From: Andrii Grynenko <andrii@fb.com>
Date: Mon, 6 Apr 2015 19:06:58 +0000 (-0700)
Subject: Add FiberManager local type
X-Git-Tag: v0.35.0~13
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0978159b6279d9484a6612c5e46193376fd83820;p=folly.git

Add FiberManager local type

Summary: This adds local type for each FiberManager. Only local of given type can be created on fibers of this FiberManager. Locals of other types will be just treated as regualar thread-locals.

Test Plan: unit test

Reviewed By: bwatling@fb.com

Subscribers: folly-diffs@, yfeldblum, chalfant

FB internal diff: D1969739

Signature: t1:1969739:1428345931:aff5deb526c179158e5881b29330ff3f6698149a
---

diff --git a/folly/AtomicLinkedList.h b/folly/AtomicLinkedList.h
index 7e9db6bd..eca8de16 100644
--- a/folly/AtomicLinkedList.h
+++ b/folly/AtomicLinkedList.h
@@ -44,6 +44,20 @@ template <class T, AtomicLinkedListHook<T> T::* HookMember>
 class AtomicLinkedList {
  public:
   AtomicLinkedList() {}
+  AtomicLinkedList(const AtomicLinkedList&) = delete;
+  AtomicLinkedList& operator=(const AtomicLinkedList&) = delete;
+  AtomicLinkedList(AtomicLinkedList&& other) noexcept {
+    auto tmp = other.head_.load();
+    other.head_ = head_.load();
+    head_ = tmp;
+  }
+  AtomicLinkedList& operator=(AtomicLinkedList&& other) noexcept {
+    auto tmp = other.head_.load();
+    other.head_ = head_.load();
+    head_ = tmp;
+
+    return *this;
+  }
 
   /**
    * Note: list must be empty on destruction.
diff --git a/folly/experimental/fibers/FiberManager-inl.h b/folly/experimental/fibers/FiberManager-inl.h
index 16c5b988..f56b0640 100644
--- a/folly/experimental/fibers/FiberManager-inl.h
+++ b/folly/experimental/fibers/FiberManager-inl.h
@@ -174,9 +174,7 @@ void FiberManager::addTask(F&& func) {
   typedef AddTaskHelper<F> Helper;
 
   auto fiber = getFiber();
-  if (currentFiber_) {
-    fiber->localData_ = currentFiber_->localData_;
-  }
+  initLocalData(*fiber);
 
   if (Helper::allocateInBuffer) {
     auto funcLoc = static_cast<typename Helper::Func*>(fiber->getUserBuffer());
@@ -199,7 +197,9 @@ template <typename F>
 void FiberManager::addTaskRemote(F&& func) {
   auto task = [&]() {
     auto currentFm = getFiberManagerUnsafe();
-    if (currentFm && currentFm->currentFiber_) {
+    if (currentFm &&
+        currentFm->currentFiber_ &&
+        currentFm->localType_ == localType_) {
       return folly::make_unique<RemoteTask>(
         std::forward<F>(func),
         currentFm->currentFiber_->localData_);
@@ -297,9 +297,7 @@ void FiberManager::addTaskFinally(F&& func, G&& finally) {
     "finally(Try<T>&&): T must be convertible from func()'s return type");
 
   auto fiber = getFiber();
-  if (currentFiber_) {
-    fiber->localData_ = currentFiber_->localData_;
-  }
+  initLocalData(*fiber);
 
   typedef AddTaskFinallyHelper<F,G> Helper;
 
@@ -383,7 +381,7 @@ inline bool FiberManager::hasActiveFiber() const {
 
 template <typename T>
 T& FiberManager::local() {
-  if (currentFiber_) {
+  if (std::type_index(typeid(T)) == localType_ && currentFiber_) {
     return currentFiber_->localData_.get<T>();
   }
   return localThread<T>();
@@ -395,6 +393,22 @@ T& FiberManager::localThread() {
   return t;
 }
 
+inline void FiberManager::initLocalData(Fiber& fiber) {
+  auto fm = getFiberManagerUnsafe();
+  if (fm && fm->currentFiber_ && fm->localType_ == localType_) {
+    fiber.localData_ = fm->currentFiber_->localData_;
+  }
+}
+
+template <typename LocalT>
+FiberManager FiberManager::create(
+    std::unique_ptr<LoopController> loopController,
+    Options options) {
+  FiberManager fm(std::move(loopController), std::move(options));
+  fm.localType_ = typeid(LocalT);
+  return fm;
+}
+
 template <typename F>
 typename FirstArgOf<F>::type::value_type
 inline await(F&& func) {
diff --git a/folly/experimental/fibers/FiberManager.cpp b/folly/experimental/fibers/FiberManager.cpp
index 2d88601a..5fb6bb95 100644
--- a/folly/experimental/fibers/FiberManager.cpp
+++ b/folly/experimental/fibers/FiberManager.cpp
@@ -48,7 +48,8 @@ FiberManager::FiberManager(std::unique_ptr<LoopController> loopController,
           throw;
         }
       }),
-    timeoutManager_(std::make_shared<TimeoutController>(*loopController_)) {
+    timeoutManager_(std::make_shared<TimeoutController>(*loopController_)),
+    localType_(typeid(void)) {
   loopController_->setFiberManager(this);
 }
 
diff --git a/folly/experimental/fibers/FiberManager.h b/folly/experimental/fibers/FiberManager.h
index d1f3ce1d..94e6c289 100644
--- a/folly/experimental/fibers/FiberManager.h
+++ b/folly/experimental/fibers/FiberManager.h
@@ -18,6 +18,7 @@
 #include <functional>
 #include <memory>
 #include <queue>
+#include <typeindex>
 #include <unordered_set>
 #include <vector>
 
@@ -91,14 +92,33 @@ class FiberManager {
   typedef std::function<void(std::exception_ptr, std::string)>
   ExceptionCallback;
 
+  FiberManager(const FiberManager&) = delete;
+  FiberManager& operator=(const FiberManager&) = delete;
+  FiberManager(FiberManager&&) = default;
+  FiberManager& operator=(FiberManager&&) = default;
+
   /**
    * Initializes, but doesn't start FiberManager loop
    *
+   * @param loopController
    * @param options FiberManager options
    */
   explicit FiberManager(std::unique_ptr<LoopController> loopController,
                         Options options = Options());
 
+  /**
+   * Initializes, but doesn't start FiberManager loop
+   *
+   * @param loopController
+   * @param options FiberManager options
+   * @tparam LocalT only local of this type may be stored on fibers.
+   *                Locals of other types will be considered thread-locals.
+   */
+  template <typename LocalT>
+  static FiberManager create(std::unique_ptr<LoopController> loopController,
+                             Options options = Options());
+
+
   ~FiberManager();
 
   /**
@@ -300,6 +320,11 @@ class FiberManager {
    */
   Fiber* getFiber();
 
+  /**
+   * Sets local data for given fiber if all conditions are met.
+   */
+  void initLocalData(Fiber& fiber);
+
   /**
    * Function passed to the await call.
    */
@@ -319,6 +344,11 @@ class FiberManager {
 
   std::shared_ptr<TimeoutController> timeoutManager_;
 
+  /**
+   * Only local of this type will be available for fibers.
+   */
+  std::type_index localType_;
+
   void runReadyFiber(Fiber* fiber);
   void remoteReadyInsert(Fiber* fiber);
 };
diff --git a/folly/experimental/fibers/test/FibersTest.cpp b/folly/experimental/fibers/test/FibersTest.cpp
index 0b79cafa..2aea08ab 100644
--- a/folly/experimental/fibers/test/FibersTest.cpp
+++ b/folly/experimental/fibers/test/FibersTest.cpp
@@ -1217,7 +1217,8 @@ TEST(FiberManager, remoteHasReadyTasks) {
 
 template <typename Data>
 void testFiberLocal() {
-  FiberManager fm(folly::make_unique<SimpleLoopController>());
+  auto fm =
+    FiberManager::create<Data>(folly::make_unique<SimpleLoopController>());
 
   fm.addTask([]() {
       EXPECT_EQ(42, local<Data>().value);