From 4fb13a18685099d1dea2fc337ab35aa006d3aca2 Mon Sep 17 00:00:00 2001
From: Matt Joiner <anacrolix@gmail.com>
Date: Sun, 27 Jun 2021 11:57:11 +1000
Subject: [PATCH] Fix race in concurrent connects in UDP tracker
---
tracker/udp/client.go | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/tracker/udp/client.go b/tracker/udp/client.go
index 59714c09..aea3ec91 100644
--- a/tracker/udp/client.go
+++ b/tracker/udp/client.go
@@ -7,10 +7,12 @@ import (
"errors"
"fmt"
"io"
+ "sync"
"time"
)
type Client struct {
+ mu sync.Mutex
connId ConnectionId
connIdIssued time.Time
Dispatcher *Dispatcher
@@ -66,6 +68,10 @@ func (cl *Client) Scrape(
}
func (cl *Client) connect(ctx context.Context) (err error) {
+ // We could get fancier here and use RWMutex, and even fire off the connection asynchronously
+ // and provide a grace period while it resolves.
+ cl.mu.Lock()
+ defer cl.mu.Unlock()
if !cl.connIdIssued.IsZero() && time.Since(cl.connIdIssued) < time.Minute {
return nil
}
--
2.51.0