DLR-SR/Noise#74 (comment) fixed:

Provided automaticGlobalSeed as C-function
DLR-SR · Dec 10, 2015 · 5ea42e7 · 5ea42e7
1 parent 8f745e1
commit 5ea42e7
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Showing 2 changed files with 36 additions and 13 deletions.
diff --git a/Modelica_Noise 1.0 Beta.1/Math/Random/Utilities/automaticGlobalSeed.mo b/Modelica_Noise 1.0 Beta.1/Math/Random/Utilities/automaticGlobalSeed.mo
@@ -1,15 +1,19 @@
 within Modelica_Noise.Math.Random.Utilities;
 function automaticGlobalSeed
-  "Creates an automatic integer seed from the current time and process id (= impure function)"
+  "Creates an automatic integer seed (typically from the current time and process id; this is an impure function)"
   output Integer seed "Automatically generated seed";
-protected
+  /*
+protected 
   Integer ms,sec,min,hour "Current system time";
   Integer pid "Current process ID";
-algorithm
+algorithm 
   (ms,sec,min,hour) := Modelica_Noise.Utilities.System.getTime();
   pid := Modelica_Noise.Utilities.System.getPid();
   seed := 1 + ms + 1000*sec + 1000*60*min + 1000*60*60*hour
-            + 6007*pid;
+  + 6007*pid;
+  */
+  external "C" seed = ModelicaRandom_automaticGlobalSeed()
+    annotation (Include = "#include \"ModelicaRandom.c\"");
 
  annotation (Documentation(info="<html>
 <h4>Syntax</h4>
@@ -18,17 +22,14 @@ seed = Utilities.<b>automaticGlobalSeed</b>();
 </pre></blockquote>
 
 <h4>Description</h4>
-<p>Returns an automatically computed seed (Integer) from:</p>
+<p>Returns an automatically computed seed (Integer). Typically, this seed is computed from:</p>
 <ol>
 <li> The current localtime by computing the number of milli-seconds up to the current hour</li>
 <li> The process id (added to the first part by multiplying it with the prime number 6007).</li>
 </ol>
-<p>Check that worst case combination can be included in an Integer:</p>
-<blockquote>
-<p>1000*60*60 = 3.6e6 &LT; 2^31 = 2147483648 (2.1e9)</p>
-</blockquote>
 <p>
-Everything is added to 1, in order to guard against the very unlikely case that the sum is zero.
+If getTime and getPid functions are not available on the target where this Modelica function
+is called, other means to compute a seed may be used.
 </p>
 
 <p>

diff --git a/Modelica_Noise 1.0 Beta.1/Resources/Include/ModelicaRandom.c b/Modelica_Noise 1.0 Beta.1/Resources/Include/ModelicaRandom.c
@@ -17,15 +17,15 @@
                      Implemented a first version.
 
    This file is licensed under the BSD 2-Clause License:
- 
+
    Copyright (C) 2015, DLR and Modelica Association.
-  
+
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are met:
 
     1. Redistributions of source code must retain the above copyright notice,
        this list of conditions and the following disclaimer.
-	  
+
     2. Redistributions in binary form must reproduce the above copyright
        notice, this list of conditions and the following disclaimer in the
        documentation and/or other materials provided with the distribution.
@@ -588,6 +588,27 @@ MODELICA_EXPORT double ModelicaRandom_impureRandom_xorshift1024star(int id) {
 
 
 
+MODELICA_EXPORT int ModelicaRandom_automaticGlobalSeed() {
+   /* Creates an automatic integer seed (typically from the current time and process id) */
+
+
+   int ms, sec, min, hour, mday, mon, year;
+   int pid;
+   int seed;
+
+   ModelicaRandom_getTime(&ms, &sec, &min, &hour, &mday, &mon, &year);
+   pid = ModelicaRandom_getpid();
+
+   /* Check that worst case combination can be included in an Integer:
+
+         1000*60*60 = 3.6e6 < 2^31 = 2147483648 (2.1e9)
+
+      Everything is added to 1, in order to guard against the very unlikely case that the sum is zero.
+   */
+   seed = 1 + ms + 1000*sec + 1000*60*min + 1000*60*60*hour + 6007*pid;
+   return seed;
+}
+
 
 /* original algorithms */
 
@@ -605,4 +626,5 @@ MODELICA_EXPORT void ModelicaRandom_convertRealToIntegers(double d, int i[]) {
 
 
 
+
 #endif