From 3eb4f7535a8bd8f0274526ed6110998f1693ecc0 Mon Sep 17 00:00:00 2001
From: Yota Toyama <raviqqe@gmail.com>
Date: Thu, 8 Feb 2018 11:58:04 +0900
Subject: [PATCH] Add Send

---
 Cargo.toml                           |  1 +
 futures-await-async-macro/src/lib.rs | 21 +++++++++++++--------
 tests/smoke.rs                       | 13 +++++++++++++
 3 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 44dad81..836e5c3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -24,5 +24,6 @@ futures-await-await-macro = { path = "futures-await-await-macro", version = "0.1
 futures = "0.1"
 
 [dev-dependencies]
+futures-cpupool = "0.1"
 tokio-core = "0.1"
 tokio-io = "0.1"
diff --git a/futures-await-async-macro/src/lib.rs b/futures-await-async-macro/src/lib.rs
index 5406ed2..65b9c92 100644
--- a/futures-await-async-macro/src/lib.rs
+++ b/futures-await-async-macro/src/lib.rs
@@ -225,26 +225,31 @@ where F: FnOnce(&Type) -> proc_macro2::TokenStream
 #[proc_macro_attribute]
 pub fn async(attribute: TokenStream, function: TokenStream) -> TokenStream {
     // Handle arguments to the #[async] attribute, if any
-    let attribute = attribute.to_string();
-    let boxed = if attribute == "( boxed )" {
-        true
-    } else if attribute == "" {
-        false
-    } else {
-        panic!("the #[async] attribute currently only takes `boxed` as an arg");
+    let (boxed, send) = match &attribute.to_string() as &str {
+        "( boxed )" => (true, false),
+        "( boxed_send )" => (true, true),
+        "" => (false, false),
+        _ => panic!("the #[async] attribute currently only takes `boxed` as an arg"),
     };
 
     async_inner(boxed, function, quote_cs! { ::futures::__rt::gen }, |output| {
         // TODO: can we lift the restriction that `futures` must be at the root of
         //       the crate?
         let output_span = first_last(&output);
-        let return_ty = if boxed {
+        let return_ty = if boxed && !send {
             quote_cs! {
                 ::futures::__rt::std::boxed::Box<::futures::Future<
                     Item = <! as ::futures::__rt::IsResult>::Ok,
                     Error = <! as ::futures::__rt::IsResult>::Err,
                 >>
             }
+        } else if boxed && send {
+            quote_cs! {
+                ::futures::__rt::std::boxed::Box<::futures::Future<
+                    Item = <! as ::futures::__rt::IsResult>::Ok,
+                    Error = <! as ::futures::__rt::IsResult>::Err,
+                > + Send>
+            }
         } else {
             // Dunno why this is buggy, hits weird typecheck errors in tests
             //
diff --git a/tests/smoke.rs b/tests/smoke.rs
index 5453016..a9d7c55 100644
--- a/tests/smoke.rs
+++ b/tests/smoke.rs
@@ -6,10 +6,12 @@
 #![feature(proc_macro, conservative_impl_trait, generators)]
 
 extern crate futures_await as futures;
+extern crate futures_cpupool;
 
 use std::io;
 
 use futures::prelude::*;
+use futures_cpupool::CpuPool;
 
 #[async]
 fn foo() -> Result<i32, i32> {
@@ -58,6 +60,11 @@ fn _foo8(a: i32, b: i32) -> Result<i32, i32> {
     return Ok(a + b)
 }
 
+#[async(boxed_send)]
+fn _foo9() -> Result<(), ()> {
+    Ok(())
+}
+
 #[async]
 fn _bar() -> Result<i32, i32> {
     await!(foo())
@@ -234,3 +241,9 @@ fn poll_stream_after_error() {
     assert_eq!(s.poll(), Err(()));
     assert_eq!(s.poll(), Ok(Async::Ready(None)));
 }
+
+#[test]
+fn run_boxed_future_in_cpu_pool() {
+    let pool = CpuPool::new_num_cpus();
+    pool.spawn(_foo9()).wait().unwrap();
+}