Issue #4692, #3595 - Stop sleeping in the implementation of `SetTimeout`

test/TimeoutTest.cpp

Index: test/TimeoutTest.cpp
===================================================================
new file mode 100644
--- /dev/null
+++ b/test/TimeoutTest.cpp
@@ -0,0 +1,220 @@
+/*
+ * This file is part of Adblock Plus <https://adblockplus.org/>,
+ * Copyright (C) 2006-2017 Eyeo GmbH
+ *
+ * Adblock Plus is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Adblock Plus is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "../src/Timeout.h"
+#include "BaseJsTest.h"
+#include "PausePoint.h"
+#include <thread>
+
+TEST(Timeout, Instance)
+{
+  DelayedExecutor x([]() {});
+}
+
+TEST(Timeout, ConstructorBodyMayNotBeNull)
+{
+  auto nullBody = std::function<void()>();
+  ASSERT_ANY_THROW({ DelayedExecutor x(nullBody); });
+}
+
+TEST(Timeout, ImmediateRunSimple)
+{
+  int count = 0;
+  DelayedExecutor x([&]() { ++count; });
+  x.RunImmediately();
+  EXPECT_EQ(1, count);
+}
+
+TEST(Timeout, DelayedRunSimple)
+{
+  int count = 0;
+  DelayedExecutor x([&]() { ++count; });
+  x.RunWithDelay(std::chrono::milliseconds(1));
+  EXPECT_EQ(1, count);
+}
+
+/**
+ * Test class exposes each aspect point in the constructor.
+ */
+class DelayedExecutorTestAspect
+  : public AspectBase<DelayedExecutorTestAspect>
+{
+  std::function<void()> runnableToSleeping;
+  std::function<void()> runFinish;
+
+public:
+  template<class LockType>
+  void RunnableToSleeping(LockType& lock)
+  {
+    AntiLock<LockType> x(lock);
+    runnableToSleeping();
+  };
+
+  void RunFinish()
+  {
+    runFinish();
+  }
+
+  DelayedExecutorTestAspect(std::function<void()> runnableToSleeping,
+    std::function<void()> runFinish)
+    : runnableToSleeping(runnableToSleeping),
+    runFinish(runFinish)
+  {}
+};
+
+class DelayedExecutorForTesting
+  : public DelayedExecutorAspected<DelayedExecutorTestAspect>
+{
+public:
+  typedef DelayedExecutorAspected<DelayedExecutorTestAspect> Base;
+  DelayedExecutorForTesting(std::function<void()> body, 
+    std::function<void()> runnableToSleeping,
+    std::function<void()> runFinish)
+    : Base(DelayedExecutorTestAspect(runnableToSleeping, runFinish), body)
+  {}
+};
+
+/**
+ * Exercises an ordinary sequence for RunWithDelay().
+ * This version tracks the sequence through test aspect points.
+ */
+TEST(Timeout, DelayedRunAspected)
+{
+  int sequence = 0;
+  auto body = [&]()
+  {
+    ASSERT_EQ(1, sequence);
+    sequence = 2;
+  };
+  auto runnableToSleeping = [&]()
+  {
+    ASSERT_EQ(0, sequence);
+    sequence = 1;
+  };
+  auto runFinish = [&]()
+  {
+    ASSERT_EQ(2, sequence);
+    sequence = 3;
+  };
+
+  DelayedExecutorForTesting x(body, runnableToSleeping, runFinish);
+  ASSERT_EQ(0, sequence);
+  x.RunWithDelay(std::chrono::milliseconds(1));
+  ASSERT_EQ(3, sequence);
+}
+
+/**
+ * Exercises an ordinary sequence for RunWithDelay().
+ * This version is in a separate thread.
+ */
+TEST(Timeout, DelayedRunAspectedThreaded)
+{
+  PausePoint pp;
+  int sequence = 0;
+  auto body = [&]()
+  {
+    sequence = 3; 
+    pp.Pause();
+  };
+  auto runnableToSleeping = [&]()
+  {
+    sequence = 2;
+    pp.Pause();
+  };
+  auto runFinish = [&]()
+  {
+    sequence = 4;
+    pp.Pause();
+  };
+  
+  std::thread th([&]()
+  {
+    DelayedExecutorForTesting x(body, runnableToSleeping, runFinish);
+    sequence = 1;
+    pp.Pause();
+    x.RunWithDelay(std::chrono::milliseconds(1));
+    sequence = 5;
+    pp.Pause();
+    sequence = 6;
+  });
+  for (int j = 1; j <= 5; ++j) {
+    pp.WaitUntilPaused();
+    ASSERT_EQ(j, sequence);
+    pp.Resume();
+  }
+  th.join();
+  ASSERT_EQ(6, sequence);
+}
+
+TEST(Timeout, DelayedRunInterrupted)
+{
+  PausePoint pp;
+  int sequence = 0;
+  auto body = [&]()
+  {
+    sequence = 3;
+    pp.Pause();
+  };
+  auto runnableToSleeping = [&]()
+  {
+    sequence = 2;
+    pp.Pause();
+  };
+  auto runFinish = [&]()
+  {
+    sequence = 4;
+    pp.Pause();
+  };
+
+  DelayedExecutorForTesting x(body, runnableToSleeping, runFinish);
+  ASSERT_EQ(0, sequence);
+  std::thread th([&]()
+  {
+    sequence = 1;
+    pp.Pause();
+    x.RunWithDelay(std::chrono::minutes(2)); // long delay to interrupt
+    sequence = 5;
+    pp.Pause();
+    sequence = 6;
+  });
+  pp.WaitUntilPaused();
+  ASSERT_EQ(1, sequence);
+  pp.Resume();
+  pp.WaitUntilPaused();
+  ASSERT_EQ(2, sequence);
+  /*
+   * We are at an aspect point where we're about to wait.
+   * We don't have the capability of interrupting the wait itself,
+   *   so we rely on a heuristic.
+   * We resume and sleep for a bit to give the scheduler a chance to wake up
+   *   the thread and for the condition variable to begin waiting.
+   * It's possible to get occasional failures with this algorithm.
+   */
+  pp.ResumeAndSleep(2);
+  // Assume the condition variable is waiting.
+  x.ForestallExecution();
+  // We skip sequence 3, where the body executes.
+  // We skip sequence 4, where DelayedExecutor changes state after execution
+  pp.WaitUntilPaused();
+  ASSERT_EQ(5, sequence);
+  pp.Resume();
+  th.join();
+  ASSERT_EQ(6, sequence);
+}
+
+
+