std::jthread::join - cppreference.com (original) (raw)

| void join(); | | (since C++20) | | ------------ | | ------------- |

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

The completion of the thread identified by *this synchronizes with the corresponding successful return from join().

No synchronization is performed on *this itself. Concurrently calling join() on the same jthread object from multiple threads constitutes a data race that results in undefined behavior.

Contents

• 1 Parameters
• 2 Return value
• 3 Postconditions
• 4 Exceptions
• 5 Error conditions
• 6 Example
• 7 References
• 8 See also

[edit] Parameters

(none)

[edit] Return value

(none)

[edit] Postconditions

joinable() is false.

[edit] Exceptions

std::system_error if an error occurs.

[edit] Error conditions

• resource_deadlock_would_occur if this->get_id() == std::this_thread::get_id() (deadlock detected).
• no_such_process if the thread is not valid.
• invalid_argument if joinable() is false.

[edit] Example

Output:

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

[edit] References

• C++23 standard (ISO/IEC 14882:2024):

• 33.4.4.3 Members [thread.jthread.mem]

• C++20 standard (ISO/IEC 14882:2020):

• 32.4.3.2 Members [thread.jthread.mem]

[edit] See also

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