Initial commit.

1 files changed, 175 insertions, 0 deletions

diff --git a/Timer.C b/Timer.C
new file mode 100644
index 0000000..d450867
--- /dev/null
+++ b/Timer.C
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+/*******************************************************************************
+ * Copyright (c) 2006 International Business Machines Corporation.             *
+ * All rights reserved. This program and the accompanying materials            *
+ * are made available under the terms of the Common Public License v1.0        *
+ * which accompanies this distribution, and is available at                    *
+ * http://www.opensource.org/licenses/cpl1.0.php                               *
+ *                                                                             *
+ * Contributors:                                                               *
+ *    Douglas M. pase - initial API and implementation                         *
+ *******************************************************************************/
+
+
+#include <stdio.h>
+#include <sys/time.h>
+
+#include "Timer.h"
+
+#include "Types.h"
+
+static int64  read_rtc();
+static void   calibrate_rtc(int n);
+static double wall_seconds();
+
+static int    wall_ticks   = -1;
+static int    rtc_ticks    = -1;
+static double wall_elapsed = -1;
+static int64  rtc_elapsed  = -1;
+static double time_factor  = -1;
+
+#if !defined(RTC) && !defined(GTOD)
+#define RTC
+#endif
+
+#if defined(RTC)
+
+double
+Timer::seconds()
+{ 
+    return (double) read_rtc() * time_factor;
+}
+
+int64
+Timer::ticks()
+{ 
+				// See pg. 406 of the AMD x86-64 Architecture
+				// Programmer's Manual, Volume 2, System Programming
+    unsigned int eax=0, edx=0;
+
+    __asm__ __volatile__(
+	"rdtsc ;"
+	"movl %%eax,%0;"
+	"movl %%edx,%1;"
+	""
+    : "=r"(eax), "=r"(edx)
+    :
+    : "%eax", "%edx"
+    );
+
+    return ((int64) edx << 32) | (int64) eax;
+}
+
+static int64
+read_rtc()
+{
+				// See pg. 406 of the AMD x86-64 Architecture
+				// Programmer's Manual, Volume 2, System Programming
+    unsigned int eax=0, edx=0;
+
+    __asm__ __volatile__(
+	"rdtsc ;"
+	"movl %%eax,%0;"
+	"movl %%edx,%1;"
+	""
+    : "=r"(eax), "=r"(edx)
+    :
+    : "%eax", "%edx"
+    );
+
+    return ((int64) edx << 32) | (int64) eax;
+}
+
+void
+Timer::calibrate()
+{
+    Timer::calibrate(1000);
+}
+
+void
+Timer::calibrate(int n)
+{
+    wall_ticks = n;
+
+    double wall_start,wall_finish,t;
+    t = wall_seconds();
+    while (t == (wall_start=wall_seconds())) {
+	;
+    }
+    int64 rtc_start = read_rtc();
+    for (int i=0; i < wall_ticks; i++) {
+	t = wall_seconds();
+	while (t == (wall_finish=wall_seconds())) {
+	    ;
+	}
+    }
+    int64 rtc_finish = read_rtc();
+
+    wall_elapsed = wall_finish - wall_start;
+    rtc_elapsed  = rtc_finish  - rtc_start;
+    time_factor  = wall_elapsed / (double) rtc_elapsed;
+}
+
+static double
+wall_seconds()
+{ 
+    struct timeval t;
+    gettimeofday(&t, NULL);
+
+    return (double) t.tv_sec + (double) t.tv_usec * 1E-6;
+}
+
+#else
+
+double
+Timer::seconds()
+{ 
+    struct timeval t;
+    gettimeofday(&t, NULL);
+
+    return (double) t.tv_sec + (double) t.tv_usec * 1E-6;
+}
+
+int64
+Timer::ticks()
+{ 
+    struct timeval t;
+    gettimeofday(&t, NULL);
+
+    return 1000000 * (int64) t.tv_sec + (int64) t.tv_usec;
+}
+
+void
+Timer::calibrate()
+{
+}
+
+void
+Timer::calibrate(int n)
+{
+}
+
+#endif
+
+static double
+min( double v1, double v2 )
+{
+    if (v2 < v1) return v2;
+    return v1;
+}
+
+double
+Timer::resolution()
+{ 
+    double a,b,c=1E9;
+    for (int i=0; i < 10; i++) {
+	a = Timer::seconds();
+	while (a == (b=Timer::seconds()))
+	    ;
+	a = Timer::seconds();
+	while (a == (b=Timer::seconds()))
+	    ;
+	c = min(b - a, c);
+    }
+
+    return c;
+}