diff options
Diffstat (limited to '')
-rw-r--r-- | dependencies/pkg/mod/golang.org/x/sync@v0.0.0-20210220032951-036812b2e83c/singleflight/singleflight_test.go | 320 |
1 files changed, 320 insertions, 0 deletions
diff --git a/dependencies/pkg/mod/golang.org/x/sync@v0.0.0-20210220032951-036812b2e83c/singleflight/singleflight_test.go b/dependencies/pkg/mod/golang.org/x/sync@v0.0.0-20210220032951-036812b2e83c/singleflight/singleflight_test.go new file mode 100644 index 0000000..3e51203 --- /dev/null +++ b/dependencies/pkg/mod/golang.org/x/sync@v0.0.0-20210220032951-036812b2e83c/singleflight/singleflight_test.go @@ -0,0 +1,320 @@ +// 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 singleflight + +import ( + "bytes" + "errors" + "fmt" + "os" + "os/exec" + "runtime" + "runtime/debug" + "strings" + "sync" + "sync/atomic" + "testing" + "time" +) + +func TestDo(t *testing.T) { + var g Group + v, err, _ := g.Do("key", func() (interface{}, error) { + return "bar", nil + }) + if got, want := fmt.Sprintf("%v (%T)", v, v), "bar (string)"; got != want { + t.Errorf("Do = %v; want %v", got, want) + } + if err != nil { + t.Errorf("Do error = %v", err) + } +} + +func TestDoErr(t *testing.T) { + var g Group + someErr := errors.New("Some error") + v, err, _ := g.Do("key", func() (interface{}, error) { + return nil, someErr + }) + if err != someErr { + t.Errorf("Do error = %v; want someErr %v", err, someErr) + } + if v != nil { + t.Errorf("unexpected non-nil value %#v", v) + } +} + +func TestDoDupSuppress(t *testing.T) { + var g Group + var wg1, wg2 sync.WaitGroup + c := make(chan string, 1) + var calls int32 + fn := func() (interface{}, error) { + if atomic.AddInt32(&calls, 1) == 1 { + // First invocation. + wg1.Done() + } + v := <-c + c <- v // pump; make available for any future calls + + time.Sleep(10 * time.Millisecond) // let more goroutines enter Do + + return v, nil + } + + const n = 10 + wg1.Add(1) + for i := 0; i < n; i++ { + wg1.Add(1) + wg2.Add(1) + go func() { + defer wg2.Done() + wg1.Done() + v, err, _ := g.Do("key", fn) + if err != nil { + t.Errorf("Do error: %v", err) + return + } + if s, _ := v.(string); s != "bar" { + t.Errorf("Do = %T %v; want %q", v, v, "bar") + } + }() + } + wg1.Wait() + // At least one goroutine is in fn now and all of them have at + // least reached the line before the Do. + c <- "bar" + wg2.Wait() + if got := atomic.LoadInt32(&calls); got <= 0 || got >= n { + t.Errorf("number of calls = %d; want over 0 and less than %d", got, n) + } +} + +// Test that singleflight behaves correctly after Forget called. +// See https://github.com/golang/go/issues/31420 +func TestForget(t *testing.T) { + var g Group + + var ( + firstStarted = make(chan struct{}) + unblockFirst = make(chan struct{}) + firstFinished = make(chan struct{}) + ) + + go func() { + g.Do("key", func() (i interface{}, e error) { + close(firstStarted) + <-unblockFirst + close(firstFinished) + return + }) + }() + <-firstStarted + g.Forget("key") + + unblockSecond := make(chan struct{}) + secondResult := g.DoChan("key", func() (i interface{}, e error) { + <-unblockSecond + return 2, nil + }) + + close(unblockFirst) + <-firstFinished + + thirdResult := g.DoChan("key", func() (i interface{}, e error) { + return 3, nil + }) + + close(unblockSecond) + <-secondResult + r := <-thirdResult + if r.Val != 2 { + t.Errorf("We should receive result produced by second call, expected: 2, got %d", r.Val) + } +} + +func TestDoChan(t *testing.T) { + var g Group + ch := g.DoChan("key", func() (interface{}, error) { + return "bar", nil + }) + + res := <-ch + v := res.Val + err := res.Err + if got, want := fmt.Sprintf("%v (%T)", v, v), "bar (string)"; got != want { + t.Errorf("Do = %v; want %v", got, want) + } + if err != nil { + t.Errorf("Do error = %v", err) + } +} + +// Test singleflight behaves correctly after Do panic. +// See https://github.com/golang/go/issues/41133 +func TestPanicDo(t *testing.T) { + var g Group + fn := func() (interface{}, error) { + panic("invalid memory address or nil pointer dereference") + } + + const n = 5 + waited := int32(n) + panicCount := int32(0) + done := make(chan struct{}) + for i := 0; i < n; i++ { + go func() { + defer func() { + if err := recover(); err != nil { + t.Logf("Got panic: %v\n%s", err, debug.Stack()) + atomic.AddInt32(&panicCount, 1) + } + + if atomic.AddInt32(&waited, -1) == 0 { + close(done) + } + }() + + g.Do("key", fn) + }() + } + + select { + case <-done: + if panicCount != n { + t.Errorf("Expect %d panic, but got %d", n, panicCount) + } + case <-time.After(time.Second): + t.Fatalf("Do hangs") + } +} + +func TestGoexitDo(t *testing.T) { + var g Group + fn := func() (interface{}, error) { + runtime.Goexit() + return nil, nil + } + + const n = 5 + waited := int32(n) + done := make(chan struct{}) + for i := 0; i < n; i++ { + go func() { + var err error + defer func() { + if err != nil { + t.Errorf("Error should be nil, but got: %v", err) + } + if atomic.AddInt32(&waited, -1) == 0 { + close(done) + } + }() + _, err, _ = g.Do("key", fn) + }() + } + + select { + case <-done: + case <-time.After(time.Second): + t.Fatalf("Do hangs") + } +} + +func TestPanicDoChan(t *testing.T) { + if runtime.GOOS == "js" { + t.Skipf("js does not support exec") + } + + if os.Getenv("TEST_PANIC_DOCHAN") != "" { + defer func() { + recover() + }() + + g := new(Group) + ch := g.DoChan("", func() (interface{}, error) { + panic("Panicking in DoChan") + }) + <-ch + t.Fatalf("DoChan unexpectedly returned") + } + + t.Parallel() + + cmd := exec.Command(os.Args[0], "-test.run="+t.Name(), "-test.v") + cmd.Env = append(os.Environ(), "TEST_PANIC_DOCHAN=1") + out := new(bytes.Buffer) + cmd.Stdout = out + cmd.Stderr = out + if err := cmd.Start(); err != nil { + t.Fatal(err) + } + + err := cmd.Wait() + t.Logf("%s:\n%s", strings.Join(cmd.Args, " "), out) + if err == nil { + t.Errorf("Test subprocess passed; want a crash due to panic in DoChan") + } + if bytes.Contains(out.Bytes(), []byte("DoChan unexpectedly")) { + t.Errorf("Test subprocess failed with an unexpected failure mode.") + } + if !bytes.Contains(out.Bytes(), []byte("Panicking in DoChan")) { + t.Errorf("Test subprocess failed, but the crash isn't caused by panicking in DoChan") + } +} + +func TestPanicDoSharedByDoChan(t *testing.T) { + if runtime.GOOS == "js" { + t.Skipf("js does not support exec") + } + + if os.Getenv("TEST_PANIC_DOCHAN") != "" { + blocked := make(chan struct{}) + unblock := make(chan struct{}) + + g := new(Group) + go func() { + defer func() { + recover() + }() + g.Do("", func() (interface{}, error) { + close(blocked) + <-unblock + panic("Panicking in Do") + }) + }() + + <-blocked + ch := g.DoChan("", func() (interface{}, error) { + panic("DoChan unexpectedly executed callback") + }) + close(unblock) + <-ch + t.Fatalf("DoChan unexpectedly returned") + } + + t.Parallel() + + cmd := exec.Command(os.Args[0], "-test.run="+t.Name(), "-test.v") + cmd.Env = append(os.Environ(), "TEST_PANIC_DOCHAN=1") + out := new(bytes.Buffer) + cmd.Stdout = out + cmd.Stderr = out + if err := cmd.Start(); err != nil { + t.Fatal(err) + } + + err := cmd.Wait() + t.Logf("%s:\n%s", strings.Join(cmd.Args, " "), out) + if err == nil { + t.Errorf("Test subprocess passed; want a crash due to panic in Do shared by DoChan") + } + if bytes.Contains(out.Bytes(), []byte("DoChan unexpectedly")) { + t.Errorf("Test subprocess failed with an unexpected failure mode.") + } + if !bytes.Contains(out.Bytes(), []byte("Panicking in Do")) { + t.Errorf("Test subprocess failed, but the crash isn't caused by panicking in Do") + } +} |