fixed emission of actorReady call in init epilogue

Author: kavon

lib/SILGen/SILGenConstructor.cpp

@@ -742,6 +742,10 @@ void SILGenFunction::emitClassConstructorInitializer(ConstructorDecl *ctor) {
 
   SILType selfTy = getLoweredLoadableType(selfDecl->getType());
   ManagedValue selfArg = B.createInputFunctionArgument(selfTy, selfDecl);
+  
+  // is this a designated initializer for a distributed actor?
+  const bool isDesignatedDistActorInit =
+    selfClassDecl->isDistributedActor() && !isDelegating;
 
   // Make sure we've hopped to the right global actor, if any.
   if (ctor->hasAsync() && !selfClassDecl->isActor()) {
@@ -780,7 +784,7 @@ void SILGenFunction::emitClassConstructorInitializer(ConstructorDecl *ctor) {
   }
 
   // Distributed actor initializers implicitly initialize their transport and id
-  if (selfClassDecl->isDistributedActor() && !isDelegating) {
+  if (isDesignatedDistActorInit) {
     initializeDistributedActorImplicitStorageInit(ctor, selfArg);
   }
 
@@ -814,6 +818,13 @@ void SILGenFunction::emitClassConstructorInitializer(ConstructorDecl *ctor) {
     failureExitBB = createBasicBlock();
     failureExitArg = failureExitBB->createPhiArgument(
         resultLowering.getLoweredType(), OwnershipKind::Owned);
+    
+    // For an async distributed actor init, we must `resignIdentity` before
+    // the clean-ups are triggered in this failure block.
+    if (isDesignatedDistActorInit && ctor->hasAsync()) {
+      // TODO: refactor emitDistributedActor_resignAddress so we can call it
+      // within this initializer.
+    }
 
     Cleanups.emitCleanupsForReturn(ctor, IsForUnwind);
     SILValue nilResult =
@@ -865,6 +876,18 @@ void SILGenFunction::emitClassConstructorInitializer(ConstructorDecl *ctor) {
       B.clearInsertionPoint();
     }
   }
+  
+  // For distributed actors, their synchronous initializers invoke "actor ready"
+  // at the very end, just before returning on a successful initialization.
+  // There is no need for injecting `resignIdentity` calls in such inits,
+  // because we can never call `actorReady` prematurely.
+  if (isDesignatedDistActorInit && !ctor->hasAsync()) {
+    RegularLocation loc(ctor);
+    loc.markAutoGenerated();
+    
+    SILGenSavedInsertionPoint savedIP(*this, ReturnDest.getBlock());
+    emitDistributedActorReady(loc, ctor, selfArg);
+  }
 
   CleanupStateRestorationScope SelfCleanupSave(Cleanups);
 
@@ -931,12 +954,6 @@ void SILGenFunction::emitClassConstructorInitializer(ConstructorDecl *ctor) {
   // Unpop our selfArg cleanup, so we can forward.
   std::move(SelfCleanupSave).pop();
 
-  // TODO(distributed): rdar://81783599 if this is a distributed actor, jump to the distributedReady block?
-  //  // For distributed actors, emit "actor ready" since we successfully initialized
-  //  if (selfClassDecl->isDistributedActor() && !isDelegating) {
-  //    emitDistributedActorReady(ctor, selfArg);
-  //  }
-
   // Finish off the epilog by returning.  If this is a failable ctor, then we
   // actually jump to the failure epilog to keep the invariant that there is
   // only one SIL return instruction per SIL function.

lib/SILGen/SILGenDistributed.cpp

@@ -388,22 +388,21 @@ void SILGenFunction::initializeDistributedActorImplicitStorageInit(
 }
 
 void SILGenFunction::emitDistributedActorReady(
-    ConstructorDecl *ctor, ManagedValue selfArg) {
+    SILLocation loc, ConstructorDecl *ctor, ManagedValue actorSelf) {
 
   auto *dc = ctor->getDeclContext();
   auto classDecl = dc->getSelfClassDecl();
   auto &C = classDecl->getASTContext();
 
   // Only designated initializers get the lifecycle handling injected
-  if (!ctor->isDesignatedInit())
-    return;
-
-  SILLocation loc = RegularLocation(ctor);
-  loc.markAutoGenerated();
+  assert(ctor->isDesignatedInit());
+  
+  // setup scope for clean-ups
+  FullExpr scope(Cleanups, CleanupLocation(loc));
 
   // === Prepare the arguments
   SILValue transportArgValue = getActorTransportArgument(C, F, ctor);
-  SILValue selfArgValue = F.getSelfArgument();
+  actorSelf = actorSelf.borrow(*this, loc);
 
   ProtocolDecl *distributedActorProto = C.getProtocol(KnownProtocolKind::DistributedActor);
   ProtocolDecl *transportProto = C.getProtocol(KnownProtocolKind::ActorTransport);
@@ -466,7 +465,7 @@ void SILGenFunction::emitDistributedActorReady(
   // ---- actually call transport.actorReady(self)
   B.createApply(
       loc, readyWitnessMethod, subs,
-      { selfArgValue, transportValue});
+      { actorSelf.getValue(), transportValue});
 }
 
 /******************************************************************************/

lib/SILGen/SILGenFunction.h

@@ -2020,7 +2020,7 @@ class LLVM_LIBRARY_VISIBILITY SILGenFunction
   /// Notify transport that actor has initialized successfully,
   /// and is ready to receive messages.
   void emitDistributedActorReady(
-      ConstructorDecl *ctor, ManagedValue selfArg);
+      SILLocation loc, ConstructorDecl *ctor, ManagedValue actorSelf);
 
   /// Inject distributed actor and transport interaction code into the destructor.
   void emitDistributedActor_resignAddress(