net/http: data race on Request.Method #3881
Description
On a proprietary test ThreadSanitizer says:
WARNING: DATA RACE at 0x00004020eb40
Write by goroutine 32:
net/http.ReadResponse()
src/pkg/net/http/response.go:110 +0x13c
net/http.(*persistConn).readLoop()
src/pkg/net/http/transport.go:564 +0x3f8
Previous read by goroutine 33:
net/http.(*Request).write()
src/pkg/net/http/request.go:321 +0xb81
net/http.(*persistConn).writeLoop()
src/pkg/net/http/transport.go:641 +0x231
Goroutine 32 (running) created at:
net/http.(*Transport).getConn()
src/pkg/net/http/transport.go:390 +0x769
net/http.(*Transport).RoundTrip()
src/pkg/net/http/transport.go:156 +0x31e
net/http.send()
src/pkg/net/http/client.go:141 +0x4e1
net/http.(*Client).doFollowingRedirects()
src/pkg/net/http/client.go:254 +0x8d8
net/http.(*Client).Get()
src/pkg/net/http/client.go:201 +0xc1
net/http.Get()
src/pkg/net/http/client.go:178 +0x55
...
testing.tRunner()
src/pkg/testing/testing.go:292 +0xb6
Goroutine 33 (running) created at:
net/http.(*Transport).getConn()
src/pkg/net/http/transport.go:391 +0x780
net/http.(*Transport).RoundTrip()
src/pkg/net/http/transport.go:156 +0x31e
net/http.send()
src/pkg/net/http/client.go:141 +0x4e1
net/http.(*Client).doFollowingRedirects()
src/pkg/net/http/client.go:254 +0x8d8
net/http.(*Client).Get()
src/pkg/net/http/client.go:201 +0xc1
net/http.Get()
src/pkg/net/http/client.go:178 +0x55
...
testing.tRunner()
src/pkg/testing/testing.go:292 +0xb6
During invocation of RoundTrip() string field Request.Method is concurrently read and
mutated.