merge from legacy branch

Author: acmorrow

.mci.yml

@@ -133,8 +133,8 @@ cxx_driver_variables:
     ## msvc2010
     msvc2010: &with_msvc2010
       toolchain_flags: --msvc-version=10.0
-      libpath: --libpath="c:\local\boost_1_55_0\lib64-msvc-10.0"
-      cpppath: --cpppath="c:\local\boost_1_55_0"
+      libpath: --libpath="c:\local\boost_1_57_0\lib64-msvc-10.0"
+      cpppath: --cpppath="c:\local\boost_1_57_0"
       dllpath: --runtime-library-search-path="c:\local\boost_1_55_0\lib64-msvc-10.0,c:\openssl\bin,c:\sasl\bin,c:\curl\dlls"
       extrapath: --extrapath="c:\openssl,c:\sasl,c:\curl"
     ## msvc2013, 32-bit boost headers
@@ -635,7 +635,7 @@ buildvariants:
     <<: *with_msvc2010_32bit
     compile_target: driver build-unit
   run_on:
-  - windows-64-compile
+  - windows-64-vs2010-compile
   tasks:
     - name: "compile"
     - name: "unit-test"
@@ -652,7 +652,7 @@ buildvariants:
     <<: *mongo_url_windows64
     <<: *with_msvc2010
   run_on:
-  - windows-64-compile
+  - windows-64-vs2010-compile
   tasks: *latest_tests
 
 ## Windows 64-bit DEBUG DYNAMIC (msvc2010)
@@ -668,7 +668,7 @@ buildvariants:
     <<: *mongo_url_windows64
     <<: *with_msvc2010
   run_on:
-  - windows-64-compile
+  - windows-64-vs2010-compile
   tasks: *latest_tests
 
 ## Windows 64-bit DYNAMIC (msvc2013)

SConstruct

@@ -562,7 +562,8 @@ if has_option('runtime-library-search-path'):
     for lib in libs:
         env.AppendENVPath(envVar, env.Dir(lib), delete_existing=0)
 
-if has_option('build-fast-and-loose'):
+# Ignore fast-and-loose option if the scons cache is enabled (see SERVER-19088)
+if has_option('build-fast-and-loose') and not has_option('cache'):
     # See http://www.scons.org/wiki/GoFastButton for details
     env.Decider('MD5-timestamp')
     env.SetOption('max_drift', 1)

src/mongo/platform/random.cpp

@@ -35,49 +35,46 @@ namespace mongo {
 
 // ---- PseudoRandom  -----
 
-int32_t PseudoRandom::nextInt32() {
-    int32_t t = _x ^ (_x << 11);
+uint32_t PseudoRandom::nextUInt32() {
+    uint32_t t = _x ^ (_x << 11);
     _x = _y;
     _y = _z;
     _z = _w;
     return _w = _w ^ (_w >> 19) ^ (t ^ (t >> 8));
 }
 
 namespace {
-const int32_t default_y = 362436069;
-const int32_t default_z = 521288629;
-const int32_t default_w = 88675123;
-}
+const uint32_t default_y = 362436069;
+const uint32_t default_z = 521288629;
+const uint32_t default_w = 88675123;
+}  // namespace
 
-PseudoRandom::PseudoRandom(int32_t seed) {
+void PseudoRandom::_init(uint32_t seed) {
     _x = seed;
     _y = default_y;
     _z = default_z;
     _w = default_w;
 }
 
-
 PseudoRandom::PseudoRandom(uint32_t seed) {
-    _x = static_cast<int32_t>(seed);
-    _y = default_y;
-    _z = default_z;
-    _w = default_w;
+    _init(seed);
 }
 
+PseudoRandom::PseudoRandom(int32_t seed) {
+    _init(static_cast<uint32_t>(seed));
+}
 
 PseudoRandom::PseudoRandom(int64_t seed) {
-    int32_t high = seed >> 32;
-    int32_t low = seed & 0xFFFFFFFF;
+    _init(static_cast<uint32_t>(seed >> 32) ^ static_cast<uint32_t>(seed));
+}
 
-    _x = high ^ low;
-    _y = default_y;
-    _z = default_z;
-    _w = default_w;
+int32_t PseudoRandom::nextInt32() {
+    return nextUInt32();
 }
 
 int64_t PseudoRandom::nextInt64() {
-    int64_t a = nextInt32();
-    int64_t b = nextInt32();
+    uint64_t a = nextUInt32();
+    uint64_t b = nextUInt32();
     return (a << 32) | b;
 }
 
@@ -157,4 +154,4 @@ SecureRandom* SecureRandom::create() {
 #error Must implement SecureRandom for platform
 
 #endif
-}
+}  // namespace mongo

src/mongo/platform/random.h

@@ -40,20 +40,20 @@ class PseudoRandom {
      * @return a number between 0 and max
      */
     int32_t nextInt32(int32_t max) {
-        return nextInt32() % max;
+        return static_cast<uint32_t>(nextInt32()) % static_cast<uint32_t>(max);
     }
 
     /**
      * @return a number between 0 and max
      */
     int64_t nextInt64(int64_t max) {
-        return nextInt64() % max;
+        return static_cast<uint64_t>(nextInt64()) % static_cast<uint64_t>(max);
     }
 
     /**
      * @return a number between 0 and max
      *
-     * This makes PsuedoRandom instances passable as the third argument to std::random_shuffle
+     * This makes PseudoRandom instances passable as the third argument to std::random_shuffle
      */
     intptr_t operator()(intptr_t max) {
         if (sizeof(intptr_t) == 4)
@@ -62,10 +62,14 @@ class PseudoRandom {
     }
 
 private:
-    int32_t _x;
-    int32_t _y;
-    int32_t _z;
-    int32_t _w;
+    void _init(uint32_t seed);
+
+    uint32_t nextUInt32();
+
+    uint32_t _x;
+    uint32_t _y;
+    uint32_t _z;
+    uint32_t _w;
 };
 
 /**
@@ -81,4 +85,4 @@ class SecureRandom {
 
     static SecureRandom* create();
 };
-}
+}  // namespace mongo

src/mongo/platform/random_test.cpp

@@ -17,6 +17,7 @@
  */
 
 #include <set>
+#include <vector>
 
 #include "mongo/platform/random.h"
 
@@ -87,6 +88,73 @@ TEST(RandomTest, R2) {
 }
 
 
+TEST(RandomTest, NextInt32SanityCheck) {
+    // Generate 1000 int32s and assert that each bit is set between 40% and 60% of the time. This is
+    // a bare minimum sanity check, not an attempt to ensure quality random numbers.
+
+    PseudoRandom a(11);
+    std::vector<int32_t> nums;
+    for (int i = 0; i < 1000; i++) {
+        nums.push_back(a.nextInt32());
+    }
+
+    for (int bit = 0; bit < 32; bit++) {
+        int onesCount = 0;
+        for (size_t i = 0; i != nums.size(); ++i) {
+            int32_t num = nums[i];
+            bool isSet = (num >> bit) & 1;
+            if (isSet)
+                onesCount++;
+        }
+
+        if (onesCount < 400 || onesCount > 600)
+            FAIL() << "bit " << bit << " was set " << (onesCount / 10.) << "% of the time.";
+    }
+}
+
+TEST(RandomTest, NextInt64SanityCheck) {
+    // Generate 1000 int64s and assert that each bit is set between 40% and 60% of the time. This is
+    // a bare minimum sanity check, not an attempt to ensure quality random numbers.
+
+    PseudoRandom a(11);
+    std::vector<int64_t> nums;
+    for (int i = 0; i < 1000; i++) {
+        nums.push_back(a.nextInt64());
+    }
+
+    for (int bit = 0; bit < 64; bit++) {
+        int onesCount = 0;
+        for (size_t i = 0; i != nums.size(); ++i) {
+            int32_t num = nums[i];
+
+            bool isSet = (num >> bit) & 1;
+            if (isSet)
+                onesCount++;
+        }
+
+        if (onesCount < 400 || onesCount > 600)
+            FAIL() << "bit " << bit << " was set " << (onesCount / 10.) << "% of the time.";
+    }
+}
+
+TEST(RandomTest, NextInt32InRange) {
+    PseudoRandom a(11);
+    for (int i = 0; i < 1000; i++) {
+        int32_t res = a.nextInt32(10);
+        ASSERT_GE(res, 0);
+        ASSERT_LT(res, 10);
+    }
+}
+
+TEST(RandomTest, NextInt64InRange) {
+    PseudoRandom a(11);
+    for (int i = 0; i < 1000; i++) {
+        int32_t res = a.nextInt64(10);
+        ASSERT_GE(res, 0);
+        ASSERT_LT(res, 10);
+    }
+}
+
 TEST(RandomTest, Secure1) {
     SecureRandom* a = SecureRandom::create();
     SecureRandom* b = SecureRandom::create();