Mojo: Base our epsilon timeouts off of TestTimeouts::tiny_timeout().

mojo/system/simple_dispatcher_unittest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // NOTE(vtl): Some of these tests are inherently flaky (e.g., if run on a
-// heavily-loaded system). Sorry. |kEpsilonMicros| may be increased to increase
-// tolerance and reduce observed flakiness.
+// heavily-loaded system). Sorry. |test::EpsilonTimeout()| may be increased to
+// increase tolerance and reduce observed flakiness (though doing so reduces the
+// meaningfulness of the test).
 
 #include "mojo/system/simple_dispatcher.h"
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_vector.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/platform_thread.h"  // For |Sleep()|.
 #include "base/time/time.h"
 #include "mojo/system/test_utils.h"
 #include "mojo/system/waiter.h"
 #include "mojo/system/waiter_test_utils.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace mojo {
 namespace system {
 namespace {
 
-const int64_t kMicrosPerMs = 1000;
-const int64_t kEpsilonMicros = 30 * kMicrosPerMs;  // 30 ms.
-
 class MockSimpleDispatcher : public SimpleDispatcher {
  public:
   MockSimpleDispatcher()
       : satisfied_flags_(MOJO_WAIT_FLAG_NONE),
         satisfiable_flags_(MOJO_WAIT_FLAG_READABLE | MOJO_WAIT_FLAG_WRITABLE) {}
 
   void SetSatisfiedFlags(MojoWaitFlags new_satisfied_flags) {
     base::AutoLock locker(lock());
 
     // Any new flags that are set should be satisfiable.
@@ skipping 46 matching lines @@
 
   // Protected by |lock()|:
   MojoWaitFlags satisfied_flags_;
   MojoWaitFlags satisfiable_flags_;
 
   DISALLOW_COPY_AND_ASSIGN(MockSimpleDispatcher);
 };
 
 TEST(SimpleDispatcherTest, Basic) {
   test::Stopwatch stopwatch;
-  int64_t elapsed_micros;
 
   scoped_refptr<MockSimpleDispatcher> d(new MockSimpleDispatcher());
   Waiter w;
 
   // Try adding a readable waiter when already readable.
   w.Init();
   d->SetSatisfiedFlags(MOJO_WAIT_FLAG_READABLE);
   EXPECT_EQ(MOJO_RESULT_ALREADY_EXISTS,
             d->AddWaiter(&w, MOJO_WAIT_FLAG_READABLE, 0));
   // Shouldn't need to remove the waiter (it was not added).
 
   // Wait (forever) for writable when already writable.
   w.Init();
   d->SetSatisfiedFlags(MOJO_WAIT_FLAG_READABLE);
   EXPECT_EQ(MOJO_RESULT_OK, d->AddWaiter(&w, MOJO_WAIT_FLAG_WRITABLE, 1));
   d->SetSatisfiedFlags(MOJO_WAIT_FLAG_WRITABLE);
   stopwatch.Start();
   EXPECT_EQ(1, w.Wait(MOJO_DEADLINE_INDEFINITE));
-  elapsed_micros = stopwatch.Elapsed();
-  EXPECT_LT(elapsed_micros, kEpsilonMicros);
+  EXPECT_LT(stopwatch.Elapsed(), test::EpsilonTimeout());
   d->RemoveWaiter(&w);
 
   // Wait for zero time for writable when already writable.
   w.Init();
   d->SetSatisfiedFlags(MOJO_WAIT_FLAG_READABLE);
   EXPECT_EQ(MOJO_RESULT_OK, d->AddWaiter(&w, MOJO_WAIT_FLAG_WRITABLE, 2));
   d->SetSatisfiedFlags(MOJO_WAIT_FLAG_WRITABLE);
   stopwatch.Start();
   EXPECT_EQ(2, w.Wait(0));
-  elapsed_micros = stopwatch.Elapsed();
-  EXPECT_LT(elapsed_micros, kEpsilonMicros);
+  EXPECT_LT(stopwatch.Elapsed(), test::EpsilonTimeout());
   d->RemoveWaiter(&w);
 
   // Wait for non-zero, finite time for writable when already writable.
   w.Init();
   d->SetSatisfiedFlags(MOJO_WAIT_FLAG_READABLE);
   EXPECT_EQ(MOJO_RESULT_OK, d->AddWaiter(&w, MOJO_WAIT_FLAG_WRITABLE, 3));
   d->SetSatisfiedFlags(MOJO_WAIT_FLAG_WRITABLE);
   stopwatch.Start();
-  EXPECT_EQ(3, w.Wait(2 * kEpsilonMicros));
-  elapsed_micros = stopwatch.Elapsed();
-  EXPECT_LT(elapsed_micros, kEpsilonMicros);
+  EXPECT_EQ(3, w.Wait(2 * test::EpsilonTimeout().InMicroseconds()));
+  EXPECT_LT(stopwatch.Elapsed(), test::EpsilonTimeout());
   d->RemoveWaiter(&w);
 
   // Wait for zero time for writable when not writable (will time out).
   w.Init();
   d->SetSatisfiedFlags(MOJO_WAIT_FLAG_READABLE);
   EXPECT_EQ(MOJO_RESULT_OK, d->AddWaiter(&w, MOJO_WAIT_FLAG_WRITABLE, 4));
   stopwatch.Start();
   EXPECT_EQ(MOJO_RESULT_DEADLINE_EXCEEDED, w.Wait(0));
-  elapsed_micros = stopwatch.Elapsed();
-  EXPECT_LT(elapsed_micros, kEpsilonMicros);
+  EXPECT_LT(stopwatch.Elapsed(), test::EpsilonTimeout());
   d->RemoveWaiter(&w);
 
   // Wait for non-zero, finite time for writable when not writable (will time
   // out).
   w.Init();
   d->SetSatisfiedFlags(MOJO_WAIT_FLAG_READABLE);
   EXPECT_EQ(MOJO_RESULT_OK, d->AddWaiter(&w, MOJO_WAIT_FLAG_WRITABLE, 4));
   stopwatch.Start();
-  EXPECT_EQ(MOJO_RESULT_DEADLINE_EXCEEDED, w.Wait(2 * kEpsilonMicros));
-  elapsed_micros = stopwatch.Elapsed();
-  EXPECT_GT(elapsed_micros, (2-1) * kEpsilonMicros);
-  EXPECT_LT(elapsed_micros, (2+1) * kEpsilonMicros);
+  EXPECT_EQ(MOJO_RESULT_DEADLINE_EXCEEDED,
+            w.Wait(2 * test::EpsilonTimeout().InMicroseconds()));
+  base::TimeDelta elapsed = stopwatch.Elapsed();
+  EXPECT_GT(elapsed, (2-1) * test::EpsilonTimeout());
+  EXPECT_LT(elapsed, (2+1) * test::EpsilonTimeout());
   d->RemoveWaiter(&w);
 
   EXPECT_EQ(MOJO_RESULT_OK, d->Close());
 }
 
 TEST(SimpleDispatcherTest, BasicUnsatisfiable) {
   test::Stopwatch stopwatch;
-  int64_t elapsed_micros;
 
   scoped_refptr<MockSimpleDispatcher> d(new MockSimpleDispatcher());
   Waiter w;
 
   // Try adding a writable waiter when it can never be writable.
   w.Init();
   d->SetSatisfiableFlags(MOJO_WAIT_FLAG_READABLE);
   d->SetSatisfiedFlags(0);
   EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION,
             d->AddWaiter(&w, MOJO_WAIT_FLAG_WRITABLE, 5));
   // Shouldn't need to remove the waiter (it was not added).
 
   // Wait (forever) for writable and then it becomes never writable.
   w.Init();
   d->SetSatisfiableFlags(MOJO_WAIT_FLAG_READABLE | MOJO_WAIT_FLAG_WRITABLE);
   EXPECT_EQ(MOJO_RESULT_OK, d->AddWaiter(&w, MOJO_WAIT_FLAG_WRITABLE, 6));
   d->SetSatisfiableFlags(MOJO_WAIT_FLAG_READABLE);
   stopwatch.Start();
   EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION, w.Wait(MOJO_DEADLINE_INDEFINITE));
-  elapsed_micros = stopwatch.Elapsed();
-  EXPECT_LT(elapsed_micros, kEpsilonMicros);
+  EXPECT_LT(stopwatch.Elapsed(), test::EpsilonTimeout());
   d->RemoveWaiter(&w);
 
   // Wait for zero time for writable and then it becomes never writable.
   w.Init();
   d->SetSatisfiableFlags(MOJO_WAIT_FLAG_READABLE | MOJO_WAIT_FLAG_WRITABLE);
   EXPECT_EQ(MOJO_RESULT_OK, d->AddWaiter(&w, MOJO_WAIT_FLAG_WRITABLE, 6));
   d->SetSatisfiableFlags(MOJO_WAIT_FLAG_READABLE);
   stopwatch.Start();
   EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION, w.Wait(0));
-  elapsed_micros = stopwatch.Elapsed();
-  EXPECT_LT(elapsed_micros, kEpsilonMicros);
+  EXPECT_LT(stopwatch.Elapsed(), test::EpsilonTimeout());
   d->RemoveWaiter(&w);
 
   // Wait for non-zero, finite time for writable and then it becomes never
   // writable.
   w.Init();
   d->SetSatisfiableFlags(MOJO_WAIT_FLAG_READABLE | MOJO_WAIT_FLAG_WRITABLE);
   EXPECT_EQ(MOJO_RESULT_OK, d->AddWaiter(&w, MOJO_WAIT_FLAG_WRITABLE, 7));
   d->SetSatisfiableFlags(MOJO_WAIT_FLAG_READABLE);
   stopwatch.Start();
-  EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION, w.Wait(2 * kEpsilonMicros));
-  elapsed_micros = stopwatch.Elapsed();
-  EXPECT_LT(elapsed_micros, kEpsilonMicros);
+  EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION,
+            w.Wait(2 * test::EpsilonTimeout().InMicroseconds()));
+  EXPECT_LT(stopwatch.Elapsed(), test::EpsilonTimeout());
   d->RemoveWaiter(&w);
 
   EXPECT_EQ(MOJO_RESULT_OK, d->Close());
 }
 
 TEST(SimpleDispatcherTest, BasicClosed) {
   test::Stopwatch stopwatch;
-  int64_t elapsed_micros;
 
   scoped_refptr<MockSimpleDispatcher> d;
   Waiter w;
 
   // Try adding a writable waiter when the dispatcher has been closed.
   d = new MockSimpleDispatcher();
   w.Init();
   EXPECT_EQ(MOJO_RESULT_OK, d->Close());
   EXPECT_EQ(MOJO_RESULT_INVALID_ARGUMENT,
             d->AddWaiter(&w, MOJO_WAIT_FLAG_WRITABLE, 8));
   // Shouldn't need to remove the waiter (it was not added).
 
   // Wait (forever) for writable and then the dispatcher is closed.
   d = new MockSimpleDispatcher();
   w.Init();
   EXPECT_EQ(MOJO_RESULT_OK, d->AddWaiter(&w, MOJO_WAIT_FLAG_WRITABLE, 9));
   EXPECT_EQ(MOJO_RESULT_OK, d->Close());
   stopwatch.Start();
   EXPECT_EQ(MOJO_RESULT_CANCELLED, w.Wait(MOJO_DEADLINE_INDEFINITE));
-  elapsed_micros = stopwatch.Elapsed();
-  EXPECT_LT(elapsed_micros, kEpsilonMicros);
+  EXPECT_LT(stopwatch.Elapsed(), test::EpsilonTimeout());
   // Don't need to remove waiters from closed dispatchers.
 
   // Wait for zero time for writable and then the dispatcher is closed.
   d = new MockSimpleDispatcher();
   w.Init();
   EXPECT_EQ(MOJO_RESULT_OK, d->AddWaiter(&w, MOJO_WAIT_FLAG_WRITABLE, 10));
   EXPECT_EQ(MOJO_RESULT_OK, d->Close());
   stopwatch.Start();
   EXPECT_EQ(MOJO_RESULT_CANCELLED, w.Wait(0));
-  elapsed_micros = stopwatch.Elapsed();
-  EXPECT_LT(elapsed_micros, kEpsilonMicros);
+  EXPECT_LT(stopwatch.Elapsed(), test::EpsilonTimeout());
   // Don't need to remove waiters from closed dispatchers.
 
   // Wait for non-zero, finite time for writable and then the dispatcher is
   // closed.
   d = new MockSimpleDispatcher();
   w.Init();
   EXPECT_EQ(MOJO_RESULT_OK, d->AddWaiter(&w, MOJO_WAIT_FLAG_WRITABLE, 11));
   EXPECT_EQ(MOJO_RESULT_OK, d->Close());
   stopwatch.Start();
-  EXPECT_EQ(MOJO_RESULT_CANCELLED, w.Wait(2 * kEpsilonMicros));
-  elapsed_micros = stopwatch.Elapsed();
-  EXPECT_LT(elapsed_micros, kEpsilonMicros);
+  EXPECT_EQ(MOJO_RESULT_CANCELLED,
+            w.Wait(2 * test::EpsilonTimeout().InMicroseconds()));
+  EXPECT_LT(stopwatch.Elapsed(), test::EpsilonTimeout());
   // Don't need to remove waiters from closed dispatchers.
 }
 
 TEST(SimpleDispatcherTest, BasicThreaded) {
   test::Stopwatch stopwatch;
   bool did_wait;
   MojoResult result;
-  int64_t elapsed_micros;
 
   // Wait for readable (already readable).
   {
     scoped_refptr<MockSimpleDispatcher> d(new MockSimpleDispatcher());
     {
       d->SetSatisfiedFlags(MOJO_WAIT_FLAG_READABLE);
       test::WaiterThread thread(d,
                                 MOJO_WAIT_FLAG_READABLE,
                                 MOJO_DEADLINE_INDEFINITE,
                                 0,
                                 &did_wait, &result);
       stopwatch.Start();
       thread.Start();
     }  // Joins the thread.
     // If we closed earlier, then probably we'd get a |MOJO_RESULT_CANCELLED|.
     EXPECT_EQ(MOJO_RESULT_OK, d->Close());
   }
-  elapsed_micros = stopwatch.Elapsed();
+  EXPECT_LT(stopwatch.Elapsed(), test::EpsilonTimeout());
   EXPECT_FALSE(did_wait);
   EXPECT_EQ(MOJO_RESULT_ALREADY_EXISTS, result);
-  EXPECT_LT(elapsed_micros, kEpsilonMicros);
 
   // Wait for readable and becomes readable after some time.
   {
     scoped_refptr<MockSimpleDispatcher> d(new MockSimpleDispatcher());
     test::WaiterThread thread(d,
                               MOJO_WAIT_FLAG_READABLE,
                               MOJO_DEADLINE_INDEFINITE,
                               1,
                               &did_wait, &result);
     stopwatch.Start();
     thread.Start();
-    base::PlatformThread::Sleep(
-        base::TimeDelta::FromMicroseconds(2 * kEpsilonMicros));
+    base::PlatformThread::Sleep(2 * test::EpsilonTimeout());
     d->SetSatisfiedFlags(MOJO_WAIT_FLAG_READABLE);
     EXPECT_EQ(MOJO_RESULT_OK, d->Close());
   }  // Joins the thread.
-  elapsed_micros = stopwatch.Elapsed();
+  base::TimeDelta elapsed = stopwatch.Elapsed();
+  EXPECT_GT(elapsed, (2-1) * test::EpsilonTimeout());
+  EXPECT_LT(elapsed, (2+1) * test::EpsilonTimeout());
   EXPECT_TRUE(did_wait);
   EXPECT_EQ(1, result);
-  EXPECT_GT(elapsed_micros, (2-1) * kEpsilonMicros);
-  EXPECT_LT(elapsed_micros, (2+1) * kEpsilonMicros);
 
   // Wait for readable and becomes never-readable after some time.
   {
     scoped_refptr<MockSimpleDispatcher> d(new MockSimpleDispatcher());
     test::WaiterThread thread(d,
                               MOJO_WAIT_FLAG_READABLE,
                               MOJO_DEADLINE_INDEFINITE,
                               2,
                               &did_wait, &result);
     stopwatch.Start();
     thread.Start();
-    base::PlatformThread::Sleep(
-        base::TimeDelta::FromMicroseconds(2 * kEpsilonMicros));
+    base::PlatformThread::Sleep(2 * test::EpsilonTimeout());
     d->SetSatisfiableFlags(MOJO_WAIT_FLAG_NONE);
     EXPECT_EQ(MOJO_RESULT_OK, d->Close());
   }  // Joins the thread.
-  elapsed_micros = stopwatch.Elapsed();
+  elapsed = stopwatch.Elapsed();
+  EXPECT_GT(elapsed, (2-1) * test::EpsilonTimeout());
+  EXPECT_LT(elapsed, (2+1) * test::EpsilonTimeout());
   EXPECT_TRUE(did_wait);
   EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION, result);
-  EXPECT_GT(elapsed_micros, (2-1) * kEpsilonMicros);
-  EXPECT_LT(elapsed_micros, (2+1) * kEpsilonMicros);
 
   // Wait for readable and dispatcher gets closed.
   {
     scoped_refptr<MockSimpleDispatcher> d(new MockSimpleDispatcher());
     test::WaiterThread thread(d,
                               MOJO_WAIT_FLAG_READABLE,
                               MOJO_DEADLINE_INDEFINITE,
                               3,
                               &did_wait, &result);
     stopwatch.Start();
     thread.Start();
-    base::PlatformThread::Sleep(
-        base::TimeDelta::FromMicroseconds(2 * kEpsilonMicros));
+    base::PlatformThread::Sleep(2 * test::EpsilonTimeout());
     EXPECT_EQ(MOJO_RESULT_OK, d->Close());
   }  // Joins the thread.
-  elapsed_micros = stopwatch.Elapsed();
+  elapsed = stopwatch.Elapsed();
+  EXPECT_GT(elapsed, (2-1) * test::EpsilonTimeout());
+  EXPECT_LT(elapsed, (2+1) * test::EpsilonTimeout());
   EXPECT_TRUE(did_wait);
   EXPECT_EQ(MOJO_RESULT_CANCELLED, result);
-  EXPECT_GT(elapsed_micros, (2-1) * kEpsilonMicros);
-  EXPECT_LT(elapsed_micros, (2+1) * kEpsilonMicros);
 
   // Wait for readable and times out.
   {
     scoped_refptr<MockSimpleDispatcher> d(new MockSimpleDispatcher());
     {
       test::WaiterThread thread(d,
                                 MOJO_WAIT_FLAG_READABLE,
-                                2 * kEpsilonMicros,
+                                2 * test::EpsilonTimeout().InMicroseconds(),
                                 4,
                                 &did_wait, &result);
       stopwatch.Start();
       thread.Start();
-      base::PlatformThread::Sleep(
-          base::TimeDelta::FromMicroseconds(1 * kEpsilonMicros));
+      base::PlatformThread::Sleep(1 * test::EpsilonTimeout());
       // Not what we're waiting for.
       d->SetSatisfiedFlags(MOJO_WAIT_FLAG_WRITABLE);
     }  // Joins the thread (after its wait times out).
     // If we closed earlier, then probably we'd get a |MOJO_RESULT_CANCELLED|.
     EXPECT_EQ(MOJO_RESULT_OK, d->Close());
   }
-  elapsed_micros = stopwatch.Elapsed();
+  elapsed = stopwatch.Elapsed();
+  EXPECT_GT(elapsed, (2-1) * test::EpsilonTimeout());
+  EXPECT_LT(elapsed, (2+1) * test::EpsilonTimeout());
   EXPECT_TRUE(did_wait);
   EXPECT_EQ(MOJO_RESULT_DEADLINE_EXCEEDED, result);
-  EXPECT_GT(elapsed_micros, (2-1) * kEpsilonMicros);
-  EXPECT_LT(elapsed_micros, (2+1) * kEpsilonMicros);
 }
 
 TEST(SimpleDispatcherTest, MultipleWaiters) {
   static const size_t kNumWaiters = 20;
 
   bool did_wait[kNumWaiters];
   MojoResult result[kNumWaiters];
 
   // All wait for readable and becomes readable after some time.
   {
     scoped_refptr<MockSimpleDispatcher> d(new MockSimpleDispatcher());
     ScopedVector<test::WaiterThread> threads;
     for (size_t i = 0; i < kNumWaiters; i++) {
       threads.push_back(new test::WaiterThread(d,
                                                MOJO_WAIT_FLAG_READABLE,
                                                MOJO_DEADLINE_INDEFINITE,
                                                static_cast<MojoResult>(i),
                                                &did_wait[i], &result[i]));
       threads.back()->Start();
     }
-    base::PlatformThread::Sleep(
-        base::TimeDelta::FromMicroseconds(2 * kEpsilonMicros));
+    base::PlatformThread::Sleep(2 * test::EpsilonTimeout());
     d->SetSatisfiedFlags(MOJO_WAIT_FLAG_READABLE);
     EXPECT_EQ(MOJO_RESULT_OK, d->Close());
   }  // Joins the threads.
   for (size_t i = 0; i < kNumWaiters; i++) {
     EXPECT_TRUE(did_wait[i]);
     EXPECT_EQ(static_cast<MojoResult>(i), result[i]);
   }
 
   // Some wait for readable, some for writable, and becomes readable after some
   // time.
   {
     scoped_refptr<MockSimpleDispatcher> d(new MockSimpleDispatcher());
     ScopedVector<test::WaiterThread> threads;
     for (size_t i = 0; i < kNumWaiters / 2; i++) {
       threads.push_back(new test::WaiterThread(d,
                                                MOJO_WAIT_FLAG_READABLE,
                                                MOJO_DEADLINE_INDEFINITE,
                                                static_cast<MojoResult>(i),
                                                &did_wait[i], &result[i]));
       threads.back()->Start();
     }
     for (size_t i = kNumWaiters / 2; i < kNumWaiters; i++) {
       threads.push_back(new test::WaiterThread(d,
                                                MOJO_WAIT_FLAG_WRITABLE,
                                                MOJO_DEADLINE_INDEFINITE,
                                                static_cast<MojoResult>(i),
                                                &did_wait[i], &result[i]));
       threads.back()->Start();
     }
-    base::PlatformThread::Sleep(
-        base::TimeDelta::FromMicroseconds(2 * kEpsilonMicros));
+    base::PlatformThread::Sleep(2 * test::EpsilonTimeout());
     d->SetSatisfiedFlags(MOJO_WAIT_FLAG_READABLE);
     // This will wake up the ones waiting to write.
     EXPECT_EQ(MOJO_RESULT_OK, d->Close());
   }  // Joins the threads.
   for (size_t i = 0; i < kNumWaiters / 2; i++) {
     EXPECT_TRUE(did_wait[i]);
     EXPECT_EQ(static_cast<MojoResult>(i), result[i]);
   }
   for (size_t i = kNumWaiters / 2; i < kNumWaiters; i++) {
     EXPECT_TRUE(did_wait[i]);
@@ skipping 14 matching lines @@
       threads.back()->Start();
     }
     for (size_t i = kNumWaiters / 2; i < kNumWaiters; i++) {
       threads.push_back(new test::WaiterThread(d,
                                                MOJO_WAIT_FLAG_WRITABLE,
                                                MOJO_DEADLINE_INDEFINITE,
                                                static_cast<MojoResult>(i),
                                                &did_wait[i], &result[i]));
       threads.back()->Start();
     }
-    base::PlatformThread::Sleep(
-        base::TimeDelta::FromMicroseconds(1 * kEpsilonMicros));
+    base::PlatformThread::Sleep(1 * test::EpsilonTimeout());
     d->SetSatisfiableFlags(MOJO_WAIT_FLAG_READABLE);
-    base::PlatformThread::Sleep(
-        base::TimeDelta::FromMicroseconds(1 * kEpsilonMicros));
+    base::PlatformThread::Sleep(1 * test::EpsilonTimeout());
     d->SetSatisfiedFlags(MOJO_WAIT_FLAG_READABLE);
     EXPECT_EQ(MOJO_RESULT_OK, d->Close());
   }  // Joins the threads.
   for (size_t i = 0; i < kNumWaiters / 2; i++) {
     EXPECT_TRUE(did_wait[i]);
     EXPECT_EQ(static_cast<MojoResult>(i), result[i]);
   }
   for (size_t i = kNumWaiters / 2; i < kNumWaiters; i++) {
     EXPECT_TRUE(did_wait[i]);
     EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION, result[i]);
   }
 
   // Some wait for readable, some for writable, and becomes readable after some
   // time.
   {
     scoped_refptr<MockSimpleDispatcher> d(new MockSimpleDispatcher());
     ScopedVector<test::WaiterThread> threads;
     for (size_t i = 0; i < kNumWaiters / 2; i++) {
-      threads.push_back(new test::WaiterThread(d,
-                                               MOJO_WAIT_FLAG_READABLE,
-                                               3 * kEpsilonMicros,
-                                               static_cast<MojoResult>(i),
-                                               &did_wait[i], &result[i]));
+      threads.push_back(
+          new test::WaiterThread(d,
+                                 MOJO_WAIT_FLAG_READABLE,
+                                 3 * test::EpsilonTimeout().InMicroseconds(),
+                                 static_cast<MojoResult>(i),
+                                 &did_wait[i], &result[i]));
       threads.back()->Start();
     }
     for (size_t i = kNumWaiters / 2; i < kNumWaiters; i++) {
-      threads.push_back(new test::WaiterThread(d,
-                                               MOJO_WAIT_FLAG_WRITABLE,
-                                               1 * kEpsilonMicros,
-                                               static_cast<MojoResult>(i),
-                                               &did_wait[i], &result[i]));
+      threads.push_back(
+          new test::WaiterThread(d,
+                                 MOJO_WAIT_FLAG_WRITABLE,
+                                 1 * test::EpsilonTimeout().InMicroseconds(),
+                                 static_cast<MojoResult>(i),
+                                 &did_wait[i], &result[i]));
       threads.back()->Start();
     }
-    base::PlatformThread::Sleep(
-        base::TimeDelta::FromMicroseconds(2 * kEpsilonMicros));
+    base::PlatformThread::Sleep(2 * test::EpsilonTimeout());
     d->SetSatisfiedFlags(MOJO_WAIT_FLAG_READABLE);
     // All those waiting for writable should have timed out.
     EXPECT_EQ(MOJO_RESULT_OK, d->Close());
   }  // Joins the threads.
   for (size_t i = 0; i < kNumWaiters / 2; i++) {
     EXPECT_TRUE(did_wait[i]);
     EXPECT_EQ(static_cast<MojoResult>(i), result[i]);
   }
   for (size_t i = kNumWaiters / 2; i < kNumWaiters; i++) {
     EXPECT_TRUE(did_wait[i]);
     EXPECT_EQ(MOJO_RESULT_DEADLINE_EXCEEDED, result[i]);
   }
 }
 
 // TODO(vtl): Stress test?
 
 }  // namespace
 }  // namespace system
 }  // namespace mojo