std::counti...quire_until(3)

💖 NAME 💖

Okay so bestie, welcome to the std::counti...quire_until(3) page from the C++ Standard Libary manual. The star of the show is std::counting_semaphore::try_acquire_until — yes, that's the whole NAME, and the page absolutely repeats it because why not 💅.

---

✨ Synopsis ✨

Here's the signature, copied exactly. The (since C++20) annotation is called out separately because she's iconic:

template< class Clock, class Duration >
bool try_acquire_until( const std::chrono::time_point<Clock,
Duration>& abs_time );

(since C++20) — this one is a C++20 girlie, no cap.

What it does: it tries to atomically decrement the internal counter by 1 if it's greater than 0. If it's not, it blocks until the counter is greater than 0 and it can successfully decrement the internal counter, or until the abs_time time point has been passed. It's giving "wait for the right moment" energy 🫶.

And heads up: the program is ill-formed if std::chrono::is_clock_v<Clock> is false. Like, compiler says nope 😭.

---

🚦 Preconditions 🚦

Clock has to meet the Clock requirements. Periodt.

---

🎀 Parameters 🎀

• abs_time — the earliest time the function must wait until in order to fail.

---

🫶 Return value 🫶

true if it decremented the internal counter, otherwise false. Simple, clean, slay.

---

😭 Exceptions 😭

It may throw std::system_error or a timeout-related exception. So yeah, she can get dramatic.

---

📝 Notes 📝

In practice, the function may take longer than abs_time to fail. Not her being late on purpose, it's just literally how it is 🙈.

---

👀 See also 👀

• release — increments the internal counter and unblocks acquirers (public member function).
• acquire — decrements the internal counter or blocks until it can (public member function).
• try_acquire — tries to decrement the internal counter without blocking (public member function).
• try_acquire_for — tries to decrement the internal counter, blocking for up to a duration time (public member function).

---

source: http://cppreference.com · version/date: 2024.06.10 · page: std::counti...quire_until(3). bye bestie, go decrement those counters responsibly 💅✨🌸