commit 94ceb12a4c48815c12a67fea5206e7fde359efd9
author Alexander Afanasyev <alexander.afanasyev@ucla.edu> Mon Feb 03 14:47:57 2014 -0800
committer Alexander Afanasyev <alexander.afanasyev@ucla.edu> Wed Feb 05 15:42:37 2014 -0800
tree ce4f44461df93c1c953d1b45e7fbfd406d7c9d32
parent d5f87930a135df5581de4ab47a821c59a1ab7369

core: Fixing scheduler, so it doesn't crash when an event is cancelled from the event invocation

Change-Id: I219df36a4ed19d75e97e676bedeba023fd53326e

daemon/core/scheduler.cpp

diff --git a/daemon/core/scheduler.cpp b/daemon/core/scheduler.cpp
index c72e279..a1759ca 100644
--- a/daemon/core/scheduler.cpp
+++ b/daemon/core/scheduler.cpp
@@ -77,6 +77,7 @@
   : m_ioService(ioService)
   , m_scheduledEvent(m_events.end())
   , m_deadlineTimer(ioService)
+  , m_isEventExecuting(false)
 {
 }
 
@@ -94,13 +95,16 @@
 {
   EventQueue::iterator i = m_events.insert(EventInfo(after, period, event));
   i->m_eventId = make_shared<EventIdImpl>(boost::cref(i));
-  
-  if (m_scheduledEvent == m_events.end() ||
-      *i < *m_scheduledEvent)
+
+  if (!m_isEventExecuting)
     {
-      m_deadlineTimer.expires_from_now(after);
-      m_deadlineTimer.async_wait(bind(&Scheduler::onEvent, this, _1));
-      m_scheduledEvent = i;
+      if (m_scheduledEvent == m_events.end() ||
+          *i < *m_scheduledEvent)
+        {
+          m_deadlineTimer.expires_from_now(after);
+          m_deadlineTimer.async_wait(bind(&Scheduler::onEvent, this, _1));
+          m_scheduledEvent = i;
+        }
     }
 
   return i->m_eventId;
@@ -122,16 +126,19 @@
   m_events.erase(static_cast<EventQueue::iterator>(*eventId));
   eventId->invalidate();
 
-  if (!m_events.empty())
+  if (!m_isEventExecuting)
     {
-      m_deadlineTimer.expires_from_now(m_events.begin()->expiresFromNow());
-      m_deadlineTimer.async_wait(bind(&Scheduler::onEvent, this, _1));
-      m_scheduledEvent = m_events.begin();
-    }
-  else
-    {
-      m_deadlineTimer.cancel();
-      m_scheduledEvent = m_events.end();
+      if (!m_events.empty())
+        {
+          m_deadlineTimer.expires_from_now(m_events.begin()->expiresFromNow());
+          m_deadlineTimer.async_wait(bind(&Scheduler::onEvent, this, _1));
+          m_scheduledEvent = m_events.begin();
+        }
+      else
+        {
+          m_deadlineTimer.cancel();
+          m_scheduledEvent = m_events.end();
+        }
     }
 }
 
@@ -142,6 +149,8 @@
     {
       return;
     }
+
+  m_isEventExecuting = true;
   
   // process all expired events
   time::Point now = time::now();
@@ -149,7 +158,7 @@
     {
       EventQueue::iterator head = m_events.begin();
       
-      head->m_event();
+      Event event = head->m_event;
       if (head->m_period < 0)
         {
           head->m_eventId->invalidate();
@@ -163,13 +172,38 @@
           i->m_eventId->reset(i);
           m_events.erase(head);
         }
+
+      try
+        {
+          event();
+        }
+      catch(...)
+        {
+          m_isEventExecuting = false;
+          for (EventQueue::iterator i = m_events.begin();
+               i != m_events.end();
+               ++i)
+            {
+              i->m_eventId->invalidate();
+            }
+          m_events.clear();
+          
+          throw;
+        }
     }
 
   if (!m_events.empty())
     {
       m_deadlineTimer.expires_from_now(m_events.begin()->m_scheduledTime - now);
       m_deadlineTimer.async_wait(bind(&Scheduler::onEvent, this, _1));
+      m_scheduledEvent = m_events.begin();
     }
+  else
+    {
+      m_scheduledEvent = m_events.end();
+    }
+
+  m_isEventExecuting = false;
 }
 
 

daemon/core/scheduler.hpp

diff --git a/daemon/core/scheduler.hpp b/daemon/core/scheduler.hpp
index 4b2e2d4..a8e60bb 100644
--- a/daemon/core/scheduler.hpp
+++ b/daemon/core/scheduler.hpp
@@ -92,6 +92,8 @@
   EventQueue m_events;
   EventQueue::iterator m_scheduledEvent;
   boost::asio::monotonic_deadline_timer m_deadlineTimer;
+
+  bool m_isEventExecuting;
 };
 
 } // namespace nfd

tests/core/scheduler.cpp

diff --git a/tests/core/scheduler.cpp b/tests/core/scheduler.cpp
index 593744b..9e673a0 100644
--- a/tests/core/scheduler.cpp
+++ b/tests/core/scheduler.cpp
@@ -89,6 +89,32 @@
   scheduler.cancelEvent(i);
 }
 
+struct SelfCancelFixture
+{
+  SelfCancelFixture()
+    : m_scheduler(m_io)
+  {
+  }
+  
+  void
+  cancelSelf()
+  {
+    m_scheduler.cancelEvent(m_selfEventId);
+  }
+  
+  boost::asio::io_service m_io; 
+  Scheduler m_scheduler;
+  EventId m_selfEventId;
+};
+
+BOOST_FIXTURE_TEST_CASE(SelfCancel, SelfCancelFixture)
+{
+  m_selfEventId = m_scheduler.scheduleEvent(time::seconds(0.1),
+                                            bind(&SelfCancelFixture::cancelSelf, this));
+  
+  BOOST_REQUIRE_NO_THROW(m_io.run());
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 } // namespace nfd