Successfully added mutexes protecting freelist access. No behaviour change.

src/c/payloads/cons.c

@@ -30,7 +30,7 @@
  * @param cdr the pointer which should form the cdr of this cons cell.
  * @return struct pso_pointer a pointer to the newly allocated cons cell.
  */
-struct pso_pointer c_cons(struct pso_pointer car, struct pso_pointer cdr) {
+struct pso_pointer make_cons(struct pso_pointer car, struct pso_pointer cdr) {
 	// todo: issue #21: must have stack frame passed in.
     struct pso_pointer result = allocate( CONSTAG, 2 );
 
@@ -84,7 +84,7 @@ struct pso_pointer c_cdr(struct pso_pointer p) {
             break;
         default:
             result =
-                make_exception( c_cons
+                make_exception( make_cons
                                 ( c_string_to_lisp_string
                                   ( L"Invalid type for cdr" ),
                                   get_tag_string( p ) ), nil, nil, nil );

src/c/payloads/cons.h

@@ -31,7 +31,7 @@ struct pso_pointer c_car( struct pso_pointer cons );
 struct pso_pointer c_cdr( struct pso_pointer cons );
 
 // todo: issue #21: must have stack frame passed in.
-struct pso_pointer c_cons( struct pso_pointer car, struct pso_pointer cdr );
+struct pso_pointer make_cons( struct pso_pointer car, struct pso_pointer cdr );
 
 struct pso_pointer destroy_cons( struct pso_pointer fp,
                                  struct pso_pointer env );

src/c/payloads/stack.c

@@ -72,7 +72,7 @@ struct pso_pointer make_frame( int arg_count, struct pso_pointer previous,
 
         for ( ; cursor < arg_count; cursor++ ) {
             more_args =
-                c_cons( va_arg( args, struct pso_pointer ), more_args );
+                make_cons( va_arg( args, struct pso_pointer ), more_args );
         }
 
         frame->payload.stack_frame.more = c_reverse( more_args );

src/c/payloads/stack.h

@@ -31,6 +31,10 @@ struct stack_frame_payload {
     struct pso_pointer more;
     /** the function to be called. */
     struct pso_pointer function;
+	/** the execute-time environment */
+	struct pso_pointer env;
+	/** a list of objects created in the context of this frame */
+	struct pso_pointer locals;
     /** the number of arguments provided. */
     uint32_t args;
     /** the depth of the stack below this frame */