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I created and executed a simple thread on my system. when I execute this program, I have the error message : Enable multithreading to use std::thread: Operation not permitted
some details about my system :
I compile the source code including the library pthread
The source code:
#include <iostream> #include <thread> using namespace std; void func(void) { cout << "test thread" << endl; } int main() { cout << "start" << endl; thread t1 (func); t1.join(); cout << "end" << endl; return 0; } 
844
std::thread Threads allow multiple functions to execute concurrently. std::thread objects may also be in the state that does not represent any thread (after default construction, move from, detach, or join), and a thread of execution may not be associated with any thread objects (after detach).
If you don't join these threads, you might end up using more resources than there are concurrent tasks, making it harder to measure the load. To be clear, if you don't call join , the thread will complete at some point anyway, it won't leak or anything.
If you have used std::thread or std::bind , you probably noticed that even if you pass a reference as parameter, it still creates a copy instead. From cppreference, The arguments to the thread function are moved or copied by value.
A thread does not operate within another thread. They are independent streams of execution within the same process and their coexistence is flat, not hierarchical. Some simple rules to follow when working with multiple threads: Creating threads is expensive, so avoid creating and destroying them rapidly.
It seems that you are trying to use C++11 threads. If it is true, then
#include <thread> and #include <iostream>, i.e. do not use " in these lines and add # in front of them.g++ -std=c++11 q.cpp -lpthread (dependency order matters for newer g++)Hint: when you are using threads in a static linked library and use this library in an executable, then you have to add the flag -pthread to the link command for the executable. Example:
g++ Obj1.o Obj2.o MyStaticLib.a -o MyExecutable -pthread If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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