Adding Noise module parameter that will allow the designer to specify a seed in order to re-run with the same RNG, also initializing the RNG with a tsc based seed by default. Updating some language around seeding the noise part.

Adding Noise module parameter that will allow the designer to specify a seed in order to re-run with the same RNG, also initializing the RNG with a tsc based seed by default. Updating some language around seeding the noise part.

src/epics/util/lib/Noise.pm

@@ -4,6 +4,10 @@ use Exporter;
 
 #//     \page Noise Noise.pm
 #//     Documentation for Noise.pm
+#//     This Noise part generates uniform random noise in the 
+#//     (0, 1) range. This block utilizes the pseudo-random number 
+#//     generator from page 342  (section 7.1) of the third edition 
+#//     of Numerical recipies. 
 #//
 #// \n
 
@@ -13,31 +17,32 @@ $init_code_printed = 0;
 1;
 
 sub partType {
-	return Noise;
+    return Noise;
 }
 
 # Print Epics communication structure into a header file
 # Current part number is passed as first argument
 sub printHeaderStruct {
-        my ($i) = @_;
+    my ($i) = @_;
 }
 
 # Print Epics variable definitions
 # Current part number is passed as first argument
 sub printEpics {
-        my ($i) = @_;
+    my ($i) = @_;
 }
 
 
 # Print variable declarations int front-end file
 # Current part number is passed as first argument
 sub printFrontEndVars  {
-        my ($i) = @_;
-	print ::OUT "static double \L$::xpartName[$i];\n";
-	if ($printed) { return; }
-	print ::OUT << "END";
-static unsigned long noise_seed = 4101842887655102017LL;\n
-static unsigned long noise_u, noise_v, noise_w;
+    my ($i) = @_;
+    print ::OUT "static double \L$::xpartName[$i];\n";
+    if ($printed) { return; }
+    print ::OUT "static unsigned long noise_seed = " . $::noiseGeneratorSeed . "ULL;\n";
+
+    print ::OUT << "END";
+static unsigned long noise_u = 0, noise_v = 0, noise_w = 0;
 inline unsigned long noise_int64() {
    noise_u = noise_u * 2862933555777941757LL + 7046029254386353087LL;
    noise_v ^= noise_v >> 17; noise_v ^= noise_v << 31; noise_v ^= noise_v >> 8;
@@ -47,10 +52,10 @@ inline unsigned long noise_int64() {
    return (noise_x + noise_v) ^ noise_w;
 }
 inline double noise_doub() { return 5.42101086242752217E-20 * noise_int64(); }
-inline noise_ran(unsigned long j) {
+inline noise_set_seed(unsigned long seed) {
    noise_v = 4101842887655102017LL;
    noise_w = 1;
-   noise_u = j ^ noise_v; noise_int64();
+   noise_u = seed ^ noise_v; noise_int64();
    noise_v = noise_u; noise_int64();
    noise_w = noise_v; noise_int64();
 }
@@ -60,8 +65,8 @@ $printed = 1;
 
 # Check inputs are connected
 sub checkInputConnect {
-        my ($i) = @_;
-        return "";
+    my ($i) = @_;
+    return "";
 }
 
 # Figure out part input code
@@ -69,23 +74,27 @@ sub checkInputConnect {
 # Argument 2 is the input number
 # Returns calculated input code
 sub fromExp {
-        my ($i, $j) = @_;
-        my $from = $::partInNum[$i][$j];
-        return "\L$::xpartName[$from]";
+    my ($i, $j) = @_;
+    my $from = $::partInNum[$i][$j];
+    return "\L$::xpartName[$from]";
 }
 
 # Return front end initialization code
 # Argument 1 is the part number
 # Returns calculated code string
 sub frontEndInitCode {
-	my ($i) = @_;
-	if ($init_code_printed) { return ""; }
-        my $calcExp  =  "\L$::xpartName[$i] = 0;\n";
-	$calcExp    .=  "for (;noise_seed == 4101842887655102017LL;) {\n";
-        $calcExp    .=  "   rdtscl(noise_seed);\n";
-        $calcExp    .=  "}\n";
-	$init_code_printed = 1;
-	return $calcExp;
+    my ($i) = @_;
+    if ($init_code_printed) { return ""; }
+    my $calcExp  =  "\L$::xpartName[$i] = 0;\n";
+    $calcExp    .=  "if (noise_seed == 0) {\n";
+    $calcExp    .=  "    rdtscl(noise_seed);\n";
+    $calcExp    .=  "    rdtscl(noise_w);\n";
+    $calcExp    .=  "    noise_seed |= (noise_w << 32ULL);\n";
+    $calcExp    .=  "}\n";
+    $calcExp    .=  "noise_set_seed(noise_seed);\n";
+
+    $init_code_printed = 1;
+    return $calcExp;
 }
 
 
@@ -93,7 +102,7 @@ sub frontEndInitCode {
 # Argument 1 is the part number
 # Returns calculated code string
 sub frontEndCode {
-	my ($i) = @_;
-        my $calcExp = "// Noise\n";
-        $calcExp .= "\L$::xpartName[$i] = noise_doub();\n";
+    my ($i) = @_;
+    my $calcExp = "// Noise\n";
+    $calcExp .= "\L$::xpartName[$i] = noise_doub();\n";
 }