From b98d9dfe522fa17ecae47632543fc1b2ce16d121 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Gustaf=20Alh=C3=A4ll?= Date: Thu, 26 Oct 2023 23:43:07 +0200 Subject: [PATCH 1/2] Use nanosleep for I_SleepDuration on *nix --- src/i_time.c | 35 ----------------------------------- src/sdl/i_system.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+), 35 deletions(-) diff --git a/src/i_time.c b/src/i_time.c index fae26abed..aa18f6e36 100644 --- a/src/i_time.c +++ b/src/i_time.c @@ -88,38 +88,3 @@ void I_UpdateTime(fixed_t timescale) g_time.timefrac = FLOAT_TO_FIXED(fractional); } } - -void I_SleepDuration(precise_t duration) -{ - UINT64 precision = I_GetPrecisePrecision(); - INT32 sleepvalue = cv_sleep.value; - UINT64 delaygranularity; - precise_t cur; - precise_t dest; - - { - double gran = round(((double)(precision / 1000) * sleepvalue * MIN_SLEEP_DURATION_MS)); - delaygranularity = (UINT64)gran; - } - - cur = I_GetPreciseTime(); - dest = cur + duration; - - // the reason this is not dest > cur is because the precise counter may wrap - // two's complement arithmetic is our friend here, though! - // e.g. cur 0xFFFFFFFFFFFFFFFE = -2, dest 0x0000000000000001 = 1 - // 0x0000000000000001 - 0xFFFFFFFFFFFFFFFE = 3 - while ((INT64)(dest - cur) > 0) - { - // If our cv_sleep value exceeds the remaining sleep duration, use the - // hard sleep function. - if (sleepvalue > 0 && (dest - cur) > delaygranularity) - { - I_Sleep(sleepvalue); - } - - // Otherwise, this is a spinloop. - - cur = I_GetPreciseTime(); - } -} diff --git a/src/sdl/i_system.c b/src/sdl/i_system.c index b05f40ee3..acc57f8d2 100644 --- a/src/sdl/i_system.c +++ b/src/sdl/i_system.c @@ -2265,6 +2265,52 @@ void I_Sleep(UINT32 ms) SDL_Delay(ms); } +void I_SleepDuration(precise_t duration) +{ +#if defined(__linux__) || defined(__FreeBSD__) + UINT64 precision = I_GetPrecisePrecision(); + struct timespec ts = { + .tv_sec = duration / precision, + .tv_nsec = duration * 1000000000 / precision % 1000000000, + }; + int status; + do status = clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, &ts); + while (status == EINTR); +#else + UINT64 precision = I_GetPrecisePrecision(); + INT32 sleepvalue = cv_sleep.value; + UINT64 delaygranularity; + precise_t cur; + precise_t dest; + + { + double gran = round(((double)(precision / 1000) * sleepvalue * MIN_SLEEP_DURATION_MS)); + delaygranularity = (UINT64)gran; + } + + cur = I_GetPreciseTime(); + dest = cur + duration; + + // the reason this is not dest > cur is because the precise counter may wrap + // two's complement arithmetic is our friend here, though! + // e.g. cur 0xFFFFFFFFFFFFFFFE = -2, dest 0x0000000000000001 = 1 + // 0x0000000000000001 - 0xFFFFFFFFFFFFFFFE = 3 + while ((INT64)(dest - cur) > 0) + { + // If our cv_sleep value exceeds the remaining sleep duration, use the + // hard sleep function. + if (sleepvalue > 0 && (dest - cur) > delaygranularity) + { + I_Sleep(sleepvalue); + } + + // Otherwise, this is a spinloop. + + cur = I_GetPreciseTime(); + } +#endif +} + #ifdef NEWSIGNALHANDLER ATTRNORETURN static FUNCNORETURN void newsignalhandler_Warn(const char *pr) { From e92787e75f7a773f78222d37d411bf2fde8c35a5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Gustaf=20Alh=C3=A4ll?= Date: Sat, 28 Oct 2023 15:44:45 +0200 Subject: [PATCH 2/2] Fix Windows build --- src/i_time.c | 6 ------ src/sdl/i_system.c | 6 ++++++ 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/src/i_time.c b/src/i_time.c index aa18f6e36..39854b242 100644 --- a/src/i_time.c +++ b/src/i_time.c @@ -30,12 +30,6 @@ static precise_t enterprecise, oldenterprecise; static fixed_t entertic, oldentertics; static double tictimer; -// A little more than the minimum sleep duration on Windows. -// May be incorrect for other platforms, but we don't currently have a way to -// query the scheduler granularity. SDL will do what's needed to make this as -// low as possible though. -#define MIN_SLEEP_DURATION_MS 2.1 - tic_t I_GetTime(void) { return g_time.time; diff --git a/src/sdl/i_system.c b/src/sdl/i_system.c index acc57f8d2..3da4e6152 100644 --- a/src/sdl/i_system.c +++ b/src/sdl/i_system.c @@ -41,6 +41,12 @@ typedef LPVOID (WINAPI *p_MapViewOfFile) (HANDLE, DWORD, DWORD, DWORD, SIZE_T); #include #undef SystemFunction036 +// A little more than the minimum sleep duration on Windows. +// May be incorrect for other platforms, but we don't currently have a way to +// query the scheduler granularity. SDL will do what's needed to make this as +// low as possible though. +#define MIN_SLEEP_DURATION_MS 2.1 + #endif #include #include