randomize glop on tests

ortools/glop/revised_simplex.cc

@@ -28,6 +28,7 @@
 #include "absl/random/bit_gen_ref.h"
 #include "absl/random/random.h"
 #include "absl/random/seed_sequences.h"
+#include "absl/strings/match.h"
 #include "absl/strings/str_cat.h"
 #include "absl/strings/str_format.h"
 #include "absl/strings/string_view.h"
@@ -93,15 +94,21 @@ class Cleanup {
 
 constexpr const uint64_t kDeterministicSeed = 42;
 
+namespace {
+
+bool UseAbslRandom() { return false; }
+
+}  // namespace
+
 RevisedSimplex::RevisedSimplex()
     : problem_status_(ProblemStatus::INIT),
       objective_(),
       basis_(),
       variable_name_(),
       direction_(),
       error_(),
-      deterministic_random_(kDeterministicSeed),
-      random_(deterministic_random_),
+      random_(UseAbslRandom() ? absl::BitGenRef(absl_random_)
+                              : absl::BitGenRef(deterministic_random_)),
       basis_factorization_(&compact_matrix_, &basis_),
       variables_info_(compact_matrix_),
       primal_edge_norms_(compact_matrix_, variables_info_,
@@ -3617,7 +3624,7 @@ Fractional RevisedSimplex::ComputeInitialProblemObjectiveValue() const {
 void RevisedSimplex::SetParameters(const GlopParameters& parameters) {
   SCOPED_TIME_STAT(&function_stats_);
   deterministic_random_.seed(parameters.random_seed());
-
+  absl_random_ = absl::BitGen(absl::SeedSeq({parameters.random_seed()}));
   initial_parameters_ = parameters;
   parameters_ = parameters;
   PropagateParameters();
@@ -3639,7 +3646,7 @@ void RevisedSimplex::DisplayIterationInfo(bool primal,
   const std::string first_word = primal ? "Primal " : "Dual ";
 
   // We display the info on each re-factorization, and it is nice to show what
-  // trigerred the issue. Note that we don't display normal refactorization when
+  // triggered the issue. Note that we don't display normal refactorization when
   // we decide that it is worth it for the solve time or we reach the fixed
   // refactorization period.
   std::string info;

ortools/glop/revised_simplex.h

@@ -729,9 +729,9 @@ class RevisedSimplex {
   // non-deterministic behavior and avoid client depending on a golden optimal
   // solution which prevent us from easily changing the solver.
   random_engine_t deterministic_random_;
-#ifndef NDEBUG
   absl::BitGen absl_random_;
-#endif
+
+  // A reference to one of the above random generators. Fixed at construction.
   absl::BitGenRef random_;
 
   // Helpers for logging the solve progress.