Changed the implementation of the High Resolution Timer to use

QueryPerformanceCounter instead of assembly code.  The docs also say that
this is MP-safe.

3 files changed, 11 insertions, 71 deletions

diff --git a/ace/High_Res_Timer.cpp b/ace/High_Res_Timer.cpp
index 9791601f274..76095a14b15 100644
--- a/ace/High_Res_Timer.cpp
+++ b/ace/High_Res_Timer.cpp
@@ -23,43 +23,6 @@ ACE_ALLOC_HOOK_DEFINE(ACE_High_Res_Timer)
 # include "ace/Synch.h"
 # include "ace/Object_Manager.h"
 
-# if defined (ACE_WIN32) && !defined (ACE_HAS_WINCE)
-
-u_long
-ACE_High_Res_Timer::get_registry_scale_factor (void)
-{
-  HKEY hk;
-  unsigned long speed;
-  unsigned long speed_size = sizeof speed;
-  unsigned long speed_type = REG_DWORD;
-
-  long rc = ::RegOpenKeyEx (HKEY_LOCAL_MACHINE,
-                            ACE_TEXT ("HARDWARE\\DESCRIPTION\\System\\CentralProcessor\\0"),
-                            NULL,
-                            KEY_READ,
-                            &hk);
-
-  if (rc != ERROR_SUCCESS)
-    // Couldn't find key
-    return 1;
-
-  rc = ::RegQueryValueEx (hk,
-                          ACE_TEXT ("~MHz"),
-                          0,
-                          &speed_type,
-                          (LPBYTE) &speed,
-                          &speed_size);
-
-  ::RegCloseKey (hk);
-
-  if (rc != ERROR_SUCCESS)
-    // Couldn't get the value
-    return 1;
-
-  return speed;
-}
-# endif /*ACE_WIN32 && ! ACE_HAS_WINCE */
-
   // Initialize the global_scale_factor_ to 1.  The first
   // ACE_High_Res_Timer instance construction will override this
   // value.
@@ -96,8 +59,11 @@ ACE_High_Res_Timer::global_scale_factor ()
       if (ACE_High_Res_Timer::global_scale_factor_ == 1u)
         {
 #         if defined (ACE_WIN32)
-            ACE_High_Res_Timer::global_scale_factor (
-              ACE_High_Res_Timer::get_registry_scale_factor ());
+            LARGE_INTEGER freq;
+            if (::QueryPerformanceFrequency (&freq))
+              // We have a high-res timer
+              ACE_High_Res_Timer::global_scale_factor (ACE_static_cast (unsigned int,
+                                                                        freq.QuadPart / 1000000));
 #         elif defined (linux) && (__alpha__)
             // Get the BogoMIPS from /proc.  It works fine on
             // Alpha and Pentium Pro.  For other CPUs, it will
@@ -178,7 +144,7 @@ ACE_High_Res_Timer::calibrate (const ACE_UINT32 usec,
 
   // The addition of 5 below rounds instead of truncates.
   const ACE_UINT32 scale_factor =
-    (ticks.whole () / actual_sleep.whole ()  +  5) /
+    (ticks.whole () / actual_sleep.whole () + 5) /
     10u /* usec/100 usec */;
   ACE_High_Res_Timer::global_scale_factor (scale_factor);
 
diff --git a/ace/High_Res_Timer.h b/ace/High_Res_Timer.h
index 6fca8eecfaa..36410c6667f 100644
--- a/ace/High_Res_Timer.h
+++ b/ace/High_Res_Timer.h
@@ -178,15 +178,6 @@ public:
   // However, setting the global_scale_factor_ appropriately will
   // result in the finest resolution possible.
 
-protected:
-
-#if defined (ACE_WIN32) && !defined (ACE_HAS_WINCE)
-  static u_long get_registry_scale_factor (void);
-  // This is used to find out the Mhz of the machine for the scale
-  // factor.  If there are any problems getting it, we just return 1
-  // (the default).
-#endif /* ACE_WIN32 */
-
 private:
   static void hrtime_to_tv (ACE_Time_Value &tv,
                             const ACE_hrtime_t hrt);
diff --git a/ace/OS.i b/ace/OS.i
index 6479f0fa4f3..bdee65fef91 100644
--- a/ace/OS.i
+++ b/ace/OS.i
@@ -8661,30 +8661,13 @@ ACE_OS::gethrtime (const ACE_HRTimer_Op op)
   asm volatile ("rpcc %0" : "=r" (now) : : "memory");
 
   return now;
-#elif defined (ACE_WIN32) && defined (ACE_HAS_PENTIUM) && !defined (ACE_HAS_WINCE)
-  // Issue the RDTSC assembler instruction to get the number of clock
-  // ticks since system boot.  RDTSC is only available on Pentiums and
-  // higher.  Thanks to Wayne Vucenic <wvucenic@netgate.net> for
-  // pointing us to intel's RDTSC instruction.  See
-  // http://www.sandpile.org/80x86/rdtsc.shtml for a description of
-  // the RDTSC instruction.  Or see Frank van Gilluwe's "The
-  // Undocumented PC" published by Addison Wesley Developers Press.
+#elif defined (ACE_WIN32) && defined (ACE_HAS_PENTIUM)
+  LARGE_INTEGER freq;
 
-  ACE_UNUSED_ARG (op);
-  unsigned long least;
-  unsigned long most;
-
-  __asm {
-    //      __asm               rdtsc
-    // VC++ doesn't know the opcode for rdtsc (OFh, 31h), so we'll
-    // emit the opcode manually.
-      __asm             _emit           0xf
-      __asm             _emit           0x31
-      __asm             mov             least,eax
-      __asm             mov             most,edx
-      }
+  ::QueryPerformanceCounter (&freq);
+
+  return freq.QuadPart;
 
-  return ACE_MAKE_QWORD (least, most);
 #elif defined (CHORUS)
   if (op == ACE_OS::ACE_HRTIMER_GETTIME)
     {