From 621e49bb465f500cc46d47e39e828cf76d6381d7 Mon Sep 17 00:00:00 2001 From: Dimitri Sokolyuk Date: Tue, 24 Jul 2018 14:35:44 +0200 Subject: update vendor --- vendor/golang.org/x/net/netutil/listen.go | 74 +++++++++++++ vendor/golang.org/x/net/netutil/listen_test.go | 147 +++++++++++++++++++++++++ 2 files changed, 221 insertions(+) create mode 100644 vendor/golang.org/x/net/netutil/listen.go create mode 100644 vendor/golang.org/x/net/netutil/listen_test.go (limited to 'vendor/golang.org/x/net/netutil') diff --git a/vendor/golang.org/x/net/netutil/listen.go b/vendor/golang.org/x/net/netutil/listen.go new file mode 100644 index 0000000..cee46e3 --- /dev/null +++ b/vendor/golang.org/x/net/netutil/listen.go @@ -0,0 +1,74 @@ +// 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{ + Listener: l, + sem: make(chan struct{}, n), + done: make(chan struct{}), + } +} + +type limitListener struct { + net.Listener + sem chan struct{} + closeOnce sync.Once // ensures the done chan is only closed once + done chan struct{} // no values sent; closed when Close is called +} + +// acquire acquires the limiting semaphore. Returns true if successfully +// accquired, false if the listener is closed and the semaphore is not +// acquired. +func (l *limitListener) acquire() bool { + select { + case <-l.done: + return false + case l.sem <- struct{}{}: + return true + } +} +func (l *limitListener) release() { <-l.sem } + +func (l *limitListener) Accept() (net.Conn, error) { + acquired := l.acquire() + // If the semaphore isn't acquired because the listener was closed, expect + // that this call to accept won't block, but immediately return an error. + c, err := l.Listener.Accept() + if err != nil { + if acquired { + l.release() + } + return nil, err + } + return &limitListenerConn{Conn: c, release: l.release}, nil +} + +func (l *limitListener) Close() error { + err := l.Listener.Close() + l.closeOnce.Do(func() { close(l.done) }) + return err +} + +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 +} diff --git a/vendor/golang.org/x/net/netutil/listen_test.go b/vendor/golang.org/x/net/netutil/listen_test.go new file mode 100644 index 0000000..f40c9aa --- /dev/null +++ b/vendor/golang.org/x/net/netutil/listen_test.go @@ -0,0 +1,147 @@ +// 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 + +import ( + "errors" + "fmt" + "io" + "io/ioutil" + "net" + "net/http" + "sync" + "sync/atomic" + "testing" + "time" + + "golang.org/x/net/internal/nettest" +) + +func TestLimitListener(t *testing.T) { + const max = 5 + attempts := (nettest.MaxOpenFiles() - max) / 2 + if attempts > 256 { // maximum length of accept queue is 128 by default + attempts = 256 + } + + l, err := net.Listen("tcp", "127.0.0.1:0") + if err != nil { + t.Fatal(err) + } + defer l.Close() + l = LimitListener(l, max) + + var open int32 + go http.Serve(l, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + if n := atomic.AddInt32(&open, 1); n > max { + t.Errorf("%d open connections, want <= %d", n, max) + } + defer atomic.AddInt32(&open, -1) + time.Sleep(10 * time.Millisecond) + fmt.Fprint(w, "some body") + })) + + var wg sync.WaitGroup + var failed int32 + for i := 0; i < attempts; i++ { + wg.Add(1) + go func() { + defer wg.Done() + c := http.Client{Timeout: 3 * time.Second} + r, err := c.Get("http://" + l.Addr().String()) + if err != nil { + t.Log(err) + atomic.AddInt32(&failed, 1) + return + } + defer r.Body.Close() + io.Copy(ioutil.Discard, r.Body) + }() + } + wg.Wait() + + // We expect some Gets to fail as the kernel's accept queue is filled, + // but most should succeed. + if int(failed) >= attempts/2 { + t.Errorf("%d requests failed within %d attempts", failed, attempts) + } +} + +type errorListener struct { + net.Listener +} + +func (errorListener) Accept() (net.Conn, error) { + return nil, errFake +} + +var errFake = errors.New("fake error from errorListener") + +// This used to hang. +func TestLimitListenerError(t *testing.T) { + donec := make(chan bool, 1) + go func() { + const n = 2 + ll := LimitListener(errorListener{}, n) + for i := 0; i < n+1; i++ { + _, err := ll.Accept() + if err != errFake { + t.Fatalf("Accept error = %v; want errFake", err) + } + } + donec <- true + }() + select { + case <-donec: + case <-time.After(5 * time.Second): + t.Fatal("timeout. deadlock?") + } +} + +func TestLimitListenerClose(t *testing.T) { + ln, err := net.Listen("tcp", "127.0.0.1:0") + if err != nil { + t.Fatal(err) + } + defer ln.Close() + ln = LimitListener(ln, 1) + + doneCh := make(chan struct{}) + defer close(doneCh) + go func() { + c, err := net.Dial("tcp", ln.Addr().String()) + if err != nil { + t.Fatal(err) + } + defer c.Close() + <-doneCh + }() + + c, err := ln.Accept() + if err != nil { + t.Fatal(err) + } + defer c.Close() + + acceptDone := make(chan struct{}) + go func() { + c, err := ln.Accept() + if err == nil { + c.Close() + t.Errorf("Unexpected successful Accept()") + } + close(acceptDone) + }() + + // Wait a tiny bit to ensure the Accept() is blocking. + time.Sleep(10 * time.Millisecond) + ln.Close() + + select { + case <-acceptDone: + case <-time.After(5 * time.Second): + t.Fatalf("Accept() still blocking") + } +} -- cgit v1.2.3