StableTasks.jl

StableTasks is a simple package with one main API StableTasks.@spawn (not exported by default).

It works like Threads.@spawn, except it is type stable to fetch from.

julia> using StableTasks, Test

julia> @inferred fetch(StableTasks.@spawn 1 + 1)
2

versus

julia> @inferred fetch(Threads.@spawn 1 + 1)
ERROR: return type Int64 does not match inferred return type Any
Stacktrace:
 [1] error(s::String)
   @ Base ./error.jl:35
 [2] top-level scope
   @ REPL[3]:1

The package also provides StableTasks.@spawnat (not exported), which is similar to StableTasks.@spawn but creates a sticky task (it won't migrate) on a specific thread.

julia> t = StableTasks.@spawnat 4 Threads.threadid();

julia> @inferred fetch(t)
4

For convenience, and similar to at Distributed.jl, there are also @fetch and @fetchfrom macros:

julia> StableTasks.@fetch 3+3
6

julia> StableTasks.@fetchfrom 2 Threads.threadid()
2