kea/src/lib/util/tests/interprocess_util.cc

// Copyright (C) 2013  Internet Systems Consortium, Inc. ("ISC")
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.

#include <gtest/gtest.h>

#include <sys/select.h>
#include <cstddef>

namespace isc {
namespace util {
namespace test {

unsigned char
parentReadState(int fd) {
  unsigned char result = 0xff;

  fd_set rfds;
  FD_ZERO(&rfds);
  FD_SET(fd, &rfds);

  struct timeval tv = {5, 0};

  const int nfds = select(fd + 1, &rfds, NULL, NULL, &tv);
  EXPECT_EQ(1, nfds);

  if (nfds == 1) {
      // Read status
      const ssize_t bytes_read = read(fd, &result, sizeof(result));
      EXPECT_EQ(sizeof(result), bytes_read);
  }

  return (result);
}

}
}
}