Mercurial > foo_out_sdl
diff foosdk/sdk/pfc/event_std.h @ 1:20d02a178406 default tip
*: check in everything else
yay
| author | Paper <paper@tflc.us> |
|---|---|
| date | Mon, 05 Jan 2026 02:15:46 -0500 |
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| children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/foosdk/sdk/pfc/event_std.h Mon Jan 05 02:15:46 2026 -0500 @@ -0,0 +1,49 @@ +#pragma once + +// Alternate lightweight implementation of pfc::event, with similar method sigantures but no support for multi-event-wait-for-any. +// It's a safe drop-in replacement for the regular event - code trying to use unsupported methods will fail to compile rather than behave incorrectly. + +// Rationale: +// Mac/Linux multi-wait-capable pipe-backed event is relatively expensive, in terms of CPU, memory and file descriptors opened. +// On Windows, event_std still outperforms regular win32 event but the difference is mostly insignificant in real life use cases. + +#include <mutex> +#include <condition_variable> +namespace pfc { + class event_std { + public: + void set_state(bool v = true) { + std::scoped_lock lock(m_mutex); + if (m_state != v) { + m_state = v; + if (v) m_condition.notify_all(); + } + } + bool is_set() const { return m_state; } + void wait() { + std::unique_lock lock(m_mutex); + m_condition.wait(lock, [this] { return this->m_state; }); + } + bool wait_for(double timeout) { + if (timeout < 0) { wait(); return true; } + std::unique_lock lock(m_mutex); + return m_condition.wait_for(lock, std::chrono::duration<double>(timeout), [this] { return this->m_state; }); + } + void wait_and_clear() { + std::unique_lock lock(m_mutex); + m_condition.wait(lock, [this] { return this->m_state; }); + m_state = false; + } + bool wait_for_and_clear(double timeout) { + if ( timeout < 0 ) {wait_and_clear(); return true;} + std::unique_lock lock(m_mutex); + bool rv = m_condition.wait_for(lock, std::chrono::duration<double>(timeout), [this] { return this->m_state; }); + if ( rv ) m_state = false; + return rv; + } + private: + volatile bool m_state = false; + std::condition_variable m_condition; + std::mutex m_mutex; + }; +}
