From 2cd0ce3f9b2d8daff93ed1d5211510346a2e2854 Mon Sep 17 00:00:00 2001
From: Jack Christensen <jack@jackchristensen.com>
Date: Thu, 2 Apr 2020 22:10:13 -0500
Subject: [PATCH] Closing a closed pool is a no-op

---
 pool.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/pool.go b/pool.go
index fb79e1c..aa0022f 100644
--- a/pool.go
+++ b/pool.go
@@ -144,6 +144,10 @@ func NewPool(constructor Constructor, destructor Destructor, maxSize int32) *Poo
 // Blocks until all resources are returned to pool and destroyed.
 func (p *Pool) Close() {
 	p.cond.L.Lock()
+	if p.closed {
+		p.cond.L.Unlock()
+		return
+	}
 	p.closed = true
 
 	for _, res := range p.idleResources {