Make WeakPtr slightly cheaper to allocate and use
This changes Flag to not inherit from a virtual interface.
Also fixing iwyu and build dependencies.
Bug: none
Change-Id: Iba6e095ec771d8975a32059041185270d32e51be
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/348940
Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#42162}
diff --git a/rtc_base/BUILD.gn b/rtc_base/BUILD.gn
index 69b4343..b3cb17c 100644
--- a/rtc_base/BUILD.gn
+++ b/rtc_base/BUILD.gn
@@ -788,6 +788,8 @@
"weak_ptr.h",
]
deps = [
+ ":checks",
+ ":macromagic",
":refcount",
"../api:scoped_refptr",
"../api:sequence_checker",
diff --git a/rtc_base/weak_ptr.cc b/rtc_base/weak_ptr.cc
index 3bfa71b..cec0808 100644
--- a/rtc_base/weak_ptr.cc
+++ b/rtc_base/weak_ptr.cc
@@ -16,25 +16,19 @@
namespace rtc {
namespace internal {
-WeakReference::Flag::Flag() : is_valid_(true) {}
-
void WeakReference::Flag::Invalidate() {
- RTC_DCHECK(checker_.IsCurrent())
- << "WeakPtrs must be invalidated on the same sequence.";
+ RTC_DCHECK_RUN_ON(&checker_);
is_valid_ = false;
}
bool WeakReference::Flag::IsValid() const {
- RTC_DCHECK(checker_.IsCurrent())
- << "WeakPtrs must be checked on the same sequence.";
+ RTC_DCHECK_RUN_ON(&checker_);
return is_valid_;
}
-WeakReference::Flag::~Flag() {}
-
WeakReference::WeakReference() {}
-WeakReference::WeakReference(const Flag* flag) : flag_(flag) {}
+WeakReference::WeakReference(const RefCountedFlag* flag) : flag_(flag) {}
WeakReference::~WeakReference() {}
@@ -55,7 +49,7 @@
WeakReference WeakReferenceOwner::GetRef() const {
// If we hold the last reference to the Flag then create a new one.
if (!HasRefs())
- flag_ = new RefCountedObject<WeakReference::Flag>();
+ flag_ = new WeakReference::RefCountedFlag();
return WeakReference(flag_.get());
}
diff --git a/rtc_base/weak_ptr.h b/rtc_base/weak_ptr.h
index 7e75b5b..67b6ec1 100644
--- a/rtc_base/weak_ptr.h
+++ b/rtc_base/weak_ptr.h
@@ -16,9 +16,11 @@
#include "api/scoped_refptr.h"
#include "api/sequence_checker.h"
+#include "rtc_base/checks.h"
#include "rtc_base/ref_count.h"
#include "rtc_base/ref_counted_object.h"
#include "rtc_base/system/no_unique_address.h"
+#include "rtc_base/thread_annotations.h"
// The implementation is borrowed from chromium except that it does not
// implement SupportsWeakPtr.
@@ -92,25 +94,28 @@
public:
// Although Flag is bound to a specific sequence, it may be
// deleted from another via base::WeakPtr::~WeakPtr().
- class Flag : public RefCountInterface {
+ class Flag {
public:
- Flag();
+ Flag() = default;
void Invalidate();
bool IsValid() const;
private:
- friend class RefCountedObject<Flag>;
+ friend class FinalRefCountedObject<Flag>;
- ~Flag() override;
+ ~Flag() = default;
RTC_NO_UNIQUE_ADDRESS ::webrtc::SequenceChecker checker_{
webrtc::SequenceChecker::kDetached};
- bool is_valid_;
+ bool is_valid_ RTC_GUARDED_BY(checker_) = true;
};
+ // `RefCountedFlag` is the reference counted (shared), non-virtual, flag type.
+ using RefCountedFlag = FinalRefCountedObject<Flag>;
+
WeakReference();
- explicit WeakReference(const Flag* flag);
+ explicit WeakReference(const RefCountedFlag* flag);
~WeakReference();
WeakReference(WeakReference&& other);
@@ -121,7 +126,7 @@
bool is_valid() const;
private:
- scoped_refptr<const Flag> flag_;
+ scoped_refptr<const RefCountedFlag> flag_;
};
class WeakReferenceOwner {
@@ -136,7 +141,7 @@
void Invalidate();
private:
- mutable scoped_refptr<RefCountedObject<WeakReference::Flag>> flag_;
+ mutable scoped_refptr<WeakReference::RefCountedFlag> flag_;
};
// This class simplifies the implementation of WeakPtr's type conversion