[nanomsg] Re: mangos has a compatibility shim
- From: Garrett D'Amore <garrett@xxxxxxxxxx>
- To: "Jason E. Aten" <j.e.aten@xxxxxxxxx>, nanomsg <nanomsg@xxxxxxxxxxxxx>
- Date: Tue, 13 May 2014 17:09:37 -0700
I’ve fixed the Send signature for mangos/compat.
So looking at this further:
myMsg, err := nnzbus.Recv(0)
if err != nil {
panic(err)
}
This happens if you *CLOSE* the socket. E.g. nnzbus.Close(). You can’t Recv
on such a socket. If go-nanomsg lets you do this, then its an error.
Interestingly enough, it appears that the underlying libnanomsg() lets you do
this, but I think its an accident (use after free) if this works at all. The
actual message would certainly never be delivered.
Your fetch_test is Linux specific, so I can’t test on the Mac (no /proc)
The earlier failures also seem to be responsible for other failures, as exiting
without closing the socket leaves the address unusable for other applications.
(No SO_REUSEADDR).
Now the other thing is that I feel pretty strongly that panic() is the wrong
choice here. At least in a library.
I also see $PATH dependencies for goq binary, etc.
I don’t think, at the moment, that mangos/compat is doing anything else wrong
here. Unfortunately I don’t have a linux vm to test with handy, so I can’t see
how much this is just linuxisms and how much might be genuine problems with
mangos.
--
Garrett D'Amore
Sent with Airmail
On May 13, 2014 at 11:27:10 AM, Garrett D'Amore (garrett@xxxxxxxxxx) wrote:
On May 13, 2014 at 10:55:54 AM, Jason E. Aten (j.e.aten@xxxxxxxxx) wrote:
Hi Garrett,
The Socket::Send() method in compat/compat.go:235 should return (int, error),
rather than just (error) to be API compatible. After I hacked that in (but how
to get the actual size sent?), I got compilation against compat just fine.
Excellent!
Ok, cool. From mangos perspective, its always the whole message.
But sadness ensued when I ran my application's test suite when built against
compat/mangos. Stuff just broke with "panic connection closed". You can try
my code and its test suite (go test -v) here: https://github.com/glycerine/goq.
You''ll just have to change one line, line 18 of goq.go, from
nn "github.com/op/go-nanomsg"
to
nn "bitbucket.org/gdamore/mangos/compat"
Thanks again for mangos and compat. I'm really looking forward using the (max
message size) DOS protection you implemented.
I’ll try this out later today.
- Garrett
Jason
On Sun, May 11, 2014 at 6:08 PM, Jason E. Aten <j.e.aten@xxxxxxxxx> wrote:
On Sun, May 11, 2014 at 5:37 PM, Garrett D'Amore <garrett@xxxxxxxxxx> wrote:
I’ve implemented (at user request) bitbucket.org/gdamore/mangos/compat
Awesome. Thanks Garrett.
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