###### (This is the documentation for SDL3, which is under heavy development and the API is changing! [SDL2](https://wiki.libsdl.org/SDL2/) is the current stable version!) # SDL_HINT_THREAD_FORCE_REALTIME_TIME_CRITICAL Specifies whether [SDL_THREAD_PRIORITY_TIME_CRITICAL](SDL_THREAD_PRIORITY_TIME_CRITICAL) should be treated as realtime. ## Header File Defined in [](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_hints.h) ## Syntax ```c #define SDL_HINT_THREAD_FORCE_REALTIME_TIME_CRITICAL "SDL_THREAD_FORCE_REALTIME_TIME_CRITICAL" ``` ## Remarks On some platforms, like Linux, a realtime priority thread may be subject to restrictions that require special handling by the application. This hint exists to let SDL know that the app is prepared to handle said restrictions. On Linux, SDL will apply the following configuration to any thread that becomes realtime: - The SCHED_RESET_ON_FORK bit will be set on the scheduling policy, - An RLIMIT_RTTIME budget will be configured to the rtkit specified limit. - Exceeding this limit will result in the kernel sending SIGKILL to the app, refer to the man pages for more information. The variable can be set to the following values: - "0": default platform specific behaviour - "1": Force [SDL_THREAD_PRIORITY_TIME_CRITICAL](SDL_THREAD_PRIORITY_TIME_CRITICAL) to a realtime scheduling policy This hint should be set before calling [SDL_SetThreadPriority](SDL_SetThreadPriority)() ## Version This hint is available since SDL 3.0.0. ---- [CategoryAPI](CategoryAPI), [CategoryAPIMacro](CategoryAPIMacro), [CategoryHints](CategoryHints)