diff options
Diffstat (limited to 'vendor/github.com/miekg/dns/vendor/golang.org/x/net/context')
12 files changed, 1605 insertions, 0 deletions
diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/context.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/context.go new file mode 100644 index 000000000..a3c021d3f --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/context.go @@ -0,0 +1,56 @@ +// Copyright 2014 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 context defines the Context type, which carries deadlines, +// cancelation signals, and other request-scoped values across API boundaries +// and between processes. +// As of Go 1.7 this package is available in the standard library under the +// name context. https://golang.org/pkg/context. +// +// Incoming requests to a server should create a Context, and outgoing calls to +// servers should accept a Context. The chain of function calls between must +// propagate the Context, optionally replacing it with a modified copy created +// using WithDeadline, WithTimeout, WithCancel, or WithValue. +// +// Programs that use Contexts should follow these rules to keep interfaces +// consistent across packages and enable static analysis tools to check context +// propagation: +// +// Do not store Contexts inside a struct type; instead, pass a Context +// explicitly to each function that needs it. The Context should be the first +// parameter, typically named ctx: +// +// func DoSomething(ctx context.Context, arg Arg) error { +// // ... use ctx ... +// } +// +// Do not pass a nil Context, even if a function permits it. Pass context.TODO +// if you are unsure about which Context to use. +// +// Use context Values only for request-scoped data that transits processes and +// APIs, not for passing optional parameters to functions. +// +// The same Context may be passed to functions running in different goroutines; +// Contexts are safe for simultaneous use by multiple goroutines. +// +// See http://blog.golang.org/context for example code for a server that uses +// Contexts. +package context // import "golang.org/x/net/context" + +// Background returns a non-nil, empty Context. It is never canceled, has no +// values, and has no deadline. It is typically used by the main function, +// initialization, and tests, and as the top-level Context for incoming +// requests. +func Background() Context { + return background +} + +// TODO returns a non-nil, empty Context. Code should use context.TODO when +// it's unclear which Context to use or it is not yet available (because the +// surrounding function has not yet been extended to accept a Context +// parameter). TODO is recognized by static analysis tools that determine +// whether Contexts are propagated correctly in a program. +func TODO() Context { + return todo +} diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/context_test.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/context_test.go new file mode 100644 index 000000000..62844131b --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/context_test.go @@ -0,0 +1,583 @@ +// Copyright 2014 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. + +// +build !go1.7 + +package context + +import ( + "fmt" + "math/rand" + "runtime" + "strings" + "sync" + "testing" + "time" +) + +// otherContext is a Context that's not one of the types defined in context.go. +// This lets us test code paths that differ based on the underlying type of the +// Context. +type otherContext struct { + Context +} + +func TestBackground(t *testing.T) { + c := Background() + if c == nil { + t.Fatalf("Background returned nil") + } + select { + case x := <-c.Done(): + t.Errorf("<-c.Done() == %v want nothing (it should block)", x) + default: + } + if got, want := fmt.Sprint(c), "context.Background"; got != want { + t.Errorf("Background().String() = %q want %q", got, want) + } +} + +func TestTODO(t *testing.T) { + c := TODO() + if c == nil { + t.Fatalf("TODO returned nil") + } + select { + case x := <-c.Done(): + t.Errorf("<-c.Done() == %v want nothing (it should block)", x) + default: + } + if got, want := fmt.Sprint(c), "context.TODO"; got != want { + t.Errorf("TODO().String() = %q want %q", got, want) + } +} + +func TestWithCancel(t *testing.T) { + c1, cancel := WithCancel(Background()) + + if got, want := fmt.Sprint(c1), "context.Background.WithCancel"; got != want { + t.Errorf("c1.String() = %q want %q", got, want) + } + + o := otherContext{c1} + c2, _ := WithCancel(o) + contexts := []Context{c1, o, c2} + + for i, c := range contexts { + if d := c.Done(); d == nil { + t.Errorf("c[%d].Done() == %v want non-nil", i, d) + } + if e := c.Err(); e != nil { + t.Errorf("c[%d].Err() == %v want nil", i, e) + } + + select { + case x := <-c.Done(): + t.Errorf("<-c.Done() == %v want nothing (it should block)", x) + default: + } + } + + cancel() + time.Sleep(100 * time.Millisecond) // let cancelation propagate + + for i, c := range contexts { + select { + case <-c.Done(): + default: + t.Errorf("<-c[%d].Done() blocked, but shouldn't have", i) + } + if e := c.Err(); e != Canceled { + t.Errorf("c[%d].Err() == %v want %v", i, e, Canceled) + } + } +} + +func TestParentFinishesChild(t *testing.T) { + // Context tree: + // parent -> cancelChild + // parent -> valueChild -> timerChild + parent, cancel := WithCancel(Background()) + cancelChild, stop := WithCancel(parent) + defer stop() + valueChild := WithValue(parent, "key", "value") + timerChild, stop := WithTimeout(valueChild, 10000*time.Hour) + defer stop() + + select { + case x := <-parent.Done(): + t.Errorf("<-parent.Done() == %v want nothing (it should block)", x) + case x := <-cancelChild.Done(): + t.Errorf("<-cancelChild.Done() == %v want nothing (it should block)", x) + case x := <-timerChild.Done(): + t.Errorf("<-timerChild.Done() == %v want nothing (it should block)", x) + case x := <-valueChild.Done(): + t.Errorf("<-valueChild.Done() == %v want nothing (it should block)", x) + default: + } + + // The parent's children should contain the two cancelable children. + pc := parent.(*cancelCtx) + cc := cancelChild.(*cancelCtx) + tc := timerChild.(*timerCtx) + pc.mu.Lock() + if len(pc.children) != 2 || !pc.children[cc] || !pc.children[tc] { + t.Errorf("bad linkage: pc.children = %v, want %v and %v", + pc.children, cc, tc) + } + pc.mu.Unlock() + + if p, ok := parentCancelCtx(cc.Context); !ok || p != pc { + t.Errorf("bad linkage: parentCancelCtx(cancelChild.Context) = %v, %v want %v, true", p, ok, pc) + } + if p, ok := parentCancelCtx(tc.Context); !ok || p != pc { + t.Errorf("bad linkage: parentCancelCtx(timerChild.Context) = %v, %v want %v, true", p, ok, pc) + } + + cancel() + + pc.mu.Lock() + if len(pc.children) != 0 { + t.Errorf("pc.cancel didn't clear pc.children = %v", pc.children) + } + pc.mu.Unlock() + + // parent and children should all be finished. + check := func(ctx Context, name string) { + select { + case <-ctx.Done(): + default: + t.Errorf("<-%s.Done() blocked, but shouldn't have", name) + } + if e := ctx.Err(); e != Canceled { + t.Errorf("%s.Err() == %v want %v", name, e, Canceled) + } + } + check(parent, "parent") + check(cancelChild, "cancelChild") + check(valueChild, "valueChild") + check(timerChild, "timerChild") + + // WithCancel should return a canceled context on a canceled parent. + precanceledChild := WithValue(parent, "key", "value") + select { + case <-precanceledChild.Done(): + default: + t.Errorf("<-precanceledChild.Done() blocked, but shouldn't have") + } + if e := precanceledChild.Err(); e != Canceled { + t.Errorf("precanceledChild.Err() == %v want %v", e, Canceled) + } +} + +func TestChildFinishesFirst(t *testing.T) { + cancelable, stop := WithCancel(Background()) + defer stop() + for _, parent := range []Context{Background(), cancelable} { + child, cancel := WithCancel(parent) + + select { + case x := <-parent.Done(): + t.Errorf("<-parent.Done() == %v want nothing (it should block)", x) + case x := <-child.Done(): + t.Errorf("<-child.Done() == %v want nothing (it should block)", x) + default: + } + + cc := child.(*cancelCtx) + pc, pcok := parent.(*cancelCtx) // pcok == false when parent == Background() + if p, ok := parentCancelCtx(cc.Context); ok != pcok || (ok && pc != p) { + t.Errorf("bad linkage: parentCancelCtx(cc.Context) = %v, %v want %v, %v", p, ok, pc, pcok) + } + + if pcok { + pc.mu.Lock() + if len(pc.children) != 1 || !pc.children[cc] { + t.Errorf("bad linkage: pc.children = %v, cc = %v", pc.children, cc) + } + pc.mu.Unlock() + } + + cancel() + + if pcok { + pc.mu.Lock() + if len(pc.children) != 0 { + t.Errorf("child's cancel didn't remove self from pc.children = %v", pc.children) + } + pc.mu.Unlock() + } + + // child should be finished. + select { + case <-child.Done(): + default: + t.Errorf("<-child.Done() blocked, but shouldn't have") + } + if e := child.Err(); e != Canceled { + t.Errorf("child.Err() == %v want %v", e, Canceled) + } + + // parent should not be finished. + select { + case x := <-parent.Done(): + t.Errorf("<-parent.Done() == %v want nothing (it should block)", x) + default: + } + if e := parent.Err(); e != nil { + t.Errorf("parent.Err() == %v want nil", e) + } + } +} + +func testDeadline(c Context, wait time.Duration, t *testing.T) { + select { + case <-time.After(wait): + t.Fatalf("context should have timed out") + case <-c.Done(): + } + if e := c.Err(); e != DeadlineExceeded { + t.Errorf("c.Err() == %v want %v", e, DeadlineExceeded) + } +} + +func TestDeadline(t *testing.T) { + t.Parallel() + const timeUnit = 500 * time.Millisecond + c, _ := WithDeadline(Background(), time.Now().Add(1*timeUnit)) + if got, prefix := fmt.Sprint(c), "context.Background.WithDeadline("; !strings.HasPrefix(got, prefix) { + t.Errorf("c.String() = %q want prefix %q", got, prefix) + } + testDeadline(c, 2*timeUnit, t) + + c, _ = WithDeadline(Background(), time.Now().Add(1*timeUnit)) + o := otherContext{c} + testDeadline(o, 2*timeUnit, t) + + c, _ = WithDeadline(Background(), time.Now().Add(1*timeUnit)) + o = otherContext{c} + c, _ = WithDeadline(o, time.Now().Add(3*timeUnit)) + testDeadline(c, 2*timeUnit, t) +} + +func TestTimeout(t *testing.T) { + t.Parallel() + const timeUnit = 500 * time.Millisecond + c, _ := WithTimeout(Background(), 1*timeUnit) + if got, prefix := fmt.Sprint(c), "context.Background.WithDeadline("; !strings.HasPrefix(got, prefix) { + t.Errorf("c.String() = %q want prefix %q", got, prefix) + } + testDeadline(c, 2*timeUnit, t) + + c, _ = WithTimeout(Background(), 1*timeUnit) + o := otherContext{c} + testDeadline(o, 2*timeUnit, t) + + c, _ = WithTimeout(Background(), 1*timeUnit) + o = otherContext{c} + c, _ = WithTimeout(o, 3*timeUnit) + testDeadline(c, 2*timeUnit, t) +} + +func TestCanceledTimeout(t *testing.T) { + t.Parallel() + const timeUnit = 500 * time.Millisecond + c, _ := WithTimeout(Background(), 2*timeUnit) + o := otherContext{c} + c, cancel := WithTimeout(o, 4*timeUnit) + cancel() + time.Sleep(1 * timeUnit) // let cancelation propagate + select { + case <-c.Done(): + default: + t.Errorf("<-c.Done() blocked, but shouldn't have") + } + if e := c.Err(); e != Canceled { + t.Errorf("c.Err() == %v want %v", e, Canceled) + } +} + +type key1 int +type key2 int + +var k1 = key1(1) +var k2 = key2(1) // same int as k1, different type +var k3 = key2(3) // same type as k2, different int + +func TestValues(t *testing.T) { + check := func(c Context, nm, v1, v2, v3 string) { + if v, ok := c.Value(k1).(string); ok == (len(v1) == 0) || v != v1 { + t.Errorf(`%s.Value(k1).(string) = %q, %t want %q, %t`, nm, v, ok, v1, len(v1) != 0) + } + if v, ok := c.Value(k2).(string); ok == (len(v2) == 0) || v != v2 { + t.Errorf(`%s.Value(k2).(string) = %q, %t want %q, %t`, nm, v, ok, v2, len(v2) != 0) + } + if v, ok := c.Value(k3).(string); ok == (len(v3) == 0) || v != v3 { + t.Errorf(`%s.Value(k3).(string) = %q, %t want %q, %t`, nm, v, ok, v3, len(v3) != 0) + } + } + + c0 := Background() + check(c0, "c0", "", "", "") + + c1 := WithValue(Background(), k1, "c1k1") + check(c1, "c1", "c1k1", "", "") + + if got, want := fmt.Sprint(c1), `context.Background.WithValue(1, "c1k1")`; got != want { + t.Errorf("c.String() = %q want %q", got, want) + } + + c2 := WithValue(c1, k2, "c2k2") + check(c2, "c2", "c1k1", "c2k2", "") + + c3 := WithValue(c2, k3, "c3k3") + check(c3, "c2", "c1k1", "c2k2", "c3k3") + + c4 := WithValue(c3, k1, nil) + check(c4, "c4", "", "c2k2", "c3k3") + + o0 := otherContext{Background()} + check(o0, "o0", "", "", "") + + o1 := otherContext{WithValue(Background(), k1, "c1k1")} + check(o1, "o1", "c1k1", "", "") + + o2 := WithValue(o1, k2, "o2k2") + check(o2, "o2", "c1k1", "o2k2", "") + + o3 := otherContext{c4} + check(o3, "o3", "", "c2k2", "c3k3") + + o4 := WithValue(o3, k3, nil) + check(o4, "o4", "", "c2k2", "") +} + +func TestAllocs(t *testing.T) { + bg := Background() + for _, test := range []struct { + desc string + f func() + limit float64 + gccgoLimit float64 + }{ + { + desc: "Background()", + f: func() { Background() }, + limit: 0, + gccgoLimit: 0, + }, + { + desc: fmt.Sprintf("WithValue(bg, %v, nil)", k1), + f: func() { + c := WithValue(bg, k1, nil) + c.Value(k1) + }, + limit: 3, + gccgoLimit: 3, + }, + { + desc: "WithTimeout(bg, 15*time.Millisecond)", + f: func() { + c, _ := WithTimeout(bg, 15*time.Millisecond) + <-c.Done() + }, + limit: 8, + gccgoLimit: 16, + }, + { + desc: "WithCancel(bg)", + f: func() { + c, cancel := WithCancel(bg) + cancel() + <-c.Done() + }, + limit: 5, + gccgoLimit: 8, + }, + { + desc: "WithTimeout(bg, 100*time.Millisecond)", + f: func() { + c, cancel := WithTimeout(bg, 100*time.Millisecond) + cancel() + <-c.Done() + }, + limit: 8, + gccgoLimit: 25, + }, + } { + limit := test.limit + if runtime.Compiler == "gccgo" { + // gccgo does not yet do escape analysis. + // TODO(iant): Remove this when gccgo does do escape analysis. + limit = test.gccgoLimit + } + if n := testing.AllocsPerRun(100, test.f); n > limit { + t.Errorf("%s allocs = %f want %d", test.desc, n, int(limit)) + } + } +} + +func TestSimultaneousCancels(t *testing.T) { + root, cancel := WithCancel(Background()) + m := map[Context]CancelFunc{root: cancel} + q := []Context{root} + // Create a tree of contexts. + for len(q) != 0 && len(m) < 100 { + parent := q[0] + q = q[1:] + for i := 0; i < 4; i++ { + ctx, cancel := WithCancel(parent) + m[ctx] = cancel + q = append(q, ctx) + } + } + // Start all the cancels in a random order. + var wg sync.WaitGroup + wg.Add(len(m)) + for _, cancel := range m { + go func(cancel CancelFunc) { + cancel() + wg.Done() + }(cancel) + } + // Wait on all the contexts in a random order. + for ctx := range m { + select { + case <-ctx.Done(): + case <-time.After(1 * time.Second): + buf := make([]byte, 10<<10) + n := runtime.Stack(buf, true) + t.Fatalf("timed out waiting for <-ctx.Done(); stacks:\n%s", buf[:n]) + } + } + // Wait for all the cancel functions to return. + done := make(chan struct{}) + go func() { + wg.Wait() + close(done) + }() + select { + case <-done: + case <-time.After(1 * time.Second): + buf := make([]byte, 10<<10) + n := runtime.Stack(buf, true) + t.Fatalf("timed out waiting for cancel functions; stacks:\n%s", buf[:n]) + } +} + +func TestInterlockedCancels(t *testing.T) { + parent, cancelParent := WithCancel(Background()) + child, cancelChild := WithCancel(parent) + go func() { + parent.Done() + cancelChild() + }() + cancelParent() + select { + case <-child.Done(): + case <-time.After(1 * time.Second): + buf := make([]byte, 10<<10) + n := runtime.Stack(buf, true) + t.Fatalf("timed out waiting for child.Done(); stacks:\n%s", buf[:n]) + } +} + +func TestLayersCancel(t *testing.T) { + testLayers(t, time.Now().UnixNano(), false) +} + +func TestLayersTimeout(t *testing.T) { + testLayers(t, time.Now().UnixNano(), true) +} + +func testLayers(t *testing.T, seed int64, testTimeout bool) { + rand.Seed(seed) + errorf := func(format string, a ...interface{}) { + t.Errorf(fmt.Sprintf("seed=%d: %s", seed, format), a...) + } + const ( + timeout = 200 * time.Millisecond + minLayers = 30 + ) + type value int + var ( + vals []*value + cancels []CancelFunc + numTimers int + ctx = Background() + ) + for i := 0; i < minLayers || numTimers == 0 || len(cancels) == 0 || len(vals) == 0; i++ { + switch rand.Intn(3) { + case 0: + v := new(value) + ctx = WithValue(ctx, v, v) + vals = append(vals, v) + case 1: + var cancel CancelFunc + ctx, cancel = WithCancel(ctx) + cancels = append(cancels, cancel) + case 2: + var cancel CancelFunc + ctx, cancel = WithTimeout(ctx, timeout) + cancels = append(cancels, cancel) + numTimers++ + } + } + checkValues := func(when string) { + for _, key := range vals { + if val := ctx.Value(key).(*value); key != val { + errorf("%s: ctx.Value(%p) = %p want %p", when, key, val, key) + } + } + } + select { + case <-ctx.Done(): + errorf("ctx should not be canceled yet") + default: + } + if s, prefix := fmt.Sprint(ctx), "context.Background."; !strings.HasPrefix(s, prefix) { + t.Errorf("ctx.String() = %q want prefix %q", s, prefix) + } + t.Log(ctx) + checkValues("before cancel") + if testTimeout { + select { + case <-ctx.Done(): + case <-time.After(timeout + 100*time.Millisecond): + errorf("ctx should have timed out") + } + checkValues("after timeout") + } else { + cancel := cancels[rand.Intn(len(cancels))] + cancel() + select { + case <-ctx.Done(): + default: + errorf("ctx should be canceled") + } + checkValues("after cancel") + } +} + +func TestCancelRemoves(t *testing.T) { + checkChildren := func(when string, ctx Context, want int) { + if got := len(ctx.(*cancelCtx).children); got != want { + t.Errorf("%s: context has %d children, want %d", when, got, want) + } + } + + ctx, _ := WithCancel(Background()) + checkChildren("after creation", ctx, 0) + _, cancel := WithCancel(ctx) + checkChildren("with WithCancel child ", ctx, 1) + cancel() + checkChildren("after cancelling WithCancel child", ctx, 0) + + ctx, _ = WithCancel(Background()) + checkChildren("after creation", ctx, 0) + _, cancel = WithTimeout(ctx, 60*time.Minute) + checkChildren("with WithTimeout child ", ctx, 1) + cancel() + checkChildren("after cancelling WithTimeout child", ctx, 0) +} diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/ctxhttp/ctxhttp.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/ctxhttp/ctxhttp.go new file mode 100644 index 000000000..606cf1f97 --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/ctxhttp/ctxhttp.go @@ -0,0 +1,74 @@ +// Copyright 2016 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. + +// +build go1.7 + +// Package ctxhttp provides helper functions for performing context-aware HTTP requests. +package ctxhttp // import "golang.org/x/net/context/ctxhttp" + +import ( + "io" + "net/http" + "net/url" + "strings" + + "golang.org/x/net/context" +) + +// Do sends an HTTP request with the provided http.Client and returns +// an HTTP response. +// +// If the client is nil, http.DefaultClient is used. +// +// The provided ctx must be non-nil. If it is canceled or times out, +// ctx.Err() will be returned. +func Do(ctx context.Context, client *http.Client, req *http.Request) (*http.Response, error) { + if client == nil { + client = http.DefaultClient + } + resp, err := client.Do(req.WithContext(ctx)) + // If we got an error, and the context has been canceled, + // the context's error is probably more useful. + if err != nil { + select { + case <-ctx.Done(): + err = ctx.Err() + default: + } + } + return resp, err +} + +// Get issues a GET request via the Do function. +func Get(ctx context.Context, client *http.Client, url string) (*http.Response, error) { + req, err := http.NewRequest("GET", url, nil) + if err != nil { + return nil, err + } + return Do(ctx, client, req) +} + +// Head issues a HEAD request via the Do function. +func Head(ctx context.Context, client *http.Client, url string) (*http.Response, error) { + req, err := http.NewRequest("HEAD", url, nil) + if err != nil { + return nil, err + } + return Do(ctx, client, req) +} + +// Post issues a POST request via the Do function. +func Post(ctx context.Context, client *http.Client, url string, bodyType string, body io.Reader) (*http.Response, error) { + req, err := http.NewRequest("POST", url, body) + if err != nil { + return nil, err + } + req.Header.Set("Content-Type", bodyType) + return Do(ctx, client, req) +} + +// PostForm issues a POST request via the Do function. +func PostForm(ctx context.Context, client *http.Client, url string, data url.Values) (*http.Response, error) { + return Post(ctx, client, url, "application/x-www-form-urlencoded", strings.NewReader(data.Encode())) +} diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/ctxhttp/ctxhttp_17_test.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/ctxhttp/ctxhttp_17_test.go new file mode 100644 index 000000000..72411b1b6 --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/ctxhttp/ctxhttp_17_test.go @@ -0,0 +1,29 @@ +// Copyright 2015 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. + +// +build !plan9,go1.7 + +package ctxhttp + +import ( + "io" + "net/http" + "net/http/httptest" + "testing" + + "context" +) + +func TestGo17Context(t *testing.T) { + ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + io.WriteString(w, "ok") + })) + defer ts.Close() + ctx := context.Background() + resp, err := Get(ctx, http.DefaultClient, ts.URL) + if resp == nil || err != nil { + t.Fatalf("error received from client: %v %v", err, resp) + } + resp.Body.Close() +} diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/ctxhttp/ctxhttp_pre17.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/ctxhttp/ctxhttp_pre17.go new file mode 100644 index 000000000..926870cc2 --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/ctxhttp/ctxhttp_pre17.go @@ -0,0 +1,147 @@ +// Copyright 2015 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. + +// +build !go1.7 + +package ctxhttp // import "golang.org/x/net/context/ctxhttp" + +import ( + "io" + "net/http" + "net/url" + "strings" + + "golang.org/x/net/context" +) + +func nop() {} + +var ( + testHookContextDoneBeforeHeaders = nop + testHookDoReturned = nop + testHookDidBodyClose = nop +) + +// Do sends an HTTP request with the provided http.Client and returns an HTTP response. +// If the client is nil, http.DefaultClient is used. +// If the context is canceled or times out, ctx.Err() will be returned. +func Do(ctx context.Context, client *http.Client, req *http.Request) (*http.Response, error) { + if client == nil { + client = http.DefaultClient + } + + // TODO(djd): Respect any existing value of req.Cancel. + cancel := make(chan struct{}) + req.Cancel = cancel + + type responseAndError struct { + resp *http.Response + err error + } + result := make(chan responseAndError, 1) + + // Make local copies of test hooks closed over by goroutines below. + // Prevents data races in tests. + testHookDoReturned := testHookDoReturned + testHookDidBodyClose := testHookDidBodyClose + + go func() { + resp, err := client.Do(req) + testHookDoReturned() + result <- responseAndError{resp, err} + }() + + var resp *http.Response + + select { + case <-ctx.Done(): + testHookContextDoneBeforeHeaders() + close(cancel) + // Clean up after the goroutine calling client.Do: + go func() { + if r := <-result; r.resp != nil { + testHookDidBodyClose() + r.resp.Body.Close() + } + }() + return nil, ctx.Err() + case r := <-result: + var err error + resp, err = r.resp, r.err + if err != nil { + return resp, err + } + } + + c := make(chan struct{}) + go func() { + select { + case <-ctx.Done(): + close(cancel) + case <-c: + // The response's Body is closed. + } + }() + resp.Body = ¬ifyingReader{resp.Body, c} + + return resp, nil +} + +// Get issues a GET request via the Do function. +func Get(ctx context.Context, client *http.Client, url string) (*http.Response, error) { + req, err := http.NewRequest("GET", url, nil) + if err != nil { + return nil, err + } + return Do(ctx, client, req) +} + +// Head issues a HEAD request via the Do function. +func Head(ctx context.Context, client *http.Client, url string) (*http.Response, error) { + req, err := http.NewRequest("HEAD", url, nil) + if err != nil { + return nil, err + } + return Do(ctx, client, req) +} + +// Post issues a POST request via the Do function. +func Post(ctx context.Context, client *http.Client, url string, bodyType string, body io.Reader) (*http.Response, error) { + req, err := http.NewRequest("POST", url, body) + if err != nil { + return nil, err + } + req.Header.Set("Content-Type", bodyType) + return Do(ctx, client, req) +} + +// PostForm issues a POST request via the Do function. +func PostForm(ctx context.Context, client *http.Client, url string, data url.Values) (*http.Response, error) { + return Post(ctx, client, url, "application/x-www-form-urlencoded", strings.NewReader(data.Encode())) +} + +// notifyingReader is an io.ReadCloser that closes the notify channel after +// Close is called or a Read fails on the underlying ReadCloser. +type notifyingReader struct { + io.ReadCloser + notify chan<- struct{} +} + +func (r *notifyingReader) Read(p []byte) (int, error) { + n, err := r.ReadCloser.Read(p) + if err != nil && r.notify != nil { + close(r.notify) + r.notify = nil + } + return n, err +} + +func (r *notifyingReader) Close() error { + err := r.ReadCloser.Close() + if r.notify != nil { + close(r.notify) + r.notify = nil + } + return err +} diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/ctxhttp/ctxhttp_pre17_test.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/ctxhttp/ctxhttp_pre17_test.go new file mode 100644 index 000000000..9159cf022 --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/ctxhttp/ctxhttp_pre17_test.go @@ -0,0 +1,79 @@ +// Copyright 2015 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. + +// +build !plan9,!go1.7 + +package ctxhttp + +import ( + "net" + "net/http" + "net/http/httptest" + "sync" + "testing" + "time" + + "golang.org/x/net/context" +) + +// golang.org/issue/14065 +func TestClosesResponseBodyOnCancel(t *testing.T) { + defer func() { testHookContextDoneBeforeHeaders = nop }() + defer func() { testHookDoReturned = nop }() + defer func() { testHookDidBodyClose = nop }() + + ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {})) + defer ts.Close() + + ctx, cancel := context.WithCancel(context.Background()) + + // closed when Do enters select case <-ctx.Done() + enteredDonePath := make(chan struct{}) + + testHookContextDoneBeforeHeaders = func() { + close(enteredDonePath) + } + + testHookDoReturned = func() { + // We now have the result (the Flush'd headers) at least, + // so we can cancel the request. + cancel() + + // But block the client.Do goroutine from sending + // until Do enters into the <-ctx.Done() path, since + // otherwise if both channels are readable, select + // picks a random one. + <-enteredDonePath + } + + sawBodyClose := make(chan struct{}) + testHookDidBodyClose = func() { close(sawBodyClose) } + + tr := &http.Transport{} + defer tr.CloseIdleConnections() + c := &http.Client{Transport: tr} + req, _ := http.NewRequest("GET", ts.URL, nil) + _, doErr := Do(ctx, c, req) + + select { + case <-sawBodyClose: + case <-time.After(5 * time.Second): + t.Fatal("timeout waiting for body to close") + } + + if doErr != ctx.Err() { + t.Errorf("Do error = %v; want %v", doErr, ctx.Err()) + } +} + +type noteCloseConn struct { + net.Conn + onceClose sync.Once + closefn func() +} + +func (c *noteCloseConn) Close() error { + c.onceClose.Do(c.closefn) + return c.Conn.Close() +} diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/ctxhttp/ctxhttp_test.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/ctxhttp/ctxhttp_test.go new file mode 100644 index 000000000..1e4155180 --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/ctxhttp/ctxhttp_test.go @@ -0,0 +1,105 @@ +// Copyright 2015 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. + +// +build !plan9 + +package ctxhttp + +import ( + "io" + "io/ioutil" + "net/http" + "net/http/httptest" + "testing" + "time" + + "golang.org/x/net/context" +) + +const ( + requestDuration = 100 * time.Millisecond + requestBody = "ok" +) + +func okHandler(w http.ResponseWriter, r *http.Request) { + time.Sleep(requestDuration) + io.WriteString(w, requestBody) +} + +func TestNoTimeout(t *testing.T) { + ts := httptest.NewServer(http.HandlerFunc(okHandler)) + defer ts.Close() + + ctx := context.Background() + res, err := Get(ctx, nil, ts.URL) + if err != nil { + t.Fatal(err) + } + defer res.Body.Close() + slurp, err := ioutil.ReadAll(res.Body) + if err != nil { + t.Fatal(err) + } + if string(slurp) != requestBody { + t.Errorf("body = %q; want %q", slurp, requestBody) + } +} + +func TestCancelBeforeHeaders(t *testing.T) { + ctx, cancel := context.WithCancel(context.Background()) + + blockServer := make(chan struct{}) + ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + cancel() + <-blockServer + io.WriteString(w, requestBody) + })) + defer ts.Close() + defer close(blockServer) + + res, err := Get(ctx, nil, ts.URL) + if err == nil { + res.Body.Close() + t.Fatal("Get returned unexpected nil error") + } + if err != context.Canceled { + t.Errorf("err = %v; want %v", err, context.Canceled) + } +} + +func TestCancelAfterHangingRequest(t *testing.T) { + ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + w.WriteHeader(http.StatusOK) + w.(http.Flusher).Flush() + <-w.(http.CloseNotifier).CloseNotify() + })) + defer ts.Close() + + ctx, cancel := context.WithCancel(context.Background()) + resp, err := Get(ctx, nil, ts.URL) + if err != nil { + t.Fatalf("unexpected error in Get: %v", err) + } + + // Cancel befer reading the body. + // Reading Request.Body should fail, since the request was + // canceled before anything was written. + cancel() + + done := make(chan struct{}) + + go func() { + b, err := ioutil.ReadAll(resp.Body) + if len(b) != 0 || err == nil { + t.Errorf(`Read got (%q, %v); want ("", error)`, b, err) + } + close(done) + }() + + select { + case <-time.After(1 * time.Second): + t.Errorf("Test timed out") + case <-done: + } +} diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/go17.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/go17.go new file mode 100644 index 000000000..d20f52b7d --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/go17.go @@ -0,0 +1,72 @@ +// Copyright 2016 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. + +// +build go1.7 + +package context + +import ( + "context" // standard library's context, as of Go 1.7 + "time" +) + +var ( + todo = context.TODO() + background = context.Background() +) + +// Canceled is the error returned by Context.Err when the context is canceled. +var Canceled = context.Canceled + +// DeadlineExceeded is the error returned by Context.Err when the context's +// deadline passes. +var DeadlineExceeded = context.DeadlineExceeded + +// WithCancel returns a copy of parent with a new Done channel. The returned +// context's Done channel is closed when the returned cancel function is called +// or when the parent context's Done channel is closed, whichever happens first. +// +// Canceling this context releases resources associated with it, so code should +// call cancel as soon as the operations running in this Context complete. +func WithCancel(parent Context) (ctx Context, cancel CancelFunc) { + ctx, f := context.WithCancel(parent) + return ctx, CancelFunc(f) +} + +// WithDeadline returns a copy of the parent context with the deadline adjusted +// to be no later than d. If the parent's deadline is already earlier than d, +// WithDeadline(parent, d) is semantically equivalent to parent. The returned +// context's Done channel is closed when the deadline expires, when the returned +// cancel function is called, or when the parent context's Done channel is +// closed, whichever happens first. +// +// Canceling this context releases resources associated with it, so code should +// call cancel as soon as the operations running in this Context complete. +func WithDeadline(parent Context, deadline time.Time) (Context, CancelFunc) { + ctx, f := context.WithDeadline(parent, deadline) + return ctx, CancelFunc(f) +} + +// WithTimeout returns WithDeadline(parent, time.Now().Add(timeout)). +// +// Canceling this context releases resources associated with it, so code should +// call cancel as soon as the operations running in this Context complete: +// +// func slowOperationWithTimeout(ctx context.Context) (Result, error) { +// ctx, cancel := context.WithTimeout(ctx, 100*time.Millisecond) +// defer cancel() // releases resources if slowOperation completes before timeout elapses +// return slowOperation(ctx) +// } +func WithTimeout(parent Context, timeout time.Duration) (Context, CancelFunc) { + return WithDeadline(parent, time.Now().Add(timeout)) +} + +// WithValue returns a copy of parent in which the value associated with key is +// val. +// +// Use context Values only for request-scoped data that transits processes and +// APIs, not for passing optional parameters to functions. +func WithValue(parent Context, key interface{}, val interface{}) Context { + return context.WithValue(parent, key, val) +} diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/go19.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/go19.go new file mode 100644 index 000000000..d88bd1db1 --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/go19.go @@ -0,0 +1,20 @@ +// Copyright 2017 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. + +// +build go1.9 + +package context + +import "context" // standard library's context, as of Go 1.7 + +// A Context carries a deadline, a cancelation signal, and other values across +// API boundaries. +// +// Context's methods may be called by multiple goroutines simultaneously. +type Context = context.Context + +// A CancelFunc tells an operation to abandon its work. +// A CancelFunc does not wait for the work to stop. +// After the first call, subsequent calls to a CancelFunc do nothing. +type CancelFunc = context.CancelFunc diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/pre_go17.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/pre_go17.go new file mode 100644 index 000000000..0f35592df --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/pre_go17.go @@ -0,0 +1,300 @@ +// Copyright 2014 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. + +// +build !go1.7 + +package context + +import ( + "errors" + "fmt" + "sync" + "time" +) + +// An emptyCtx is never canceled, has no values, and has no deadline. It is not +// struct{}, since vars of this type must have distinct addresses. +type emptyCtx int + +func (*emptyCtx) Deadline() (deadline time.Time, ok bool) { + return +} + +func (*emptyCtx) Done() <-chan struct{} { + return nil +} + +func (*emptyCtx) Err() error { + return nil +} + +func (*emptyCtx) Value(key interface{}) interface{} { + return nil +} + +func (e *emptyCtx) String() string { + switch e { + case background: + return "context.Background" + case todo: + return "context.TODO" + } + return "unknown empty Context" +} + +var ( + background = new(emptyCtx) + todo = new(emptyCtx) +) + +// Canceled is the error returned by Context.Err when the context is canceled. +var Canceled = errors.New("context canceled") + +// DeadlineExceeded is the error returned by Context.Err when the context's +// deadline passes. +var DeadlineExceeded = errors.New("context deadline exceeded") + +// WithCancel returns a copy of parent with a new Done channel. The returned +// context's Done channel is closed when the returned cancel function is called +// or when the parent context's Done channel is closed, whichever happens first. +// +// Canceling this context releases resources associated with it, so code should +// call cancel as soon as the operations running in this Context complete. +func WithCancel(parent Context) (ctx Context, cancel CancelFunc) { + c := newCancelCtx(parent) + propagateCancel(parent, c) + return c, func() { c.cancel(true, Canceled) } +} + +// newCancelCtx returns an initialized cancelCtx. +func newCancelCtx(parent Context) *cancelCtx { + return &cancelCtx{ + Context: parent, + done: make(chan struct{}), + } +} + +// propagateCancel arranges for child to be canceled when parent is. +func propagateCancel(parent Context, child canceler) { + if parent.Done() == nil { + return // parent is never canceled + } + if p, ok := parentCancelCtx(parent); ok { + p.mu.Lock() + if p.err != nil { + // parent has already been canceled + child.cancel(false, p.err) + } else { + if p.children == nil { + p.children = make(map[canceler]bool) + } + p.children[child] = true + } + p.mu.Unlock() + } else { + go func() { + select { + case <-parent.Done(): + child.cancel(false, parent.Err()) + case <-child.Done(): + } + }() + } +} + +// parentCancelCtx follows a chain of parent references until it finds a +// *cancelCtx. This function understands how each of the concrete types in this +// package represents its parent. +func parentCancelCtx(parent Context) (*cancelCtx, bool) { + for { + switch c := parent.(type) { + case *cancelCtx: + return c, true + case *timerCtx: + return c.cancelCtx, true + case *valueCtx: + parent = c.Context + default: + return nil, false + } + } +} + +// removeChild removes a context from its parent. +func removeChild(parent Context, child canceler) { + p, ok := parentCancelCtx(parent) + if !ok { + return + } + p.mu.Lock() + if p.children != nil { + delete(p.children, child) + } + p.mu.Unlock() +} + +// A canceler is a context type that can be canceled directly. The +// implementations are *cancelCtx and *timerCtx. +type canceler interface { + cancel(removeFromParent bool, err error) + Done() <-chan struct{} +} + +// A cancelCtx can be canceled. When canceled, it also cancels any children +// that implement canceler. +type cancelCtx struct { + Context + + done chan struct{} // closed by the first cancel call. + + mu sync.Mutex + children map[canceler]bool // set to nil by the first cancel call + err error // set to non-nil by the first cancel call +} + +func (c *cancelCtx) Done() <-chan struct{} { + return c.done +} + +func (c *cancelCtx) Err() error { + c.mu.Lock() + defer c.mu.Unlock() + return c.err +} + +func (c *cancelCtx) String() string { + return fmt.Sprintf("%v.WithCancel", c.Context) +} + +// cancel closes c.done, cancels each of c's children, and, if +// removeFromParent is true, removes c from its parent's children. +func (c *cancelCtx) cancel(removeFromParent bool, err error) { + if err == nil { + panic("context: internal error: missing cancel error") + } + c.mu.Lock() + if c.err != nil { + c.mu.Unlock() + return // already canceled + } + c.err = err + close(c.done) + for child := range c.children { + // NOTE: acquiring the child's lock while holding parent's lock. + child.cancel(false, err) + } + c.children = nil + c.mu.Unlock() + + if removeFromParent { + removeChild(c.Context, c) + } +} + +// WithDeadline returns a copy of the parent context with the deadline adjusted +// to be no later than d. If the parent's deadline is already earlier than d, +// WithDeadline(parent, d) is semantically equivalent to parent. The returned +// context's Done channel is closed when the deadline expires, when the returned +// cancel function is called, or when the parent context's Done channel is +// closed, whichever happens first. +// +// Canceling this context releases resources associated with it, so code should +// call cancel as soon as the operations running in this Context complete. +func WithDeadline(parent Context, deadline time.Time) (Context, CancelFunc) { + if cur, ok := parent.Deadline(); ok && cur.Before(deadline) { + // The current deadline is already sooner than the new one. + return WithCancel(parent) + } + c := &timerCtx{ + cancelCtx: newCancelCtx(parent), + deadline: deadline, + } + propagateCancel(parent, c) + d := deadline.Sub(time.Now()) + if d <= 0 { + c.cancel(true, DeadlineExceeded) // deadline has already passed + return c, func() { c.cancel(true, Canceled) } + } + c.mu.Lock() + defer c.mu.Unlock() + if c.err == nil { + c.timer = time.AfterFunc(d, func() { + c.cancel(true, DeadlineExceeded) + }) + } + return c, func() { c.cancel(true, Canceled) } +} + +// A timerCtx carries a timer and a deadline. It embeds a cancelCtx to +// implement Done and Err. It implements cancel by stopping its timer then +// delegating to cancelCtx.cancel. +type timerCtx struct { + *cancelCtx + timer *time.Timer // Under cancelCtx.mu. + + deadline time.Time +} + +func (c *timerCtx) Deadline() (deadline time.Time, ok bool) { + return c.deadline, true +} + +func (c *timerCtx) String() string { + return fmt.Sprintf("%v.WithDeadline(%s [%s])", c.cancelCtx.Context, c.deadline, c.deadline.Sub(time.Now())) +} + +func (c *timerCtx) cancel(removeFromParent bool, err error) { + c.cancelCtx.cancel(false, err) + if removeFromParent { + // Remove this timerCtx from its parent cancelCtx's children. + removeChild(c.cancelCtx.Context, c) + } + c.mu.Lock() + if c.timer != nil { + c.timer.Stop() + c.timer = nil + } + c.mu.Unlock() +} + +// WithTimeout returns WithDeadline(parent, time.Now().Add(timeout)). +// +// Canceling this context releases resources associated with it, so code should +// call cancel as soon as the operations running in this Context complete: +// +// func slowOperationWithTimeout(ctx context.Context) (Result, error) { +// ctx, cancel := context.WithTimeout(ctx, 100*time.Millisecond) +// defer cancel() // releases resources if slowOperation completes before timeout elapses +// return slowOperation(ctx) +// } +func WithTimeout(parent Context, timeout time.Duration) (Context, CancelFunc) { + return WithDeadline(parent, time.Now().Add(timeout)) +} + +// WithValue returns a copy of parent in which the value associated with key is +// val. +// +// Use context Values only for request-scoped data that transits processes and +// APIs, not for passing optional parameters to functions. +func WithValue(parent Context, key interface{}, val interface{}) Context { + return &valueCtx{parent, key, val} +} + +// A valueCtx carries a key-value pair. It implements Value for that key and +// delegates all other calls to the embedded Context. +type valueCtx struct { + Context + key, val interface{} +} + +func (c *valueCtx) String() string { + return fmt.Sprintf("%v.WithValue(%#v, %#v)", c.Context, c.key, c.val) +} + +func (c *valueCtx) Value(key interface{}) interface{} { + if c.key == key { + return c.val + } + return c.Context.Value(key) +} diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/pre_go19.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/pre_go19.go new file mode 100644 index 000000000..b105f80be --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/pre_go19.go @@ -0,0 +1,109 @@ +// Copyright 2014 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. + +// +build !go1.9 + +package context + +import "time" + +// A Context carries a deadline, a cancelation signal, and other values across +// API boundaries. +// +// Context's methods may be called by multiple goroutines simultaneously. +type Context interface { + // Deadline returns the time when work done on behalf of this context + // should be canceled. Deadline returns ok==false when no deadline is + // set. Successive calls to Deadline return the same results. + Deadline() (deadline time.Time, ok bool) + + // Done returns a channel that's closed when work done on behalf of this + // context should be canceled. Done may return nil if this context can + // never be canceled. Successive calls to Done return the same value. + // + // WithCancel arranges for Done to be closed when cancel is called; + // WithDeadline arranges for Done to be closed when the deadline + // expires; WithTimeout arranges for Done to be closed when the timeout + // elapses. + // + // Done is provided for use in select statements: + // + // // Stream generates values with DoSomething and sends them to out + // // until DoSomething returns an error or ctx.Done is closed. + // func Stream(ctx context.Context, out chan<- Value) error { + // for { + // v, err := DoSomething(ctx) + // if err != nil { + // return err + // } + // select { + // case <-ctx.Done(): + // return ctx.Err() + // case out <- v: + // } + // } + // } + // + // See http://blog.golang.org/pipelines for more examples of how to use + // a Done channel for cancelation. + Done() <-chan struct{} + + // Err returns a non-nil error value after Done is closed. Err returns + // Canceled if the context was canceled or DeadlineExceeded if the + // context's deadline passed. No other values for Err are defined. + // After Done is closed, successive calls to Err return the same value. + Err() error + + // Value returns the value associated with this context for key, or nil + // if no value is associated with key. Successive calls to Value with + // the same key returns the same result. + // + // Use context values only for request-scoped data that transits + // processes and API boundaries, not for passing optional parameters to + // functions. + // + // A key identifies a specific value in a Context. Functions that wish + // to store values in Context typically allocate a key in a global + // variable then use that key as the argument to context.WithValue and + // Context.Value. A key can be any type that supports equality; + // packages should define keys as an unexported type to avoid + // collisions. + // + // Packages that define a Context key should provide type-safe accessors + // for the values stores using that key: + // + // // Package user defines a User type that's stored in Contexts. + // package user + // + // import "golang.org/x/net/context" + // + // // User is the type of value stored in the Contexts. + // type User struct {...} + // + // // key is an unexported type for keys defined in this package. + // // This prevents collisions with keys defined in other packages. + // type key int + // + // // userKey is the key for user.User values in Contexts. It is + // // unexported; clients use user.NewContext and user.FromContext + // // instead of using this key directly. + // var userKey key = 0 + // + // // NewContext returns a new Context that carries value u. + // func NewContext(ctx context.Context, u *User) context.Context { + // return context.WithValue(ctx, userKey, u) + // } + // + // // FromContext returns the User value stored in ctx, if any. + // func FromContext(ctx context.Context) (*User, bool) { + // u, ok := ctx.Value(userKey).(*User) + // return u, ok + // } + Value(key interface{}) interface{} +} + +// A CancelFunc tells an operation to abandon its work. +// A CancelFunc does not wait for the work to stop. +// After the first call, subsequent calls to a CancelFunc do nothing. +type CancelFunc func() diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/withtimeout_test.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/withtimeout_test.go new file mode 100644 index 000000000..e6f56691d --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/net/context/withtimeout_test.go @@ -0,0 +1,31 @@ +// Copyright 2014 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 context_test + +import ( + "fmt" + "time" + + "golang.org/x/net/context" +) + +// This example passes a context with a timeout to tell a blocking function that +// it should abandon its work after the timeout elapses. +func ExampleWithTimeout() { + // Pass a context with a timeout to tell a blocking function that it + // should abandon its work after the timeout elapses. + ctx, cancel := context.WithTimeout(context.Background(), 50*time.Millisecond) + defer cancel() + + select { + case <-time.After(1 * time.Second): + fmt.Println("overslept") + case <-ctx.Done(): + fmt.Println(ctx.Err()) // prints "context deadline exceeded" + } + + // Output: + // context deadline exceeded +} |