Convert ACL random to C++11 random features

diff --git a/src/acl/Random.cc b/src/acl/Random.cc
index 45fd0b2b4daeb48216487db9d06d7128de1899c3..22b21ed036ffa936f5bc5dc8eec6be819aab65e2 100644 (file)
--- a/src/acl/Random.cc
+++ b/src/acl/Random.cc
@@ -15,6 +15,8 @@
 #include "Parsing.h"
 #include "wordlist.h"
 
+#include <random>
+
 ACL *
 ACLRandom::clone() const
 {
@@ -82,7 +84,7 @@ ACLRandom::parse()
     } else if (sscanf(t, "%[0-9]/%[0-9]", bufa, bufb) == 2) {
         int a = xatoi(bufa);
         int b = xatoi(bufb);
-        if (a <= 0 || b <= 0) {
+        if (a <= 0 || b <= 0 || a > b) {
             debugs(28, DBG_CRITICAL, "ERROR: ACL random with bad pattern: '" << t << "'");
             return;
         } else
@@ -101,8 +103,14 @@ ACLRandom::parse()
 int
 ACLRandom::match(ACLChecklist *)
 {
-    // make up the random value
-    double random = ((double)rand() / (double)RAND_MAX);
+    // make up the random value.
+    // The fixed-value default seed is fine because we are
+    // actually matching whether the random value is above
+    // or below the configured threshold ratio.
+    static std::mt19937 mt;
+    static std::uniform_real_distribution<> dist(0, 1);
+
+    const double random = dist(mt);
 
     debugs(28, 3, "ACL Random: " << name << " " << pattern << " test: " << data << " > " << random << " = " << ((data > random)?"MATCH":"NO MATCH") );
     return (data > random)?1:0;