Merge pull request #61 from bicycle1885/refactor-compute

Refactor compute.jl

Author: shashi

Diff for: src/compute.jl

@@ -148,26 +148,25 @@ function thunkize(ctx, c::Cat)
 end
 thunkize(ctx, x::AbstractChunk) = x
 thunkize(ctx, x::Thunk) = x
+
 function finish_task!(state, node, node_order; free=true)
-    deps = sort([i for i in state[:dependents][node]], by=node_order)
-    immediate_next = false
     if istask(node) && node.cache
         node.cache_ref = Nullable{Any}(state[:cache][node])
     end
-    for dep in deps
+    immediate_next = false
+    for dep in sort!(collect(state[:dependents][node]), by=node_order)
         set = state[:waiting][dep]
         pop!(set, node)
         if isempty(set)
             pop!(state[:waiting], dep)
-            immediate_next = true
             push!(state[:ready], dep)
+            immediate_next = true
         end
         # todo: free data
     end
     for inp in inputs(node)
         if inp in keys(state[:waiting_data])
             s = state[:waiting_data][inp]
-            #@show s
             if node in s
                 pop!(s, node)
             end
@@ -197,12 +196,7 @@ function compute(ctx, d::Thunk)
     ps = procs(ctx)
     chan = Channel{Any}(32)
     deps = dependents(d)
-    ndeps = noffspring(deps)
-    ord = order(d, ndeps)
-
-    sort_ord = collect(ord)
-    sortord = x -> istask(x[1]) ? x[1].id : 0
-    sort_ord = sort(sort_ord, by=sortord)
+    ord = order(d, noffspring(deps))
 
     node_order = x -> -get(ord, x, 0)
     state = start_state(deps, node_order)
@@ -218,21 +212,16 @@ function compute(ctx, d::Thunk)
 
     while !isempty(state[:waiting]) || !isempty(state[:ready]) || !isempty(state[:running])
         proc, thunk_id, res = take!(chan)
-
         if isa(res, CapturedException) || isa(res, RemoteException)
             rethrow(res)
         end
         node = _thunk_dict[thunk_id]
         @logmsg("W$(proc.pid) - $node ($(node.f)) input:$(node.inputs)")
         state[:cache][node] = res
-        #@show state[:cache]
-        #@show ord
-        # if any of this guy's dependents are waiting,
-        # update them
-        @dbg timespan_start(ctx, :scheduler, thunk_id, master)
 
+        # if any of this guy's dependents are waiting, update them
+        @dbg timespan_start(ctx, :scheduler, thunk_id, master)
         immediate_next = finish_task!(state, node, node_order)
-
         if !isempty(state[:ready])
             if immediate_next
                 # fast path
@@ -248,7 +237,6 @@ function compute(ctx, d::Thunk)
         end
         @dbg timespan_end(ctx, :scheduler, thunk_id, master)
     end
-
     state[:cache][d]
 end
 
@@ -342,7 +330,6 @@ function fire_task!(ctx, thunk, proc, state, chan, node_order)
     data = map(thunk.inputs) do x
         istask(x) ? state[:cache][x] : x
     end
-
     async_apply(ctx, proc, thunk.id, thunk.f, data, chan, thunk.get_result, thunk.persist)
 end
 
@@ -364,8 +351,6 @@ function dependents(node::Thunk, deps=Dict())
     deps
 end
 
-
-
 """
 recursively find the number of taks dependent on each task in the DAG.
 Input: dependents dict
@@ -383,7 +368,6 @@ function noffspring(n, dpents)
     end
 end
 
-
 """
 Given a root node of the DAG, calculates a total order for tie-braking
 
@@ -397,18 +381,16 @@ Args:
     - ndeps: result of `noffspring`
 """
 function order(node::Thunk, ndeps)
-    order([node], ndeps, 0)[2]
-end
-
-function order(nodes::AbstractArray, ndeps, c, output=Dict())
-
-    for node in nodes
-        c+=1
-        output[node] = c
-        nxt = sort(Any[n for n in inputs(node)], by=k->get(ndeps,k,0))
-        c, output = order(nxt, ndeps, c, output)
+    function recur(nodes, s)
+        for n in nodes
+            output[n] = s += 1
+            s = recur(sort!(collect(Any, inputs(n)), by=k->get(ndeps,k,0)), s)
+        end
+        return s
     end
-    c, output
+    output = Dict{Any,Int}()
+    recur([node], 0)
+    return output
 end
 
 function start_state(deps::Dict, node_order)