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std::thread::joinable

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< cpp‎ | thread‎ | thread
Revision as of 17:33, 9 July 2013 by P12bot (Talk | contribs)

bool joinable();
(since C++11)

Checks if the thread object identifies an active thread of execution. Specifically, returns true if get_id() != std::thread::id(). So a default constructed thread is not joinable.

A thread that has finished executing code, but has not yet been joined is still considered an active thread of execution and is therefore joinable.

Contents

Parameters

(none)

Return value

true if the thread object identifies an active thread of execution, false otherwise

Exceptions

noexcept specification:  
noexcept
  

Example

#include <iostream>
#include <thread>
#include <chrono>
 
void foo()
{
    std::this_thread::sleep_for(std::chrono::seconds(1));
}
 
int main()
{
    std::thread t;
    std::cout << "before starting, joinable: " << t.joinable() << '\n';
 
    t = std::thread(foo);
    std::cout << "after starting, joinable: " << t.joinable() << '\n';
 
    t.join();
}

Output:

before starting, joinable: 0
after starting, joinable: 1

See also

returns the id of the thread
(public member function) [edit]
waits for a thread to finish its execution
(public member function) [edit]
permits the thread to execute independently from the thread handle
(public member function) [edit]