Fix rare deadlock on multiple concurrent conn.Close() calls.

connection.go

@@ -370,6 +370,7 @@ func (me *Connection) shutdown(err *Error) {
  if err != nil {
  me.errors <- err
  }
+ close(me.errors) // Since the channel is buffered, the waiting goroutine will recieve the result.
 
  me.conn.Close()
 
@@ -618,7 +619,10 @@ func (me *Connection) call(req message, res ...message) error {
  }
 
  select {
- case err := <-me.errors:
+ case err, ok := <-me.errors:
+ if !ok {
+ return ErrClosed
+ }
  return err
 
  case msg := <-me.rpc:

connection_test.go

@@ -2,6 +2,7 @@ package amqp
 
 import (
  "log"
+ "sync"
  "testing"
 )
 
@@ -34,3 +35,23 @@ func TestQueueDeclareOnAClosedConnectionFails(t *testing.T) {
  log.Fatalf("queue.declare on a closed connection %s is expected to fail", conn)
  }
 }
+
+func TestConcurrentClose(t *testing.T) {
+ conn, err := Dial("amqp://guest:guest@localhost:5672/")
+ if err != nil {
+ log.Fatalf("Could't connect to amqp server, err = %s", err)
+ }
+
+ wg := sync.WaitGroup{}
+ wg.Add(5)
+ for i := 0; i < 5; i++ {
+ go func() {
+ err := conn.Close()
+ if err != nil && err != ErrClosed {
+ log.Fatalf("Expected nil or ErrClosed - got %#v, type is %T", err, err)
+ }
+ wg.Done()
+ }()
+ }
+ wg.Wait()
+}