Concurrent Queue is thread-safe first in - first out (FIFO) collection.
Concurrent Queue is thread-safe first in - first out (FIFO) collection/container.
Questions tagged [concurrent-queue]
93 questions
32
votes
3 answers
Try Dequeue in ConcurrentQueue
The TryDequeue in ConcurrentQueue will return false if no items in queue.
If the queue is empty I need that my queue will wait until new item to be added in queue and it dequeue that new one, and the process will continues like that.
Should I use…
C-va
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22
votes
2 answers
Is it safe to put TryDequeue in a while loop?
I have not used concurrent queue before.
Is it OK to use TryDequeue as below, in a while loop? Could this not get stuck forever?
var cq = new ConcurrentQueue();
cq.Enqueue("test");
string retValue;
while(!cq.TryDequeue(out retValue))
{
…
ManInMoon
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15
votes
3 answers
How to create no-duplicates ConcurrentQueue?
I need a concurrent collection that doesn't allow duplicates (to use in BlockingCollection as Producer/Consumer).
I don't need strict order of elements.
From another hand i want to minimize the maximum time of element "live" in collection. I.e.…
Oleg Vazhnev
- 23,239
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6
votes
3 answers
How to multithread queue processing
C++ containers are supposed to be thread-safe by default. I must be using queue to multithread incorrectly because for this code:
#include
using std::thread;
#include
using std::cout;
using std::endl;
#include
using…
Chris Redford
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6
votes
0 answers
Using Concurrency::concurrent_queue together with std::unique_ptr
I want to use the Concurrency library of Visual Studio 2010 to pass actions between threads.
I have my class SimpleAction and pointers to it are stored in the Concurrency::concurrent_queue.
Using this definition, and 'consumption' logic it…
Patrick
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5
votes
1 answer
ConcurrentQueue .Net: Multithreaded consumer
I had a very basic question which is more around concepts of ConcurrentQueue. A queue is FIFO. When multiple threads start accessing it, how do we guarantee FIFO?
Suppose, I have added Apple, Oranges, Lemon, Peach and Apricot - in that order. The…
Kallol
- 264
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4
votes
1 answer
What is the difference between TryDequeue and TryTake in a ConcurrentQueue<>?
In the ConcurrentQeueue<> class, and extra method TryDequeue() is defined. But, as it implements IProducerConsumerCollection<>, it also has a TryTake() method. According to the docs, they both do the same thing:
TryDequeue:
Tries to remove and…
Bart Friederichs
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4
votes
1 answer
Why can't complexity of ConcurrentLinkedQueue.size() be constant?
Javadoc for ConcurrentLinkedQueue explicitly states that the complexity of the size() method is O(n). I find this surprising. I would follow the stock LinkedList.size() approach by accumulating the size in a counter. Given the asynchronous nature of…
Igor Urisman
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4
votes
1 answer
Pattern to remove elements from ConcurrentQueue after peeking
I have one producer and multiple consumers. I am using ConcurrentQueue. I am using C# but I think my problem is language agnostics.
There can be non-unique consumers. i.e. more than one consumers can be interested in same message. So, non-unique…
Ashish Negi
- 5,193
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4
votes
2 answers
RxJS parallel queue with concurrent workers?
Let's say I want to I download 10,000 files. I can easily build a queue of those 10,000 files (happy to take advice if any of this can be done better),
import request from 'request-promise-native';
import {from} from 'rxjs';
let reqs = [];
for (…
Evan Carroll
- 78,363
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4
votes
1 answer
Worker Threads Blocking When ConcurrentQueue has too many items
This is a weird one, I have a Thread[] of worker threads which each process items in a ConcurrentQueue until the queue is empty, at which point the rest of the program continues.
This works until about ~1500 items at which point all threads…
ScottishTapWater
- 3,656
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4
votes
5 answers
Why do ConcurrentQueue and ConcurrentDictionary have "Try" methods - TryAdd, TryDequeue - instead of Add and Dequeue?
ConcurrentQueue has TryDequeue method.
Queue has just Dequeue method.
In ConcurrentDictionary there is no Add method, but we have TryAdd instead.
My question is:
What is the diffrence between these concurrent collection methods? Why they are…
Kamil
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4
votes
2 answers
ConcurrentQueue and Parallel.ForEach
I have a ConcurrentQueue with a list of URLs that I need to get the the source of. When using the Parallel.ForEach with the ConcurrentQueue object as the input parameter, the Pop method won't work nothing (Should return a string).
I'm using Parallel…
Zroq
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4
votes
1 answer
Example of TBB concurrent_queue use
The Intel Thread Building Blocks library includes a concurrent_queue container.
Unfortunately, digging around on the internet has yet to yield an example of a concurrent_queue being used in a parallel manner by the TBB library.
Could someone provide…
Richard
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3
votes
2 answers
Why concurrent queue with sync act like serial queue?
Could anyone help me to understand this code I created:
let cq = DispatchQueue(label: "downloadQueue", attributes: .concurrent)
cq.sync {
for i in 0..<10 {
sleep(2)
print(i)
}
}
print("all finished!")
And the output is serial order…
RobotX
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