From 94602ba9b7982cda26a7c632ae3c8db33bfe89d0 Mon Sep 17 00:00:00 2001
From: langhuihui <178529795@qq.com>
Date: Fri, 27 Sep 2024 13:44:09 +0800
Subject: [PATCH] fix: race

---
 util/ring-writer.go | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/util/ring-writer.go b/util/ring-writer.go
index b65e551..c9dd485 100644
--- a/util/ring-writer.go
+++ b/util/ring-writer.go
@@ -81,19 +81,20 @@ func (rb *RingWriter[T, F]) Reduce(size int) {
 	p := rb.Unlink(size)
 	pSize := size
 	rb.Size -= size
+	// 遍历即将回收的节点，如果有读锁未释放，则丢弃，不回收该节点
 	for i := 0; i < size; i++ {
-		if p.Value.StartWrite() {
+		if !p.Value.IsDiscarded() && p.Value.StartWrite() { // 尝试加写锁，成功则说明该节点可正常回收
 			p.Value.Reset()
 			p.Value.Ready()
 			rb.poolSize++
 		} else {
 			p.Value.Reset()
 			if pSize == 1 {
-				// last one，无法删除最后一个节点，直接返回即可
+				// last one，无法删除最后一个节点，直接返回即可（不回收）
 				return
 			}
 			p = p.Prev()
-			p.Unlink(1)
+			p.Unlink(1) // 丢弃该节点,不回收
 			pSize--
 		}
 		p = p.Next()