Increase RC size to 64 bits

commit_hash:31d021c482ac2a3f99e86bf1a2aca7231c86c11d

3 files changed, 13 insertions, 14 deletions

diff --git a/library/cpp/yt/memory/atomic_intrusive_ptr.h b/library/cpp/yt/memory/atomic_intrusive_ptr.h
index ae0a307182..72405053c0 100644
--- a/library/cpp/yt/memory/atomic_intrusive_ptr.h
+++ b/library/cpp/yt/memory/atomic_intrusive_ptr.h
@@ -6,13 +6,10 @@ namespace NYT {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-// Atomic ptr based on https://github.com/facebook/folly/blob/main/folly/concurrency/AtomicSharedPtr.h
-
-// Operators * and -> for TAtomicIntrusivePtr are useless because it is not safe to work with atomic ptr such way
-// Safe usage is to convert to TIntrusivePtr.
-
-// Max TAtomicIntrusivePtr count per object is (2**16 = 2**32 / 2**16).
-
+//! Atomic pointer with split reference counting.
+/*
+ *  \see https://github.com/facebook/folly/blob/main/folly/concurrency/AtomicSharedPtr.h
+*/
 template <class T>
 class TAtomicIntrusivePtr
 {
@@ -39,7 +36,7 @@ public:
     bool CompareAndSwap(TRawPtr& comparePtr, T* target);
     bool CompareAndSwap(TRawPtr& comparePtr, TIntrusivePtr<T> target);
 
-    // Result is suitable only for comparison. Not dereference.
+    //! Result is only suitable for comparison, not dereference.
     TRawPtr Get() const;
 
     explicit operator bool() const;
diff --git a/library/cpp/yt/memory/ref_counted-inl.h b/library/cpp/yt/memory/ref_counted-inl.h
index 9ffdf328eb..6c20db8c41 100644
--- a/library/cpp/yt/memory/ref_counted-inl.h
+++ b/library/cpp/yt/memory/ref_counted-inl.h
@@ -90,7 +90,7 @@ Y_FORCE_INLINE void DestroyRefCountedImpl(T* obj)
         return;
     }
 
-    YT_ASSERT(offset < std::numeric_limits<ui16>::max());
+    YT_ASSERT(offset < (1ULL << PackedPtrTagBits));
 
     auto* vTablePtr = reinterpret_cast<TPackedPtr*>(basePtr);
     *vTablePtr = TTaggedPtr<void(void*, ui16)>(&NYT::NDetail::TMemoryReleaser<T>::Do, offset).Pack();
@@ -187,7 +187,7 @@ Y_FORCE_INLINE void TRefCounter::Ref(int n) const noexcept
     // It is safe to use relaxed here, since new reference is always created from another live reference.
     auto value = StrongCount_.fetch_add(n, std::memory_order::relaxed);
     YT_ASSERT(value > 0);
-    YT_ASSERT(value <= std::numeric_limits<int>::max() - n);
+    YT_ASSERT(value <= std::numeric_limits<TRefCount>::max() - n);
 
     YT_ASSERT(WeakCount_.load(std::memory_order::relaxed) > 0);
 }
@@ -199,7 +199,7 @@ Y_FORCE_INLINE void TRefCounter::DangerousRef(int n) const noexcept
     // Relaxed is fine as per lukyan@, the caller guarantees object liveness.
     auto value = StrongCount_.fetch_add(n, std::memory_order::relaxed);
     YT_ASSERT(value >= 0);
-    YT_ASSERT(value <= std::numeric_limits<int>::max() - n);
+    YT_ASSERT(value <= std::numeric_limits<TRefCount>::max() - n);
 
     YT_ASSERT(WeakCount_.load(std::memory_order::relaxed) > 0);
 }
@@ -207,7 +207,7 @@ Y_FORCE_INLINE void TRefCounter::DangerousRef(int n) const noexcept
 Y_FORCE_INLINE bool TRefCounter::TryRef() const noexcept
 {
     auto value = StrongCount_.load(std::memory_order::relaxed);
-    YT_ASSERT(value >= 0 && value < std::numeric_limits<int>::max());
+    YT_ASSERT(value >= 0 && value < std::numeric_limits<TRefCount>::max());
     YT_ASSERT(WeakCount_.load(std::memory_order::relaxed) > 0);
 
     while (value != 0 && !StrongCount_.compare_exchange_weak(value, value + 1));
diff --git a/library/cpp/yt/memory/ref_counted.h b/library/cpp/yt/memory/ref_counted.h
index ed55aee6ee..6abef3bf05 100644
--- a/library/cpp/yt/memory/ref_counted.h
+++ b/library/cpp/yt/memory/ref_counted.h
@@ -63,8 +63,10 @@ public:
     bool WeakUnref() const;
 
 private:
-    mutable std::atomic<int> StrongCount_ = 1;
-    mutable std::atomic<int> WeakCount_ = 1;
+    // NB: Must we 64 bit as TAtomicIntrusivePtr grabs refs in 64K batches.
+    using TRefCount = i64;
+    mutable std::atomic<TRefCount> StrongCount_ = 1;
+    mutable std::atomic<TRefCount> WeakCount_ = 1;
 };
 
 ////////////////////////////////////////////////////////////////////////////////