lib.h

这是Linux环境下的蓝牙源代码

/*
 *
 *  BlueZ - Bluetooth protocol stack for Linux
 *
 *  Copyright (C) 2002-2003  Maxim Krasnyansky <[e-mail]>
 *  Copyright (C) 2002-2008  Marcel Holtmann <[e-mail]>
 *
 *
 *  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 2 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, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include <sys/types.h>
#include <errno.h>
#include <signal.h>

#ifndef min
#define min(a,b)    ( (a)<(b) ? (a):(b) )
#endif

/* IO cancelation */
extern volatile sig_atomic_t __io_canceled;

static inline void io_init(void)
{
	__io_canceled = 0;
}

static inline void io_cancel(void)
{
	__io_canceled = 1;
}

/* Read exactly len bytes (Signal safe)*/
static inline int read_n(int fd, char *buf, int len)
{
	register int t = 0, w;

	while (!__io_canceled && len > 0) {
		if ((w = read(fd, buf, len)) < 0) {
			if (errno == EINTR || errno == EAGAIN)
				continue;
			return -1;
		}
		if (!w)
			return 0;
		len -= w;
		buf += w;
		t += w;
	}

	return t;
}

/* Write exactly len bytes (Signal safe)*/
static inline int write_n(int fd, char *buf, int len)
{
	register int t = 0, w;

	while (!__io_canceled && len > 0) {
		if ((w = write(fd, buf, len)) < 0) {
			if (errno == EINTR || errno == EAGAIN)
				continue;
			return -1;
		}
		if (!w)
			return 0;
		len -= w;
		buf += w;
		t += w;
	}

	return t;
}