net: TestDialMultiFDLeak is flaky on darwin

[rsc]

It is failing quite consistently (maybe 25% of the time) on OS X builders. Here's one.
http://build.golang.org/log/25c086232cf1db386eace9f6ff5060178ed86e78

--- FAIL: TestDialMultiFDLeak (0.41s)
    dial_test.go:409: tcp sessions: 4, open sessions: 4, closing sessions: 0
    dial_test.go:412: got 4 open sessions; expected 2
FAIL
FAIL    net 3.495s

[gopherbot]

Comment 1:

CL https://golang.org/cl/144070044 mentions this issue.

[mikioh]

Comment 2:

didn't realize that darwin replaced conventional tcp_close with more fine-grained,
thread-aware, ip routing/packet path-aware and fast tcp_close, also they introduced
tcp_gc and some recycle mech., pretty interesting.
https://github.com/opensource-apple/xnu/blob/10.9/bsd/netinet/tcp_subr.c#L987

[mikioh]

Comment 3:

for now (or until they've made this sort of features stable, well, i guess it's just for
mobile usecases and the journey will last a bit long time) skipping this test on darwin
makes sense.

[mikioh]

Comment 4:

fwiw the purpose of TestDialMultiFDLeak is simply to verify the following codepath:
func dialMulti(...) {
        go func(ra Addr) {
                :
                } else if err == nil {
                                // We have to return the resources
                                // that belong to the other
                                // connections here for avoiding
                                // unnecessary resource starvation.
                                c.Close()
                }

[griesemer]

Comment 5:

Labels changed: added repo-main.