base: Re-apply WeakPtr support for SequencedWorkerPools, fixing deadlock

base/sequence_checker_unittest.cc

Index: base/sequence_checker_unittest.cc
diff --git a/base/sequence_checker_unittest.cc b/base/sequence_checker_unittest.cc
index 4fc3027cf820f9563cd25e2c916fe0f65277c2c6..7df76149260a9ffd2bf23807f4c48d02b4389f8e 100644
--- a/base/sequence_checker_unittest.cc
+++ b/base/sequence_checker_unittest.cc
@@ -1,29 +1,339 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// 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.
 
-#include "base/sequence_checker.h"
-
-#include <cstddef>
-
-#include "base/compiler_specific.h"
+#include "base/basictypes.h"
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/location.h"
+#include "base/logging.h"
 #include "base/memory/ref_counted.h"
-#include "base/test/null_task_runner.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/message_loop/message_loop.h"
+#include "base/sequence_checker.h"
+#include "base/test/sequenced_worker_pool_owner.h"
+#include "base/threading/thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+// Duplicated from base/sequence_checker.h so that we can be good citizens
+// there and undef the macro.
+#if (!defined(NDEBUG) || defined(DCHECK_ALWAYS_ON))
+#define ENABLE_SEQUENCE_CHECKER 1
+#else
+#define ENABLE_SEQUENCE_CHECKER 0
+#endif
+
 namespace base {
 
 namespace {
 
-// Call various methods of SequenceChecker to make sure nothing blows
-// up in either debug or release mode.
-TEST(SequenceCheckerTest, Basic) {
-  SequenceChecker sequence_checker(new NullTaskRunner());
-  sequence_checker.CalledOnValidSequence();
-  sequence_checker.ChangeSequence(NULL);
-  sequence_checker.CalledOnValidSequence();
+const size_t kNumWorkerThreads = 3;
+
+// Simple class to exercise the basics of SequenceChecker.
+// DoStuff should verify that it's called on a valid sequenced thread.
+// SequenceCheckedObject can be destroyed on any thread (like WeakPtr).
+class SequenceCheckedObject {
+ public:
+  SequenceCheckedObject() {}
+  ~SequenceCheckedObject() {}
+
+  // Verifies that it was called on the same thread as the constructor.
+  void DoStuff() {
+    DCHECK(sequence_checker_.CalledOnValidSequencedThread());
+  }
+
+  void DetachFromSequence() {
+    sequence_checker_.DetachFromSequence();
+  }
+
+ private:
+  SequenceChecker sequence_checker_;
+
+  DISALLOW_COPY_AND_ASSIGN(SequenceCheckedObject);
+};
+
+class SequenceCheckerTest : public testing::Test {
+ public:
+  SequenceCheckerTest() : other_thread_("sequence_checker_test_other_thread") {}
+
+  virtual ~SequenceCheckerTest() {}
+
+  virtual void SetUp() OVERRIDE {
+    other_thread_.Start();
+    ResetPool();
+  }
+
+  virtual void TearDown() OVERRIDE {
+    other_thread_.Stop();
+    pool()->Shutdown();
+  }
+
+ protected:
+  base::Thread* other_thread() { return &other_thread_; }
+
+  const scoped_refptr<SequencedWorkerPool>& pool() {
+    return pool_owner_->pool();
+  }
+
+  void PostDoStuffToWorkerPool(SequenceCheckedObject* sequence_checked_object,
+                               const std::string& token_name) {
+    pool()->PostNamedSequencedWorkerTask(
+        token_name,
+        FROM_HERE,
+        base::Bind(&SequenceCheckedObject::DoStuff,
+                   base::Unretained(sequence_checked_object)));
+  }
+
+  void PostDoStuffToOtherThread(
+      SequenceCheckedObject* sequence_checked_object) {
+    other_thread()->message_loop()->PostTask(
+        FROM_HERE,
+        base::Bind(&SequenceCheckedObject::DoStuff,
+                   base::Unretained(sequence_checked_object)));
+  }
+
+  void PostDeleteToOtherThread(
+      scoped_ptr<SequenceCheckedObject> sequence_checked_object) {
+    other_thread()->message_loop()->DeleteSoon(
+        FROM_HERE,
+        sequence_checked_object.release());
+  }
+
+  // Destroys the SequencedWorkerPool instance, blocking until it is fully shut
+  // down, and creates a new instance.
+  void ResetPool() {
+    pool_owner_.reset(new SequencedWorkerPoolOwner(kNumWorkerThreads, "test"));
+  }
+
+  void MethodOnDifferentThreadDeathTest();
+  void DetachThenCallFromDifferentThreadDeathTest();
+  void DifferentSequenceTokensDeathTest();
+  void WorkerPoolAndSimpleThreadDeathTest();
+  void TwoDifferentWorkerPoolsDeathTest();
+
+ private:
+  MessageLoop message_loop_;  // Needed by SequencedWorkerPool to function.
+  base::Thread other_thread_;
+  scoped_ptr<SequencedWorkerPoolOwner> pool_owner_;
+};
+
+TEST_F(SequenceCheckerTest, CallsAllowedOnSameThread) {
+  scoped_ptr<SequenceCheckedObject> sequence_checked_object(
+      new SequenceCheckedObject);
+
+  // Verify that DoStuff doesn't assert.
+  sequence_checked_object->DoStuff();
+
+  // Verify that the destructor doesn't assert.
+  sequence_checked_object.reset();
+}
+
+TEST_F(SequenceCheckerTest, DestructorAllowedOnDifferentThread) {
+  scoped_ptr<SequenceCheckedObject> sequence_checked_object(
+      new SequenceCheckedObject);
+
+  // Verify the destructor doesn't assert when called on a different thread.
+  PostDeleteToOtherThread(sequence_checked_object.Pass());
+  other_thread()->Stop();
+}
+
+TEST_F(SequenceCheckerTest, DetachFromSequence) {
+  scoped_ptr<SequenceCheckedObject> sequence_checked_object(
+      new SequenceCheckedObject);
+
+  // Verify that DoStuff doesn't assert when called on a different thread after
+  // a call to DetachFromSequence.
+  sequence_checked_object->DetachFromSequence();
+
+  PostDoStuffToOtherThread(sequence_checked_object.get());
+  other_thread()->Stop();
+}
+
+TEST_F(SequenceCheckerTest, SameSequenceTokenValid) {
+  scoped_ptr<SequenceCheckedObject> sequence_checked_object(
+      new SequenceCheckedObject);
+
+  sequence_checked_object->DetachFromSequence();
+  PostDoStuffToWorkerPool(sequence_checked_object.get(), "A");
+  PostDoStuffToWorkerPool(sequence_checked_object.get(), "A");
+  PostDoStuffToWorkerPool(sequence_checked_object.get(), "A");
+  PostDoStuffToWorkerPool(sequence_checked_object.get(), "A");
+  pool()->FlushForTesting();
+
+  PostDeleteToOtherThread(sequence_checked_object.Pass());
+  other_thread()->Stop();
+}
+
+TEST_F(SequenceCheckerTest, DetachSequenceTokenValid) {
+  scoped_ptr<SequenceCheckedObject> sequence_checked_object(
+      new SequenceCheckedObject);
+
+  sequence_checked_object->DetachFromSequence();
+  PostDoStuffToWorkerPool(sequence_checked_object.get(), "A");
+  PostDoStuffToWorkerPool(sequence_checked_object.get(), "A");
+  pool()->FlushForTesting();
+
+  sequence_checked_object->DetachFromSequence();
+  PostDoStuffToWorkerPool(sequence_checked_object.get(), "B");
+  PostDoStuffToWorkerPool(sequence_checked_object.get(), "B");
+  pool()->FlushForTesting();
+
+  PostDeleteToOtherThread(sequence_checked_object.Pass());
+  other_thread()->Stop();
+}
+
+#if GTEST_HAS_DEATH_TEST || !ENABLE_SEQUENCE_CHECKER
+
+void SequenceCheckerTest::MethodOnDifferentThreadDeathTest() {
+  scoped_ptr<SequenceCheckedObject> sequence_checked_object(
+      new SequenceCheckedObject);
+
+  // DoStuff should assert in debug builds only when called on a
+  // different thread.
+  PostDoStuffToOtherThread(sequence_checked_object.get());
+  other_thread()->Stop();
+}
+
+#if ENABLE_SEQUENCE_CHECKER
+TEST_F(SequenceCheckerTest, MethodNotAllowedOnDifferentThreadDeathTestInDebug) {
+  // The default style "fast" does not support multi-threaded tests.
+  ::testing::FLAGS_gtest_death_test_style = "threadsafe";
+  ASSERT_DEATH({
+    MethodOnDifferentThreadDeathTest();
+  }, "");
+}
+#else
+TEST_F(SequenceCheckerTest, MethodAllowedOnDifferentThreadDeathTestInRelease) {
+  MethodOnDifferentThreadDeathTest();
+}
+#endif  // ENABLE_SEQUENCE_CHECKER
+
+void SequenceCheckerTest::DetachThenCallFromDifferentThreadDeathTest() {
+  scoped_ptr<SequenceCheckedObject> sequence_checked_object(
+      new SequenceCheckedObject);
+
+  // DoStuff doesn't assert when called on a different thread
+  // after a call to DetachFromSequence.
+  sequence_checked_object->DetachFromSequence();
+  PostDoStuffToOtherThread(sequence_checked_object.get());
+  other_thread()->Stop();
+
+  // DoStuff should assert in debug builds only after moving to
+  // another thread.
+  sequence_checked_object->DoStuff();
+}
+
+#if ENABLE_SEQUENCE_CHECKER
+TEST_F(SequenceCheckerTest, DetachFromSequenceDeathTestInDebug) {
+  // The default style "fast" does not support multi-threaded tests.
+  ::testing::FLAGS_gtest_death_test_style = "threadsafe";
+  ASSERT_DEATH({
+    DetachThenCallFromDifferentThreadDeathTest();
+  }, "");
+}
+#else
+TEST_F(SequenceCheckerTest, DetachFromThreadDeathTestInRelease) {
+  DetachThenCallFromDifferentThreadDeathTest();
+}
+#endif  // ENABLE_SEQUENCE_CHECKER
+
+void SequenceCheckerTest::DifferentSequenceTokensDeathTest() {
+  scoped_ptr<SequenceCheckedObject> sequence_checked_object(
+      new SequenceCheckedObject);
+
+  sequence_checked_object->DetachFromSequence();
+  PostDoStuffToWorkerPool(sequence_checked_object.get(), "A");
+  PostDoStuffToWorkerPool(sequence_checked_object.get(), "A");
+  PostDoStuffToWorkerPool(sequence_checked_object.get(), "B");
+  PostDoStuffToWorkerPool(sequence_checked_object.get(), "B");
+  pool()->FlushForTesting();
+
+  PostDeleteToOtherThread(sequence_checked_object.Pass());
+  other_thread()->Stop();
 }
 
+#if ENABLE_SEQUENCE_CHECKER
+TEST_F(SequenceCheckerTest, DifferentSequenceTokensDeathTestInDebug) {
+  // The default style "fast" does not support multi-threaded tests.
+  ::testing::FLAGS_gtest_death_test_style = "threadsafe";
+  ASSERT_DEATH({
+    DifferentSequenceTokensDeathTest();
+  }, "");
+}
+#else
+TEST_F(SequenceCheckerTest,
+     DifferentSequenceTokensDeathTestInRelease) {
+  DifferentSequenceTokensDeathTest();
+}
+#endif  // ENABLE_SEQUENCE_CHECKER
+
+void SequenceCheckerTest::WorkerPoolAndSimpleThreadDeathTest() {
+  scoped_ptr<SequenceCheckedObject> sequence_checked_object(
+      new SequenceCheckedObject);
+
+  sequence_checked_object->DetachFromSequence();
+  PostDoStuffToWorkerPool(sequence_checked_object.get(), "A");
+  PostDoStuffToWorkerPool(sequence_checked_object.get(), "A");
+  pool()->FlushForTesting();
+
+  PostDoStuffToOtherThread(sequence_checked_object.get());
+  other_thread()->Stop();
+}
+
+#if ENABLE_SEQUENCE_CHECKER
+TEST_F(SequenceCheckerTest, WorkerPoolAndSimpleThreadDeathTestInDebug) {
+  // The default style "fast" does not support multi-threaded tests.
+  ::testing::FLAGS_gtest_death_test_style = "threadsafe";
+  ASSERT_DEATH({
+    WorkerPoolAndSimpleThreadDeathTest();
+  }, "");
+}
+#else
+TEST_F(SequenceCheckerTest,
+     WorkerPoolAndSimpleThreadDeathTestInRelease) {
+  WorkerPoolAndSimpleThreadDeathTest();
+}
+#endif  // ENABLE_SEQUENCE_CHECKER
+
+void SequenceCheckerTest::TwoDifferentWorkerPoolsDeathTest() {
+  scoped_ptr<SequenceCheckedObject> sequence_checked_object(
+      new SequenceCheckedObject);
+
+  sequence_checked_object->DetachFromSequence();
+  PostDoStuffToWorkerPool(sequence_checked_object.get(), "A");
+  PostDoStuffToWorkerPool(sequence_checked_object.get(), "A");
+  pool()->FlushForTesting();
+
+  SequencedWorkerPoolOwner second_pool_owner(kNumWorkerThreads, "test2");
+  second_pool_owner.pool()->PostNamedSequencedWorkerTask(
+      "A",
+      FROM_HERE,
+      base::Bind(&SequenceCheckedObject::DoStuff,
+                 base::Unretained(sequence_checked_object.get())));
+  second_pool_owner.pool()->FlushForTesting();
+  second_pool_owner.pool()->Shutdown();
+}
+
+#if ENABLE_SEQUENCE_CHECKER
+TEST_F(SequenceCheckerTest, TwoDifferentWorkerPoolsDeathTestInDebug) {
+  // The default style "fast" does not support multi-threaded tests.
+  ::testing::FLAGS_gtest_death_test_style = "threadsafe";
+  ASSERT_DEATH({
+    TwoDifferentWorkerPoolsDeathTest();
+  }, "");
+}
+#else
+TEST_F(SequenceCheckerTest,
+     TwoDifferentWorkerPoolsDeathTestInRelease) {
+  TwoDifferentWorkerPoolsDeathTest();
+}
+#endif  // ENABLE_SEQUENCE_CHECKER
+
+#endif  // GTEST_HAS_DEATH_TEST || !ENABLE_SEQUENCE_CHECKER
+
 }  // namespace
 
 }  // namespace base
+
+// Just in case we ever get lumped together with other compilation units.
+#undef ENABLE_SEQUENCE_CHECKER