X-Git-Url: https://git.donarmstrong.com/?p=rsem.git;a=blobdiff_plain;f=sampling.h;h=88200909d4b6e8bf13854808fa72f835ce20cdcb;hp=417140395b8b78801af1808fc93bf6d3eca9d602;hb=683863b75f8d8bef2461039a6911b0e9619cc113;hpb=1c7a81621434a852a7f7e11d61621e50ba1b7f2a

diff --git a/sampling.h b/sampling.h
index 4171403..8820090 100644
--- a/sampling.h
+++ b/sampling.h
@@ -5,17 +5,39 @@
 #include<cstdio>
 #include<cassert>
 #include<vector>
+#include<set>
 
 #include "boost/random.hpp"
 
-boost::mt19937 rng(time(NULL));
-boost::uniform_01<boost::mt19937> rg(rng);
+typedef unsigned int seedType;
+typedef boost::mt19937 engine_type;
+typedef boost::gamma_distribution<> gamma_dist;
+typedef boost::uniform_01<engine_type> uniform01;
+typedef boost::variate_generator<engine_type&, gamma_dist> gamma_generator;
+
+class engineFactory {
+public:
+	static engine_type *new_engine() {
+		seedType seed;
+		static engine_type seedEngine(time(NULL));
+		static std::set<seedType> seedSet;			// empty set of seeds
+		std::set<seedType>::iterator iter;
+
+		do {
+			seed = seedEngine();
+			iter = seedSet.find(seed);
+		} while (iter != seedSet.end());
+		seedSet.insert(seed);
+
+		return new engine_type(seed);
+	}
+};
 
 // arr should be cumulative!
 // interval : [,)
 // random number should be in [0, arr[len - 1])
 // If by chance arr[len - 1] == 0.0, one possibility is to sample uniformly from 0...len-1
-int sample(std::vector<double>& arr, int len) {
+int sample(uniform01& rg, std::vector<double>& arr, int len) {
   int l, r, mid;
   double prb = rg() * arr[len - 1];