when spawn runs something on the local machine, it needs to copy

variable bindings to simulate what happens when closures are copied to
other machines. fixes the bug described in issue #80.

j/inference.j

@@ -300,6 +300,7 @@ fieldtype_tfunc = function (A, s, name)
 end
 t_func[fieldtype] = (2, 2, fieldtype_tfunc)
 t_func[Expr] = (3, 3, (a,b,c)->Expr)
+t_func[Box] = (1, 1, (a,)->Box)
 
 # TODO: handle e.g. apply_type(T, R::Union(Type{Int32},Type{Float64}))
 apply_type_tfunc = function (A, args...)

j/multi.j

@@ -1071,6 +1071,15 @@ let lastp = 1
                 lastp = 1
             end
         end
+        if p==myid()
+            # for local spawn, simulate semantics of copying bindings
+            if isa(env,Tuple)
+                env = map(x->(isa(x,Box)?Box(x.contents):x), env)
+                linfo = ccall(:jl_closure_linfo, Any, (Any,), thunk)
+                thunk = ccall(:jl_new_closure_internal, Any, (Any, Any),
+                              linfo, env)::Function
+            end
+        end
         spawnat(p, thunk)
     end
 end

src/alloc.c

@@ -915,3 +915,12 @@ JL_CALLABLE(jl_f_new_expr)
     ex->etype = args[2];
     return (jl_value_t*)ex;
 }
+
+JL_CALLABLE(jl_f_new_box)
+{
+    JL_NARGS(Box, 1, 1);
+    jl_value_t *box = (jl_value_t*)alloc_2w();
+    box->type = jl_box_any_type;
+    ((jl_value_t**)box)[1] = args[0];
+    return box;
+}

src/builtin_proto.h

@@ -4,6 +4,7 @@
 // declarations for julia-callable builtin functions
 
 JL_CALLABLE(jl_f_new_expr);
+JL_CALLABLE(jl_f_new_box);
 JL_CALLABLE(jl_weakref_ctor);
 JL_CALLABLE(jl_new_array_internal);
 JL_CALLABLE(jl_f_throw);

src/dump.c

@@ -973,6 +973,7 @@ void jl_init_serializer()
     VALUE_TAGS = (ptrint_t)ptrhash_get(&ser_tag, jl_null);
 
     void *fptrs[] = { jl_f_new_expr,
+                      jl_f_new_box,
                       jl_weakref_ctor, 
                       jl_new_array_internal, 
                       jl_f_throw, 

src/jltypes.c

@@ -1926,6 +1926,7 @@ static jl_tuple_t *jl_typevars(size_t n, ...)
 }
 
 JL_CALLABLE(jl_f_new_expr);
+JL_CALLABLE(jl_f_new_box);
 
 extern void jl_init_int32_cache();
 
@@ -2165,7 +2166,7 @@ void jl_init_types()
                            jl_any_type, jl_null,
                            jl_tuple(1, jl_symbol("contents")),
                            jl_tuple(1, jl_any_type));
-    //jl_add_constructors(jl_box_type);
+    jl_box_type->fptr = jl_f_new_box;
     jl_box_typename = jl_box_type->name;
     jl_box_any_type = (jl_type_t*)jl_box_type;