github.com/ader1990/go@v0.0.0-20140630135419-8c24447fa791/src/pkg/net/http/z_last_test.go (about)

     1  // Copyright 2013 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package http_test
     6  
     7  import (
     8  	"net/http"
     9  	"runtime"
    10  	"sort"
    11  	"strings"
    12  	"testing"
    13  	"time"
    14  )
    15  
    16  func interestingGoroutines() (gs []string) {
    17  	buf := make([]byte, 2<<20)
    18  	buf = buf[:runtime.Stack(buf, true)]
    19  	for _, g := range strings.Split(string(buf), "\n\n") {
    20  		sl := strings.SplitN(g, "\n", 2)
    21  		if len(sl) != 2 {
    22  			continue
    23  		}
    24  		stack := strings.TrimSpace(sl[1])
    25  		if stack == "" ||
    26  			strings.Contains(stack, "created by net.startServer") ||
    27  			strings.Contains(stack, "created by testing.RunTests") ||
    28  			strings.Contains(stack, "closeWriteAndWait") ||
    29  			strings.Contains(stack, "testing.Main(") ||
    30  			// These only show up with GOTRACEBACK=2; Issue 5005 (comment 28)
    31  			strings.Contains(stack, "runtime.goexit") ||
    32  			strings.Contains(stack, "created by runtime.gc") ||
    33  			strings.Contains(stack, "runtime.MHeap_Scavenger") {
    34  			continue
    35  		}
    36  		gs = append(gs, stack)
    37  	}
    38  	sort.Strings(gs)
    39  	return
    40  }
    41  
    42  // Verify the other tests didn't leave any goroutines running.
    43  // This is in a file named z_last_test.go so it sorts at the end.
    44  func TestGoroutinesRunning(t *testing.T) {
    45  	if testing.Short() {
    46  		t.Skip("not counting goroutines for leakage in -short mode")
    47  	}
    48  	gs := interestingGoroutines()
    49  
    50  	n := 0
    51  	stackCount := make(map[string]int)
    52  	for _, g := range gs {
    53  		stackCount[g]++
    54  		n++
    55  	}
    56  
    57  	t.Logf("num goroutines = %d", n)
    58  	if n > 0 {
    59  		t.Error("Too many goroutines.")
    60  		for stack, count := range stackCount {
    61  			t.Logf("%d instances of:\n%s", count, stack)
    62  		}
    63  	}
    64  }
    65  
    66  func afterTest(t *testing.T) {
    67  	http.DefaultTransport.(*http.Transport).CloseIdleConnections()
    68  	if testing.Short() {
    69  		return
    70  	}
    71  	var bad string
    72  	badSubstring := map[string]string{
    73  		").readLoop(":                                  "a Transport",
    74  		").writeLoop(":                                 "a Transport",
    75  		"created by net/http/httptest.(*Server).Start": "an httptest.Server",
    76  		"timeoutHandler":                               "a TimeoutHandler",
    77  		"net.(*netFD).connect(":                        "a timing out dial",
    78  		").noteClientGone(":                            "a closenotifier sender",
    79  	}
    80  	var stacks string
    81  	for i := 0; i < 4; i++ {
    82  		bad = ""
    83  		stacks = strings.Join(interestingGoroutines(), "\n\n")
    84  		for substr, what := range badSubstring {
    85  			if strings.Contains(stacks, substr) {
    86  				bad = what
    87  			}
    88  		}
    89  		if bad == "" {
    90  			return
    91  		}
    92  		// Bad stuff found, but goroutines might just still be
    93  		// shutting down, so give it some time.
    94  		time.Sleep(250 * time.Millisecond)
    95  	}
    96  	t.Errorf("Test appears to have leaked %s:\n%s", bad, stacks)
    97  }