Fix destructor race in Job

src/ripple/core/JobQueue.h

@@ -180,7 +180,7 @@ private:
     //
     // Invariants:
     //  <none>
-    void finishJob (Job const& job);
+    void finishJob (JobType type);
 
     template <class Rep, class Period>
     void on_dequeue (JobType type,

src/ripple/core/impl/Job.cpp

@@ -80,6 +80,10 @@ void Job::doJob ()
     m_loadEvent->reName (mName);
 
     mJob (*this);
+
+    // Destroy the lambda, otherwise we won't include
+    // its duration in the time measurement
+    mJob = std::function<void(Job&)>();
 }
 
 void Job::rename (std::string const& newName)

src/ripple/core/impl/JobQueue.cpp

@@ -407,14 +407,11 @@ JobQueue::getNextJob (Job& job)
 }
 
 void
-JobQueue::finishJob (Job const& job)
+JobQueue::finishJob (JobType type)
 {
-    JobType const type = job.getType ();
-
-    assert (m_jobSet.find (job) == m_jobSet.end ());
     assert(type != jtINVALID);
 
-    JobTypeData& data (getJobTypeData (type));
+    JobTypeData& data = getJobTypeData (type);
 
     // Queue a deferred task if possible
     if (data.deferred > 0)
@@ -456,6 +453,9 @@ void JobQueue::on_execute (JobType type,
 
 void
 JobQueue::processTask ()
+{
+    JobType type;
+
     {
         Job job;
 
@@ -487,10 +487,16 @@ JobQueue::processTask ()
             JLOG(m_journal.trace) << "Skipping processTask ('" << data.name () << "')";
         }
 
+        type = job.getType();
+    }
+
     {
         std::lock_guard <std::mutex> lock (m_mutex);
-        finishJob (job);
+        finishJob (type);
         --m_processCount;
+        // Job should be destroyed before calling checkStopped
+        // otherwise destructors with side effects can access
+        // parent objects that are already destroyed.
         checkStopped (lock);
     }