From: Pekka Riikonen <priikone@silcnet.org>
Date: Sat, 1 Sep 2007 09:25:58 +0000 (+0000)
Subject: 	Added silc_timer_tick and silc_timer_synchronize.
X-Git-Tag: 1.2.beta1~134
X-Git-Url: http://git.silcnet.org/gitweb/?p=crypto.git;a=commitdiff_plain;h=ab2995608e4061f88231bdba3f1f5f2709503701

	Added silc_timer_tick and silc_timer_synchronize.
---

diff --git a/lib/silcutil/silctimer.c b/lib/silcutil/silctimer.c
index 90371274..3973752e 100644
--- a/lib/silcutil/silctimer.c
+++ b/lib/silcutil/silctimer.c
@@ -25,12 +25,13 @@ void silc_timer_start(SilcTimer timer)
 {
   struct timeval curtime;
 
-  memset(timer, 0, sizeof(timer));
-
   silc_gettimeofday(&curtime);
   timer->start_sec = curtime.tv_sec;
   timer->start_usec = curtime.tv_usec;
-
+  timer->timer_sec = 0;
+  timer->timer_usec = 0;
+  timer->sync_diff = 0;
+  timer->sync_tdiff = 0;
   timer->running = TRUE;
 }
 
@@ -48,6 +49,7 @@ void silc_timer_stop(SilcTimer timer)
   }
   timer->timer_sec = curtime.tv_sec - timer->start_sec;
   timer->timer_usec = curtime.tv_usec - timer->start_usec;
+  timer->timer_usec -= timer->sync_diff;
 
   timer->running = FALSE;
 }
@@ -90,6 +92,7 @@ void silc_timer_value(SilcTimer timer,
     }
     timer->timer_sec = curtime.tv_sec - timer->start_sec;
     timer->timer_usec = curtime.tv_usec - timer->start_usec;
+    timer->timer_usec -= timer->sync_diff;
   }
 
   if (elapsed_time_seconds)
@@ -125,3 +128,40 @@ SilcBool silc_timer_is_running(SilcTimer timer)
 {
   return timer->running;
 }
+
+#if 0
+void silc_timer_synchronize(SilcTimer timer)
+{
+  SilcUInt32 tdiff, cumu, i;
+  SilcUInt64 t1, t2, tcumu;
+
+  /* Sync normal timer */
+  for (i = 0, cumu = 0; i < 5; i++) {
+    silc_timer_start(timer);
+    silc_timer_stop(timer);
+    silc_timer_value(timer, NULL, &tdiff);
+    cumu += tdiff;
+  }
+
+  timer->sync_diff = cumu;
+  if (timer->sync_diff > 5)
+    timer->sync_diff /= 5;
+
+  /* Sync CPU tick count */
+  tcumu = 0;
+  t1 = silc_timer_tick(timer, FALSE);
+  t2 = silc_timer_tick(timer, FALSE);
+  tcumu += (t2 - t1);
+  t1 = silc_timer_tick(timer, FALSE);
+  t2 = silc_timer_tick(timer, FALSE);
+  tcumu += (t2 - t1);
+  t1 = silc_timer_tick(timer, FALSE);
+  t2 = silc_timer_tick(timer, FALSE);
+  tcumu += (t2 - t1);
+  timer->sync_tdiff = tcumu / 3;
+
+  t1 = silc_timer_tick(timer, FALSE);
+  t2 = silc_timer_tick(timer, TRUE);
+  timer->sync_tdiff += (int)(t2 - t1);
+}
+#endif
diff --git a/lib/silcutil/silctimer.h b/lib/silcutil/silctimer.h
index c53da041..845b46a7 100644
--- a/lib/silcutil/silctimer.h
+++ b/lib/silcutil/silctimer.h
@@ -165,4 +165,125 @@ SilcBool silc_timer_is_running(SilcTimer timer);
 
 #include "silctimer_i.h"
 
+/****f* silcutil/SilcTimerAPI/silc_timer_tick
+ *
+ * SYNOPSIS
+ *
+ *    SilcUInt64 silc_timer_tick(SilcTimer &timer, SilcBool adjust)
+ *
+ * DESCRIPTION
+ *
+ *    Returns the current CPU tick count.  You should call the
+ *    silc_timer_synchronize before using this function to make sure the
+ *    overhead of measuring the CPU tick count is not included in the
+ *    tick count.  If the `adjust' is TRUE and the silc_timer_synchronize
+ *    has been called the returned value is adjusted to be more accurate.
+ *
+ * EXAMPLES
+ *
+ *    // Synchronize timer for more accurate CPU tick counts
+ *    silc_timer_synchronize(&timer);
+ *    start = silc_timer_tick(&timer, FALSE);
+ *    do_something();
+ *    stop = silc_tiemr_tick(&timer, TRUE);
+ *
+ ***/
+
+static inline
+SilcUInt64 silc_timer_tick(SilcTimer timer, SilcBool adjust)
+{
+#if defined(__GNUC__) || defined(__ICC)
+#ifdef SILC_I486
+  SilcUInt64 x;
+  asm volatile ("rdtsc" : "=A" (x));
+  return adjust ? x - timer->sync_tdiff : x;
+
+#elif SILC_X86_64
+  SilcUInt64 x;
+  SilcUInt32 hi, lo;
+  asm volatile ("rdtsc" : "=a" (lo), "=d" (hi));
+  x = ((SilcUInt64)lo | ((SilcUInt64)hi << 32));
+  return adjust ? x - timer->sync_tdiff : x;
+
+#elif SILC_POWERPC
+  SilcUInt32 hi, lo, tmp;
+  asm volatile ("0:            \n\t"
+                "mftbu   %0    \n\t"
+                "mftb    %1    \n\t"
+                "mftbu   %2    \n\t"
+                "cmpw    %2,%0 \n\t"
+                "bne     0b    \n"
+                : "=r" (hi), "=r" (lo), "=r" (tmp));
+  x = ((SilcUInt64)lo | ((SilcUInt64)hi << 32));
+  return adjust ? x - timer->sync_tdiff : x;
+#endif /* SILC_I486 */
+
+#elif defined(SILC_WIN32)
+  __asm rdtsc
+
+#else
+  return 0;
+#endif /* __GNUC__ || __ICC */
+}
+
+/****f* silcutil/SilcTimerAPI/silc_timer_synchronize
+ *
+ * SYNOPSIS
+ *
+ *    void silc_timer_synchronize(SilcTimer timer);
+ *
+ * DESCRIPTION
+ *
+ *    Synchronizes the `timer'.  This call will attempt to synchronize the
+ *    timer for more accurate results with high resolution timing.  Call
+ *    this before you start using time `timer'.
+ *
+ * EXAMPLE
+ *
+ *    // Synchronized timer
+ *    silc_timer_synchronize(&timer);
+ *    silc_timer_start(&timer);
+ *    ... time passes ...
+ *    silc_timer_stop(&timer);
+ *    silc_timer_value(&timer, &elapsed_sec, &elapsed_usec);
+ *
+ ***/
+
+static inline
+void silc_timer_synchronize(SilcTimer timer)
+{
+  SilcUInt32 tdiff, cumu, i;
+  SilcUInt64 t1, t2;
+
+  /* Sync normal timer */
+  for (i = 0, cumu = 0; i < 5; i++) {
+    silc_timer_start(timer);
+    silc_timer_stop(timer);
+    silc_timer_value(timer, NULL, &tdiff);
+    cumu += (int)tdiff;
+  }
+
+  timer->sync_diff = cumu;
+  if (timer->sync_diff > 5)
+    timer->sync_diff /= 5;
+
+  /* Sync CPU tick count */
+  cumu = 0;
+  t1 = silc_timer_tick(timer, FALSE);
+  t2 = silc_timer_tick(timer, FALSE);
+  cumu += (t2 - t1);
+  t1 = silc_timer_tick(timer, FALSE);
+  t2 = silc_timer_tick(timer, FALSE);
+  cumu += (t2 - t1);
+  t1 = silc_timer_tick(timer, FALSE);
+  t2 = silc_timer_tick(timer, FALSE);
+  cumu += (t2 - t1);
+
+  timer->sync_tdiff = cumu / 3;
+
+  t1 = silc_timer_tick(timer, FALSE);
+  t2 = silc_timer_tick(timer, TRUE);
+  timer->sync_tdiff += (int)(t2 - t1);
+}
+
 #endif /* SILCTIMER_H */
diff --git a/lib/silcutil/silctimer_i.h b/lib/silcutil/silctimer_i.h
index 3709f4f9..cefaac04 100644
--- a/lib/silcutil/silctimer_i.h
+++ b/lib/silcutil/silctimer_i.h
@@ -29,7 +29,9 @@ struct SilcTimerObject {
   SilcUInt64 timer_sec;		/* Timer seconds */
   SilcUInt32 start_usec;	/* Start microseconds */
   SilcUInt32 timer_usec;	/* Timer microseconds */
-  unsigned int running  : 1;	/* Set when timer is running */
+  unsigned int running    : 1;	/* Set when timer is running */
+  unsigned int sync_diff  : 15;	/* Synchronization delta */
+  unsigned int sync_tdiff : 16;	/* Synchronization tick delta */
 };
 
 #endif /* SILCTIMER_I_H */
diff --git a/lib/silcutil/tests/test_silcmutex.c b/lib/silcutil/tests/test_silcmutex.c
index 4b1a732b..49367adb 100644
--- a/lib/silcutil/tests/test_silcmutex.c
+++ b/lib/silcutil/tests/test_silcmutex.c
@@ -16,47 +16,9 @@ typedef struct {
 SilcMutex mutex;
 SilcUInt64 cpu_freq = 0;
 int max_locks, max_locks2;
+SilcTimerStruct timer;
 
-/* RDTSC */
-#ifdef SILC_I486
-static __inline__ unsigned long long rdtsc(void)
-{
-  unsigned long long int x;
-  __asm__ volatile (".byte 0x0f, 0x31" : "=A" (x));
-  return x;
-}
-
-#elif SILC_X86_64
-typedef unsigned long long int unsigned long long;
-static __inline__ unsigned long long rdtsc(void)
-{
-  unsigned hi, lo;
-  __asm__ __volatile__ ("rdtsc" : "=a"(lo), "=d"(hi));
-  return ( (unsigned long long)lo)|( ((unsigned long long)hi)<<32 );
-}
-
-#elif SILC_POWERPC
-typedef unsigned long long int unsigned long long;
-static __inline__ unsigned long long rdtsc(void)
-{
-  unsigned long long int result = 0;
-  unsigned long int upper, lower,tmp;
-  __asm__ volatile(
-                "0:                  \n"
-                "\tmftbu   %0           \n"
-                "\tmftb    %1           \n"
-                "\tmftbu   %2           \n"
-                "\tcmpw    %2,%0        \n"
-                "\tbne     0b         \n"
-                : "=r"(upper),"=r"(lower),"=r"(tmp)
-                );
-  result = upper;
-  result = result << 32;
-  result = result | lower;
-
-  return result;
-}
-#endif
+#define rdtsc() silc_timer_tick(&timer)
 
 void *mutex_thread(void *context)
 {
@@ -117,13 +79,12 @@ int main(int argc, char **argv)
   int k, i, j, o = 0;
   SilcBool success;
 
-  if (argc <= 1) {
-    fprintf(stderr, "Usage: ./test_silcmutex <cpu_freq_mhz>\n");
-    fprintf(stderr, "Example: ./test_silcmutex 3000\n");
-    exit(1);
-  }
-  cpu_freq = (SilcUInt64)atoi(argv[1]);
-  cpu_freq *= 1000;	/* Will give us milliseconds */
+  silc_timer_synchronize(&timer);
+  val = rdtsc();
+  sleep(1);
+  val = rdtsc() - val;
+  val /= 1000;			/* Gives us milliseconds */
+  fprintf(stderr, "CPU frequency: %llu\n", val);
 
   max_locks = MAX_LOCKS;
 
diff --git a/lib/silcutil/tests/test_silctimer.c b/lib/silcutil/tests/test_silctimer.c
index f7354d3b..11e17ed3 100644
--- a/lib/silcutil/tests/test_silctimer.c
+++ b/lib/silcutil/tests/test_silctimer.c
@@ -73,6 +73,10 @@ int main(int argc, char **argv)
   if (!schedule)
     goto err;
 
+  silc_timer_synchronize(&timer);
+  SILC_LOG_DEBUG(("sync_diff: %d", timer.sync_diff));
+  SILC_LOG_DEBUG(("sync_tdiff: %d", timer.sync_tdiff));
+
   SILC_LOG_DEBUG(("Start timer"));
   silc_timer_start(&timer);