From 9271b95c87d71d1c1b5539261db51e0ec4e53aee Mon Sep 17 00:00:00 2001
From: Jeff Muizelaar <jrmuizel@gmail.com>
Date: Wed, 17 Jul 2019 00:29:22 -0400
Subject: [PATCH] Avoid a copy of the Future when initializing the Box. (#29)

Future's can be pretty big (> 1500 bytes) so this probably worth doing.

I confirmed with memcpy-find that this did infact eliminate two ~1500
byte copies from the actix-web basic example.
---
 actix-rt/Cargo.toml     | 1 +
 actix-rt/src/arbiter.rs | 6 ++++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/actix-rt/Cargo.toml b/actix-rt/Cargo.toml
index d00346f3..a059c6e0 100644
--- a/actix-rt/Cargo.toml
+++ b/actix-rt/Cargo.toml
@@ -24,3 +24,4 @@ tokio-current-thread = "0.1"
 tokio-executor = "0.1.5"
 tokio-reactor = "0.1.7"
 tokio-timer = "0.2.8"
+copyless = "0.1.4"
diff --git a/actix-rt/src/arbiter.rs b/actix-rt/src/arbiter.rs
index 0fba710c..b7cdca0a 100644
--- a/actix-rt/src/arbiter.rs
+++ b/actix-rt/src/arbiter.rs
@@ -11,6 +11,8 @@ use tokio_current_thread::spawn;
 use crate::builder::Builder;
 use crate::system::System;
 
+use copyless::BoxHelper;
+
 thread_local!(
     static ADDR: RefCell<Option<Arbiter>> = RefCell::new(None);
     static RUNNING: Cell<bool> = Cell::new(false);
@@ -141,9 +143,9 @@ impl Arbiter {
     {
         RUNNING.with(move |cell| {
             if cell.get() {
-                spawn(Box::new(future));
+                spawn(Box::alloc().init(future));
             } else {
-                Q.with(move |cell| cell.borrow_mut().push(Box::new(future)));
+                Q.with(move |cell| cell.borrow_mut().push(Box::alloc().init(future)));
             }
         });
     }