debug

src/remotecall.jl

@@ -667,11 +667,13 @@ All asynchronous remote calls return `Future`s and set the
 value to the return value of the call upon completion.
 """
 function put!(r::Future, v)
+    println("put!($(repr(r)), $(repr(v))) on thread $(Threads.threadid())")
     if r.where == myid()
         rid = remoteref_id(r)
         rv = lookup_ref(rid)
         isready(rv) && error("Future can be set only once")
         @lock r.lock begin
+            println("lock acquired on thread $(Threads.threadid()) on worker $(myid())")
             put!(rv, v) # this notifies the tasks waiting on the channel in fetch
             set_future_cache(r, v) # set the cache before leaving the lock, so that the notified tasks already see it cached
         end
@@ -691,6 +693,7 @@ function set_future_cache(r::Future, v)
 end
 
 function put_future(rid, v, caller)
+    println("put_future on thread $(Threads.threadid()) on worker $(myid())")
     rv = lookup_ref(rid)
     isready(rv) && error("Future can be set only once")
     put!(rv, v)