feat(worker): add requestgc api

Author: pankgeorg

src/Malt.jl

@@ -632,7 +632,18 @@ function interrupt(w::InProcessWorker)
     nothing
 end
 
+"""
+    Malt.requestgc(w::Worker)
 
+Request a garbage collection on the worker `w`. This is a non-blocking call (on the worker).
+"""
+function requestgc(w::Worker)
+    if !isrunning(w)
+        @warn "Tried to gc a worker that has already shut down." summary(w)
+    else
+        remote_eval_wait(Main, worker, :(Base.notify(Main._gc_event)))
+    end
+end
 
 
 # Based on `Base.task_done_hook`

src/worker.jl

@@ -161,6 +161,17 @@ format_error(err, bt) = sprint() do io
 end
 
 const _channel_cache = Dict{UInt64, AbstractChannel}()
+const _gc_event = Threads.Event(true)
+
+const _gc_task = Threads.@spawn :default begin
+    for _i in Iterators.countfrom(1)
+        wait(_gc_event)
+        sleep(5) # debounce 5 seconds
+        GC.gc(true)
+        # ignore all events after the gc
+        @atomic _gc_event.set = false
+    end
+end
 
 if abspath(PROGRAM_FILE) == @__FILE__
     main()