std::thread::join

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

 

Thread support library

Threads
thread (C++11)
this_thread namespace
get_id (C++11) yield (C++11)	sleep_for (C++11) sleep_until (C++11)
Mutual exclusion
mutex (C++11) timed_mutex (C++11)	recursive_mutex (C++11) recursive_timed_mutex (C++11)
Generic lock management
lock_guard (C++11) unique_lock (C++11) defer_lock_t try_to_lock_t adopt_lock_t (C++11) (C++11) (C++11)	lock (C++11) try_lock (C++11) defer_lock try_to_lock adopt_lock (C++11) (C++11) (C++11)
Condition variables
condition_variable (C++11)
condition_variable_any (C++11)
notify_all_at_thread_exit (C++11)
cv_status (C++11)
Futures
promise (C++11) future (C++11) shared_future (C++11) packaged_task (C++11) async (C++11)	launch (C++11) future_status (C++11) future_error (C++11) future_category (C++11) future_errc (C++11)

 

std::thread

Member classes

thread::id

Member functions

thread::thread

thread::~thread

thread::operator=

Observers

thread::joinable

thread::get_id

thread::native_handle

thread::hardware_concurrency

Operations

thread::join

thread::detach

thread::swap

Non-member functions

std::swap

 

void join();		(since C++11)

Blocks the current thread until the thread identified by *this finishes its execution.

Parameters

(none)

Return value

(none)

Exceptions

std::system_error if joinable() == false or an error occurs.

Example

run this code

#include <iostream>
#include <thread>
#include <chrono>
 
void foo()
{
    // simulate expensive operation
    std::this_thread::sleep_for(std::chrono::seconds(1));
}
 
void bar()
{
    // simulate expensive operation
    std::this_thread::sleep_for(std::chrono::seconds(1));
}
 
int main()
{
    std::cout << "starting first helper...\n";
    std::thread helper1(foo);
 
    std::cout << "starting second helper...\n";
    std::thread helper2(bar);
 
    std::cout << "waiting for helpers to finish...\n";
    helper1.join();
    helper2.join();
 
    std::cout << "done!\n";
}

Output:

starting first helper...
starting second helper...
waiting for helpers to finish...
done!

See also

detach	permits the thread to execute independently from the thread handle (public member function)
joinable	checks whether the thread is joinable, i.e. potentially running in parallel context (public member function)