net/http: TimeoutHandler should start timer when serving request

TimeoutHandler was starting the Timer when the handler was created,
instead of when serving a request. It also was sharing it between
multiple requests, which is incorrect, as the requests might start
at different times.

Store the timeout duration and create the Timer when ServeHTTP is
called. Different requests will have different timers.

The testing plumbing was simplified to store the channel used to
control when timeout happens. It overrides the regular timer.

Fixes #14568.

Change-Id: I4bd51a83f412396f208682d3ae5e382db5f8dc81
Reviewed-on: https://go-review.googlesource.com/20046
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/src/net/http/export_test.go b/src/net/http/export_test.go
index e14181a21b..94d55ab2f6 100644
--- a/src/net/http/export_test.go
+++ b/src/net/http/export_test.go
@@ -59,9 +59,9 @@ func SetTestHookServerServe(fn func(*Server, net.Listener)) { testHookServerServ
 
 func NewTestTimeoutHandler(handler Handler, ch <-chan time.Time) Handler {
 	return &timeoutHandler{
-		handler: handler,
-		timeout: func() <-chan time.Time { return ch },
-		// (no body and nil cancelTimer)
+		handler:     handler,
+		testTimeout: ch,
+		// (no body)
 	}
 }