glib: add 'futures' feature

This reduces the amount of extra dependencies for projects who don't
need or use futures, such as QEMU atm.

Signed-off-by: Marc-André Lureau <[email protected]>

Author: elmarco

glib/Cargo.toml

@@ -19,11 +19,11 @@ name = "glib"
 [dependencies]
 libc.workspace = true
 bitflags.workspace = true
-futures-core = { version = "0.3", default-features = false }
-futures-task = { version = "0.3", default-features = false }
-futures-executor = "0.3"
-futures-channel = "0.3"
-futures-util = "0.3"
+futures-core = { version = "0.3", default-features = false, optional = true }
+futures-task = { version = "0.3", default-features = false, optional = true }
+futures-executor = { version = "0.3", optional = true }
+futures-channel = { version = "0.3", optional = true }
+futures-util = { version = "0.3", optional = true }
 glib-sys.workspace = true
 gobject-sys.workspace = true
 glib-macros = { workspace = true, default-features = false }
@@ -39,7 +39,7 @@ trybuild2 = "1"
 criterion = "0.7.0"
 
 [features]
-default = ["gio"]
+default = ["gio", "futures"]
 v2_58 = ["glib-sys/v2_58", "gobject-sys/v2_58"]
 v2_60 = ["v2_58", "glib-sys/v2_60"]
 v2_62 = ["v2_60", "glib-sys/v2_62", "gobject-sys/v2_62"]
@@ -59,7 +59,8 @@ log = ["rs-log"]
 log_kv = ["log", "rs-log/kv"]
 log_macros = ["log"]
 compiletests = []
-gio = ["gio-sys"]
+gio = ["gio-sys", "futures"]
+futures = ["futures-core", "futures-task", "futures-executor", "futures-channel", "futures-util"]
 
 [[test]]
 name = "subclass_compiletest"

glib/src/functions.rs

@@ -283,6 +283,7 @@ pub fn file_open_tmp(
 ///
 /// This can be called from any thread and will execute the future from the thread
 /// where main context is running, e.g. via a `MainLoop`.
+#[cfg(feature = "futures")]
 pub fn spawn_future<R: Send + 'static, F: std::future::Future<Output = R> + Send + 'static>(
     f: F,
 ) -> crate::JoinHandle<R> {
@@ -298,6 +299,7 @@ pub fn spawn_future<R: Send + 'static, F: std::future::Future<Output = R> + Send
 /// This can be called only from the thread where the main context is running, e.g.
 /// from any other `Future` that is executed on this main context, or after calling
 /// `with_thread_default` or `acquire` on the main context.
+#[cfg(feature = "futures")]
 pub fn spawn_future_local<R: 'static, F: std::future::Future<Output = R> + 'static>(
     f: F,
 ) -> crate::JoinHandle<R> {

glib/src/lib.rs

@@ -231,12 +231,18 @@ pub use self::bridged_logging::{
 #[macro_use]
 pub mod subclass;
 
+#[cfg(feature = "futures")]
 mod main_context_futures;
+#[cfg(feature = "futures")]
 pub use main_context_futures::{JoinError, JoinHandle, SpawnWithinJoinHandle};
+#[cfg(feature = "futures")]
 mod source_futures;
+#[cfg(feature = "futures")]
 pub use self::source_futures::*;
 
+#[cfg(feature = "futures")]
 mod future_with_timeout;
+#[cfg(feature = "futures")]
 pub use self::future_with_timeout::*;
 
 mod thread_pool;

glib/src/thread_pool.rs

@@ -1,8 +1,11 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
-use std::{future::Future, panic, ptr};
+use std::{panic, ptr};
 
+#[cfg(feature = "futures")]
 use futures_channel::oneshot;
+#[cfg(feature = "futures")]
+use std::future::Future;
 
 use crate::{ffi, translate::*};
 
@@ -104,6 +107,7 @@ impl ThreadPool {
         }
     }
 
+    #[cfg(feature = "futures")]
     pub fn push_future<T: Send + 'static, F: FnOnce() -> T + Send + 'static>(
         &self,
         func: F,
@@ -241,6 +245,7 @@ mod tests {
         assert_eq!(receiver.recv(), Ok(true));
     }
 
+    #[cfg(feature = "futures")]
     #[test]
     fn test_push_future() {
         let c = crate::MainContext::new();

glib/tests/clone.rs

@@ -9,7 +9,6 @@ use std::{
     thread,
 };
 
-use futures_executor::block_on;
 use glib::clone;
 
 struct State {
@@ -1053,11 +1052,12 @@ fn test_clone_macro_body() {
     assert_eq!(10, *v.lock().expect("failed to lock"));
 }
 
+#[cfg(feature = "futures")]
 #[test]
 fn test_clone_macro_async_kinds() {
     let v = Rc::new(RefCell::new(1));
 
-    block_on(clone!(
+    futures_executor::block_on(clone!(
         #[weak]
         v,
         async move {