@Fdhvdu I have an object in my code and i want to call a member function of this object by

add_and_detach

it is not possible to call i got this error error: invalid use of non-static member function

is it possible to use this library inside the object to call the member function of the class ? this is important because i can not define this async function outside the class or as public, it uses the all private members that initialized and many other objects inside it.

Regards,

@Fdhvdu

i want to know if i defined the pool with max size 10 and some part of my code based on receiving requests add_and_detach the thread to this pool once the threadpool max size exceeds what will happen ?

i need to know the excess threads will wait to finished the current number of threads and once the working threads release/finished, the waited threads will execute ? or all the new threads fired immediately without controlling on the max size of pool ?

@Fdhvdu i just installed and execute your sample for thread pooling. after execution stage 1 (same result on other usage in all 3 remaining stages) i see the result below that it is not correct :

stage 1 add_and_detach - thread 4 wait 0 sec add_and_detach - thread 4 wait 0 sec add_and_detach - thread 4 wait 1 sec add_and_detach - thread 4 wait 3 sec

as you see the all thread shows number 4, as their thread no, that it is not correct! you send the i as a variable to the function add_and_detach_func but it seems it is not working correctly

        for(size_t i{0};i!=tp.size();++i)
                tp.add_and_detach(add_and_detach_func,i);

        std::size_t add_and_detach_func(const std::size_t i)
        {
                using namespace std;
                const auto sec{get()};
                this_thread::sleep_for(chrono::seconds{sec});
                lock_guard<mutex> lock{mut};
                cout<<"add_and_detach - thread "<<i<<" wait "<<sec<<" sec"<<endl;
                return i;
        }

more info :

Compiler : g++ (Ubuntu 7.4.0-1ubuntu1~18.04.1) 7.4.0 OS: Ubuntu 18.04.1 LTS (GNU/Linux 4.15.0-54-generic x86_64)

download the lastest code. and compile, getting following error.

[email protected]:~/threadpool/ThreadPool$ g++ -std=c++17 tutorial/example.cpp src/* ../lib/src/Scope_guard.cpp 
In file included from src/../../lib/header/thread/CWait_bounded_queue.hpp:6:0,
                 from src/CThreadPool.cpp:6:
src/../../lib/header/thread/CLock_bounded_queue.hpp:10:9: fatal error: ../tool/CScopeGuard.hpp: No such file or directory
 #include"../tool/CScopeGuard.hpp"
         ^~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
In file included from src/../../lib/header/thread/CWait_bounded_queue.hpp:6:0,
                 from src/IThreadPoolItemExecutor.cpp:6:
src/../../lib/header/thread/CLock_bounded_queue.hpp:10:9: fatal error: ../tool/CScopeGuard.hpp: No such file or directory
 #include"../tool/CScopeGuard.hpp"
         ^~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.

try to rename Scope_guard.cpp to CScope_guard.cpp didn't get any better.

[email protected]:~/threadpool/ThreadPool$ g++ -std=c++17 tutorial/example.cpp src/* ../lib/src/CScope_guard.cpp 
In file included from src/../../lib/header/thread/CWait_bounded_queue.hpp:6:0,
                 from src/CThreadPool.cpp:6:
src/../../lib/header/thread/CLock_bounded_queue.hpp:10:9: fatal error: ../tool/CScopeGuard.hpp: No such file or directory
 #include"../tool/CScopeGuard.hpp"
         ^~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
In file included from src/../../lib/header/thread/CWait_bounded_queue.hpp:6:0,
                 from src/IThreadPoolItemExecutor.cpp:6:
src/../../lib/header/thread/CLock_bounded_queue.hpp:10:9: fatal error: ../tool/CScopeGuard.hpp: No such file or directory
 #include"../tool/CScopeGuard.hpp"
         ^~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.

I am trying to compile the example. thanks.

Hello there,

I'm developing a software which going to process heavy network traffics. (so many short-lived network sessions) And I have difficulty to select a good threadpool library for my use-case.

My first attempt was to use CTPL (https://github.com/vit-vit/CTPL), which provides non-blocking queue (from Boost - with no lib dependency). From performance perspective I didn't get good result, as matter of fact, when i compare the threadpool performance vs creating the threads on-fly , I get better result from creating threads over and over again !

So first, as you published your benchmark versus other libraries. I'd be appreciated if you could include CTPL into your benchmark tests.

Also, in other posts, I found your working on your library for improvement. Is there any time-line for next release ?

Thanks.

Thank you for writing and publishing this thread pool implementation. It seems like a glaring hole in the C++ STL / Boost etc. As it stands std::async is totally unusable (runs "deferred" or one thread per task and blows up). C++20 offers "new futures", but no task launching/scheduling as far as I can see.

So a pool is totally necessary!

I noticed that your ReadMe says "TODO work stealing". Does you pool take this Sean Parent talk into account?

https://www.youtube.com/watch?v=zULU6Hhp42w&feature=emb_logo

This blog has a minimal implementation which does:

https://vorbrodt.blog/2019/02/27/advanced-thread-pool/ https://github.com/mvorbrodt/blog

change example.cpp pool size to 1024

using namespace std;
	nThread::CThreadPool tp{1024};
	queue<nThread::CThreadPool::thread_id> que;

and running the test. get stuck as following output

add - thread 752 wait 3 sec
add_and_detach - thread 1024 wait 1 sec
add - thread 762 wait 0 sec
add_and_detach - thread 1024 wait 2 sec
add_and_detach - thread 1024 wait 3 sec
add - thread 758 wait 2 sec
add_and_detach - thread 1024 wait 1 sec
add - thread 759 wait 2 sec
add_and_detach - thread 1024 wait 2 sec
add - thread 755 wait 3 sec
add_and_detach - thread 1024 wait 3 sec
add - thread 757 wait 3 sec
add - thread 763 wait 1 sec
add - thread 760 wait 3 sec
add_and_detach - thread 1024 wait 3 sec
add - thread 767 wait 1 sec
add - thread 764 wait 2 sec
add - thread 765 wait 2 sec
add - thread 768 wait 1 sec
add - thread 766 wait 3 sec