<thread>

thread

public member function
<thread>

std::thread::detach

void detach();
Detach thread
Detaches the thread represented by the object from the calling thread, allowing them to execute independently from each other.

Both threads continue without blocking nor synchronizing in any way. Note that when either one ends execution, its resources are released.

After a call to this function, the thread object becomes non-joinable and can be destroyed safely.

Parameters

none

Return value

none

Example

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#include <iostream>       // std::cout
#include <thread>         // std::thread, std::this_thread::sleep_for
#include <chrono>         // std::chrono::seconds
 
void pause_thread(int n) 
{
  std::this_thread::sleep_for (std::chrono::seconds(n));
  std::cout << "pause of " << n << " seconds ended\n";
}
 
int main() 
{
  std::cout << "Spawning and detaching 3 threads...\n";
  std::thread (pause_thread,1).detach();
  std::thread (pause_thread,2).detach();
  std::thread (pause_thread,3).detach();
  std::cout << "Done spawning threads.\n";

  std::cout << "(the main thread will now pause for 5 seconds)\n";
  // give the detached threads time to finish (but not guaranteed!):
  pause_thread(5);
  return 0;
}


Output (after 5 seconds):
Spawning and detaching 3 threads...
Done spawning threads.
(the main thread will now pause for 5 seconds)
pause of 1 seconds ended
pause of 2 seconds ended
pause of 3 seconds ended
pause of 5 seconds ended

Data races

The object is modified.

Exception safety

Basic guarantee: if an exception is thrown by this member function, the thread object is left in a valid state.

If the call fails, a system_error exception is thrown:
exception typeerror conditiondescription
system_errorerrc::invalid_argumentThe thread object is not joinable
system_errorerrc::no_such_processThe thread object is not valid

See also