reducing the execution range of locks to improve concurrency has a significant improvement on the DoChan method

0xdoomxy · 0xdoomxy · commit ee123ad9d699 · 2024-11-27T14:32:05.000+08:00
diff --git a/singleflight/singleflight.go b/singleflight/singleflight.go
@@ -154,12 +154,11 @@ func (g *Group) doCall(c *call, key string, fn func() (interface{}, error)) {
 		}
 
 		g.mu.Lock()
-		defer g.mu.Unlock()
 		c.wg.Done()
 		if g.m[key] == c {
 			delete(g.m, key)
 		}
-
+		g.mu.Unlock()
 		if e, ok := c.err.(*panicError); ok {
 			// In order to prevent the waiting channels from being blocked forever,
 			// needs to ensure that this panic cannot be recovered.

Original file line number	Diff line number	Diff line change
`@@ -154,12 +154,11 @@ func (g Group) doCall(c call, key string, fn func() (interface{}, error)) {`
`154`	`154`	`}`
`155`	`155`
`156`	`156`	`g.mu.Lock()`
`157`		`- defer g.mu.Unlock()`
`158`	`157`	`c.wg.Done()`
`159`	`158`	`if g.m[key] == c {`
`160`	`159`	`delete(g.m, key)`
`161`	`160`	`}`
`162`		`-`
	`161`	`+ g.mu.Unlock()`
`163`	`162`	`if e, ok := c.err.(*panicError); ok {`
`164`	`163`	`// In order to prevent the waiting channels from being blocked forever,`
`165`	`164`	`// needs to ensure that this panic cannot be recovered.`