From 524ea2c0ec0bdb7a9ed405e8607566c5a2a89391 Mon Sep 17 00:00:00 2001
From: liujialiang <liujialiang10@huawei.com>
Date: Fri, 18 Mar 2022 19:21:55 +0800
Subject: [PATCH] Optimize RefBase 1.Exchange the ordering of increasing of
 strong and weak in IncStrongRef 2.Add
 atomic_thread_fence(std::memory_order_acquire) to ensure that "delete"
 operation happens after decrement. 3.Modified
 RefCounter::AttemptIncStrongRef. We should confirm INITIAL_PRIMARY_VALUE must
 only sub once. 4.Modified RefCounter::DecWeakRefCount. Delete the judge of
 the value of atomicStrong_, due to the add of atomicStrong_ is
 memory_order_relexed, which can not be seen here.

Signed-off-by: liujialiang <liujialiang10@huawei.com>
Change-Id: I53c0a414ffe03530c31e10bfbcec3fc369ab324e
---
 base/src/refbase.cpp | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/base/src/refbase.cpp b/base/src/refbase.cpp
index 1b2968e..a64f895 100644
--- a/base/src/refbase.cpp
+++ b/base/src/refbase.cpp
@@ -79,6 +79,7 @@ void RefCounter::DecRefCount()
 {
     if (atomicRefCount_.load(std::memory_order_relaxed) > 0) {
         if (atomicRefCount_.fetch_sub(1, std::memory_order_release) == 1) {
+            std::atomic_thread_fence(std::memory_order_acquire);
             delete (this);
         }
     }
@@ -152,7 +153,8 @@ int RefCounter::DecWeakRefCount(const void*)
         return curCount;
     }
 
-    if (IsLifeTimeExtended() && GetStrongRefCount() == 0) {
+    std::atomic_thread_fence(std::memory_order_acquire);
+    if (IsLifeTimeExtended()) {
         if (callback_) {
             callback_();
         }
@@ -230,7 +232,7 @@ bool RefCounter::AttemptIncStrongRef(const void *objectId, int &outCount)
     }
 
 ATTEMPT_SUCCESS:
-    if (curCount >= INITIAL_PRIMARY_VALUE) {
+    if (curCount == INITIAL_PRIMARY_VALUE) {
         outCount = curCount;
         atomicStrong_.fetch_sub(INITIAL_PRIMARY_VALUE, std::memory_order_release);
         return true;
@@ -348,8 +350,8 @@ void RefBase::IncStrongRef(const void *objectId)
         return;
     }
 
-    const int curCount = refs_->IncStrongRefCount(objectId);
     IncWeakRef(objectId);
+    const int curCount = refs_->IncStrongRefCount(objectId);
     if (curCount == INITIAL_PRIMARY_VALUE) {
         OnFirstStrongRef(objectId);
     }
@@ -369,6 +371,7 @@ void RefBase::DecStrongRef(const void *objectId)
     RefCounter * const refs = refs_;
     const int curCount = refs->DecStrongRefCount(objectId);
     if (curCount == 1) {
+        std::atomic_thread_fence(std::memory_order_acquire);
         OnLastStrongRef(objectId);
         if (!refs->IsLifeTimeExtended()) {
             if (refs->callback_) {
-- 
Gitee