net/http: wasi deadlock

[arejula27]

Go version

go version go1.21.7 linux/amd64

Output of go env in your module/workspace:

GO111MODULE=''
GOARCH='amd64'
GOBIN=''
GOCACHE='/home/arejula27/.cache/go-build'
GOENV='/home/arejula27/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMODCACHE='/home/arejula27/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/home/arejula27/go'
GOPRIVATE=''
GOPROXY='direct'
GOROOT='/usr/lib/golang'
GOSUMDB='off'
GOTMPDIR=''
GOTOOLCHAIN='local'
GOTOOLDIR='/usr/lib/golang/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.21.7'
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='gcc'
CXX='g++'
CGO_ENABLED='1'
GOMOD='/home/arejula27/workspaces/go-lab/echo/go.mod'
GOWORK='/home/arejula27/workspaces/go-lab/go.work'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build2105186211=/tmp/go-build -gno-record-gcc-switches'

What did you do?

I compiled simple web servers using GOOS=wasip1 GOARCH=wasm and try to run it.

What did you see happen?

The program crash because it detects a deadclock

What did you expect to see?

To run correctly

[panjf2000]

Did you run this example in the expected environment: GOOS=wasip1 GOARCH=wasm?

[panjf2000]

And it reproduces constantly?

[AndrusGerman]

Exactly the same problem in Windows.

[odeke-em]

Kindly cc-ing @neelance

[mauri870]

I believe the wasip1 port does not support creating sockets, so you can't really have http servers with it.

An excerpt from the WASI blog post:

A notable missing feature in the wasip1 API is a full implementation of network sockets. wasip1 only defines functions that operate on already opened sockets, making it impossible to support some of the most popular features of the Go standard library, such as HTTP servers. Hosts like Wasmer and WasmEdge implement extensions to the wasip1 API, allowing the opening of network sockets. While these extensions are not implemented by the Go compiler, there exists a third party library, github.com/stealthrocket/net, which uses go:wasmimport to allow the use of net.Dial and net.Listen on supported Wasm hosts. This enables the creation of net/http servers and other network related functionality when using this package.

[bcmills]

In particular, the wasip1/wasm port uses a fake network stack that can only accept other connections from the same process. If there are no other goroutines in the same process that can dial a connection, then the program is indeed deadlocked.

[bcmills]

@AndrusGerman

Exactly the same problem in Windows.

Go's Windows networking stack is pretty much completely separate from the fake wasm net stack. If you are seeing a problem on Windows, please file a new issue and fill out the issue template.

[Malix-Labs]

WASIp1 doesn't support socket, but WASIp2 does.

This issue is potentially fixable by #65333

See https://github.com/WebAssembly/WASI/tree/main/preview2#wasi-preview-2-contents

And specifically

• https://github.com/WebAssembly/wasi-http
• https://github.com/WebAssembly/wasi-sockets

Note that WASIp2 has consideration and drawbacks (from @sylvain101010)

[arejula27]

Did you run this example in the expected environment: GOOS=wasip1 GOARCH=wasm?

Yes, i compiled It with this GOOS=wasip1 GOARCH=wasm

[seankhliao]

Closing this as sockets aren't supported for wasi

[Malix-Labs]

sockets aren't supported for wasi

Not yet at least, indeed;
Better to close as not planned for now