Remove use of C++11 randomization engines

test/cpp/qps/interarrival.h

@@ -36,7 +36,8 @@
 
 #include <chrono>
 #include <cmath>
-#include <random>
+#include <cstdlib>
+#include <vector>
 
 #include <grpc++/config.h>
 
@@ -141,17 +142,16 @@ class ParetoDist GRPC_FINAL : public RandomDist {
 // in an efficient re-entrant way. The random table is built at construction
 // time, and each call must include the thread id of the invoker
 
-typedef std::default_random_engine qps_random_engine;
-
 class InterarrivalTimer {
  public:
   InterarrivalTimer() {}
   void init(const RandomDist& r, int threads, int entries = 1000000) {
-    qps_random_engine gen;
-    std::uniform_real_distribution<double> uniform(0.0, 1.0);
     for (int i = 0; i < entries; i++) {
+      // rand is the only choice that is portable across POSIX and Windows
+      // and that supports new and old compilers
+      double uniform_0_1 = rand() / RAND_MAX;
       random_table_.push_back(std::chrono::nanoseconds(
-          static_cast<int64_t>(1e9 * r(uniform(gen)))));
+        static_cast<int64_t>(1e9 * r(uniform_0_1))));
     }
     // Now set up the thread positions
     for (int i = 0; i < threads; i++) {