various improvements to the Synchronized tests

Summary:
Add a runParallel() helper function, to clean up logic that was copy-and-pasted
through most of the test functions.  Additionally, clean up the tests to avoid
unnecessary sleeps.  Also fix backwards arguments to EXPECT_EQ() calls--gtest
assumes the first argument is the expected value, and the second argument is
the value being checked.

Reviewed By: yfeldblum

Differential Revision: D3521565

fbshipit-source-id: e4f007d52c114080cff1fd7a0a407fba39fa8b0e

folly/test/SynchronizedTest.cpp

@@ -27,7 +27,7 @@
 #include <folly/test/SynchronizedTestLib.h>
 #include <gtest/gtest.h>
 
-namespace {
+using namespace folly::sync_tests;
 
 template <class Mutex>
 class SynchronizedTest : public testing::Test {};
@@ -224,4 +224,3 @@ TEST_F(SynchronizedLockTest, NestedSyncUnSync2) {
   }
   EXPECT_EQ((CountPair{4, 4}), FakeMutex::getLockUnlockCount());
 }
-}

folly/test/SynchronizedTestLib.h

@@ -28,21 +28,17 @@
 //
 // ... similar for testConcurrency, testDualLocking, etc.
 
-
+namespace folly {
+namespace sync_tests {
 template <class Mutex> void testBasic();
-
 template <class Mutex> void testConcurrency();
-
 template <class Mutex> void testDualLocking();
-
 template <class Mutex> void testDualLockingWithConst();
-
 template <class Mutex> void testTimedSynchronized();
-
 template <class Mutex> void testTimedSynchronizedWithConst();
-
 template <class Mutex> void testConstCopy();
-
 template <class Mutex> void testInPlaceConstruction();
+}
+}
 
 #include <folly/test/SynchronizedTestLib-inl.h>