/*
 * Copyright (C) 1999, 2001,2005 by Manfred Spraul.
 * 
 * Redistribution of this file is permitted under the terms of the GNU 
 * General Public License (GPL)
 * $Header: /home/manfred/cvs-tree/pipetest/test8.cpp,v 1.1 2005/02/05 08:35:01 manfred Exp $
 */

#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <limits.h>
#include <errno.h>

#define WRITE_LEN	128	/* less than PIPE_BUF */

int buffer[WRITE_LEN];

void dummy(int sig)
{
}

int main()
{
	int pipes[2];
	int ret;

	ret = pipe(pipes);
	if(ret != 0) {
		printf("pipe creation failed, ret %d, errno %d.\n",
				ret, errno);
		exit(1);
	}
	ret = fork();
	if(!ret) {
		/* child: read from pipe */
		printf("child: trying to read %d bytes.\n", WRITE_LEN);
		ret = read(pipes[0], buffer, WRITE_LEN);
		/* never executed! */
		printf("child: read returned %d.\n", ret);
		printf("SIGSTOP test result: SIGSTOP completely broken\n");
	} else {
		/* synchronize with timer - the following block must be atomic */
		sleep(1);
		/* begin atomic block */
		ret = kill(ret, SIGSTOP);
		if (ret != 0) {
			printf("Sending SIGSTOP failed, aborting (errno=%d).\n", errno);
			exit(1);
		}
		ret = write(pipes[1], buffer, WRITE_LEN);
		if (ret != WRITE_LEN) {
			printf("Writing to pipe buffer failed, aborting (errno=%d).\n", errno);
			exit(1);
		}
		/* end of atomic block */
		printf("parent: yielding\n");
		sleep(1);
		ret = fcntl(pipes[0], F_SETFL, O_NONBLOCK);
		if (ret != 0) {
			printf("fcntl(,,O_NONBLOCK) failed, aborting (errno=%d).\n", errno);
			exit(1);
		}
		ret = read(pipes[0], buffer, WRITE_LEN);
		printf("parent: read returned %d.\n", ret);
		printf("\n\n");
		printf("SIGSTOP test result:\n");
		printf("Expected values:\n");
		printf("	%d for OS with synchroneous SIGSTOP\n", WRITE_LEN);
		printf("	-1 for OS with asynchroneous SIGSTOP (errno EAGAIN=%d)\n", EAGAIN);
		printf("Got: %d (errno: %d)\n", ret, errno);
		close(pipes[1]);
		close(pipes[0]);
	}
}