Use clock_gettime and getrusage to compute real and user time.

Better handling of clock jumps, from Scott Cheloa.

src/usr.bin/openssl/apps_posix.c

@@ -116,31 +116,48 @@
  * Functions that need to be overridden by non-POSIX operating systems.
  */
 
-#include <sys/times.h>
+#include <sys/resource.h>
+#include <sys/time.h>
 
-#include <unistd.h>
+#include <time.h>
 
 #include "apps.h"
 
-double
-app_tminterval(int stop, int usertime)
+static double
+real_interval(int stop)
 {
-	double ret = 0;
-	struct tms rus;
-	clock_t now = times(&rus);
-	static clock_t tmstart;
+	static struct timespec start;
+	struct timespec elapsed, now;
+
+	clock_gettime(CLOCK_MONOTONIC, &now);
+	if (stop) {
+		timespecsub(&now, &start, &elapsed);
+		return elapsed.tv_sec + elapsed.tv_nsec / 1000000000.0;
+	}
+	start = now;
+	return 0.0;
+}
 
-	if (usertime)
-		now = rus.tms_utime;
+static double
+user_interval(int stop)
+{
+	static struct timeval start;
+	struct timeval elapsed;
+	struct rusage now;
 
-	if (stop == TM_START)
-		tmstart = now;
-	else {
-		long int tck = sysconf(_SC_CLK_TCK);
-		ret = (now - tmstart) / (double) tck;
+	getrusage(RUSAGE_SELF, &now);
+	if (stop) {
+		timersub(&now.ru_utime, &start, &elapsed);
+		return elapsed.tv_sec + elapsed.tv_usec / 1000000.0;
 	}
+	start = now.ru_utime;
+	return 0.0;
+}
 
-	return (ret);
+double
+app_tminterval(int stop, int usertime)
+{
+	return (usertime) ? user_interval(stop) : real_interval(stop);
 }
 
 int