Enable inlining of trivial CoreBase methods

Summary: D22371899 et seq outlined part of the CoreBase implementation. However, in some cases (at least for opt builds), inlining trivial methods makes the code smaller. This comes from a combination of avoiding register spills and reducing exception handling code.

Reviewed By: ot

Differential Revision: D48133157

fbshipit-source-id: fac62aded9b298c92d8d3b75fd88d069d3388728

folly/futures/detail/Core.cpp

@@ -42,20 +42,6 @@ void UniqueDeleter::operator()(DeferredExecutor* ptr) {
   }
 }
 
-KeepAliveOrDeferred::KeepAliveOrDeferred() noexcept : state_(State::Deferred) {
-  ::new (&deferred_) DW{};
-}
-
-KeepAliveOrDeferred::KeepAliveOrDeferred(KA ka) noexcept
-    : state_(State::KeepAlive) {
-  ::new (&keepAlive_) KA{std::move(ka)};
-}
-
-KeepAliveOrDeferred::KeepAliveOrDeferred(DW deferred) noexcept
-    : state_(State::Deferred) {
-  ::new (&deferred_) DW{std::move(deferred)};
-}
-
 KeepAliveOrDeferred::KeepAliveOrDeferred(KeepAliveOrDeferred&& other) noexcept
     : state_(other.state_) {
   switch (state_) {
@@ -316,21 +302,6 @@ bool CoreBase::hasResult() const noexcept {
   return State() != (state & allowed);
 }
 
-Executor* CoreBase::getExecutor() const {
-  if (!executor_.isKeepAlive()) {
-    return nullptr;
-  }
-  return executor_.getKeepAliveExecutor();
-}
-
-DeferredExecutor* CoreBase::getDeferredExecutor() const {
-  if (!executor_.isDeferred()) {
-    return {};
-  }
-
-  return executor_.getDeferredExecutor();
-}
-
 DeferredWrapper CoreBase::stealDeferredExecutor() {
   if (executor_.isKeepAlive()) {
     return {};
@@ -436,9 +407,6 @@ class CoreBase::CoreAndCallbackReference {
   CoreBase* core_{nullptr};
 };
 
-CoreBase::CoreBase(State state, unsigned char attached)
-    : state_(state), attached_(attached) {}
-
 CoreBase::~CoreBase() {
   auto interrupt = interrupt_.load(std::memory_order_acquire);
   auto pointer = interrupt & ~InterruptMask;

folly/futures/detail/Core.h

@@ -83,9 +83,18 @@ class KeepAliveOrDeferred {
   using DW = DeferredWrapper;
 
  public:
-  KeepAliveOrDeferred() noexcept;
-  /* implicit */ KeepAliveOrDeferred(KA ka) noexcept;
-  /* implicit */ KeepAliveOrDeferred(DW deferred) noexcept;
+  KeepAliveOrDeferred() noexcept : state_(State::Deferred), deferred_(DW{}) {}
+
+  /* implicit */ KeepAliveOrDeferred(KA ka) noexcept
+      : state_(State::KeepAlive) {
+    ::new (&keepAlive_) KA{std::move(ka)};
+  }
+
+  /* implicit */ KeepAliveOrDeferred(DW deferred) noexcept
+      : state_(State::Deferred) {
+    ::new (&deferred_) DW{std::move(deferred)};
+  }
+
   KeepAliveOrDeferred(KeepAliveOrDeferred&& other) noexcept;
 
   ~KeepAliveOrDeferred();
@@ -474,7 +483,8 @@ class CoreBase {
   }
 
  protected:
-  CoreBase(State state, unsigned char attached);
+  CoreBase(State state, unsigned char attached) noexcept
+      : state_(state), attached_(attached) {}
 
   virtual ~CoreBase();
 
@@ -701,6 +711,21 @@ class Core final : private ResultHolder<T>, public CoreBase {
   }
 };
 
+inline Executor* CoreBase::getExecutor() const {
+  if (!executor_.isKeepAlive()) {
+    return nullptr;
+  }
+  return executor_.getKeepAliveExecutor();
+}
+
+inline DeferredExecutor* CoreBase::getDeferredExecutor() const {
+  if (!executor_.isDeferred()) {
+    return {};
+  }
+
+  return executor_.getDeferredExecutor();
+}
+
 #if FOLLY_USE_EXTERN_FUTURE_UNIT
 // limited to the instances unconditionally forced by the futures library
 extern template class Core<folly::Unit>;