/* Copyright (C) 2008 by Daniel Stenberg et al

 *

 * Permission to use, copy, modify, and distribute this software and its

 * documentation for any purpose and without fee is hereby granted, provided

 * that the above copyright notice appear in all copies and that both that

 * copyright notice and this permission notice appear in supporting

 * documentation, and that the name of M.I.T. not be used in advertising or

 * publicity pertaining to distribution of the software without specific,

 * written prior permission.  M.I.T. makes no representations about the

 * suitability of this software for any purpose.  It is provided "as is"

 * without express or implied warranty.

 */

#include "ares_setup.h"

#include "ares.h"

#include "ares_private.h"

#if defined(WIN32) && !defined(MSDOS)

struct timeval ares__tvnow(void)

{

  /*

  ** GetTickCount() is available on _all_ Windows versions from W95 up

  ** to nowadays. Returns milliseconds elapsed since last system boot,

  ** increases monotonically and wraps once 49.7 days have elapsed.

  */

  struct timeval now;

  DWORD milliseconds = GetTickCount();

  now.tv_sec = milliseconds / 1000;

  now.tv_usec = (milliseconds % 1000) * 1000;

  return now;

}

#elif defined(HAVE_CLOCK_GETTIME_MONOTONIC)

struct timeval ares__tvnow(void)

{

  /*

  ** clock_gettime() is granted to be increased monotonically when the

  ** monotonic clock is queried. Time starting point is unspecified, it

  ** could be the system start-up time, the Epoch, or something else,

  ** in any case the time starting point does not change once that the

  ** system has started up.

  */

  struct timeval now;

  struct timespec tsnow;

  if(0 == clock_gettime(CLOCK_MONOTONIC, &tsnow)) {

    now.tv_sec = tsnow.tv_sec;

    now.tv_usec = tsnow.tv_nsec / 1000;

  }

  /*

  ** Even when the configure process has truly detected monotonic clock

  ** availability, it might happen that it is not actually available at

  ** run-time. When this occurs simply fallback to other time source.

  */

#ifdef HAVE_GETTIMEOFDAY

  else

    (void)gettimeofday(&now, NULL);  /* LCOV_EXCL_LINE */

#else

  else {

    now.tv_sec = (long)time(NULL);

    now.tv_usec = 0;

  }

#endif

  return now;

}

#elif defined(HAVE_GETTIMEOFDAY)

struct timeval ares__tvnow(void)

{

  /*

  ** gettimeofday() is not granted to be increased monotonically, due to

  ** clock drifting and external source time synchronization it can jump

  ** forward or backward in time.

  */

  struct timeval now;

  (void)gettimeofday(&now, NULL);

  return now;

}

#else

struct timeval ares__tvnow(void)

{

  /*

  ** time() returns the value of time in seconds since the Epoch.

  */

  struct timeval now;

  now.tv_sec = (long)time(NULL);

  now.tv_usec = 0;

  return now;

}

#endif

#if 0 /* Not used */

/*

 * Make sure that the first argument is the more recent time, as otherwise

 * we'll get a weird negative time-diff back...

 *

 * Returns: the time difference in number of milliseconds.

 */

long ares__tvdiff(struct timeval newer, struct timeval older)

{

  return (newer.tv_sec-older.tv_sec)*1000+

    (newer.tv_usec-older.tv_usec)/1000;

}

#endif