GCWorkContext should always have 'static and Send

wks · Aug 24, 2023 · 1617f54 · 1617f54
1 parent b414746
commit 1617f54
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Showing 4 changed files with 14 additions and 12 deletions.
diff --git a/src/plan/immix/global.rs b/src/plan/immix/global.rs
@@ -173,8 +173,8 @@ impl<VM: VMBinding> Immix<VM> {
     /// to schedule a full heap collection. A plan must call set_collection_kind and set_gc_status before this method.
     pub(crate) fn schedule_immix_full_heap_collection<
         PlanType: Plan<VM = VM>,
-        FastContext: Send + 'static + GCWorkContext<VM = VM, PlanType = PlanType>,
-        DefragContext: Send + 'static + GCWorkContext<VM = VM, PlanType = PlanType>,
+        FastContext: GCWorkContext<VM = VM, PlanType = PlanType>,
+        DefragContext: GCWorkContext<VM = VM, PlanType = PlanType>,
     >(
         plan: &'static DefragContext::PlanType,
         immix_space: &ImmixSpace<VM>,

diff --git a/src/scheduler/gc_work.rs b/src/scheduler/gc_work.rs
@@ -42,7 +42,7 @@ impl<C: GCWorkContext> Prepare<C> {
     }
 }
 
-impl<C: GCWorkContext + 'static> GCWork<C::VM> for Prepare<C> {
+impl<C: GCWorkContext> GCWork<C::VM> for Prepare<C> {
     fn do_work(&mut self, worker: &mut GCWorker<C::VM>, mmtk: &'static MMTK<C::VM>) {
         trace!("Prepare Global");
         // We assume this is the only running work packet that accesses plan at the point of execution
@@ -110,7 +110,7 @@ impl<C: GCWorkContext> Release<C> {
     }
 }
 
-impl<C: GCWorkContext + 'static> GCWork<C::VM> for Release<C> {
+impl<C: GCWorkContext> GCWork<C::VM> for Release<C> {
     fn do_work(&mut self, worker: &mut GCWorker<C::VM>, mmtk: &'static MMTK<C::VM>) {
         trace!("Release Global");
 
@@ -187,7 +187,7 @@ impl<C: GCWorkContext> StopMutators<C> {
     }
 }
 
-impl<C: GCWorkContext + Send + 'static> GCWork<C::VM> for StopMutators<C> {
+impl<C: GCWorkContext> GCWork<C::VM> for StopMutators<C> {
     fn do_work(&mut self, worker: &mut GCWorker<C::VM>, mmtk: &'static MMTK<C::VM>) {
         trace!("stop_all_mutators start");
         mmtk.plan.base().prepare_for_stack_scanning();
@@ -445,7 +445,7 @@ impl<VM: VMBinding> GCWork<VM> for VMPostForwarding<VM> {
 
 pub struct ScanMutatorRoots<C: GCWorkContext>(pub &'static mut Mutator<C::VM>);
 
-impl<C: GCWorkContext + 'static> GCWork<C::VM> for ScanMutatorRoots<C> {
+impl<C: GCWorkContext> GCWork<C::VM> for ScanMutatorRoots<C> {
     fn do_work(&mut self, worker: &mut GCWorker<C::VM>, mmtk: &'static MMTK<C::VM>) {
         trace!("ScanMutatorRoots for mutator {:?}", self.0.get_tls());
         let base = &mmtk.plan.base();
@@ -480,7 +480,7 @@ impl<C: GCWorkContext> ScanVMSpecificRoots<C> {
     }
 }
 
-impl<C: GCWorkContext + Send + 'static> GCWork<C::VM> for ScanVMSpecificRoots<C> {
+impl<C: GCWorkContext> GCWork<C::VM> for ScanVMSpecificRoots<C> {
     fn do_work(&mut self, worker: &mut GCWorker<C::VM>, mmtk: &'static MMTK<C::VM>) {
         trace!("ScanStaticRoots");
         let factory = ProcessEdgesWorkRootsWorkFactory::<

diff --git a/src/scheduler/scheduler.rs b/src/scheduler/scheduler.rs
@@ -108,10 +108,7 @@ impl<VM: VMBinding> GCWorkScheduler<VM> {
     }
 
     /// Schedule all the common work packets
-    pub fn schedule_common_work<C: GCWorkContext<VM = VM> + 'static + Send>(
-        &self,
-        plan: &'static C::PlanType,
-    ) {
+    pub fn schedule_common_work<C: GCWorkContext<VM = VM>>(&self, plan: &'static C::PlanType) {
         use crate::plan::Plan;
         use crate::scheduler::gc_work::*;
         // Stop & scan mutators (mutator scanning can happen before STW)

diff --git a/src/scheduler/work.rs b/src/scheduler/work.rs
@@ -50,7 +50,12 @@ use crate::plan::Plan;
 /// needs this trait to schedule different work packets. For certain plans,
 /// they may need to provide several types that implement this trait, e.g. one for
 /// nursery GC, one for mature GC.
-pub trait GCWorkContext {
+///
+/// Note: Because `GCWorkContext` is often used as parameters of implementations of `GCWork`, we
+/// let GCWorkContext require `Send + 'static`.  Since `GCWorkContext` is just a group of
+/// associated types, its implementations should not have any actual fields other than
+/// `PhantomData`, and will automatically have `Send + 'static`.
+pub trait GCWorkContext: Send + 'static {
     type VM: VMBinding;
     type PlanType: Plan<VM = Self::VM>;
     // We should use SFTProcessEdges as the default value for this associate type. However, this requires