Make DestructorCheck::Safety no-copy, no-move

[folly.git] / folly / io / async / EventBase.cpp

diff --git a/folly/io/async/EventBase.cpp b/folly/io/async/EventBase.cpp
index 062ec2d3dd4e1f2726a31644eb126cb6a7311115..cf8a87fa84b5072db3ef48e1eda081b39402c0fd 100644 (file)
--- a/folly/io/async/EventBase.cpp
+++ b/folly/io/async/EventBase.cpp
@@ -40,7 +40,7 @@ namespace folly {
 class EventBase::FunctionRunner
     : public NotificationQueue<EventBase::Func>::Consumer {
  public:
-  void messageAvailable(Func&& msg) override {
+  void messageAvailable(Func&& msg) noexcept override {
     // In libevent2, internal events do not break the loop.
     // Most users would expect loop(), followed by runInEventBaseThread(),
     // to break the loop and check if it should exit or not.
@@ -54,21 +54,7 @@ class EventBase::FunctionRunner
       // wake up the loop.  We can ignore these messages.
       return;
     }
-
-    // The function should never throw an exception, because we have no
-    // way of knowing what sort of error handling to perform.
-    //
-    // If it does throw, log a message and abort the program.
-    try {
-      msg();
-    } catch (const std::exception& ex) {
-      LOG(ERROR) << "runInEventBaseThread() function threw a "
-                 << typeid(ex).name() << " exception: " << ex.what();
-      abort();
-    } catch (...) {
-      LOG(ERROR) << "runInEventBaseThread() function threw an exception";
-      abort();
-    }
+    msg();
   }
 };
 
@@ -108,7 +94,7 @@ EventBase::EventBase(bool enableTimeMeasurement)
     // The value 'current_base' (libevent 1) or
     // 'event_global_current_base_' (libevent 2) is filled in by event_set(),
     // allowing examination of its value without an explicit reference here.
-    // If ev.ev_base is NULL, then event_init() must be called, otherwise
+    // If ev.ev_base is nullptr, then event_init() must be called, otherwise
     // call event_base_new().
     event_set(&ev, 0, 0, nullptr, nullptr);
     if (!ev.ev_base) {
@@ -197,12 +183,10 @@ EventBase::~EventBase() {
     event_base_free(evb_);
   }
 
-  {
-    std::lock_guard<std::mutex> lock(localStorageMutex_);
-    for (auto storage : localStorageToDtor_) {
-      storage->onEventBaseDestruction(*this);
-    }
+  for (auto storage : localStorageToDtor_) {
+    storage->onEventBaseDestruction(*this);
   }
+
   VLOG(5) << "EventBase(): Destroyed.";
 }
 
@@ -408,16 +392,23 @@ ssize_t EventBase::loopKeepAliveCount() {
         loopKeepAliveCountAtomic_.exchange(0, std::memory_order_relaxed);
   }
   DCHECK_GE(loopKeepAliveCount_, 0);
+
   return loopKeepAliveCount_;
 }
 
 void EventBase::applyLoopKeepAlive() {
-  if (loopKeepAliveActive_ && loopKeepAliveCount() == 0) {
+  auto keepAliveCount = loopKeepAliveCount();
+  // Make sure default VirtualEventBase won't hold EventBase::loop() forever.
+  if (virtualEventBase_ && virtualEventBase_->keepAliveCount() == 1) {
+    --keepAliveCount;
+  }
+
+  if (loopKeepAliveActive_ && keepAliveCount == 0) {
     // Restore the notification queue internal flag
     fnRunner_->stopConsuming();
     fnRunner_->startConsumingInternal(this, queue_.get());
     loopKeepAliveActive_ = false;
-  } else if (!loopKeepAliveActive_ && loopKeepAliveCount() > 0) {
+  } else if (!loopKeepAliveActive_ && keepAliveCount > 0) {
     // Update the notification queue event to treat it as a normal
     // (non-internal) event.  The notification queue event always remains
     // installed, and the main loop won't exit with it installed.
@@ -749,7 +740,7 @@ const char* EventBase::getLibeventMethod() { return event_get_method(); }
 
 VirtualEventBase& EventBase::getVirtualEventBase() {
   folly::call_once(virtualEventBaseInitFlag_, [&] {
-    virtualEventBase_ = folly::make_unique<VirtualEventBase>(*this);
+    virtualEventBase_ = std::make_unique<VirtualEventBase>(*this);
   });
 
   return *virtualEventBase_;