Split sequence checker on two headers before moving to API

Bug: webrtc:12419
Change-Id: I8d5acfec0c0654efc70ca089dc6a862503939220
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/205524
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33152}

rtc_base/synchronization/BUILD.gn

@@ -44,15 +44,25 @@ rtc_library("mutex") {
   }
 }
 
-rtc_library("sequence_checker") {
+rtc_source_set("sequence_checker") {
+  sources = [ "sequence_checker.h" ]
+  deps = [
+    ":sequence_checker_internal",
+    "..:checks",
+    "..:deprecation",
+    "..:macromagic",
+  ]
+}
+
+rtc_library("sequence_checker_internal") {
+  visibility = [ ":sequence_checker" ]
   sources = [
-    "sequence_checker.cc",
+    "sequence_checker_internal.cc",
-    "sequence_checker.h",
+    "sequence_checker_internal.h",
   ]
   deps = [
     ":mutex",
     "..:checks",
-    "..:criticalsection",
     "..:macromagic",
     "..:platform_thread_types",
     "..:stringutils",

rtc_base/synchronization/sequence_checker.h

@@ -12,53 +12,12 @@
 
 #include <type_traits>
 
-#include "api/task_queue/task_queue_base.h"
+#include "rtc_base/checks.h"
-#include "rtc_base/platform_thread_types.h"
+#include "rtc_base/deprecation.h"
-#include "rtc_base/synchronization/mutex.h"
+#include "rtc_base/synchronization/sequence_checker_internal.h"
-#include "rtc_base/system/rtc_export.h"
 #include "rtc_base/thread_annotations.h"
 
 namespace webrtc {
-// Real implementation of SequenceChecker, for use in debug mode, or
-// for temporary use in release mode (e.g. to RTC_CHECK on a threading issue
-// seen only in the wild).
-//
-// Note: You should almost always use the SequenceChecker class to get the
-// right version for your build configuration.
-class RTC_EXPORT SequenceCheckerImpl {
- public:
-  SequenceCheckerImpl();
-  ~SequenceCheckerImpl();
-
-  bool IsCurrent() const;
-  // Changes the task queue or thread that is checked for in IsCurrent. This can
-  // be useful when an object may be created on one task queue / thread and then
-  // used exclusively on another thread.
-  void Detach();
-
-  // Returns a string that is formatted to match with the error string printed
-  // by RTC_CHECK() when a condition is not met.
-  // This is used in conjunction with the RTC_DCHECK_RUN_ON() macro.
-  std::string ExpectationToString() const;
-
- private:
-  mutable Mutex lock_;
-  // These are mutable so that IsCurrent can set them.
-  mutable bool attached_ RTC_GUARDED_BY(lock_);
-  mutable rtc::PlatformThreadRef valid_thread_ RTC_GUARDED_BY(lock_);
-  mutable const TaskQueueBase* valid_queue_ RTC_GUARDED_BY(lock_);
-  mutable const void* valid_system_queue_ RTC_GUARDED_BY(lock_);
-};
-
-// Do nothing implementation, for use in release mode.
-//
-// Note: You should almost always use the SequenceChecker class to get the
-// right version for your build configuration.
-class SequenceCheckerDoNothing {
- public:
-  bool IsCurrent() const { return true; }
-  void Detach() {}
-};
 
 // SequenceChecker is a helper class used to help verify that some methods
 // of a class are called on the same task queue or thread. A
@@ -80,27 +39,16 @@ class SequenceCheckerDoNothing {
 //
 // In Release mode, IsCurrent will always return true.
 #if RTC_DCHECK_IS_ON
-class RTC_LOCKABLE SequenceChecker : public SequenceCheckerImpl {};
+class RTC_LOCKABLE SequenceChecker
+    : public webrtc_sequence_checker_internal::SequenceCheckerImpl {};
 #else
-class RTC_LOCKABLE SequenceChecker : public SequenceCheckerDoNothing {};
+class RTC_LOCKABLE SequenceChecker
+    : public webrtc_sequence_checker_internal::SequenceCheckerDoNothing {};
 #endif  // RTC_ENABLE_THREAD_CHECKER
 
 namespace webrtc_seq_check_impl {
-// Helper class used by RTC_DCHECK_RUN_ON (see example usage below).
+// TODO(titovartem): Remove when downstream deps are updated
-class RTC_SCOPED_LOCKABLE SequenceCheckerScope {
+using ::webrtc::webrtc_sequence_checker_internal::SequenceCheckerScope;
- public:
-  template <typename ThreadLikeObject>
-  explicit SequenceCheckerScope(const ThreadLikeObject* thread_like_object)
-      RTC_EXCLUSIVE_LOCK_FUNCTION(thread_like_object) {}
-  SequenceCheckerScope(const SequenceCheckerScope&) = delete;
-  SequenceCheckerScope& operator=(const SequenceCheckerScope&) = delete;
-  ~SequenceCheckerScope() RTC_UNLOCK_FUNCTION() {}
-
-  template <typename ThreadLikeObject>
-  static bool IsCurrent(const ThreadLikeObject* thread_like_object) {
-    return thread_like_object->IsCurrent();
-  }
-};
 }  // namespace webrtc_seq_check_impl
 }  // namespace webrtc
 
@@ -170,18 +118,18 @@ class RTC_SCOPED_LOCKABLE SequenceCheckerScope {
   RTC_THREAD_ANNOTATION_ATTRIBUTE__(exclusive_locks_required(x))
 
 namespace webrtc {
-std::string ExpectationToString(const webrtc::SequenceChecker* checker);
 
-// Catch-all implementation for types other than explicitly supported above.
+// Deprecated. Do not use.
 template <typename ThreadLikeObject>
-std::string ExpectationToString(const ThreadLikeObject*) {
+RTC_DEPRECATED std::string ExpectationToString(const ThreadLikeObject* o) {
-  return std::string();
+  return webrtc::webrtc_sequence_checker_internal::ExpectationToString(o);
 }
 
 }  // namespace webrtc
 
 #define RTC_DCHECK_RUN_ON(x)                                               \
-  webrtc::webrtc_seq_check_impl::SequenceCheckerScope seq_check_scope(x); \
+  webrtc::webrtc_sequence_checker_internal::SequenceCheckerScope scope(x); \
-  RTC_DCHECK((x)->IsCurrent()) << webrtc::ExpectationToString(x)
+  RTC_DCHECK((x)->IsCurrent())                                             \
+      << webrtc::webrtc_sequence_checker_internal::ExpectationToString(x)
 
 #endif  // RTC_BASE_SYNCHRONIZATION_SEQUENCE_CHECKER_H_

rtc_base/synchronization/sequence_checker_internal.cc

@@ -7,15 +7,19 @@
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
-#include "rtc_base/synchronization/sequence_checker.h"
+#include "rtc_base/synchronization/sequence_checker_internal.h"
+
+#include <string>
 
 #if defined(WEBRTC_MAC)
 #include <dispatch/dispatch.h>
 #endif
 
+#include "rtc_base/checks.h"
 #include "rtc_base/strings/string_builder.h"
 
 namespace webrtc {
+namespace webrtc_sequence_checker_internal {
 namespace {
 // On Mac, returns the label of the current dispatch queue; elsewhere, return
 // null.
@@ -29,21 +33,12 @@ const void* GetSystemQueueRef() {
 
 }  // namespace
 
-std::string ExpectationToString(const webrtc::SequenceChecker* checker) {
-#if RTC_DCHECK_IS_ON
-  return checker->ExpectationToString();
-#endif
-  return std::string();
-}
-
 SequenceCheckerImpl::SequenceCheckerImpl()
     : attached_(true),
       valid_thread_(rtc::CurrentThreadRef()),
       valid_queue_(TaskQueueBase::Current()),
       valid_system_queue_(GetSystemQueueRef()) {}
 
-SequenceCheckerImpl::~SequenceCheckerImpl() = default;
-
 bool SequenceCheckerImpl::IsCurrent() const {
   const TaskQueueBase* const current_queue = TaskQueueBase::Current();
   const rtc::PlatformThreadRef current_thread = rtc::CurrentThreadRef();
@@ -109,4 +104,12 @@ std::string SequenceCheckerImpl::ExpectationToString() const {
 }
 #endif  // RTC_DCHECK_IS_ON
 
+std::string ExpectationToString(const SequenceCheckerImpl* checker) {
+#if RTC_DCHECK_IS_ON
+  return checker->ExpectationToString();
+#endif
+  return std::string();
+}
+
+}  // namespace webrtc_sequence_checker_internal
 }  // namespace webrtc

rtc_base/synchronization/sequence_checker_internal.h

@@ -0,0 +1,93 @@
+/*
+ *  Copyright 2020 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#ifndef RTC_BASE_SYNCHRONIZATION_SEQUENCE_CHECKER_INTERNAL_H_
+#define RTC_BASE_SYNCHRONIZATION_SEQUENCE_CHECKER_INTERNAL_H_
+
+#include <string>
+#include <type_traits>
+
+#include "api/task_queue/task_queue_base.h"
+#include "rtc_base/platform_thread_types.h"
+#include "rtc_base/synchronization/mutex.h"
+#include "rtc_base/system/rtc_export.h"
+#include "rtc_base/thread_annotations.h"
+
+namespace webrtc {
+namespace webrtc_sequence_checker_internal {
+
+// Real implementation of SequenceChecker, for use in debug mode, or
+// for temporary use in release mode (e.g. to RTC_CHECK on a threading issue
+// seen only in the wild).
+//
+// Note: You should almost always use the SequenceChecker class to get the
+// right version for your build configuration.
+class RTC_EXPORT SequenceCheckerImpl {
+ public:
+  SequenceCheckerImpl();
+  ~SequenceCheckerImpl() = default;
+
+  bool IsCurrent() const;
+  // Changes the task queue or thread that is checked for in IsCurrent. This can
+  // be useful when an object may be created on one task queue / thread and then
+  // used exclusively on another thread.
+  void Detach();
+
+  // Returns a string that is formatted to match with the error string printed
+  // by RTC_CHECK() when a condition is not met.
+  // This is used in conjunction with the RTC_DCHECK_RUN_ON() macro.
+  std::string ExpectationToString() const;
+
+ private:
+  mutable Mutex lock_;
+  // These are mutable so that IsCurrent can set them.
+  mutable bool attached_ RTC_GUARDED_BY(lock_);
+  mutable rtc::PlatformThreadRef valid_thread_ RTC_GUARDED_BY(lock_);
+  mutable const TaskQueueBase* valid_queue_ RTC_GUARDED_BY(lock_);
+  mutable const void* valid_system_queue_ RTC_GUARDED_BY(lock_);
+};
+
+// Do nothing implementation, for use in release mode.
+//
+// Note: You should almost always use the SequenceChecker class to get the
+// right version for your build configuration.
+class SequenceCheckerDoNothing {
+ public:
+  bool IsCurrent() const { return true; }
+  void Detach() {}
+};
+
+// Helper class used by RTC_DCHECK_RUN_ON (see example usage below).
+class RTC_SCOPED_LOCKABLE SequenceCheckerScope {
+ public:
+  template <typename ThreadLikeObject>
+  explicit SequenceCheckerScope(const ThreadLikeObject* thread_like_object)
+      RTC_EXCLUSIVE_LOCK_FUNCTION(thread_like_object) {}
+  SequenceCheckerScope(const SequenceCheckerScope&) = delete;
+  SequenceCheckerScope& operator=(const SequenceCheckerScope&) = delete;
+  ~SequenceCheckerScope() RTC_UNLOCK_FUNCTION() {}
+
+  template <typename ThreadLikeObject>
+  static bool IsCurrent(const ThreadLikeObject* thread_like_object) {
+    return thread_like_object->IsCurrent();
+  }
+};
+
+std::string ExpectationToString(const SequenceCheckerImpl* checker);
+
+// Catch-all implementation for types other than explicitly supported above.
+template <typename ThreadLikeObject>
+std::string ExpectationToString(const ThreadLikeObject*) {
+  return std::string();
+}
+
+}  // namespace webrtc_sequence_checker_internal
+}  // namespace webrtc
+
+#endif  // RTC_BASE_SYNCHRONIZATION_SEQUENCE_CHECKER_INTERNAL_H_