Databases
StackOverflow2013
Postsdbo
POMultithreading Multiple Producer and Consumer Threads Won't Sync BlockingCollection Race Condition
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POMultithreading Multiple Producer and Consumer Threads Won't Sync BlockingCollection Race Condition
    primarykey
    data
    text
    <p>I have multiple producers and multiple consumers. My shared resource is the BlockingCollection. However, my code only works if I have one consumer. I know it is a race condition since the output is different each time I run the code. </p> <p>I thought BlockingCollection would take care of all the syncing etc. but it does not.</p> <p>How can I sync my shared resource among all the producers and consumers then?</p> <p>Here is my code:</p> <pre><code>/// &lt;summary&gt; /// PURE PRODUCER TYPE /// &lt;/summary&gt; class Caller { private BlockingCollection&lt;Call&gt; incommingCalls; public Caller(BlockingCollection&lt;Call&gt; calls) { incommingCalls = calls; //start the producer thread Thread thread = new Thread(new ThreadStart(placeCall)); thread.Start(); } public void placeCall() { incommingCalls.Add(myCall); } } /// &lt;summary&gt; /// CONSUMER /// &lt;/summary&gt; class Fresher : Employee { private BlockingCollection&lt;Call&gt; calls; public Fresher(BlockingCollection&lt;Call&gt; incalls) { calls = incalls; Thread thread = new Thread(new ThreadStart(HandleCalls)); thread.Start(); } /// &lt;summary&gt; /// /// &lt;/summary&gt; public void HandleCalls() { while (!incommingCalls.IsCompleted) { Call item; if (incommingCalls.TryTake(out item, 100000)) { //do something with the call } //else do nothing - just wait } } /// &lt;summary&gt; /// /// &lt;/summary&gt; class CallCenter { private BlockingCollection&lt;Call&gt; fresherCalls; private List&lt;Caller&gt; myCallers; private List&lt;Employee&gt; myFreshers; public CallCenter() { //initial incomming calls to the fresher queue fresherCalls = new BlockingCollection&lt;Call&gt;(); myFreshers = new List&lt;Employee&gt;(); myCallers = new List&lt;Caller&gt;(); generate_freshers(); //generate to start the producer generate_callers(); } /// &lt;summary&gt; /// /// &lt;/summary&gt; private void generate_freshers() { for (int i = 0; i &lt; 1; i++ ) { myFreshers.Add(new Fresher(fresherCalls, tlCalls, locker2)); } } /// &lt;summary&gt; /// /// &lt;/summary&gt; private void generate_callers() { for (int i = 0; i &lt; 20; i++ ) { myCallers.Add(new Caller(fresherCalls, locker)); } } } </code></pre>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USuser1261710
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POMultithreading Multiple Producer and Consumer Threads Won't Sync BlockingCollection Race Condition
      1. This table or related slice is empty.
      1. VTUpMod
    1. COWhat is the behavior that you're seeing which you expect is incorrect?
      singulars
      1. POMultithreading Multiple Producer and Consumer Threads Won't Sync BlockingCollection Race Condition
      1. USReed Copsey
    2. COI expect that the first Employee will take the first call, the second will take the second call etc... but they are all rotating around and the result is not predictable...
      singulars
      1. POMultithreading Multiple Producer and Consumer Threads Won't Sync BlockingCollection Race Condition
      1. USuser1261710
    3. COYou can't guarantee calls are processed in the same order when you have multiple producers/consumers. It's going to depend on the operating system's task scheduler. What makes you say that things aren't working? Does it miss calls or process them incorrectly when you have multiple consumers?
      singulars
      1. POMultithreading Multiple Producer and Consumer Threads Won't Sync BlockingCollection Race Condition
      1. USJim Mischel
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload