Merge #71

71: Disable multithreading for all wasm32 targets. r=torkleyy a=BartAdv

With the coming of `wasm32-unknown-unknown` it might be good idea to use `target_arch = "wasm32"` to detect whether to build with multithreading support or not.

Cargo.toml

@@ -21,10 +21,18 @@ travis-ci = { repository = "torkleyy/shred" }
 arrayvec = "0.3"
 fxhash = "0.2"
 mopa = "0.2"
-pulse = "0.5"
-rayon = "0.8"
+pulse = { version = "0.5", optional = true }
+rayon = { version = "0.8", optional = true }
 shred-derive = { path = "shred-derive", version = "0.3" }
 smallvec = "0.4"
 
 [dev-dependencies]
 cgmath = "0.15"
+
+[features]
+default = ["parallel"]
+parallel = ["pulse", "rayon"]
+
+[[example]]
+name = "par_seq"
+required-features = ["parallel"]

src/dispatch/builder.rs

@@ -90,7 +90,7 @@ pub struct DispatcherBuilder<'a, 'b> {
     map: FxHashMap<String, SystemId>,
     stages_builder: StagesBuilder<'a>,
     thread_local: ThreadLocal<'b>,
-    #[cfg(not(target_os = "emscripten"))]
+    #[cfg(feature = "parallel")]
     thread_pool:
         Option<::std::sync::Arc<::rayon::ThreadPool>>,
 }
@@ -239,7 +239,7 @@ impl<'a, 'b> DispatcherBuilder<'a, 'b> {
     /// Same as
     /// [`add_pool()`](struct.DispatcherBuilder.html#method.add_pool),
     /// but returns `self` to enable method chaining.
-    #[cfg(not(target_os = "emscripten"))]
+    #[cfg(feature = "parallel")]
     pub fn with_pool(mut self, pool: ::std::sync::Arc<::rayon::ThreadPool>) -> Self {
         self.add_pool(pool);
 
@@ -248,7 +248,7 @@ impl<'a, 'b> DispatcherBuilder<'a, 'b> {
 
     /// Attach a rayon thread pool to the builder
     /// and use that instead of creating one.
-    #[cfg(not(target_os = "emscripten"))]
+    #[cfg(feature = "parallel")]
     pub fn add_pool(&mut self, pool: ::std::sync::Arc<::rayon::ThreadPool>) {
         self.thread_pool = Some(pool);
     }
@@ -261,14 +261,14 @@ impl<'a, 'b> DispatcherBuilder<'a, 'b> {
     pub fn build(self) -> Dispatcher<'a, 'b> {
         use dispatch::dispatcher::new_dispatcher;
 
-        #[cfg(not(target_os = "emscripten"))]
+        #[cfg(feature = "parallel")]
         let d = new_dispatcher(
             self.stages_builder.build(),
             self.thread_local,
             self.thread_pool.unwrap_or_else(Self::create_thread_pool),
         );
 
-        #[cfg(target_os = "emscripten")]
+        #[cfg(not(feature = "parallel"))]
         let d = new_dispatcher(self.stages_builder.build(), self.thread_local);
 
         d
@@ -281,7 +281,7 @@ impl<'a, 'b> DispatcherBuilder<'a, 'b> {
         SystemId(id)
     }
 
-    #[cfg(not(target_os = "emscripten"))]
+    #[cfg(feature = "parallel")]
     fn create_thread_pool() -> ::std::sync::Arc<::rayon::ThreadPool> {
         use std::sync::Arc;
         use rayon::{Configuration, ThreadPool};
@@ -292,7 +292,7 @@ impl<'a, 'b> DispatcherBuilder<'a, 'b> {
     }
 }
 
-#[cfg(not(target_os = "emscripten"))]
+#[cfg(feature = "parallel")]
 impl<'b> DispatcherBuilder<'static, 'b> {
     /// Builds an async dispatcher.
     ///

src/dispatch/dispatcher.rs

@@ -9,7 +9,8 @@ use system::RunNow;
 pub struct Dispatcher<'a, 'b> {
     stages: Vec<Stage<'a>>,
     thread_local: ThreadLocal<'b>,
-    #[cfg(not(target_os = "emscripten"))] thread_pool: ::std::sync::Arc<::rayon::ThreadPool>,
+    #[cfg(feature = "parallel")]
+    thread_pool: ::std::sync::Arc<::rayon::ThreadPool>,
 }
 
 impl<'a, 'b> Dispatcher<'a, 'b> {
@@ -29,10 +30,10 @@ impl<'a, 'b> Dispatcher<'a, 'b> {
     /// [`dispatch_par`]: struct.Dispatcher.html#method.dispatch_par
     /// [`dispatch_seq`]: struct.Dispatcher.html#method.dispatch_seq
     pub fn dispatch(&mut self, res: &Resources) {
-        #[cfg(not(target_os = "emscripten"))]
+        #[cfg(feature = "parallel")]
         self.dispatch_par(res);
 
-        #[cfg(target_os = "emscripten")]
+        #[cfg(not(feature = "parallel"))]
         self.dispatch_seq(res);
 
         self.dispatch_thread_local(res);
@@ -44,12 +45,11 @@ impl<'a, 'b> Dispatcher<'a, 'b> {
     /// This operation blocks the
     /// executing thread.
     ///
-    /// Only available on platforms with
-    /// multithreading support (so not on emscripten).
+    /// Only available with "parallel" feature enabled.
     ///
     /// Please note that this method assumes that no resource
     /// is currently borrowed. If that's the case, it panics.
-    #[cfg(not(target_os = "emscripten"))]
+    #[cfg(feature = "parallel")]
     pub fn dispatch_par(&mut self, res: &Resources) {
         let stages = &mut self.stages;
 
@@ -88,7 +88,7 @@ pub struct SystemId(pub usize);
 pub type SystemExecSend<'b> = Box<for<'a> RunNow<'a> + Send + 'b>;
 pub type ThreadLocal<'a> = SmallVec<[Box<for<'b> RunNow<'b> + 'a>; 4]>;
 
-#[cfg(not(target_os = "emscripten"))]
+#[cfg(feature = "parallel")]
 pub fn new_dispatcher<'a, 'b>(
     stages: Vec<Stage<'a>>,
     thread_local: ThreadLocal<'b>,
@@ -101,7 +101,7 @@ pub fn new_dispatcher<'a, 'b>(
     }
 }
 
-#[cfg(target_os = "emscripten")]
+#[cfg(not(feature = "parallel"))]
 pub fn new_dispatcher<'a, 'b>(
     stages: Vec<Stage<'a>>,
     thread_local: ThreadLocal<'b>,
@@ -185,6 +185,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg(feature = "parallel")]
     fn stages_async() {
         let mut d = new_builder().build_async(new_resources());
 

src/dispatch/mod.rs

@@ -1,15 +1,15 @@
-#[cfg(not(target_os = "emscripten"))]
+#[cfg(feature = "parallel")]
 pub use self::async::AsyncDispatcher;
 pub use self::builder::DispatcherBuilder;
 pub use self::dispatcher::Dispatcher;
-#[cfg(not(target_os = "emscripten"))]
+#[cfg(feature = "parallel")]
 pub use self::par_seq::{Par, ParSeq, Seq};
 
-#[cfg(not(target_os = "emscripten"))]
+#[cfg(feature = "parallel")]
 mod async;
 mod builder;
 mod dispatcher;
-#[cfg(not(target_os = "emscripten"))]
+#[cfg(feature = "parallel")]
 mod par_seq;
 mod stage;
 mod util;

src/dispatch/stage.rs

@@ -76,7 +76,7 @@ impl<'a> Stage<'a> {
         Default::default()
     }
 
-    #[cfg(not(target_os = "emscripten"))]
+    #[cfg(feature = "parallel")]
     pub fn execute(&mut self, res: &Resources) {
         use rayon::prelude::*;
 

src/lib.rs

@@ -61,9 +61,9 @@ extern crate arrayvec;
 extern crate fxhash;
 #[macro_use]
 extern crate mopa;
-#[cfg(not(target_os = "emscripten"))]
+#[cfg(feature = "parallel")]
 extern crate pulse;
-#[cfg(not(target_os = "emscripten"))]
+#[cfg(feature = "parallel")]
 extern crate rayon;
 extern crate smallvec;
 
@@ -73,9 +73,9 @@ mod res;
 mod system;
 
 pub use dispatch::{Dispatcher, DispatcherBuilder};
-#[cfg(not(target_os = "emscripten"))]
+#[cfg(feature = "parallel")]
 pub use dispatch::{Par, ParSeq, Seq};
-#[cfg(not(target_os = "emscripten"))]
+#[cfg(feature = "parallel")]
 pub use dispatch::AsyncDispatcher;
 pub use res::{Fetch, FetchId, FetchIdMut, FetchMut, Resource, ResourceId, Resources};
 pub use system::{RunNow, RunningTime, System, SystemData};