diff options
Diffstat (limited to 'vendor/github.com/miekg/dns/vendor/golang.org/x/net/netutil/listen.go')
-rw-r--r-- | vendor/github.com/miekg/dns/vendor/golang.org/x/net/netutil/listen.go | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/net/netutil/listen.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/netutil/listen.go new file mode 100644 index 000000000..56f43bf65 --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/netutil/listen.go @@ -0,0 +1,48 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package netutil provides network utility functions, complementing the more +// common ones in the net package. +package netutil // import "golang.org/x/net/netutil" + +import ( + "net" + "sync" +) + +// LimitListener returns a Listener that accepts at most n simultaneous +// connections from the provided Listener. +func LimitListener(l net.Listener, n int) net.Listener { + return &limitListener{l, make(chan struct{}, n)} +} + +type limitListener struct { + net.Listener + sem chan struct{} +} + +func (l *limitListener) acquire() { l.sem <- struct{}{} } +func (l *limitListener) release() { <-l.sem } + +func (l *limitListener) Accept() (net.Conn, error) { + l.acquire() + c, err := l.Listener.Accept() + if err != nil { + l.release() + return nil, err + } + return &limitListenerConn{Conn: c, release: l.release}, nil +} + +type limitListenerConn struct { + net.Conn + releaseOnce sync.Once + release func() +} + +func (l *limitListenerConn) Close() error { + err := l.Conn.Close() + l.releaseOnce.Do(l.release) + return err +} |