Add support for using MemPool with DistributedNext.jl

.github/workflows/test.yml

@@ -13,7 +13,6 @@ jobs:
     strategy:
       matrix:
         julia-version:
-          - '1.8'
           - '1.9'
           - '1.10'
           - '1.11'

Project.toml

@@ -8,7 +8,9 @@ version = "0.4.10"
 ConcurrentCollections = "5060bff5-0b44-40c5-b522-fcd3ca5cecdd"
 DataStructures = "864edb3b-99cc-5e75-8d2d-829cb0a9cfe8"
 Distributed = "8ba89e20-285c-5b6f-9357-94700520ee1b"
+DistributedNext = "fab6aee4-877b-4bac-a744-3eca44acbb6f"
 Mmap = "a63ad114-7e13-5084-954f-fe012c677804"
+Preferences = "21216c6a-2e73-6563-6e65-726566657250"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 ScopedValues = "7e506255-f358-4e82-b7e4-beb19740aa63"
 Serialization = "9e88b42a-f829-5b0c-bbe9-9e923198166b"
@@ -18,12 +20,15 @@ UnsafeAtomics = "013be700-e6cd-48c3-b4a1-df204f14c38f"
 [compat]
 ConcurrentCollections = "0.1"
 DataStructures = "0.18"
+DistributedNext = "1"
+Preferences = "1"
 ScopedValues = "1"
 UnsafeAtomics = "0.2"
-julia = "1.8"
+julia = "1.9"
 
 [extras]
 Distributed = "8ba89e20-285c-5b6f-9357-94700520ee1b"
+Preferences = "21216c6a-2e73-6563-6e65-726566657250"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 Serialization = "9e88b42a-f829-5b0c-bbe9-9e923198166b"
 Sockets = "6462fe0b-24de-5631-8697-dd941f90decc"

src/MemPool.jl

@@ -1,5 +1,6 @@
 module MemPool
 
+import Preferences: @load_preference, @set_preferences!
 using Serialization, Sockets, Random
 import Serialization: serialize, deserialize
 export DRef, FileRef, poolset, poolget, mmwrite, mmread, cleanup
@@ -52,6 +53,20 @@ unwrap_payload(f::FileRef) = unwrap_payload(open(deserialize, f.file, "r+"))
 
 approx_size(f::FileRef) = f.size
 
+# Preferences settings
+
+"""
+    set_distributed_package!(value[="Distributed|DistributedNext"])
+
+Set a [preference](https://github.com/JuliaPackaging/Preferences.jl) for using
+either the Distributed.jl stdlib or DistributedNext.jl. You will need to restart
+Julia after setting a new preference.
+"""
+function set_distributed_package!(value)
+    @set_preferences!("distributed-package" => value)
+    @info "MemPool.jl preference has been set, restart your Julia session for this change to take effect!"
+end
+
 include("io.jl")
 include("lock.jl")
 include("read_write_lock.jl")

src/datastore.jl

@@ -1,4 +1,10 @@
-using Distributed
+if @load_preference("distributed-package") == "DistributedNext"
+    using DistributedNext
+    import DistributedNext: ClusterSerializer, worker_id_from_socket
+else
+    using Distributed
+    import Distributed: ClusterSerializer, worker_id_from_socket
+end
 
 mutable struct DRef
     owner::Int
@@ -26,13 +32,13 @@ function Serialization.serialize(io::AbstractSerializer, d::DRef)
 
     _pooltransfer_send(io, d)
 end
-function _pooltransfer_send(io::Distributed.ClusterSerializer, d::DRef)
-    pid = Distributed.worker_id_from_socket(io.io)
+function _pooltransfer_send(io::ClusterSerializer, d::DRef)
+    pid = worker_id_from_socket(io.io)
     if pid != -1
         pooltransfer_send_local(d, pid)
         return
     end
-    pid = Distributed.worker_id_from_socket(io)
+    pid = worker_id_from_socket(io)
     if pid != -1
         pooltransfer_send_local(d, pid)
         return
@@ -60,7 +66,7 @@ function Serialization.deserialize(io::AbstractSerializer, dt::Type{DRef})
     _pooltransfer_recv(io, d)
     return d
 end
-function _pooltransfer_recv(io::Distributed.ClusterSerializer, d)
+function _pooltransfer_recv(io::ClusterSerializer, d)
     # Add a new reference manually, and unref on finalization
     DEBUG_REFCOUNTING[] && _enqueue_work(Core.print, "<- (", d.owner, ", ", d.id, ") at ", myid(), "\n")
     poolref(d, true)

test/runtests.jl

@@ -855,6 +855,17 @@ end
     MemPool.retain_on_device!(sdevice, x1, false)
 end
 
+@testset "Preferences" begin
+    cmd = `$(Base.julia_cmd()) --startup-file=no --project -E 'using MemPool; parentmodule(MemPool.addprocs)'`
+
+    cd(dirname(Base.active_project())) do
+        @test readchomp(cmd) == "Distributed"
+
+        MemPool.set_distributed_package!("DistributedNext")
+        @test readchomp(cmd) == "DistributedNext"
+    end
+end
+
 #= TODO
 Allocate, write non-CPU A, write non-CPU B, handle for A was explicitly deleted
 Allocate, chain write and reads such that write starts before, and finishes after, read, ensure ordering is correct