view loadtools/tpinterf2.c @ 619:f82551c77e58

libserial-newlnx: ASYNC_LOW_LATENCY patch reverted Reports from Das Signal indicate that loadtools performance on Debian is about the same as on Slackware, and that including or omitting the ASYNC_LOW_LATENCY patch from Serg makes no difference. Because the patch in question does not appear to be necessary, it is being reverted until and unless someone other than Serg reports an actual real-world system on which loadtools operation times are slowed compared to the Mother's Slackware reference and on which Slackware-like performance can be restored by setting the ASYNC_LOW_LATENCY flag.
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 27 Feb 2020 01:09:48 +0000
parents e7502631a0f9
children 8d7dcfd9df53
line wrap: on
line source

/*
 * This module provides a more advanced target interface function
 * than tpinterf.c - programmatic capture of target responses,
 * for dumps etc.  It will be linked by fc-loadtool, but not fc-chainload.
 */

#include <sys/types.h>
#include <sys/time.h>
#include <sys/errno.h>
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <stdlib.h>

extern int errno;

extern int target_fd;

/*
 * This functions reads the serial output from the target until a
 * '=' prompt is received.  All intermediate output is parsed into
 * lines and passed to a callback function.
 *
 * The callback function is called with a pointer to each received
 * line, stored in a buffer ending in NUL, with CRLF stripped.
 * The callback function is expected to return an int.  If the
 * callback return value is negative, this function returns immediately
 * with that negative value.  If the callback return value is positive
 * or zero, it is added to an accumulator.
 *
 * Termination: this function returns when it has received a '=' at
 * the beginning of a line (return value is the callback return
 * accumulator, or 0 if no lines came), if the callback returns a
 * negative value (that value is returned), or if an error is detected
 * within this function (return value -1, and an error message
 * printed on stderr).
 */
tpinterf_capture_output(timeout, callback)
	int timeout;	/* seconds */
	int (*callback)();
{
	char buf[512], *cp;
	char line[1024], *dp = line;
	fd_set fds;
	struct timeval tv;
	int cc, linelen = 0;
	int totout = 0, cbret;

	for (;;) {
		FD_ZERO(&fds);
		FD_SET(target_fd, &fds);
		tv.tv_sec = timeout;
		tv.tv_usec = 0;
		cc = select(target_fd+1, &fds, NULL, NULL, &tv);
		if (cc < 0) {
			if (errno == EINTR)
				continue;
			perror("select");
			return(-1);
		}
		if (cc < 1) {
			fprintf(stderr,
		"error: timeout waiting for \'=\' prompt from target\n");
			return(-1);
		}
		cc = read(target_fd, buf, sizeof buf);
		if (cc <= 0) {
			perror("read after successful select");
			return(-1);
		}
		for (cp = buf; cc; cp++) {
			cc--;
			if (*cp == '=' && !linelen && !cc)
				return(totout);
			if (*cp == '\r')
				continue;
			if (*cp == '\n') {
				*dp = '\0';
				cbret = callback(line);
				if (cbret < 0)
					return(cbret);
				totout += cbret;
				dp = line;
				linelen = 0;
				continue;
			}
			*dp++ = *cp;
			linelen++;
			if (linelen >= sizeof line) {
				fprintf(stderr,
			"error: target response line length exceeds buffer\n");
				return(-1);
			}
		}
	}
}

/* single line response capture mechanism */
/* same line buffer size as in tpinterf_capture_output() */
char target_response_line[1024];

static
oneline_catcher(linein)
	char *linein;
{
	strcpy(target_response_line, linein);
	return(1);
}

tpinterf_capture_output_oneline(timeout)
{
	return tpinterf_capture_output(timeout, oneline_catcher);
}