From 21ed1f0c6d90f8a734150130eda1b3426f00c308 Mon Sep 17 00:00:00 2001
From: Jiaming Yuan <jm.yuan@outlook.com>
Date: Thu, 7 May 2020 14:52:38 +0800
Subject: [PATCH] Support 64bit seed. (#5643)

---
 include/xgboost/generic_parameters.h |  2 +-
 tests/cpp/test_learner.cc            | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/include/xgboost/generic_parameters.h b/include/xgboost/generic_parameters.h
index 7713d6b2b..752342b9a 100644
--- a/include/xgboost/generic_parameters.h
+++ b/include/xgboost/generic_parameters.h
@@ -17,7 +17,7 @@ struct GenericParameter : public XGBoostParameter<GenericParameter> {
 
  public:
   // stored random seed
-  int seed;
+  int64_t seed;
   // whether seed the PRNG each iteration
   bool seed_per_iteration;
   // number of threads to use if OpenMP is enabled
diff --git a/tests/cpp/test_learner.cc b/tests/cpp/test_learner.cc
index 4216e6e0b..a69fce19d 100644
--- a/tests/cpp/test_learner.cc
+++ b/tests/cpp/test_learner.cc
@@ -260,4 +260,26 @@ TEST(Learner, GPUConfiguration) {
   }
 }
 #endif  // defined(XGBOOST_USE_CUDA)
+
+TEST(Learner, Seed) {
+  auto m = RandomDataGenerator{10, 10, 0}.GenerateDMatrix();
+  std::unique_ptr<Learner> learner {
+    Learner::Create({m})
+  };
+  auto seed = std::numeric_limits<int64_t>::max();
+  learner->SetParam("seed", std::to_string(seed));
+  learner->Configure();
+  Json config { Object() };
+  learner->SaveConfig(&config);
+  ASSERT_EQ(std::to_string(seed),
+            get<String>(config["learner"]["generic_param"]["seed"]));
+
+  seed = std::numeric_limits<int64_t>::min();
+  learner->SetParam("seed", std::to_string(seed));
+  learner->Configure();
+  learner->SaveConfig(&config);
+  ASSERT_EQ(std::to_string(seed),
+            get<String>(config["learner"]["generic_param"]["seed"]));
+}
+
 }  // namespace xgboost