golang/0020-release-branch.go1.15-net-http-add-connections-back-.patch
2021-06-18 15:46:44 +08:00

130 lines
4.6 KiB
Diff

From 1c60e0d928764b1b755c494d4a760eb51b99bc90 Mon Sep 17 00:00:00 2001
From: Michael Fraenkel <michael.fraenkel@gmail.com>
Date: Wed, 2 Dec 2020 17:07:27 -0700
Subject: [PATCH 20/44] [release-branch.go1.15] net/http: add connections back
that haven't been canceled
Issue #41600 fixed the issue when a second request canceled a connection
while the first request was still in roundTrip.
This uncovered a second issue where a request was being canceled (in
roundtrip) but the connection was put back into the idle pool for a
subsequent request.
The fix is the similar except its now in readLoop instead of roundTrip.
A persistent connection is only added back if it successfully removed
the cancel function; otherwise we know the roundTrip has started
cancelRequest.
Fixes #42935.
Updates #42942.
Change-Id: Ia56add20880ccd0c1ab812d380d8628e45f6f44c
Reviewed-on: https://go-review.googlesource.com/c/go/+/274973
Trust: Dmitri Shuralyov <dmitshur@golang.org>
Trust: Damien Neil <dneil@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
(cherry picked from commit 854a2f8e01a554d8052445563863775406a04b71)
Reviewed-on: https://go-review.googlesource.com/c/go/+/297910
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Conflict:NA
Reference:https://github.com/golang/go/commit/1c60e0d928764b1b755c494d4a760eb51b99bc90
---
src/net/http/transport.go | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)
diff --git a/src/net/http/transport.go b/src/net/http/transport.go
index 6fb2ea5663..6e430b9885 100644
--- a/src/net/http/transport.go
+++ b/src/net/http/transport.go
@@ -766,7 +766,8 @@ func (t *Transport) CancelRequest(req *Request) {
}
// Cancel an in-flight request, recording the error value.
-func (t *Transport) cancelRequest(key cancelKey, err error) {
+// Returns whether the request was canceled.
+func (t *Transport) cancelRequest(key cancelKey, err error) bool {
t.reqMu.Lock()
cancel := t.reqCanceler[key]
delete(t.reqCanceler, key)
@@ -774,6 +775,8 @@ func (t *Transport) cancelRequest(key cancelKey, err error) {
if cancel != nil {
cancel(err)
}
+
+ return cancel != nil
}
//
@@ -2087,18 +2090,17 @@ func (pc *persistConn) readLoop() {
}
if !hasBody || bodyWritable {
- pc.t.setReqCanceler(rc.cancelKey, nil)
+ replaced := pc.t.replaceReqCanceler(rc.cancelKey, nil)
// Put the idle conn back into the pool before we send the response
// so if they process it quickly and make another request, they'll
// get this same conn. But we use the unbuffered channel 'rc'
// to guarantee that persistConn.roundTrip got out of its select
// potentially waiting for this persistConn to close.
- // but after
alive = alive &&
!pc.sawEOF &&
pc.wroteRequest() &&
- tryPutIdleConn(trace)
+ replaced && tryPutIdleConn(trace)
if bodyWritable {
closeErr = errCallerOwnsConn
@@ -2160,12 +2162,12 @@ func (pc *persistConn) readLoop() {
// reading the response body. (or for cancellation or death)
select {
case bodyEOF := <-waitForBodyRead:
- pc.t.setReqCanceler(rc.cancelKey, nil) // before pc might return to idle pool
+ replaced := pc.t.replaceReqCanceler(rc.cancelKey, nil) // before pc might return to idle pool
alive = alive &&
bodyEOF &&
!pc.sawEOF &&
pc.wroteRequest() &&
- tryPutIdleConn(trace)
+ replaced && tryPutIdleConn(trace)
if bodyEOF {
eofc <- struct{}{}
}
@@ -2561,6 +2563,7 @@ func (pc *persistConn) roundTrip(req *transportRequest) (resp *Response, err err
cancelChan := req.Request.Cancel
ctxDoneChan := req.Context().Done()
pcClosed := pc.closech
+ canceled := false
for {
testHookWaitResLoop()
select {
@@ -2582,8 +2585,7 @@ func (pc *persistConn) roundTrip(req *transportRequest) (resp *Response, err err
}
case <-pcClosed:
pcClosed = nil
- // check if we are still using the connection
- if pc.t.replaceReqCanceler(req.cancelKey, nil) {
+ if canceled || pc.t.replaceReqCanceler(req.cancelKey, nil) {
if debugRoundTrip {
req.logf("closech recv: %T %#v", pc.closed, pc.closed)
}
@@ -2607,10 +2609,10 @@ func (pc *persistConn) roundTrip(req *transportRequest) (resp *Response, err err
}
return re.res, nil
case <-cancelChan:
- pc.t.cancelRequest(req.cancelKey, errRequestCanceled)
+ canceled = pc.t.cancelRequest(req.cancelKey, errRequestCanceled)
cancelChan = nil
case <-ctxDoneChan:
- pc.t.cancelRequest(req.cancelKey, req.Context().Err())
+ canceled = pc.t.cancelRequest(req.cancelKey, req.Context().Err())
cancelChan = nil
ctxDoneChan = nil
}
--
2.27.0