std::jthread::detach

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< cpp‎ | thread‎ | jthread

 
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std::jthread
 
void detach();
 (since C++20)

Separates the thread of execution from the jthread object, allowing execution to continue independently. Any allocated resources will be freed once the thread exits.

After calling detach *this no longer owns any thread.

Parameters

(none)

Return value

(none)

Postconditions

joinable is false

Exceptions

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

Example

Run this code
#include <iostream>
#include <chrono>
#include <thread>
 
void independentThread() 
{
    std::cout << "Starting concurrent thread.\n";
    std::this_thread::sleep_for(std::chrono::seconds(2));
    std::cout << "Exiting concurrent thread.\n";
}
 
void threadCaller() 
{
    std::cout << "Starting thread caller.\n";
    std::jthread t(independentThread);
    t.detach();
    std::this_thread::sleep_for(std::chrono::seconds(1));
    std::cout << "Exiting thread caller.\n";
}
 
int main() 
{
    threadCaller();
    std::this_thread::sleep_for(std::chrono::seconds(5));
}

Possible output: 

Starting thread caller.
Starting concurrent thread.
Exiting thread caller.
Exiting concurrent thread.

References

  • C++23 standard (ISO/IEC 14882:2023):
  • 33.4.4.3 Members [thread.jthread.mem]
  • C++20 standard (ISO/IEC 14882:2020):
  • 32.4.3.2 Members [thread.jthread.mem]

See also

 waits for the thread to finish its execution
(public member function)
checks whether the thread is joinable, i.e. potentially running in parallel context
(public member function)
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