| // Copyright 2009 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 net |
| |
| import ( |
| "flag" |
| "fmt" |
| "testing" |
| "time" |
| ) |
| |
| var testDNSFlood = flag.Bool("dnsflood", false, "whether to test dns query flooding") |
| |
| func TestDNSThreadLimit(t *testing.T) { |
| if !*testDNSFlood { |
| t.Skip("test disabled; use -dnsflood to enable") |
| } |
| |
| const N = 10000 |
| c := make(chan int, N) |
| for i := 0; i < N; i++ { |
| go func(i int) { |
| LookupIP(fmt.Sprintf("%d.net-test.golang.org", i)) |
| c <- 1 |
| }(i) |
| } |
| // Don't bother waiting for the stragglers; stop at 0.9 N. |
| for i := 0; i < N*9/10; i++ { |
| if i%100 == 0 { |
| //println("TestDNSThreadLimit:", i) |
| } |
| <-c |
| } |
| |
| // If we're still here, it worked. |
| } |
| |
| func TestLookupIPDeadline(t *testing.T) { |
| if !*testDNSFlood { |
| t.Skip("test disabled; use -dnsflood to enable") |
| } |
| |
| const N = 5000 |
| const timeout = 3 * time.Second |
| c := make(chan error, 2*N) |
| for i := 0; i < N; i++ { |
| name := fmt.Sprintf("%d.net-test.golang.org", i) |
| go func() { |
| _, err := lookupIPDeadline(name, time.Now().Add(timeout/2)) |
| c <- err |
| }() |
| go func() { |
| _, err := lookupIPDeadline(name, time.Now().Add(timeout)) |
| c <- err |
| }() |
| } |
| qstats := struct { |
| succeeded, failed int |
| timeout, temporary, other int |
| unknown int |
| }{} |
| deadline := time.After(timeout + time.Second) |
| for i := 0; i < 2*N; i++ { |
| select { |
| case <-deadline: |
| t.Fatal("deadline exceeded") |
| case err := <-c: |
| switch err := err.(type) { |
| case nil: |
| qstats.succeeded++ |
| case Error: |
| qstats.failed++ |
| if err.Timeout() { |
| qstats.timeout++ |
| } |
| if err.Temporary() { |
| qstats.temporary++ |
| } |
| if !err.Timeout() && !err.Temporary() { |
| qstats.other++ |
| } |
| default: |
| qstats.failed++ |
| qstats.unknown++ |
| } |
| } |
| } |
| |
| // A high volume of DNS queries for sub-domain of golang.org |
| // would be coordinated by authoritative or recursive server, |
| // or stub resolver which implements query-response rate |
| // limitation, so we can expect some query successes and more |
| // failures including timeout, temporary and other here. |
| // As a rule, unknown must not be shown but it might possibly |
| // happen due to issue 4856 for now. |
| t.Logf("%v succeeded, %v failed (%v timeout, %v temporary, %v other, %v unknown)", qstats.succeeded, qstats.failed, qstats.timeout, qstats.temporary, qstats.other, qstats.unknown) |
| } |