std::barrier::wait(3)

📦 version 2024.07.05, in nixpkgs unstable, opensuse-leap 16.0

💅 std::barrier::wait — the manual page, but make it make sense

okay bestie, welcome to std::barrier::wait from the C++ Standard Library (yes the header literally says "Libary", we don't talk about it 💀). This is the page for the function that just... sits there and waits. Iconic behaviour honestly.

✨ NAME ✨

std::barrier::wait — literally std::barrier::wait. That's the whole name. No notes. 🎀

🌸 SYNOPSIS 🌸

void wait( arrival_token&& arrival ) const;  (since C++20)

So it's void, it takes an rvalue ref to an arrival_token, and it's const. She's giving "I don't change anything, I just wait" energy. 🦋

💖 DESCRIPTION 💖

Okay so here's the tea, and you need to follow along because there are three whole situations:

  • Situation one, the main character case: if arrival is associated with the phase synchronization point for the current phase of *this, then it blocks at the synchronization point associated with arrival until the phase completion step of the synchronization point's phase is run. So yeah — it waits. At the sync point. Until that phase's completion step runs. Slay. ⭐
  • Situation two, the "you're a little late but it's fine" case: if arrival is associated with the phase synchronization point for the immediately preceding phase of *this, it returns immediately. No waiting. In and out. 🫶
  • Situation three, the "bestie what are you doing" case: otherwise — meaning arrival is associated with the phase synchronization point for an earlier phase of *this, or with any phase of a barrier object other than *this — the behavior is undefined. 💀
fr fr, undefined behaviour is not a vibe. Do not pass a token from some other barrier, and do not pass a stale token from a way-earlier phase. That's the whole warning. Respect it. 😭

🎀 PARAMETERS 🎀

  • arrival — an arrival_token obtained by a previous call to arrive on the same barrier. Same barrier. SAME. BARRIER. 🔥

🌈 RETURN VALUE 🌈

(none)

That's it. She returns nothing. She's not here to give, she's here to wait. periodt. 💅

🧚 EXCEPTIONS 🧚

Throws std::system_error with an error code allowed for mutex types on error. So like, if something goes wrong, that's what you're catching. 🌸

🍓 EXAMPLE 🍓

This section is incomplete Reason: no example

yeah... no example. Not me showing up to the group chat with nothing to contribute 🙈. Anyway, the section exists, and now you know it exists, and that's the whole point. 💜

👑 SEE ALSO 👑

  • arrive — arrives at barrier and decrements the expected count (public member function). She's the one who makes the token you feed to wait. Bestie duo, honestly. ✨

🔥 CATEGORY 🔥

  • Todo no example

(mood. we're all a work in progress.) 💅

okay that's the whole page, tysm for coming to my TED talk 🫶 This lil masterpiece came from http://cppreference.com and it's dated 2024.06.10 — go drink some water and go wait at a synchronization point, ily 💖🌺

📦 where this page comes from