Value-initialize the Data union member of folly::Function

[folly.git] / folly / test / RandomTest.cpp

diff --git a/folly/test/RandomTest.cpp b/folly/test/RandomTest.cpp
index cc576ae4995a2b09fc81394e76ee0d2b87a32543..d36275750033eec1dc9a64b96612b8c7ddb2a3f1 100644 (file)
--- a/folly/test/RandomTest.cpp
+++ b/folly/test/RandomTest.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 Facebook, Inc.
+ * Copyright 2017 Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,13 +16,15 @@
 
 #include <folly/Random.h>
 
-#include <glog/logging.h>
-#include <gtest/gtest.h>
-
 #include <algorithm>
+#include <random>
 #include <thread>
+#include <unordered_set>
 #include <vector>
-#include <random>
+
+#include <glog/logging.h>
+
+#include <folly/portability/GTest.h>
 
 using namespace folly;
 
@@ -30,13 +32,13 @@ TEST(Random, StateSize) {
   using namespace folly::detail;
 
   // uint_fast32_t is uint64_t on x86_64, w00t
-  EXPECT_EQ(sizeof(uint_fast32_t) / 4 + 3,
-            StateSize<std::minstd_rand0>::value);
-  EXPECT_EQ(624, StateSize<std::mt19937>::value);
+  EXPECT_EQ(
+      sizeof(uint_fast32_t) / 4 + 3, StateSizeT<std::minstd_rand0>::value);
+  EXPECT_EQ(624, StateSizeT<std::mt19937>::value);
 #if FOLLY_HAVE_EXTRANDOM_SFMT19937
-  EXPECT_EQ(624, StateSize<__gnu_cxx::sfmt19937>::value);
+  EXPECT_EQ(624, StateSizeT<__gnu_cxx::sfmt19937>::value);
 #endif
-  EXPECT_EQ(24, StateSize<std::ranlux24_base>::value);
+  EXPECT_EQ(24, StateSizeT<std::ranlux24_base>::value);
 }
 
 TEST(Random, Simple) {
@@ -65,12 +67,14 @@ TEST(Random, FixedSeed) {
   // clang-format on
 
   ConstantRNG gen;
+
+  // Pick a constant random number...
+  auto value = Random::rand32(10, gen);
+
   // Loop to make sure it really is constant.
   for (int i = 0; i < 1024; ++i) {
     auto result = Random::rand32(10, gen);
-    // TODO: This is a little bit brittle; standard library changes could break
-    // it, if it starts implementing distribution types differently.
-    EXPECT_EQ(0, result);
+    EXPECT_EQ(value, result);
   }
 }
 
@@ -91,3 +95,46 @@ TEST(Random, MultiThreaded) {
     EXPECT_LT(seeds[i], seeds[i+1]);
   }
 }
+
+TEST(Random, sanity) {
+  // edge cases
+  EXPECT_EQ(folly::Random::rand32(0), 0);
+  EXPECT_EQ(folly::Random::rand32(12, 12), 0);
+  EXPECT_EQ(folly::Random::rand64(0), 0);
+  EXPECT_EQ(folly::Random::rand64(12, 12), 0);
+
+  // 32-bit repeatability, uniqueness
+  constexpr int kTestSize = 1000;
+  {
+    std::vector<uint32_t> vals;
+    folly::Random::DefaultGenerator rng;
+    rng.seed(0xdeadbeef);
+    for (int i = 0; i < kTestSize; ++i) {
+      vals.push_back(folly::Random::rand32(rng));
+    }
+    rng.seed(0xdeadbeef);
+    for (int i = 0; i < kTestSize; ++i) {
+      EXPECT_EQ(vals[i], folly::Random::rand32(rng));
+    }
+    EXPECT_EQ(
+        vals.size(),
+        std::unordered_set<uint32_t>(vals.begin(), vals.end()).size());
+  }
+
+  // 64-bit repeatability, uniqueness
+  {
+    std::vector<uint64_t> vals;
+    folly::Random::DefaultGenerator rng;
+    rng.seed(0xdeadbeef);
+    for (int i = 0; i < kTestSize; ++i) {
+      vals.push_back(folly::Random::rand64(rng));
+    }
+    rng.seed(0xdeadbeef);
+    for (int i = 0; i < kTestSize; ++i) {
+      EXPECT_EQ(vals[i], folly::Random::rand64(rng));
+    }
+    EXPECT_EQ(
+        vals.size(),
+        std::unordered_set<uint64_t>(vals.begin(), vals.end()).size());
+  }
+}