* man/httperf.1: New documentation regarding the variable periodic rates

* src/httperf.c: New functionality for variable periodic rates
* src/httperf.h: ditto
* src/timer.c: ditto

httperf/AUTHORS

@@ -1,6 +1,23 @@
-Ted Bullock		(compiler fixes, alloca include)
-Tai Jin			(zero-length content fix)
-David Mosberger		(main sources, wsesslog crash fix)
-Martin Arlitt		(SSL support, timer reset fix)
-Stephane Eranian	(wlog URI generator)
-Richard Carter		(wsesslog workload generator)
+David Mosberger
+  main sources
+  wsesslog crash fix
+
+Martin Arlitt
+  SSL support
+  timer reset fix
+
+Ted Bullock
+  compiler warning fixes
+  gnu auto tool build system
+
+Tai Jin
+  zero-length content fix
+
+Stephane Eranian
+  wlog URI generator
+
+Richard Carter
+  wsesslog workload generator
+
+Andrew Hately
+  variable rates of period between sessions/requests

httperf/ChangeLog

@@ -1,3 +1,10 @@
+2007-05-27  Andrew Hateley <andrew.hateley@gmail.com>
+
+	* man/httperf.1: New documentation regarding the variable periodic rates
+	* src/httperf.c: New functionality for variable periodic rates
+	* src/httperf.h: ditto
+	* src/timer.c: ditto
+
 2007-03-31  Ted Bullock <tbullock@canada.com>
 
 	* *.c and *.h: Adjusted license to explicitly list HP copyright as

httperf/src/gen/rate.c

@@ -42,6 +42,9 @@
 #include <rate.h>
 #include <timer.h>
 
+int current_rate = 0;
+Time duration_in_current_rate = 0;
+
 /* By pushing the random number generator state into the caller via
    the xsubi array below, we gain some test repeatability.  For
    example, let us say one generator was starting sessions, and a
@@ -75,6 +78,24 @@ next_arrival_time_exp (Rate_Generator *rg)
   return -mean*log (1.0 - erand48 (rg->xsubi));
 }
 
+static Time
+next_arrival_time_variable (Rate_Generator *rg)
+{
+  Time next;
+
+  next = rg->rate->iat[current_rate];
+  duration_in_current_rate += next;
+
+  if (duration_in_current_rate >= rg->rate->duration[current_rate])
+    {
+      current_rate++;
+      if (current_rate >= rg->rate->numRates)
+	current_rate = 0;
+      duration_in_current_rate = 0;
+    }
+  return (next);
+}
+
 static void
 tick (Timer *t, Any_Type arg)
 {
@@ -133,6 +154,7 @@ rate_generator_start (Rate_Generator *rg, Event_Type completion_event)
 	case DETERMINISTIC: func = next_arrival_time_det; break;
 	case UNIFORM:	    func = next_arrival_time_uniform; break;
 	case EXPONENTIAL:   func = next_arrival_time_exp; break;
+	case VARIABLE:      func = next_arrival_time_variable; break;
 	default:
 	  fprintf (stderr, "%s: unrecognized interarrival distribution %d\n",
 		   prog_name, rg->rate->dist);

httperf/src/httperf.c

@@ -139,6 +139,7 @@ static struct option longopts[] =
     {"think-timeout",required_argument, (int *) &param.think_timeout,	0},
     {"timeout",      required_argument,	(int *) &param.timeout,		0},
     {"uri",	     required_argument, (int *) &param.uri,		0},
+    {"use-timer-cache", no_argument,    &param.use_timer_cache,         1},
     {"verbose",	     no_argument,	0,				'v'},
     {"version",	     no_argument,	0,				'V'},
     {"wlog",	     required_argument, (int *) &param.wlog,            0},
@@ -169,7 +170,9 @@ usage (void)
 	  "\t[--think-timeout X] [--timeout X] [--uri S] [--verbose] "
 	  "[--version]\n"
 	  "\t[--wlog y|n,file] [--wsess N,N,X] [--wsesslog N,X,file]\n"
-	  "\t[--wset N,X]\n",
+	  "\t[--wset N,X]\n"
+	  "\t[--period [v]T1,D1[,T2,D2]\n"
+	  "\t[--use-timer-cache]\n",
 	  prog_name);
 }
 
@@ -230,6 +233,8 @@ main (int argc, char **argv)
   void *flag;
   Time t;
 
+  int numRates = 0;
+
 #ifdef __FreeBSD__
   /* This works around a bug in earlier versions of FreeBSD that cause
      non-finite IEEE arithmetic to cause SIGFPE instead of the
@@ -409,6 +414,7 @@ main (int argc, char **argv)
 		  case 'd': param.rate.dist = DETERMINISTIC; break;
 		  case 'u': param.rate.dist = UNIFORM; break;
 		  case 'e': param.rate.dist = EXPONENTIAL; break;
+		  case 'v': param.rate.dist = VARIABLE; break;
 		  default:
 		    fprintf (stderr, "%s: illegal interarrival distribution "
 			     "'%c' in %s\n",
@@ -461,6 +467,62 @@ main (int argc, char **argv)
 					     + param.rate.max_iat);
 		  break;
 
+		case VARIABLE:
+		  while(1)
+		    {
+		      if (numRates >= NUM_RATES)
+			{
+			  fprintf (stderr, "%s: too many rates\n",
+				   prog_name);
+			  exit (1);
+			}
+
+		      param.rate.iat[numRates] = strtod (optarg, &end);
+		      if (errno == ERANGE || end == optarg ||
+			  param.rate.iat[numRates] < 0)
+			{
+			  fprintf (stderr, "%s: illegal minimum interarrival"
+				   " time %s\n", prog_name, optarg);
+			  exit (1);
+			}
+
+		      if (*end != ',')
+			{
+			  fprintf (stderr, "%s: interarrival time not "
+				   "followed by `,duration' (rest: `%s')\n",
+				   prog_name, end);
+			  exit (1);
+			}
+
+		      optarg = end + 1;
+		      param.rate.duration[numRates] = strtod (optarg, &end);
+		      if (errno == ERANGE || end == optarg ||
+			  param.rate.duration[numRates] < 0)
+			{
+			  fprintf (stderr, "%s: illegal duration %s\n",
+				   prog_name, optarg);
+			  exit (1);
+			}
+
+		      if (numRates == 0)
+			param.rate.mean_iat = param.rate.iat[numRates];
+		      else
+			param.rate.mean_iat += param.rate.iat[numRates];
+
+		      numRates++;
+
+		      if (*end != ',')
+			{
+			  param.rate.numRates = numRates;
+			  break;
+			}
+		      else
+			optarg = end + 1;
+		    }
+
+		  param.rate.mean_iat /= numRates;
+		  break;
+
 		default:
 		  fprintf (stderr, "%s: internal error parsing %s\n",
 			   prog_name, optarg);
@@ -893,6 +955,20 @@ main (int argc, char **argv)
 	  printf (" --period=e%g", param.rate.mean_iat);
 	  break;
 
+	case VARIABLE:
+	  {
+	    int m;
+	    printf (" --period=v");
+	    for(m=0; m<param.rate.numRates; m++)
+	      {
+		if (m != 0)
+		  printf (",");
+		printf ("%g,%g", param.rate.iat[m],
+			param.rate.duration[m]);
+	      }
+	  }
+	  break;
+
 	default:
 	  printf("--period=??");
 	  break;
@@ -911,6 +987,7 @@ main (int argc, char **argv)
   if (param.additional_header)
     printf (" --add-header='%s'", param.additional_header);
   if (param.method) printf (" --method=%s", param.method);
+  if (param.use_timer_cache) printf (" --use-timer-cache");
   if (param.wsesslog.num_sessions)
     {
       /* This overrides any --wsess, --num-conns, --num-calls,

httperf/src/httperf.h

@@ -46,6 +46,8 @@ typedef double Time;
 #define NELEMS(a)	((sizeof (a)) / sizeof ((a)[0]))
 #define TV_TO_SEC(tv)	((tv).tv_sec + 1e-6*(tv).tv_usec)
 
+#define NUM_RATES 16
+
 typedef union
   {
     char c;
@@ -65,6 +67,7 @@ typedef enum Dist_Type
   {
     DETERMINISTIC,	/* also called fixed-rate */
     UNIFORM,		/* over interval [min_iat,max_iat) */
+    VARIABLE,           /* allows varying input load */
     EXPONENTIAL		/* with mean mean_iat */
   }
 Dist_Type;
@@ -98,6 +101,9 @@ typedef struct Rate_Info
     Time mean_iat;		/* mean interarrival time */
     Time min_iat;		/* min interarrival time (for UNIFORM) */
     Time max_iat;	        /* max interarrival time (for UNIFORM) */
+    int numRates;               /* number of rates we want to use */
+    Time iat[NUM_RATES];
+    Time duration[NUM_RATES];
   }
 Rate_Info;
 
@@ -134,6 +140,7 @@ typedef struct Cmdline_Params
     int ssl_reuse;	/* reuse SSL Session ID */
     const char *ssl_cipher_list; /* client's list of SSL cipher suites */
 #endif
+    int use_timer_cache;
     const char *additional_header;	/* additional request header(s) */
     const char *method;	/* default call method */
     struct

httperf/src/timer.c

@@ -75,7 +75,10 @@ timer_now_forced (void)
 Time
 timer_now (void)
 {
-  return now;
+  if(param.use_timer_cache)
+    return now;
+  else
+    return timer_now_forced ();
 }
 
 void