Implement Base.isempty(::RemoteChannel)

[JamesWrigley]

The default method from Base has the nasty side-effect of take!()'ing from the underlying channel.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.18%. Comparing base (729ba6a) to head (8b5983b).
Report is 3 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #107      +/-   ##
==========================================
+ Coverage   79.16%   79.18%   +0.02%     
==========================================
  Files          10       10              
  Lines        1896     1898       +2     
==========================================
+ Hits         1501     1503       +2     
  Misses        395      395              

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[JamesWrigley]

(bump)

[JamesWrigley]

(bump)

[JamesWrigley]

(bump)

[JamesWrigley]

(bump)

[LilithHafner]

This also makes isempty return true instead of hanging when the channel is empty.

[JamesWrigley]

This also makes isempty return false instead of hanging when the channel is empty.

Huh?

julia> using Distributed

julia> addprocs(1)
1-element Vector{Int64}:
 2

julia> x = RemoteChannel()
RemoteChannel{Channel{Any}}(1, 1, 3)

julia> remotecall_fetch(isempty, 2, x)
true

[LilithHafner]

Huh. That's weird.

Screencast.from.2024-11-16.16-29-17.webm

[LilithHafner]

And when I interrupt

julia> remotecall_fetch(isempty, 2, x)
^CERROR: InterruptException:
Stacktrace:
  [1] try_yieldto(undo::typeof(Base.ensure_rescheduled))
    @ Base ./task.jl:958
  [2] wait()
    @ Base ./task.jl:1022
  [3] wait(c::Base.GenericCondition{ReentrantLock}; first::Bool)
    @ Base ./condition.jl:130
  [4] wait
    @ ./condition.jl:125 [inlined]
  [5] take_buffered(c::Channel{Any})
    @ Base ./channels.jl:493
  [6] take!(c::Channel{Any})
    @ Base ./channels.jl:487
  [7] take!(::Distributed.RemoteValue)
    @ Distributed ~/.julia/juliaup/julia-1.11.1+0.aarch64.linux.gnu/share/julia/stdlib/v1.11/Distributed/src/remotecall.jl:726
  [8] remotecall_fetch(f::Function, w::Distributed.Worker, args::RemoteChannel{Channel{Any}}; kwargs::@Kwargs{})
    @ Distributed ~/.julia/juliaup/julia-1.11.1+0.aarch64.linux.gnu/share/julia/stdlib/v1.11/Distributed/src/remotecall.jl:461
  [9] remotecall_fetch(f::Function, w::Distributed.Worker, args::RemoteChannel{Channel{Any}})
    @ Distributed ~/.julia/juliaup/julia-1.11.1+0.aarch64.linux.gnu/share/julia/stdlib/v1.11/Distributed/src/remotecall.jl:454
 [10] remotecall_fetch(f::Function, id::Int64, args::RemoteChannel{Channel{Any}})
    @ Distributed ~/.julia/juliaup/julia-1.11.1+0.aarch64.linux.gnu/share/julia/stdlib/v1.11/Distributed/src/remotecall.jl:492
 [11] top-level scope
    @ REPL[5]:1

[JamesWrigley]

To clarify, in my code snippet I started Julia with julia --project to use this branch. I still don't understand how you saw isempty() return false?

[LilithHafner]

I still don't understand how you saw isempty() return false?

I miss spoke. It correctly returns true when the collection is empty.

[LilithHafner]

LGTM

[ViralBShah]

@JamesWrigley I have invited you to have commit access to the repo. Thanks for the PRs!

[JamesWrigley]

Cool, thanks :)