fix oversites in libbsp/unix/posix

c/src/lib/libbsp/unix/posix/timer/timer.c

@@ -0,0 +1,71 @@
+/*  timer.c
+ *
+ *  This file manages the interval timer on the PA-RISC.
+ *
+ *  NOTE: It is important that the timer start/stop overhead be
+ *        determined when porting or modifying this code.
+ *
+ *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
+ *  On-Line Applications Research Corporation (OAR).
+ *  All rights assigned to U.S. Government, 1994.
+ *
+ *  This material may be reproduced by or for the U.S. Government pursuant
+ *  to the copyright license under the clause at DFARS 252.227-7013.  This
+ *  notice must appear in all copies of this file and its derivatives.
+ *
+ *  $Id$
+ */
+
+#include <rtems.h>
+
+#include <time.h>
+
+struct timeval  Timer_start;
+struct timeval  Timer_stop;
+struct timezone Time_zone;
+
+rtems_boolean   Timer_driver_Find_average_overhead;
+
+void Timer_initialize()
+{
+   gettimeofday( &Timer_start, &Time_zone );
+}
+
+#define AVG_OVERHEAD      0  /* It typically takes xxx microseconds */
+                             /* (XX countdowns) to start/stop the timer. */
+#define LEAST_VALID       10 /* Don't trust a value lower than this */
+
+int Read_timer()
+{
+  int total;
+
+  gettimeofday( &Timer_stop, &Time_zone );
+
+  if ( Timer_stop.tv_sec == Timer_start.tv_sec )
+    total = Timer_stop.tv_usec - Timer_start.tv_usec;
+  else {
+    total  = 1000000 - Timer_start.tv_usec;
+    total += (Timer_stop.tv_sec - Timer_start.tv_sec - 1) * 1000000;
+    total += Timer_stop.tv_usec;
+  }
+
+  if ( Timer_driver_Find_average_overhead == 1 )
+      return total;          /* in countdown units */
+  else {
+    if ( total < LEAST_VALID )
+        return 0;            /* below timer resolution */
+    return total - AVG_OVERHEAD;
+  }
+}
+
+rtems_status_code Empty_function( void )
+{
+  return RTEMS_SUCCESSFUL;
+}
+
+void Set_find_average_overhead(
+  rtems_boolean find_flag
+)
+{
+  Timer_driver_Find_average_overhead = find_flag;
+}