Message-ID: <004101c29f53$919af9f0$0100a8c0@p4>
From: "Andrew Cottrell" <acottrel AT ihug DOT com DOT au>
To: <djgpp-workers AT delorie DOT com>
References: <10212071847 DOT AA13093 AT clio DOT rice DOT edu> <004401c29e90$dc1ccf30$0100a8c0 AT p4>
Subject: Re: XP delay() again - potential solution
Date: Mon, 9 Dec 2002 18:20:48 +1100
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Reply-To: djgpp-workers AT delorie DOT com

Try # 2:-

I haev hopefully incorporated all of the feedback from everyone in this
attempt.


*** \djgppcvs\src\libc\dos\dos\delay.c Tue Mar 21 18:35:38 1995
--- src\libc\dos\dos\delay.c Mon Dec  9 18:08:16 2002
***************
*** 1,10 ****
--- 1,16 ----
+ /* Copyright (C) 2002 DJ Delorie, see COPYING.DJ for details */
  /* Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details */
+
  #include <dos.h>
  #include <dpmi.h>

+
+ #define tick_per_day (24*60*60*10000/182)
+
  void delay(unsigned msec)
  {
      __dpmi_regs r;
+
      while (msec)
      {
          unsigned usec;
***************
*** 16,21 ****
--- 22,66 ----
          r.x.cx = usec>>16;
          r.x.dx = usec & 0xffff;
          __dpmi_int(0x15, &r);
+         if ((r.x.flags & 1) || (r.h.ah == 0x83))
+         {
+             /* INT 15 FAILED, so fall back to the Time Of Day Tick */
+             unsigned long start_tick;
+             unsigned long end_tick;
+
+             r.h.ah = 0x00;
+             __dpmi_int(0x1A, &r);
+
+             start_tick = (r.x.cx << 16) + (r.x.dx & 0xffff);
+             end_tick = (msec*182)/10000 + start_tick;
+
+             if ((msec%10000/182) > (5000/182)) /* Manual round ticks */
+             {
+                 end_tick++;
+             }
+             if (end_tick > tick_per_day)  /* Tick time past midnight */
+             {
+                 /* check for midnight */
+                 while (r.h.al == 0)
+                 {
+                     r.h.ah = 0x00;
+                     __dpmi_int(0x1A, &r);
+                     __dpmi_yield();
+                 }
+                 end_tick = end_tick - tick_per_day;
+             }
+
+             while (((r.x.cx << 16) + (r.x.dx & 0xffff)) <= end_tick)
+             {
+                 r.h.ah = 0x00;
+                 __dpmi_int(0x1A, &r);
+                 __dpmi_yield();
+             }
+             msec = 0;  /* waited the required time */
+         }
+         else
+         {
              msec -= msec_this;
          }
      }
+ }



*** \djgppcvs\src\libc\dos\dos\delay.txh Mon Sep  6 22:39:32 1999
--- src\libc\dos\dos\delay.txh Mon Dec  9 18:16:48 2002
***************
*** 13,22 ****
  It uses the @code{int 15h} delay function to relinquish the CPU to other
  programs that might need it.

! Some operating systems that emulate DOS, such as OS/2 and Windows/NT,
! hang the DOS session when the @key{Pause} key is pressed during the call
! to @code{delay}.  Plain DOS and Windows 3.X and 9X are known to not have
! this bug.

  @subheading Return Value

--- 13,35 ----
  It uses the @code{int 15h} delay function to relinquish the CPU to other
  programs that might need it.

! Some operating systems that emulate DOS, such as OS/2, Windows/NT, Windows
2000
! and Windows XP hang the DOS session when the @key{Pause} key is pressed
during
! the call to @code{delay}.  Plain DOS and Windows 3.X and 9X are known to
! not have this bug. On Windows 2000 and XP to exit the pause press any key.
!
! Some operating systems, such as Windows 2000 and XP which do not support
! @code{int 15h}. @code{int 1ah} is used instead on these operating
! systems. This method has lower accuracy in the delay length.
!
! Windows 2000 and XP delay resolution is 54.9 millisecond. Under Windows
! 2000 and XP the delay function uses the Time Of Day Tick which occurs
! 18.2 times per second. This limits the accuracy of the delay to around
! 27 milliseconds on Windows 2000 and XP. On Windows 2000 and XP the
Programable
! Interval Timer works and is a source of higher resolution than delay
! currently uses. Unfortunately PIT and Time Of Day tic does not appear
! to be coordinated.
!

  @subheading Return Value