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Fix reentrant rlock in loadbalancer.dialContext 

Signed-off-by: Brad Davidson <brad.davidson@rancher.com>
pull/10536/head
Brad Davidson 2024-07-12 16:03:15 +00:00 committed by Brad Davidson
parent 38a4f183bc
commit 4bf6fffe45
1 changed files with 5 additions and 3 deletions
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8
pkg/agent/loadbalancer/servers.go
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@ -111,10 +111,12 @@ func (lb *LoadBalancer) setServers(serverAddresses []string) bool {
return true return true
} }
// nextServer attempts to get the next server in the loadbalancer server list.
// If another goroutine has already updated the current server address to point at
// a different address than just failed, nothing is changed. Otherwise, a new server address
// is stored to the currentServerAddress field, and returned for use.
// This function must always be called by a goroutine that holds a read lock on the loadbalancer mutex.
func (lb *LoadBalancer) nextServer(failedServer string) (string, error) { func (lb *LoadBalancer) nextServer(failedServer string) (string, error) {
lb.mutex.RLock()
defer lb.mutex.RUnlock()
// note: these fields are not protected by the mutex, so we clamp the index value and update // note: these fields are not protected by the mutex, so we clamp the index value and update
// the index/current address using local variables, to avoid time-of-check vs time-of-use // the index/current address using local variables, to avoid time-of-check vs time-of-use
// race conditions caused by goroutine A incrementing it in between the time goroutine B // race conditions caused by goroutine A incrementing it in between the time goroutine B