1 files changed, 34 insertions, 0 deletions
diff --git a/src/common/time.c b/src/common/time.c
new file mode 100644
index 0000000..84d8fe1
--- /dev/null
+++ b/src/common/time.c
@@ -0,0 +1,34 @@
+#include "../h/gsupport.h"
+
+/*
+ * millisec - returns execution time in milliseconds. Time is measured
+ *  from the function's first call. The granularity of the time is
+ *  generally larger than one millisecond and on some systems it may
+ *  only be accurate to the second.
+ *
+ * For some unfathomable reason, the Open Group's "Single Unix Specification"
+ *  requires that the ANSI C clock() function be defined in units of 1/1000000
+ *  second.  This means that the result overflows a 32-bit signed clock_t
+ *  value only about 35 minutes.  Consequently, we use the POSIX standard
+ *  times() function instead.
+ */
+
+long millisec()
+   {
+   static long clockres = 0;
+   static long starttime = 0;
+   long curtime;
+   struct tms tp;
+
+   times(&tp);
+   curtime = tp.tms_utime + tp.tms_stime;
+   if (clockres == 0) {
+      #ifdef CLK_TCK
+         clockres = CLK_TCK;
+      #else
+         clockres = sysconf(_SC_CLK_TCK);
+      #endif
+      starttime = curtime;
+      }
+   return (long) ((1000.0 / clockres) * (curtime - starttime));
+   }