remove Cpp2WorkerFactory

Summary:
In preparation for a global IOThreadPoolExecutor - we can't override the workerFactory if we are using a global one.

Instead, add a new getEventBases() to IOTHreadPoolExecutro and just run code on each eventBase.  For shutdown, explicitly add a stop(), instead of doing the work after loop() as exited

Cpp2Worker required minor changes to be able to use EventBaseManager's eventbase vs. their own

Test Plan: fbconfig -r thrift/lib/cpp2; fbmake runtests

Reviewed By: jsedgwick@fb.com

Subscribers: trunkagent, andrewcox, doug, fugalh, alandau, bmatheny, mshneer, folly-diffs@

FB internal diff: D1734795

Signature: t1:1734795:1418759367:b45f419e5cbc482a64a5873d9e00e3bcb071db5a

folly/experimental/wangle/concurrent/IOThreadPoolExecutor.cpp

@@ -153,6 +153,16 @@ void IOThreadPoolExecutor::stopThreads(size_t n) {
   }
 }
 
+std::vector<EventBase*> IOThreadPoolExecutor::getEventBases() {
+  std::vector<EventBase*> bases;
+  RWSpinLock::ReadHolder{&threadListLock_};
+  for (const auto& thread : threadList_.get()) {
+    auto ioThread = std::static_pointer_cast<IOThread>(thread);
+    bases.push_back(ioThread->eventBase);
+  }
+  return bases;
+}
+
 // threadListLock_ is readlocked
 uint64_t IOThreadPoolExecutor::getPendingTaskCount() {
   uint64_t count = 0;

folly/experimental/wangle/concurrent/IOThreadPoolExecutor.h

@@ -41,6 +41,8 @@ class IOThreadPoolExecutor : public ThreadPoolExecutor, public IOExecutor {
 
   EventBase* getEventBase() override;
 
+  std::vector<EventBase*> getEventBases();
+
  private:
   struct FOLLY_ALIGN_TO_AVOID_FALSE_SHARING IOThread : public Thread {
     IOThread(IOThreadPoolExecutor* pool)

folly/experimental/wangle/concurrent/NamedThreadFactory.h

@@ -44,6 +44,10 @@ class NamedThreadFactory : public ThreadFactory {
     prefix_ = prefix.str();
   }
 
+  std::string getNamePrefix() {
+    return prefix_;
+  }
+
  private:
   std::string prefix_;
   std::atomic<uint64_t> suffix_;