Creating a thread from a member class function [duplicate] - c++

Question

This question already has answers here:
Using boost thread and a non-static class function
(5 answers)
Closed 5 years ago.
Here is my class.h
class threads_queue{
private:
boost::condition_variable the_condition_variable;
public:
//boost::atomic<bool> done;
boost::lockfree::spsc_queue<std::pair<char, std::string>> q{100};
//threads_queue() : done(false) {};
void static run_function();
void add_query(std::string, std::string);
void get_query(void);
};
& Here is class.cpp
void threads_queue::get_query(void){
std::pair<char, std::string> value;
//to do..
}
void threads_queue::add_query(std::string str, std::string work){
//to do ..
}
void run_function(){
//Here I want to create two threads
//First thread like
boost::thread producer_thread(add_query);
boost::thread consumer_thread(get_query);
producer_thread.join();
//done = true;
consumer_thread.join()
}
I'm following this example:
http://www.boost.org/doc/libs/1_54_0/doc/html/lockfree/examples.html
But the problem is when I want to create a thread I always get an error, it does not work
Here were my attempts to solve the error:
1.
boost::thread consumer_thread(&threads_queue::get_query);
I got this error:
Called object type 'void (threads_queue::*)()' is not a function or
function pointer
2.
boost::thread consumer_thread(&threads_queue::get_query, this);
I got this error:
Invalid use of 'this' outside of a non-static member function
3.
boost::thread* thr = new boost::thread(boost::bind(&threads_queue::get_query));
I got this error:
/usr/local/include/boost/bind/bind.hpp:75:22: Type 'void
(threads_queue::*)()' cannot be used prior to '::' because it has no
members
I am not how could this problem be solved, any help?
UPDATE
This topic has great discussion of the problem:
Using boost thread and a non-static class function
My main problem was I forgot to add
threads_queue::
before the run() in my cpp file, there are Mikhail comments below where were a great help: .

Answer 1

There is a lot wrong with your code.
Non-static members are specific to a class. In addition to the function you need to pass an instance of the class to boost::thread's constructor. This has nothing to do with threads or boost.
threads_queue should "own" the threads, and probably should be renamed to something like thread container. The whole class should at minimal be non-copyable.
Here is a complete example written by somebody other than me.
/ Copyright (C) 2009 Tim Blechmann
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//[spsc_queue_example
#include <boost/thread/thread.hpp>
#include <boost/lockfree/spsc_queue.hpp>
#include <iostream>
#include <boost/atomic.hpp>
int producer_count = 0;
boost::atomic_int consumer_count (0);
boost::lockfree::spsc_queue<int, boost::lockfree::capacity<1024> > spsc_queue;
const int iterations = 10000000;
void producer(void)
{
for (int i = 0; i != iterations; ++i) {
int value = ++producer_count;
while (!spsc_queue.push(value))
;
}
}
boost::atomic<bool> done (false);
void consumer(void)
{
int value;
while (!done) {
while (spsc_queue.pop(value))
++consumer_count;
}
while (spsc_queue.pop(value))
++consumer_count;
}
int main(int argc, char* argv[])
{
using namespace std;
cout << "boost::lockfree::queue is ";
if (!spsc_queue.is_lock_free())
cout << "not ";
cout << "lockfree" << endl;
boost::thread producer_thread(producer);
boost::thread consumer_thread(consumer);
producer_thread.join();
done = true;
consumer_thread.join();
cout << "produced " << producer_count << " objects." << endl;
cout << "consumed " << consumer_count << " objects." << endl;
}
//]