示例#1
0
// A persistent read function.
static ssize_t read_r(int fd, void *buf, size_t count, size_t ms)
{
	double tMax = ms / 1000.0; // convert to seconds
	PosixTimer t;
	int r;
	unsigned int total = 0;
	while (total < count) {
		r = read(fd, ((unsigned char *)buf) + total, count - total);
		// did something seriously go wrong?
		if (r < 0 && errno != EINTR) {
			__dbg(string("PosixSerial: failed to read: ") + string(strerror(errno)));
			throw PosixSerial::ReadFailure();
		} else if (r > 0) {
			// progress!
			total += r;
			t.start(); // restart the timer
		}
		// are we out of time?
		if (ms > 0 && t.elapsed() > tMax) {
			__dbg(string("PosixSerial: read timed out"));
			throw PosixSerial::ReadTimeout();
		}
	}
	return total;
}
示例#2
0
// A persistent write function.
static ssize_t write_r(int fd, const void *buf, size_t count, size_t ms)
{
	double tMax = ms / 1000.0; // convert to seconds
	PosixTimer t;
	int r;
	unsigned int written = 0;
	while (written < count) {
		r = write(fd, ((const unsigned char *)buf) + written, count - written);
		// did something seriously go wrong?
		if (r < 0 && errno != EINTR) {
			__dbg(string("PosixSerial: failed to write: ") + string(strerror(errno)));
			throw PosixSerial::WriteFailure();
		} else if (r > 0) {
			// progress!
			written += r;
			t.start(); // restart the timer
		}
		// are we out of time?
		if (ms > 0 && t.elapsed() > tMax) {
			__dbg(string("PosixSerial: write timed out"));
			throw PosixSerial::WriteTimeout();
		}
	}
	return written;
}