public Consumer(string id, PCQueue pcQueue, LocationList constituencyList, ProgressManager progManager)
{
this.id = id;
finished = false; // Initially not finished
this.pcQueue = pcQueue;
this.constituencyList = constituencyList;
this.progManager = progManager;
(T = new Thread(run)).Start(); // Create a new thread for this consumer and get it started
RunningThreads++; // Increment the number of running consumer threads;
}
public void RunProducerConsumer()
{
//Create cyclist list to hold individual cyclist objects read from datasets
locList = new LocationList();
// Create progress manager with number of files to process
ProgressManager progManager = new ProgressManager(configData.configRecords.Count);
// Output message to indicate that the program has started
progressLbl.Text = "Creating and starting all producers and consumers";
// Create a PCQueue instance, give it a capacity of 4
var pcQueue = new PCQueue(4);
// Create 2 Producer instances and 2 Consumer instances, these will begin executing on
// their respective threads as soon as they are instantiated
Producer[] producers = { new Producer("P1", pcQueue, configData, IOhandler),
new Producer("P2", pcQueue, configData, IOhandler) };
Consumer[] consumers = { new Consumer("C1", pcQueue, locList, progManager),
new Consumer("C2", pcQueue, locList, progManager) };
// Keep producing and consuming until all work items are completed
while (progManager.ItemsRemaining > 0)
{
;
}
// Output message to indicate that the program is shutting down
progressLbl.Text = "Shutting down all producers and consumers";
// Deactivate the PCQueue so it does not prevent waiting producer and/or consumer threads
// from completing
pcQueue.Active = false;
// Iterate through producers and signal them to finish
foreach (var p in producers)
{
p.Finished = true;
}
// Iterate through consumers and signal them to finish
foreach (var c in consumers)
{
c.Finished = true;
}
// We need to ensure that no thread waiting on Monitor.Wait() is stranded with
// no Monitor.Pulse() now possible since all producer and consumer threads have
// been signalled to stop, in the worse case all such threads could be stranded
// so pulse that many times to ensure enough pulses are made available (or the
// program can halt erroneously), wasted pulse are simply ignored
for (int i = 0; i < (Producer.RunningThreads + Consumer.RunningThreads); i++)
{
lock (pcQueue)
{
// Pulse the PCQueue to signal any waiting threads
Monitor.Pulse(pcQueue);
// Give a short break to the main thread so the pulses have time to be
// detected by any potentially waiting producer and/or consumer threads
Thread.Sleep(100);
}
}
// Once all producer and consumer threads have finally finished we can gracefully
// shutdown the main thread, this is achieved by spinning on a while() loop until
// there are no running threads, in this case we do not mind the main thread
// spinning as we are about to shutdown the program
while ((Producer.RunningThreads > 0) || (Consumer.RunningThreads > 0))
{
; // Wait by spinning
}
Console.WriteLine();
progressLbl.Text = "All producers and consumers shut down";
}