Merge pull request #31 from leapmotion/test-priorityboost

Moving another performance test over to the dedicated benchmarking project

src/autowiring/benchmark/CMakeLists.txt

@@ -4,6 +4,7 @@ endif()
 
 set(AutowiringBenchmarkTest_SRCS
   AutowiringBenchmarkTest.cpp
+  CanBoostPriorityTest.cpp
 )
 
 ADD_MSVC_PRECOMPILED_HEADER("stdafx.h" "stdafx.cpp" AutowiringBenchmarkTest_SRCS)

src/autowiring/benchmark/CanBoostPriorityTest.cpp

@@ -0,0 +1,82 @@
+#include "stdafx.h"
+#include <autowiring/CoreThread.h>
+
+class BoostPriorityTest:
+  public testing::Test
+{};
+
+template<ThreadPriority priority>
+class JustIncrementsANumber:
+  public CoreThread
+{
+public:
+  JustIncrementsANumber() :
+    val(0)
+  {}
+
+  volatile int64_t val;
+
+  // This will be a hotly contested conditional variable
+  AutoRequired<std::mutex> contended;
+
+  void Run(void) override {
+    ElevatePriority p(*this, priority);
+
+    while(!ShouldStop()) {
+      // Obtain the lock and then increment our value:
+      std::lock_guard<std::mutex> lk(*contended);
+      val++;
+    }
+  }
+};
+
+#ifdef _MSC_VER
+#include "windows.h"
+
+TEST_F(BoostPriorityTest, VerifyCanBoostPriority) {
+  AutoCurrentContext ctxt;
+
+  // Create two spinners and kick them off at the same time:
+  AutoRequired<JustIncrementsANumber<ThreadPriority::BelowNormal>> lower;
+  AutoRequired<JustIncrementsANumber<ThreadPriority::Normal>> higher;
+  ctxt->Initiate();
+
+  // We want all of our threads to run on ONE cpu for awhile, and then we want to put it back at exit
+  DWORD_PTR originalAffinity, systemAffinity;
+  GetProcessAffinityMask(GetCurrentProcess(), &originalAffinity, &systemAffinity);
+  SetProcessAffinityMask(GetCurrentProcess(), 1);
+  auto onreturn = MakeAtExit([originalAffinity] {
+    SetProcessAffinityMask(GetCurrentProcess(), originalAffinity);
+  });
+
+  // Poke the conditional variable a lot:
+  AutoRequired<std::mutex> contended;
+  for(size_t i = 100; i--;) {
+    // We sleep while holding contention lock to force waiting threads into the sleep queue.  The reason we have to do
+    // this is due to the way that mutex is implemented under the hood.  The STL mutex uses a high-frequency variable
+    // and attempts to perform a CAS (check-and-set) on this variable.  If it succeeds, the lock is obtained; if it
+    // fails, it will put the thread into a non-ready state by calling WaitForSingleObject on Windows or one of the
+    // mutex_lock methods on Unix.
+    //
+    // When a thread can't be run, it's moved from the OS's ready queue to the sleep queue.  The scheduler knows that
+    // the thread can be moved back to the ready queue if a particular object is signalled, but in the case of a lock,
+    // only one of the threads waiting on the object can actually be moved to the ready queue.  It's at THIS POINT that
+    // the operating system consults the thread priority--if only thread can be moved over, then the highest priority
+    // thread will wind up in the ready queue every time.
+    //
+    // Thread priority does _not_ necessarily influence the amount of time the scheduler allocates allocated to a ready
+    // thread with respect to other threads of the same process.  This is why we hold the lock for a full millisecond,
+    // in order to force the thread over to the sleep queue and ensure that the priority resolution mechanism is
+    // directly tested.
+    std::lock_guard<std::mutex> lk(*contended);
+    std::this_thread::sleep_for(std::chrono::milliseconds(1));
+  }
+
+  // Need to terminate before we try running a comparison.
+  ctxt->SignalTerminate();
+
+  ASSERT_LE(lower->val, higher->val) << "A lower-priority thread was moved out of the sleep queue more frequently than a high-priority thread";
+}
+#else
+#pragma message "Warning:  SetThreadPriority not implemented on Unix"
+#endif

src/autowiring/test/CoreThreadTest.cpp

@@ -363,31 +363,6 @@ TEST_F(CoreThreadTest, WaitBeforeInitiate) {
   ASSERT_TRUE(ctxt->Wait(std::chrono::seconds(0))) << "Failed to wait on a context which should have already been stopped";
 }
 
-template<ThreadPriority priority>
-class JustIncrementsANumber:
-  public CoreThread
-{
-public:
-  JustIncrementsANumber():
-    val(0)
-  {}
-
-  volatile int64_t val;
-
-  // This will be a hotly contested conditional variable
-  AutoRequired<std::mutex> contended;
-
-  void Run(void) override {
-    ElevatePriority p(*this, priority);
-
-    while(!ShouldStop()) {
-      // Obtain the lock and then increment our value:
-      std::lock_guard<std::mutex> lk(*contended);
-      val++;
-    }
-  }
-};
-
 TEST_F(CoreThreadTest, ReentrantStopOnTeardown) {
   AutoCurrentContext ctxt;
   std::shared_ptr<CoreThread> ct = AutoRequired<CoreThread>();
@@ -462,54 +437,3 @@ TEST_F(CoreThreadTest, PendAfterShutdown) {
   // Verify that the lambda was destroyed more or less right away
   ASSERT_TRUE(v.unique()) << "Shared pointer in a lambda closure appears to have been leaked";
 }
-
-#ifdef _MSC_VER
-#include "windows.h"
-
-TEST_F(CoreThreadTest, VerifyCanBoostPriority) {
-  AutoCurrentContext ctxt;
-
-  // Create two spinners and kick them off at the same time:
-  AutoRequired<JustIncrementsANumber<ThreadPriority::BelowNormal>> lower;
-  AutoRequired<JustIncrementsANumber<ThreadPriority::Normal>> higher;
-  ctxt->Initiate();
-
-  // We want all of our threads to run on ONE cpu for awhile, and then we want to put it back at exit
-  DWORD_PTR originalAffinity, systemAffinity;
-  GetProcessAffinityMask(GetCurrentProcess(), &originalAffinity, &systemAffinity);
-  SetProcessAffinityMask(GetCurrentProcess(), 1);
-  auto onreturn = MakeAtExit([originalAffinity] {
-    SetProcessAffinityMask(GetCurrentProcess(), originalAffinity);
-  });
-
-  // Poke the conditional variable a lot:
-  AutoRequired<std::mutex> contended;
-  for(size_t i = 100; i--;) {
-    // We sleep while holding contention lock to force waiting threads into the sleep queue.  The reason we have to do
-    // this is due to the way that mutex is implemented under the hood.  The STL mutex uses a high-frequency variable
-    // and attempts to perform a CAS (check-and-set) on this variable.  If it succeeds, the lock is obtained; if it
-    // fails, it will put the thread into a non-ready state by calling WaitForSingleObject on Windows or one of the
-    // mutex_lock methods on Unix.
-    //
-    // When a thread can't be run, it's moved from the OS's ready queue to the sleep queue.  The scheduler knows that
-    // the thread can be moved back to the ready queue if a particular object is signalled, but in the case of a lock,
-    // only one of the threads waiting on the object can actually be moved to the ready queue.  It's at THIS POINT that
-    // the operating system consults the thread priority--if only thread can be moved over, then the highest priority
-    // thread will wind up in the ready queue every time.
-    //
-    // Thread priority does _not_ necessarily influence the amount of time the scheduler allocates allocated to a ready
-    // thread with respect to other threads of the same process.  This is why we hold the lock for a full millisecond,
-    // in order to force the thread over to the sleep queue and ensure that the priority resolution mechanism is
-    // directly tested.
-    std::lock_guard<std::mutex> lk(*contended);
-    std::this_thread::sleep_for(std::chrono::milliseconds(1));
-  }
-
-  // Need to terminate before we try running a comparison.
-  ctxt->SignalTerminate();
-
-  ASSERT_LE(lower->val, higher->val) << "A lower-priority thread was moved out of the sleep queue more frequently than a high-priority thread";
-}
-#else
-#pragma message "Warning:  SetThreadPriority not implemented on Unix"
-#endif