net: close fds eagerly in DialTimeout
Integrates with the pollserver now.
Uses the old implementation on windows and plan9.
Fixes #2631
R=paul, iant, adg, bendaglish, rsc
CC=golang-dev
https://golang.org/cl/6815049
diff --git a/src/pkg/net/dial_test.go b/src/pkg/net/dial_test.go
index 869c3cb..34a15f2 100644
--- a/src/pkg/net/dial_test.go
+++ b/src/pkg/net/dial_test.go
@@ -7,6 +7,8 @@
import (
"flag"
"fmt"
+ "io"
+ "os"
"regexp"
"runtime"
"testing"
@@ -222,3 +224,79 @@
}
}
}
+
+func TestDialTimeoutFDLeak(t *testing.T) {
+ if runtime.GOOS != "linux" {
+ // TODO(bradfitz): test on other platforms
+ t.Logf("skipping test on %s", runtime.GOOS)
+ return
+ }
+
+ ln := newLocalListener(t)
+ defer ln.Close()
+
+ type connErr struct {
+ conn Conn
+ err error
+ }
+ dials := listenerBacklog + 100
+ maxGoodConnect := listenerBacklog + 5 // empirically 131 good ones (of 128). who knows?
+ resc := make(chan connErr)
+ for i := 0; i < dials; i++ {
+ go func() {
+ conn, err := DialTimeout("tcp", ln.Addr().String(), 500*time.Millisecond)
+ resc <- connErr{conn, err}
+ }()
+ }
+
+ var firstErr string
+ var ngood int
+ var toClose []io.Closer
+ for i := 0; i < dials; i++ {
+ ce := <-resc
+ if ce.err == nil {
+ ngood++
+ if ngood > maxGoodConnect {
+ t.Errorf("%d good connects; expected at most %d", ngood, maxGoodConnect)
+ }
+ toClose = append(toClose, ce.conn)
+ continue
+ }
+ err := ce.err
+ if firstErr == "" {
+ firstErr = err.Error()
+ } else if err.Error() != firstErr {
+ t.Fatalf("inconsistent error messages: first was %q, then later %q", firstErr, err)
+ }
+ }
+ for _, c := range toClose {
+ c.Close()
+ }
+ for i := 0; i < 100; i++ {
+ if got := numFD(); got < dials {
+ // Test passes.
+ return
+ }
+ time.Sleep(10 * time.Millisecond)
+ }
+ if got := numFD(); got >= dials {
+ t.Errorf("num fds after %d timeouts = %d; want <%d", dials, got, dials)
+ }
+}
+
+func numFD() int {
+ if runtime.GOOS == "linux" {
+ f, err := os.Open("/proc/self/fd")
+ if err != nil {
+ panic(err)
+ }
+ defer f.Close()
+ names, err := f.Readdirnames(0)
+ if err != nil {
+ panic(err)
+ }
+ return len(names)
+ }
+ // All tests using this should be skipped anyway, but:
+ panic("numFDs not implemented on " + runtime.GOOS)
+}
