From f568259a6cde3091eab9cd0b93f561eb4248c663 Mon Sep 17 00:00:00 2001
From: liujialiang <liujialiang10@huawei.com>
Date: Wed, 9 Feb 2022 21:05:06 +0800
Subject: [PATCH] Anothor way to fix RefBase released repetitively by using
 atomic_flag.

Signed-off-by: liujialiang <liujialiang10@huawei.com>
---
 base/include/refbase.h |  2 +-
 base/src/refbase.cpp   | 40 +++++++++++-----------------------------
 2 files changed, 12 insertions(+), 30 deletions(-)

diff --git a/base/include/refbase.h b/base/include/refbase.h
index 4c4c24b..95cb816 100755
--- a/base/include/refbase.h
+++ b/base/include/refbase.h
@@ -28,7 +28,6 @@ class RefBase;
 class RefCounter {
 public:
     using RefPtrCallback = std::function<void()>;
-    friend class RefBase;
 
     RefCounter();
 
@@ -153,6 +152,7 @@ public:
     virtual bool OnAttemptPromoted(const void *objectId);
 
 private:
+    std::atomic_flag lock = ATOMIC_FLAG_INIT;
     RefCounter *refs_ = nullptr;
 };
 
diff --git a/base/src/refbase.cpp b/base/src/refbase.cpp
index a05709e..32b048e 100755
--- a/base/src/refbase.cpp
+++ b/base/src/refbase.cpp
@@ -148,24 +148,11 @@ int RefCounter::DecWeakRefCount(const void*)
         curCount = atomicWeak_.fetch_sub(1, std::memory_order_release);
     }
 
-    if (curCount != 1) {
-        return curCount;
-    }
-
-    if (IsLifeTimeExtended() && GetStrongRefCount() == 0) {
+    int strongRefCount = GetStrongRefCount();
+    if (curCount == 1 || (strongRefCount == 0 && !IsLifeTimeExtended())) {
         if (callback_) {
             callback_();
         }
-    } else {
-        // only weak ptr case: no strong reference, delete the object
-        if (GetStrongRefCount() == INITIAL_PRIMARY_VALUE) {
-            if (callback_) {
-                callback_();
-            }
-        } else {
-            // free RefCounter
-            delete (this);
-        }
     }
 
     return curCount;
@@ -247,6 +234,7 @@ ATTEMPT_SUCCESS:
 
 RefBase::RefBase() : refs_(new RefCounter())
 {
+    lock.clear(std::memory_order_release);
     refs_->IncRefCount();
     refs_->SetCallback(std::bind(&RefBase::RefPtrCallback, this));
 }
@@ -254,6 +242,7 @@ RefBase::RefBase() : refs_(new RefCounter())
 RefBase::RefBase(const RefBase &)
 {
     refs_ = new RefCounter();
+    lock.clear(std::memory_order_release);
     if (refs_ != nullptr) {
         refs_->IncRefCount();
         refs_->SetCallback(std::bind(&RefBase::RefPtrCallback, this));
@@ -262,6 +251,9 @@ RefBase::RefBase(const RefBase &)
 
 void RefBase::RefPtrCallback()
 {
+    if (lock.test_and_set(std::memory_order_acquire)) {
+        return;
+    }
     delete this;
 }
 
@@ -279,6 +271,7 @@ RefBase &RefBase::operator=(const RefBase &)
     }
 
     refs_ = new RefCounter();
+    lock.clear(std::memory_order_release);
     if (refs_ != nullptr) {
         refs_->IncRefCount();
         refs_->SetCallback(std::bind(&RefBase::RefPtrCallback, this));
@@ -313,12 +306,7 @@ RefBase::~RefBase()
 {
     if (refs_ != nullptr) {
         refs_->RemoveCallback();
-        if (refs_->IsLifeTimeExtended() && refs_->GetWeakRefCount() == 0) {
-            refs_->DecRefCount();
-        }
-        if (refs_->GetStrongRefCount() == INITIAL_PRIMARY_VALUE) {
-            delete refs_;
-        }
+        refs_->DecRefCount();
         refs_ = nullptr;
     }
 }
@@ -352,18 +340,12 @@ void RefBase::DecStrongRef(const void *objectId)
         return;
     }
 
-    RefCounter *const refs = refs_;
-    const int curCount = refs->DecStrongRefCount(objectId);
+    const int curCount = refs_->DecStrongRefCount(objectId);
     if (curCount == 1) {
         OnLastStrongRef(objectId);
-        if (!refs->IsLifeTimeExtended()) {
-            if (refs->callback_) {
-                refs->callback_();
-            }
-        }
     }
 
-    refs->DecWeakRefCount(objectId);
+    DecWeakRef(objectId);
 }
 
 int RefBase::GetSptrRefCount()
-- 
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