Vendor ConcurrentStack, remove ConcurrentCollections dep

.github/workflows/test.yml

@@ -16,6 +16,7 @@ jobs:
           - '1.9'
           - '1.10'
           - '1.11'
+          - '1.12'
           - 'nightly'
       fail-fast: false
     name: Test with Julia ${{ matrix.julia-version }}

Project.toml

@@ -5,7 +5,6 @@ desc = "a simple distributed data store"
 version = "0.4.14"
 
 [deps]
-ConcurrentCollections = "5060bff5-0b44-40c5-b522-fcd3ca5cecdd"
 Distributed = "8ba89e20-285c-5b6f-9357-94700520ee1b"
 DistributedNext = "fab6aee4-877b-4bac-a744-3eca44acbb6f"
 Mmap = "a63ad114-7e13-5084-954f-fe012c677804"
@@ -16,7 +15,6 @@ Serialization = "9e88b42a-f829-5b0c-bbe9-9e923198166b"
 Sockets = "6462fe0b-24de-5631-8697-dd941f90decc"
 
 [compat]
-ConcurrentCollections = "0.1"
 DistributedNext = "1"
 Preferences = "1"
 ScopedValues = "1"

src/MemPool.jl

@@ -6,7 +6,6 @@ import Serialization: serialize, deserialize
 export DRef, FileRef, poolset, poolget, mmwrite, mmread, cleanup
 import .Threads: ReentrantLock
 using ScopedValues
-using ConcurrentCollections
 
 ## Wrapping-unwrapping of payloads:
 
@@ -70,6 +69,7 @@ end
 include("io.jl")
 include("lock.jl")
 include("read_write_lock.jl")
+include("stack.jl")
 include("clock.jl")
 include("datastore.jl")
 

src/stack.jl

@@ -0,0 +1,50 @@
+# Adapted from ConcurrentCollections.jl/src/stack.jl
+
+mutable struct TSNode{T}
+    value::T
+    @atomic next::Union{TSNode{T},Nothing}
+end
+
+TSNode{T}(value::T) where {T} = TSNode{T}(value, nothing)
+
+mutable struct ConcurrentStack{T}
+    @atomic next::Union{TSNode{T},Nothing}
+end
+
+ConcurrentStack{T}() where {T} = ConcurrentStack{T}(nothing)
+
+function Base.push!(stack::ConcurrentStack{T}, v) where {T}
+    v = convert(T, v)
+    node = TSNode{T}(v)
+
+    next = @atomic stack.next
+    while true
+        @atomic node.next = next
+        next, ok = @atomicreplace(stack.next, next => node)
+        ok && break
+    end
+
+    return stack
+end
+
+function maybepop!(stack::ConcurrentStack)
+    while true
+        node = @atomic stack.next
+        node === nothing && return nothing
+
+        next = @atomic node.next
+        next, ok = @atomicreplace(stack.next, node => next)
+        if ok
+            return Some(node.value)
+        end
+    end
+end
+
+function Base.pop!(stack::ConcurrentStack)
+    r = maybepop!(stack)
+    if r === nothing
+        error("stack is empty")
+    else
+        return something(r)
+    end
+end