hires.xs

source of perl for linux application,

/*
 * 
 * Copyright (c) 1996-2002 Douglas E. Wegscheid.  All rights reserved.
 * 
 * Copyright (c) 2002,2003,2004,2005,2006,2007 Jarkko Hietaniemi.  All rights reserved.
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the same terms as Perl itself.
 */

#ifdef __cplusplus
extern "C" {
#endif
#define PERL_NO_GET_CONTEXT
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
#include "ppport.h"
#if defined(__CYGWIN__) && defined(HAS_W32API_WINDOWS_H)
# include <w32api/windows.h>
# define CYGWIN_WITH_W32API
#endif
#ifdef WIN32
# include <time.h>
#else
# include <sys/time.h>
#endif
#ifdef HAS_SELECT
# ifdef I_SYS_SELECT
#  include <sys/select.h>
# endif
#endif
#if defined(TIME_HIRES_CLOCK_GETTIME_SYSCALL) || defined(TIME_HIRES_CLOCK_GETRES_SYSCALL)
#include <syscall.h>
#endif
#ifdef __cplusplus
}
#endif

#define IV_1E6 1000000
#define IV_1E7 10000000
#define IV_1E9 1000000000

#define NV_1E6 1000000.0
#define NV_1E7 10000000.0
#define NV_1E9 1000000000.0

#ifndef PerlProc_pause
#   define PerlProc_pause() Pause()
#endif

#ifdef HAS_PAUSE
#   define Pause   pause
#else
#   undef Pause /* In case perl.h did it already. */
#   define Pause() sleep(~0) /* Zzz for a long time. */
#endif

/* Though the cpp define ITIMER_VIRTUAL is available the functionality
 * is not supported in Cygwin as of August 2004, ditto for Win32.
 * Neither are ITIMER_PROF or ITIMER_REALPROF implemented.  --jhi
 */
#if defined(__CYGWIN__) || defined(WIN32)
#   undef ITIMER_VIRTUAL
#   undef ITIMER_PROF
#   undef ITIMER_REALPROF
#endif

#if defined(TIME_HIRES_CLOCK_GETTIME) && defined(_STRUCT_ITIMERSPEC)

/* HP-UX has CLOCK_XXX values but as enums, not as defines.
 * The only way to detect these would be to test compile for each. */
# ifdef __hpux
#  define CLOCK_REALTIME CLOCK_REALTIME
#  define CLOCK_VIRTUAL  CLOCK_VIRTUAL
#  define CLOCK_PROFILE  CLOCK_PROFILE
# endif /* # ifdef __hpux */

#endif /* #if defined(TIME_HIRES_CLOCK_GETTIME) && defined(_STRUCT_ITIMERSPEC) */

#if defined(WIN32) || defined(CYGWIN_WITH_W32API)

#ifndef HAS_GETTIMEOFDAY
#   define HAS_GETTIMEOFDAY
#endif

/* shows up in winsock.h?
struct timeval {
 long tv_sec;
 long tv_usec;
}
*/

typedef union {
    unsigned __int64	ft_i64;
    FILETIME		ft_val;
} FT_t;

#define MY_CXT_KEY "Time::HiRes_" XS_VERSION

typedef struct {
    unsigned long run_count;
    unsigned __int64 base_ticks;
    unsigned __int64 tick_frequency;
    FT_t base_systime_as_filetime;
    unsigned __int64 reset_time;
} my_cxt_t;

START_MY_CXT

/* Number of 100 nanosecond units from 1/1/1601 to 1/1/1970 */
#ifdef __GNUC__
# define Const64(x) x##LL
#else
# define Const64(x) x##i64
#endif
#define EPOCH_BIAS  Const64(116444736000000000)

#ifdef Const64
# ifdef __GNUC__
#  define IV_1E6LL  1000000LL /* Needed because of Const64() ##-appends LL (or i64). */
#  define IV_1E7LL  10000000LL
#  define IV_1E9LL  1000000000LL
# else
#  define IV_1E6i64 1000000i64
#  define IV_1E7i64 10000000i64
#  define IV_1E9i64 1000000000i64
# endif
#endif

/* NOTE: This does not compute the timezone info (doing so can be expensive,
 * and appears to be unsupported even by glibc) */

/* dMY_CXT needs a Perl context and we don't want to call PERL_GET_CONTEXT
   for performance reasons */

#undef gettimeofday
#define gettimeofday(tp, not_used) _gettimeofday(aTHX_ tp, not_used)

/* If the performance counter delta drifts more than 0.5 seconds from the
 * system time then we recalibrate to the system time.  This means we may
 * move *backwards* in time! */
#define MAX_PERF_COUNTER_SKEW Const64(5000000) /* 0.5 seconds */

/* Reset reading from the performance counter every five minutes.
 * Many PC clocks just seem to be so bad. */
#define MAX_PERF_COUNTER_TICKS Const64(300000000) /* 300 seconds */

static int
_gettimeofday(pTHX_ struct timeval *tp, void *not_used)
{
    dMY_CXT;

    unsigned __int64 ticks;
    FT_t ft;

    if (MY_CXT.run_count++ == 0 ||
	MY_CXT.base_systime_as_filetime.ft_i64 > MY_CXT.reset_time) {
        QueryPerformanceFrequency((LARGE_INTEGER*)&MY_CXT.tick_frequency);
        QueryPerformanceCounter((LARGE_INTEGER*)&MY_CXT.base_ticks);
        GetSystemTimeAsFileTime(&MY_CXT.base_systime_as_filetime.ft_val);
        ft.ft_i64 = MY_CXT.base_systime_as_filetime.ft_i64;
	MY_CXT.reset_time = ft.ft_i64 + MAX_PERF_COUNTER_TICKS;
    }
    else {
	__int64 diff;
        QueryPerformanceCounter((LARGE_INTEGER*)&ticks);
        ticks -= MY_CXT.base_ticks;
        ft.ft_i64 = MY_CXT.base_systime_as_filetime.ft_i64
                    + Const64(IV_1E7) * (ticks / MY_CXT.tick_frequency)
                    +(Const64(IV_1E7) * (ticks % MY_CXT.tick_frequency)) / MY_CXT.tick_frequency;
	diff = ft.ft_i64 - MY_CXT.base_systime_as_filetime.ft_i64;
	if (diff < -MAX_PERF_COUNTER_SKEW || diff > MAX_PERF_COUNTER_SKEW) {
	    MY_CXT.base_ticks += ticks;
            GetSystemTimeAsFileTime(&MY_CXT.base_systime_as_filetime.ft_val);
            ft.ft_i64 = MY_CXT.base_systime_as_filetime.ft_i64;
	}
    }

    /* seconds since epoch */
    tp->tv_sec = (long)((ft.ft_i64 - EPOCH_BIAS) / Const64(IV_1E7));

    /* microseconds remaining */
    tp->tv_usec = (long)((ft.ft_i64 / Const64(10)) % Const64(IV_1E6));

    return 0;
}
#endif

#if defined(WIN32) && !defined(ATLEASTFIVEOHOHFIVE)
static unsigned int
sleep(unsigned int t)
{
    Sleep(t*1000);
    return 0;
}
#endif

#if !defined(HAS_GETTIMEOFDAY) && defined(VMS)
#define HAS_GETTIMEOFDAY

#include <lnmdef.h>
#include <time.h> /* gettimeofday */
#include <stdlib.h> /* qdiv */
#include <starlet.h> /* sys$gettim */
#include <descrip.h>
#ifdef __VAX
#include <lib$routines.h> /* lib$ediv() */
#endif

/*
        VMS binary time is expressed in 100 nano-seconds since
        system base time which is 17-NOV-1858 00:00:00.00
*/

#define DIV_100NS_TO_SECS  10000000L
#define DIV_100NS_TO_USECS 10L

/* 
        gettimeofday is supposed to return times since the epoch
        so need to determine this in terms of VMS base time
*/
static $DESCRIPTOR(dscepoch,"01-JAN-1970 00:00:00.00");

#ifdef __VAX
static long base_adjust[2]={0L,0L};
#else
static __int64 base_adjust=0;
#endif

/* 

   If we don't have gettimeofday, then likely we are on a VMS machine that
   operates on local time rather than UTC...so we have to zone-adjust.
   This code gleefully swiped from VMS.C 

*/
/* method used to handle UTC conversions:
 *   1 == CRTL gmtime();  2 == SYS$TIMEZONE_DIFFERENTIAL;  3 == no correction
 */
static int gmtime_emulation_type;
/* number of secs to add to UTC POSIX-style time to get local time */
static long int utc_offset_secs;
static struct dsc$descriptor_s fildevdsc = 
  { 12, DSC$K_DTYPE_T, DSC$K_CLASS_S, "LNM$FILE_DEV" };
static struct dsc$descriptor_s *fildev[] = { &fildevdsc, NULL };

static time_t toutc_dst(time_t loc) {
  struct tm *rsltmp;

  if ((rsltmp = localtime(&loc)) == NULL) return -1;
  loc -= utc_offset_secs;
  if (rsltmp->tm_isdst) loc -= 3600;
  return loc;
}

static time_t toloc_dst(time_t utc) {
  struct tm *rsltmp;

  utc += utc_offset_secs;
  if ((rsltmp = localtime(&utc)) == NULL) return -1;
  if (rsltmp->tm_isdst) utc += 3600;
  return utc;
}

#define _toutc(secs)  ((secs) == (time_t) -1 ? (time_t) -1 : \
       ((gmtime_emulation_type || timezone_setup()), \
       (gmtime_emulation_type == 1 ? toutc_dst(secs) : \
       ((secs) - utc_offset_secs))))

#define _toloc(secs)  ((secs) == (time_t) -1 ? (time_t) -1 : \
       ((gmtime_emulation_type || timezone_setup()), \
       (gmtime_emulation_type == 1 ? toloc_dst(secs) : \
       ((secs) + utc_offset_secs))))

static int
timezone_setup(void) 
{
  struct tm *tm_p;

  if (gmtime_emulation_type == 0) {
    int dstnow;
    time_t base = 15 * 86400; /* 15jan71; to avoid month/year ends between    */
                              /* results of calls to gmtime() and localtime() */
                              /* for same &base */

    gmtime_emulation_type++;
    if ((tm_p = gmtime(&base)) == NULL) { /* CRTL gmtime() is a fake */
      char off[LNM$C_NAMLENGTH+1];;

      gmtime_emulation_type++;
      if (!Perl_vmstrnenv("SYS$TIMEZONE_DIFFERENTIAL",off,0,fildev,0)) {
        gmtime_emulation_type++;
        utc_offset_secs = 0;
        Perl_warn(aTHX_ "no UTC offset information; assuming local time is UTC");
      }
      else { utc_offset_secs = atol(off); }
    }
    else { /* We've got a working gmtime() */
      struct tm gmt, local;

      gmt = *tm_p;
      tm_p = localtime(&base);
      local = *tm_p;
      utc_offset_secs  = (local.tm_mday - gmt.tm_mday) * 86400;
      utc_offset_secs += (local.tm_hour - gmt.tm_hour) * 3600;
      utc_offset_secs += (local.tm_min  - gmt.tm_min)  * 60;
      utc_offset_secs += (local.tm_sec  - gmt.tm_sec);
    }
  }
  return 1;
}


int
gettimeofday (struct timeval *tp, void *tpz)
{
 long ret;
#ifdef __VAX
 long quad[2];
 long quad1[2];
 long div_100ns_to_secs;
 long div_100ns_to_usecs;
 long quo,rem;
 long quo1,rem1;
#else
 __int64 quad;
 __qdiv_t ans1,ans2;
#endif
/*
        In case of error, tv_usec = 0 and tv_sec = VMS condition code.
        The return from function is also set to -1.
        This is not exactly as per the manual page.
*/

 tp->tv_usec = 0;

#ifdef __VAX
 if (base_adjust[0]==0 && base_adjust[1]==0) {
#else
 if (base_adjust==0) { /* Need to determine epoch adjustment */
#endif
        ret=sys$bintim(&dscepoch,&base_adjust);
        if (1 != (ret &&1)) {
                tp->tv_sec = ret;
                return -1;
        }
 }

 ret=sys$gettim(&quad); /* Get VMS system time */
 if ((1 && ret) == 1) {
#ifdef __VAX
        quad[0] -= base_adjust[0]; /* convert to epoch offset */
        quad[1] -= base_adjust[1]; /* convert 2nd half of quadword */
        div_100ns_to_secs = DIV_100NS_TO_SECS;
        div_100ns_to_usecs = DIV_100NS_TO_USECS;
        lib$ediv(&div_100ns_to_secs,&quad,&quo,&rem);
        quad1[0] = rem;
        quad1[1] = 0L;
        lib$ediv(&div_100ns_to_usecs,&quad1,&quo1,&rem1);
        tp->tv_sec = quo; /* Whole seconds */
        tp->tv_usec = quo1; /* Micro-seconds */
#else
        quad -= base_adjust; /* convert to epoch offset */
        ans1=qdiv(quad,DIV_100NS_TO_SECS);
        ans2=qdiv(ans1.rem,DIV_100NS_TO_USECS);
        tp->tv_sec = ans1.quot; /* Whole seconds */
        tp->tv_usec = ans2.quot; /* Micro-seconds */
#endif
 } else {
        tp->tv_sec = ret;
        return -1;
 }
# ifdef VMSISH_TIME
# ifdef RTL_USES_UTC
  if (VMSISH_TIME) tp->tv_sec = _toloc(tp->tv_sec);
# else
  if (!VMSISH_TIME) tp->tv_sec = _toutc(tp->tv_sec);
# endif
# endif
 return 0;
}
#endif


 /* Do not use H A S _ N A N O S L E E P
  * so that Perl Configure doesn't scan for it (and pull in -lrt and
  * the like which are not usually good ideas for the default Perl).
  * (We are part of the core perl now.)
  * The TIME_HIRES_NANOSLEEP is set by Makefile.PL. */
#if !defined(HAS_USLEEP) && defined(TIME_HIRES_NANOSLEEP)
#define HAS_USLEEP
#define usleep hrt_nanosleep  /* could conflict with ncurses for static build */

void
hrt_nanosleep(unsigned long usec) /* This is used to emulate usleep. */
{
    struct timespec res;
    res.tv_sec = usec / IV_1E6;
    res.tv_nsec = ( usec - res.tv_sec * IV_1E6 ) * 1000;
    nanosleep(&res, NULL);
}

#endif /* #if !defined(HAS_USLEEP) && defined(TIME_HIRES_NANOSLEEP) */

#if !defined(HAS_USLEEP) && defined(HAS_SELECT)
#ifndef SELECT_IS_BROKEN
#define HAS_USLEEP
#define usleep hrt_usleep  /* could conflict with ncurses for static build */

void