Do not migrate tasks to a different thread pool (#32)

Change the try_with_timeout method so that it does not migrate
a task to a different thread pool.

Project.toml

@@ -1,7 +1,7 @@
 name = "ConcurrentUtilities"
 uuid = "f0e56b4a-5159-44fe-b623-3e5288b988bb"
 authors = ["Jacob Quinn <quinn.jacobd@gmail.com>"]
-version = "2.3.1"
+version = "2.4.0"
 
 [deps]
 Serialization = "9e88b42a-f829-5b0c-bbe9-9e923198166b"

src/ConcurrentUtilities.jl

@@ -4,6 +4,14 @@ export Lockable, OrderedSynchronizer, reset!, ReadWriteLock, readlock, readunloc
     Workers, remote_eval, remote_fetch, Worker, terminate!, WorkerTerminatedException,
     Pool, acquire, release, drain!, try_with_timeout, TimeoutException
 
+macro samethreadpool_spawn(expr)
+    if isdefined(Base.Threads, :threadpool)
+        esc(:(Threads.@spawn Threads.threadpool() $expr))
+    else
+        esc(:(Threads.@spawn $expr))
+    end
+end
+
 include("try_with_timeout.jl")
 include("workers.jl")
 using .Workers

src/try_with_timeout.jl

@@ -77,7 +77,7 @@ function try_with_timeout(f, timeout, ::Type{T}=Any) where {T}
     ch = Channel{T}(0)
     x = TimedOut(ch)
     timer = Timer(tm -> !isready(ch) && close(ch, TimeoutException(timeout)), timeout)
-    Threads.@spawn begin
+    @samethreadpool_spawn begin
         try
             put!(ch, $f(x)::T)
         catch e

test/try_with_timeout.jl

@@ -26,4 +26,11 @@ using ConcurrentUtilities, Test
         @test e isa CapturedException
         rethrow(e.ex)
     end
+
+    # try_with_timeout should not migrate the task to a different thread pool
+    if isdefined(Base.Threads, :threadpool)
+        @test try_with_timeout(_ -> Threads.threadpool(), 1) == Threads.threadpool()
+        @test read(`julia -t 1,1 -E 'using ConcurrentUtilities; try_with_timeout(_ -> Threads.threadpool(), 1)'`, String) == ":interactive\n"
+        @test read(`julia -t 1,1 -E 'using ConcurrentUtilities; fetch(Threads.@spawn begin try_with_timeout(_ -> Threads.threadpool(), 1) end)'`, String) == ":default\n"
+    end
 end