Using interactive thread pool for latency-sensitive route

[simsurace]

This is my (failed) attempt at separating light vs. heavy workloads in different threads to retain responsiveness:

using Dates, HTTP

const ROUTER = HTTP.Router()

function low_latency(req)
    Threads.@spawn :interactive begin # also tried without this
        @info "$(now())> $(Threads.threadpool()) tid: $(Threads.threadid())"
        return "Done with low latency task"
    end
end
HTTP.register!(ROUTER, "GET", "/low", low_latency)

function high_latency(req)
    Threads.@spawn begin
        s = sum(randn(10^8))
        @info "$(now())> $(Threads.threadpool()) tid: $(Threads.threadid()), sum = $s"
        return "Done with high latency task"
    end
end
HTTP.register!(ROUTER, "GET", "/high", high_latency)

function requestHandler(req)
    resp = ROUTER(req)
    return HTTP.Response(200, resp)
end

HTTP.serve(requestHandler, "0.0.0.0", 7777)

• Running this in julia +beta -t 1,1 does not give the intended behavior, maybe due to Interactive threads in Julia v1.9.0-beta do not give expected results JuliaLang/julia#48580.
• Running this with julia +beta -t 2,1 will throw an error upon receiving a request:

┌ Error: handle_connection handler error
│   exception =
│    AssertionError: 0 < tid <= v
│    Stacktrace:
│      [1] _length_assert()
│        @ URIs ~/.julia/packages/URIs/6ecRe/src/URIs.jl:694
│      [2] access_threaded(f::typeof(URIs.uri_reference_regex_f), v::Vector{URIs.RegexAndMatchData})
│        @ URIs ~/.julia/packages/URIs/6ecRe/src/URIs.jl:685
│      [3] parse_uri_reference(str::String; strict::Bool)
│        @ URIs ~/.julia/packages/URIs/6ecRe/src/URIs.jl:125
│      [4] parse_uri_reference
│        @ ~/.julia/packages/URIs/6ecRe/src/URIs.jl:123 [inlined]
│      [5] URI
│        @ ~/.julia/packages/URIs/6ecRe/src/URIs.jl:146 [inlined]
│      [6] gethandler
│        @ ~/.julia/packages/HTTP/z8l0i/src/Handlers.jl:391 [inlined]
│      [7] (::HTTP.Handlers.Router{typeof(HTTP.Handlers.default404), typeof(HTTP.Handlers.default405), Nothing})(req::HTTP.Messages.Request)
│        @ HTTP.Handlers ~/.julia/packages/HTTP/z8l0i/src/Handlers.jl:427
│      [8] requestHandler(req::HTTP.Messages.Request)
│        @ Main ./REPL[7]:2
│      [9] (::HTTP.Handlers.var"#1#2"{typeof(requestHandler)})(stream::HTTP.Streams.Stream{HTTP.Messages.Request, HTTP.ConnectionPool.Connection{Sockets.TCPSocket}})
│        @ HTTP.Handlers ~/.julia/packages/HTTP/z8l0i/src/Handlers.jl:58
│     [10] #invokelatest#2
│        @ ./essentials.jl:816 [inlined]
│     [11] invokelatest
│        @ ./essentials.jl:813 [inlined]
│     [12] handle_connection(f::Function, c::HTTP.ConnectionPool.Connection{Sockets.TCPSocket}, listener::HTTP.Servers.Listener{Nothing, Sockets.TCPServer}, readtimeout::Int64, access_log::Nothing)
│        @ HTTP.Servers ~/.julia/packages/HTTP/z8l0i/src/Servers.jl:447
│     [13] macro expansion
│        @ ~/.julia/packages/HTTP/z8l0i/src/Servers.jl:385 [inlined]
│     [14] (::HTTP.Servers.var"#16#17"{HTTP.Handlers.var"#1#2"{typeof(requestHandler)}, HTTP.Servers.Listener{Nothing, Sockets.TCPServer}, Set{HTTP.ConnectionPool.Connection}, Int64, Nothing, Base.Semaphore, HTTP.ConnectionPool.Connection{Sockets.TCPSocket}})()
│        @ HTTP.Servers ./task.jl:514
└ @ HTTP.Servers ~/.julia/packages/HTTP/z8l0i/src/Servers.jl:461

[simsurace]

Superseded by #1040