Merge of ThreadChecker and SequencedTaskChecker.
Introduces SequenceChecker, merging the functionality of ThreadChecker
and SequencedTaskChecker. Also making the two latter use the former as
the underlying implementation for backwards compatibility.
This allows code that uses thread checker to accept running on a thread
pool backed task queue.
Bug: webrtc:10365
Change-Id: Ifefc4925694f263088a8a095fdf98a2407c62081
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/129721
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27365}diff --git a/rtc_base/thread_checker.h b/rtc_base/thread_checker.h
index 43f7320..d3daa6f 100644
--- a/rtc_base/thread_checker.h
+++ b/rtc_base/thread_checker.h
@@ -13,159 +13,14 @@
#ifndef RTC_BASE_THREAD_CHECKER_H_
#define RTC_BASE_THREAD_CHECKER_H_
-// Apart from debug builds, we also enable the thread checker in
-// builds with RTC_DCHECK_IS_ON so that trybots and waterfall bots
-// with this define will get the same level of thread checking as
-// debug bots.
-#define RTC_ENABLE_THREAD_CHECKER RTC_DCHECK_IS_ON
-
-#include "rtc_base/checks.h"
-#include "rtc_base/constructor_magic.h"
-#include "rtc_base/thread_annotations.h"
-#include "rtc_base/thread_checker_impl.h"
+#include "rtc_base/synchronization/sequence_checker.h"
namespace rtc {
-
-// Do nothing implementation, for use in release mode.
-//
-// Note: You should almost always use the ThreadChecker class to get the
-// right version for your build configuration.
-class ThreadCheckerDoNothing {
+// TODO(srte): Replace usages of this with SequenceChecker.
+class ThreadChecker : public webrtc::SequenceChecker {
public:
- bool CalledOnValidThread() const { return true; }
-
- void DetachFromThread() {}
+ bool CalledOnValidThread() const { return IsCurrent(); }
+ void DetachFromThread() { Detach(); }
};
-
-// ThreadChecker is a helper class used to help verify that some methods of a
-// class are called from the same thread. It provides identical functionality to
-// base::NonThreadSafe, but it is meant to be held as a member variable, rather
-// than inherited from base::NonThreadSafe.
-//
-// While inheriting from base::NonThreadSafe may give a clear indication about
-// the thread-safety of a class, it may also lead to violations of the style
-// guide with regard to multiple inheritance. The choice between having a
-// ThreadChecker member and inheriting from base::NonThreadSafe should be based
-// on whether:
-// - Derived classes need to know the thread they belong to, as opposed to
-// having that functionality fully encapsulated in the base class.
-// - Derived classes should be able to reassign the base class to another
-// thread, via DetachFromThread.
-//
-// If neither of these are true, then having a ThreadChecker member and calling
-// CalledOnValidThread is the preferable solution.
-//
-// Example:
-// class MyClass {
-// public:
-// void Foo() {
-// RTC_DCHECK(thread_checker_.CalledOnValidThread());
-// ... (do stuff) ...
-// }
-//
-// private:
-// ThreadChecker thread_checker_;
-// }
-//
-// In Release mode, CalledOnValidThread will always return true.
-#if RTC_ENABLE_THREAD_CHECKER
-class RTC_LOCKABLE ThreadChecker : public ThreadCheckerImpl {};
-#else
-class RTC_LOCKABLE ThreadChecker : public ThreadCheckerDoNothing {};
-#endif // RTC_ENABLE_THREAD_CHECKER
-
-#undef RTC_ENABLE_THREAD_CHECKER
-
-namespace internal {
-class RTC_SCOPED_LOCKABLE AnnounceOnThread {
- public:
- template <typename ThreadLikeObject>
- explicit AnnounceOnThread(const ThreadLikeObject* thread_like_object)
- RTC_EXCLUSIVE_LOCK_FUNCTION(thread_like_object) {}
- ~AnnounceOnThread() RTC_UNLOCK_FUNCTION() {}
-
- template <typename ThreadLikeObject>
- static bool IsCurrent(const ThreadLikeObject* thread_like_object) {
- return thread_like_object->IsCurrent();
- }
- static bool IsCurrent(const rtc::ThreadChecker* checker) {
- return checker->CalledOnValidThread();
- }
-
- private:
- RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(AnnounceOnThread);
-};
-
-} // namespace internal
} // namespace rtc
-
-// RTC_RUN_ON/RTC_GUARDED_BY/RTC_DCHECK_RUN_ON macros allows to annotate
-// variables are accessed from same thread/task queue.
-// Using tools designed to check mutexes, it checks at compile time everywhere
-// variable is access, there is a run-time dcheck thread/task queue is correct.
-//
-// class ExampleThread {
-// public:
-// void NeedVar1() {
-// RTC_DCHECK_RUN_ON(network_thread_);
-// transport_->Send();
-// }
-//
-// private:
-// rtc::Thread* network_thread_;
-// int transport_ RTC_GUARDED_BY(network_thread_);
-// };
-//
-// class ExampleThreadChecker {
-// public:
-// int CalledFromPacer() RTC_RUN_ON(pacer_thread_checker_) {
-// return var2_;
-// }
-//
-// void CallMeFromPacer() {
-// RTC_DCHECK_RUN_ON(&pacer_thread_checker_)
-// << "Should be called from pacer";
-// CalledFromPacer();
-// }
-//
-// private:
-// int pacer_var_ RTC_GUARDED_BY(pacer_thread_checker_);
-// rtc::ThreadChecker pacer_thread_checker_;
-// };
-//
-// class TaskQueueExample {
-// public:
-// class Encoder {
-// public:
-// rtc::TaskQueue* Queue() { return encoder_queue_; }
-// void Encode() {
-// RTC_DCHECK_RUN_ON(encoder_queue_);
-// DoSomething(var_);
-// }
-//
-// private:
-// rtc::TaskQueue* const encoder_queue_;
-// Frame var_ RTC_GUARDED_BY(encoder_queue_);
-// };
-//
-// void Encode() {
-// // Will fail at runtime when DCHECK is enabled:
-// // encoder_->Encode();
-// // Will work:
-// rtc::scoped_refptr<Encoder> encoder = encoder_;
-// encoder_->Queue()->PostTask([encoder] { encoder->Encode(); });
-// }
-//
-// private:
-// rtc::scoped_refptr<Encoder> encoder_;
-// }
-
-// Document if a function expected to be called from same thread/task queue.
-#define RTC_RUN_ON(x) \
- RTC_THREAD_ANNOTATION_ATTRIBUTE__(exclusive_locks_required(x))
-
-#define RTC_DCHECK_RUN_ON(thread_like_object) \
- rtc::internal::AnnounceOnThread thread_announcer(thread_like_object); \
- RTC_DCHECK(rtc::internal::AnnounceOnThread::IsCurrent(thread_like_object))
-
#endif // RTC_BASE_THREAD_CHECKER_H_