[PATCH] Enhanced select(2) test

[Paolo Bonzini]

Here is the test I'm using to check the correctness of sys_select.  It
is a subset of test-poll.c.

Ok?

Paolo

/* Test of <sys/select.h> substitute.
   Copyright (C) 2007, 2008 Free Software Foundation, Inc.

   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 3 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, see <http://www.gnu.org/licenses/>.  */

/* Written by Bruno Haible <address@hidden>, 2007.  */
/* Enhanced by Paolo Bonzini, 2008.  */

#include <config.h>

#include <stdio.h>
#include <string.h>
#include <sys/select.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdbool.h>
#include <errno.h>
#include "sockets.h"

enum { SEL_IN = 1, SEL_OUT = 2, SEL_EXC = 4 };

#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
# define WIN32_NATIVE
#endif

#ifdef WIN32_NATIVE
#include <io.h>
#define pipe(x) _pipe(x, 256, O_BINARY)
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif

#ifndef SO_REUSEPORT
#define SO_REUSEPORT    SO_REUSEADDR
#endif

#define TEST_PORT       12345


/* Minimal testing infrastructure.  */

static int failures;

static void
failed (const char *reason)
{
  if (++failures > 1)
    printf ("  ");
  printf ("failed (%s)\n", reason);
}

static int
test (void (*fn) (void), const char *msg)
{
  failures = 0;
  printf ("%s... ", msg);
  fflush (stdout);
  fn ();

  if (!failures)
    printf ("passed\n");

  return failures;
}


/* Funny socket code.  */

static int
open_server_socket ()
{
  int s, x;
  struct sockaddr_in ia;

  s = socket (AF_INET, SOCK_STREAM, 0);

  memset (&ia, 0, sizeof (ia));
  ia.sin_family = AF_INET;
  inet_pton (AF_INET, "127.0.0.1", &ia.sin_addr);
  ia.sin_port = htons (TEST_PORT);
  if (bind (s, (struct sockaddr *) &ia, sizeof (ia)) < 0)
    {
      perror ("bind");
      exit (77);
    }

  x = 1;
  setsockopt (s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof (x));

  if (listen (s, 1) < 0)
    {
      perror ("listen");
      exit (77);
    }

  return s;
}

static int
connect_to_socket (int blocking)
{
  int s;
  struct sockaddr_in ia;

  s = socket (AF_INET, SOCK_STREAM, 0);

  memset (&ia, 0, sizeof (ia));
  ia.sin_family = AF_INET;
  inet_pton (AF_INET, "127.0.0.1", &ia.sin_addr);
  ia.sin_port = htons (TEST_PORT);

  if (!blocking)
    {
#ifdef WIN32_NATIVE
      unsigned long iMode = 1;
      ioctl (s, FIONBIO, (char *) &iMode);
 
#elif defined F_GETFL
      int oldflags = fcntl (s, F_GETFL, NULL);
 
      if (!(oldflags & O_NONBLOCK))
        fcntl (s, F_SETFL, oldflags | O_NONBLOCK);
#endif
    }

  if (connect (s, (struct sockaddr *) &ia, sizeof (ia)) < 0
      && (blocking || errno != EINPROGRESS))
    {
      perror ("connect");
      exit (77);
    }

  return s;
}


/* A slightly more convenient interface to poll(2).  */

static int
do_select (int fd, int ev, struct timeval *tv)
{
  fd_set rfds, wfds, xfds;
  int r, rev;

  FD_ZERO (&rfds);
  FD_ZERO (&wfds);
  FD_ZERO (&xfds);
  if (ev & SEL_IN)
    FD_SET (fd, &rfds);
  if (ev & SEL_OUT)
    FD_SET (fd, &wfds);
  if (ev & SEL_EXC)
    FD_SET (fd, &xfds);
  r = select (fd + 1, &rfds, &wfds, &xfds, tv);
  if (r < 0)
    return r;

  rev = 0;
  if (FD_ISSET (fd, &rfds))
    rev |= SEL_IN;
  if (FD_ISSET (fd, &wfds))
    rev |= SEL_OUT;
  if (FD_ISSET (fd, &xfds))
    rev |= SEL_EXC;
  if (rev && r == 0)
    failed ("select returned 0");
  if (rev & ~ev)
    failed ("select returned unrequested events");

  return rev;
}

static int
do_select_nowait (int fd, int ev)
{
  static struct timeval tv0;
  return do_select (fd, ev, &tv0);
}

static int
do_select_wait (int fd, int ev)
{
  return do_select (fd, ev, NULL);
}


/* Test poll(2) for TTYs.  */

#ifdef INTERACTIVE
static void
test_tty (void)
{
  if (do_select_nowait (0, SEL_IN) != 0)
    failed ("can read");
  if (do_select_nowait (0, SEL_OUT) == 0)
    failed ("cannot write");

  if (do_select_wait (0, SEL_IN) == 0)
    failed ("return with infinite timeout");

  getchar ();
  if (do_select_nowait (0, SEL_IN) != 0)
    failed ("can read after getc");
}
#endif


/* Test poll(2) for unconnected nonblocking sockets.  */

static void
test_connect_first (void)
{
  int s = open_server_socket ();
  struct sockaddr_in ia;
  socklen_t addrlen;

  int c1, c2;

  if (do_select_nowait (s, SEL_IN | SEL_EXC) != 0)
    failed ("can read, socket not connected");

  c1 = connect_to_socket (false);

  if (do_select_wait (s, SEL_IN | SEL_EXC) != SEL_IN)
    failed ("expecting readability on passive socket");
  if (do_select_nowait (s, SEL_IN | SEL_EXC) != SEL_IN)
    failed ("expecting readability on passive socket");

  addrlen = sizeof (ia);
  c2 = accept (s, (struct sockaddr *) &ia, &addrlen);
  close (s);
  close (c1);
  close (c2);
}


/* Test poll(2) for unconnected blocking sockets.  */

static void
test_accept_first (void)
{
#ifndef WIN32_NATIVE
  int s = open_server_socket ();
  struct sockaddr_in ia;
  socklen_t addrlen;
  char buf[3];
  int c, pid;

  pid = fork ();
  if (pid < 0)
    return;

  if (pid == 0)
    {
      addrlen = sizeof (ia);
      c = accept (s, (struct sockaddr *) &ia, &addrlen);
      close (s);
      write (c, "foo", 3);
      read (c, buf, 3);
      shutdown (c, SHUT_RD);
      close (c);
      exit (0);
    }
  else
    {
      close (s);
      c = connect_to_socket (true);
      if (do_select_nowait (c, SEL_OUT) != SEL_OUT)
        failed ("cannot write after blocking connect");
      write (c, "foo", 3);
      wait (&pid);
      if (do_select_wait (c, SEL_IN) != SEL_IN)
        failed ("cannot read data left in the socket by closed process");
      read (c, buf, 3);
      write (c, "foo", 3);
      close (c);
    }
#endif
}


/* Common code for pipes and connected sockets.  */

static void
test_pair (int rd, int wd)
{
  char buf[3];
  if (do_select_wait (wd, SEL_IN | SEL_OUT | SEL_EXC) != SEL_OUT)
    failed ("expecting writability before writing");
  if (do_select_nowait (wd, SEL_IN | SEL_OUT | SEL_EXC) != SEL_OUT)
    failed ("expecting writability before writing");

  write (wd, "foo", 3);
  if (do_select_wait (rd, SEL_IN) != SEL_IN)
    failed ("expecting readability after writing");
  if (do_select_nowait (rd, SEL_IN) != SEL_IN)
    failed ("expecting readability after writing");

  read (rd, buf, 3);
}


/* Test poll(2) on connected sockets.  */

static void
test_socket_pair (void)
{
  struct sockaddr_in ia;

  socklen_t addrlen = sizeof (ia);
  int s = open_server_socket ();
  int c1 = connect_to_socket (false);
  int c2 = accept (s, (struct sockaddr *) &ia, &addrlen);

  close (s);

  test_pair (c1, c2);
  close (c1);
  write (c2, "foo", 3);
  close (c2);
}


/* Test poll(2) on pipes.  */

static void
test_pipe (void)
{
  int fd[2];

  pipe (fd);
  test_pair (fd[0], fd[1]);
  close (fd[0]);
  close (fd[1]);
}


/* Do them all.  */

int
main ()
{
  int result;

  gl_sockets_startup (SOCKETS_1_1);

#ifdef INTERACTIVE
  printf ("Please press Enter\n");
  test (test_tty, "TTY");
#endif

  result = test (test_connect_first, "Unconnected socket test");
  result += test (test_socket_pair, "Connected sockets test");
  result += test (test_accept_first, "General socket test with fork");
  result += test (test_pipe, "Pipe test");

  exit (result);
}