acl_last_error();

	if (in->errnum == ACL_EINTR) {
		if (nagain++ < 5) {