queueMicrotask added

components/script/dom/globalscope.rs

@@ -4,6 +4,7 @@
 
 use crate::dom::bindings::cell::DomRefCell;
 use crate::dom::bindings::codegen::Bindings::EventSourceBinding::EventSourceBinding::EventSourceMethods;
+use crate::dom::bindings::codegen::Bindings::VoidFunctionBinding::VoidFunction;
 use crate::dom::bindings::codegen::Bindings::WindowBinding::WindowMethods;
 use crate::dom::bindings::codegen::Bindings::WorkerGlobalScopeBinding::WorkerGlobalScopeMethods;
 use crate::dom::bindings::conversions::{root_from_object, root_from_object_static};
@@ -32,7 +33,7 @@ use crate::dom::performance::Performance;
 use crate::dom::window::Window;
 use crate::dom::workerglobalscope::WorkerGlobalScope;
 use crate::dom::workletglobalscope::WorkletGlobalScope;
-use crate::microtask::{Microtask, MicrotaskQueue};
+use crate::microtask::{Microtask, MicrotaskQueue, UserMicrotask};
 use crate::script_module::ModuleTree;
 use crate::script_runtime::{CommonScriptMsg, JSContext as SafeJSContext, ScriptChan, ScriptPort};
 use crate::script_thread::{MainThreadScriptChan, ScriptThread};
@@ -1772,6 +1773,13 @@ impl GlobalScope {
         self.timers.clear_timeout_or_interval(self, handle);
     }
 
+    pub fn queue_function_as_microtask(&self, callback: Rc<VoidFunction>) {
+        self.enqueue_microtask(Microtask::User(UserMicrotask {
+            callback: callback,
+            pipeline: self.pipeline_id(),
+        }))
+    }
+
     pub fn fire_timer(&self, handle: TimerEventId) {
         self.timers.fire_timer(handle, self);
     }

components/script/dom/webidls/WindowOrWorkerGlobalScope.webidl

@@ -20,6 +20,9 @@ interface mixin WindowOrWorkerGlobalScope {
   long setInterval(TimerHandler handler, optional long timeout = 0, any... arguments);
   void clearInterval(optional long handle = 0);
 
+  // microtask queuing
+  void queueMicrotask(VoidFunction callback);
+
   // ImageBitmap
   // Promise<ImageBitmap> createImageBitmap(ImageBitmapSource image, optional ImageBitmapOptions options);
   // Promise<ImageBitmap> createImageBitmap(

components/script/dom/window.rs

@@ -11,6 +11,7 @@ use crate::dom::bindings::codegen::Bindings::HistoryBinding::HistoryBinding::His
 use crate::dom::bindings::codegen::Bindings::MediaQueryListBinding::MediaQueryListBinding::MediaQueryListMethods;
 use crate::dom::bindings::codegen::Bindings::PermissionStatusBinding::PermissionState;
 use crate::dom::bindings::codegen::Bindings::RequestBinding::RequestInit;
+use crate::dom::bindings::codegen::Bindings::VoidFunctionBinding::VoidFunction;
 use crate::dom::bindings::codegen::Bindings::WindowBinding::{
     self, FrameRequestCallback, WindowMethods, WindowPostMessageOptions,
 };
@@ -871,6 +872,12 @@ impl WindowMethods for Window {
         self.ClearTimeout(handle);
     }
 
+    // https://html.spec.whatwg.org/multipage/#dom-queuemicrotask
+    fn QueueMicrotask(&self, callback: Rc<VoidFunction>) {
+        self.upcast::<GlobalScope>()
+            .queue_function_as_microtask(callback);
+    }
+
     // https://html.spec.whatwg.org/multipage/#dom-window
     fn Window(&self) -> DomRoot<WindowProxy> {
         self.window_proxy()

components/script/dom/workerglobalscope.rs

@@ -5,6 +5,7 @@
 use crate::compartments::InCompartment;
 use crate::dom::bindings::cell::{DomRefCell, Ref};
 use crate::dom::bindings::codegen::Bindings::RequestBinding::RequestInit;
+use crate::dom::bindings::codegen::Bindings::VoidFunctionBinding::VoidFunction;
 use crate::dom::bindings::codegen::Bindings::WorkerBinding::WorkerType;
 use crate::dom::bindings::codegen::Bindings::WorkerGlobalScopeBinding::WorkerGlobalScopeMethods;
 use crate::dom::bindings::codegen::UnionTypes::{RequestOrUSVString, StringOrFunction};
@@ -341,6 +342,12 @@ impl WorkerGlobalScopeMethods for WorkerGlobalScope {
         self.ClearTimeout(handle);
     }
 
+    // https://html.spec.whatwg.org/multipage/#dom-queuemicrotask
+    fn QueueMicrotask(&self, callback: Rc<VoidFunction>) {
+        self.upcast::<GlobalScope>()
+            .queue_function_as_microtask(callback);
+    }
+
     #[allow(unrooted_must_root)]
     // https://fetch.spec.whatwg.org/#fetch-method
     fn Fetch(

components/script/microtask.rs

@@ -9,6 +9,7 @@
 use crate::dom::bindings::callback::ExceptionHandling;
 use crate::dom::bindings::cell::DomRefCell;
 use crate::dom::bindings::codegen::Bindings::PromiseBinding::PromiseJobCallback;
+use crate::dom::bindings::codegen::Bindings::VoidFunctionBinding::VoidFunction;
 use crate::dom::bindings::root::DomRoot;
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::htmlimageelement::ImageElementMicrotask;
@@ -34,6 +35,7 @@ pub struct MicrotaskQueue {
 #[derive(JSTraceable, MallocSizeOf)]
 pub enum Microtask {
     Promise(EnqueuedPromiseCallback),
+    User(UserMicrotask),
     MediaElement(MediaElementMicrotask),
     ImageElement(ImageElementMicrotask),
     CustomElementReaction,
@@ -52,6 +54,15 @@ pub struct EnqueuedPromiseCallback {
     pub pipeline: PipelineId,
 }
 
+/// A microtask that comes from a queueMicrotask() Javascript call,
+/// identical to EnqueuedPromiseCallback once it's on the queue
+#[derive(JSTraceable, MallocSizeOf)]
+pub struct UserMicrotask {
+    #[ignore_malloc_size_of = "Rc has unclear ownership"]
+    pub callback: Rc<VoidFunction>,
+    pub pipeline: PipelineId,
+}
+
 impl MicrotaskQueue {
     /// Add a new microtask to this queue. It will be invoked as part of the next
     /// microtask checkpoint.
@@ -95,6 +106,11 @@ impl MicrotaskQueue {
                             let _ = job.callback.Call_(&*target, ExceptionHandling::Report);
                         }
                     },
+                    Microtask::User(ref job) => {
+                        if let Some(target) = target_provider(job.pipeline) {
+                            let _ = job.callback.Call_(&*target, ExceptionHandling::Report);
+                        }
+                    },
                     Microtask::MediaElement(ref task) => {
                         task.handler();
                     },