From 30f41c02aec763d32e62351452da9ef582bc3472 Mon Sep 17 00:00:00 2001 From: 3gg <3gg@shellblade.net> Date: Fri, 6 Mar 2026 13:30:59 -0800 Subject: Move contrib libraries to contrib repo --- contrib/SDL-3.2.8/src/thread/windows/SDL_syssem.c | 351 ---------------------- 1 file changed, 351 deletions(-) delete mode 100644 contrib/SDL-3.2.8/src/thread/windows/SDL_syssem.c (limited to 'contrib/SDL-3.2.8/src/thread/windows/SDL_syssem.c') diff --git a/contrib/SDL-3.2.8/src/thread/windows/SDL_syssem.c b/contrib/SDL-3.2.8/src/thread/windows/SDL_syssem.c deleted file mode 100644 index ba35add..0000000 --- a/contrib/SDL-3.2.8/src/thread/windows/SDL_syssem.c +++ /dev/null @@ -1,351 +0,0 @@ -/* - Simple DirectMedia Layer - Copyright (C) 1997-2025 Sam Lantinga - - This software is provided 'as-is', without any express or implied - warranty. In no event will the authors be held liable for any damages - arising from the use of this software. - - Permission is granted to anyone to use this software for any purpose, - including commercial applications, and to alter it and redistribute it - freely, subject to the following restrictions: - - 1. The origin of this software must not be misrepresented; you must not - claim that you wrote the original software. If you use this software - in a product, an acknowledgment in the product documentation would be - appreciated but is not required. - 2. Altered source versions must be plainly marked as such, and must not be - misrepresented as being the original software. - 3. This notice may not be removed or altered from any source distribution. -*/ -#include "SDL_internal.h" - -#ifdef SDL_THREAD_WINDOWS - -/** - * Semaphore functions using the Win32 API - * There are two implementations available based on: - * - Kernel Semaphores. Available on all OS versions. (kern) - * Heavy-weight inter-process kernel objects. - * - Atomics and WaitOnAddress API. (atom) - * Faster due to significantly less context switches. - * Requires Windows 8 or newer. - * which are chosen at runtime. - */ - -#include "../../core/windows/SDL_windows.h" - -typedef SDL_Semaphore *(*pfnSDL_CreateSemaphore)(Uint32); -typedef void (*pfnSDL_DestroySemaphore)(SDL_Semaphore *); -typedef bool (*pfnSDL_WaitSemaphoreTimeoutNS)(SDL_Semaphore *, Sint64); -typedef Uint32 (*pfnSDL_GetSemaphoreValue)(SDL_Semaphore *); -typedef void (*pfnSDL_SignalSemaphore)(SDL_Semaphore *); - -typedef struct SDL_semaphore_impl_t -{ - pfnSDL_CreateSemaphore Create; - pfnSDL_DestroySemaphore Destroy; - pfnSDL_WaitSemaphoreTimeoutNS WaitTimeoutNS; - pfnSDL_GetSemaphoreValue Value; - pfnSDL_SignalSemaphore Signal; -} SDL_sem_impl_t; - -// Implementation will be chosen at runtime based on available Kernel features -static SDL_sem_impl_t SDL_sem_impl_active = { 0 }; - -/** - * Atomic + WaitOnAddress implementation - */ - -// APIs not available on WinPhone 8.1 -// https://www.microsoft.com/en-us/download/details.aspx?id=47328 - -typedef BOOL(WINAPI *pfnWaitOnAddress)(volatile VOID *, PVOID, SIZE_T, DWORD); -typedef VOID(WINAPI *pfnWakeByAddressSingle)(PVOID); - -static pfnWaitOnAddress pWaitOnAddress = NULL; -static pfnWakeByAddressSingle pWakeByAddressSingle = NULL; - -typedef struct SDL_semaphore_atom -{ - LONG count; -} SDL_sem_atom; - -static SDL_Semaphore *SDL_CreateSemaphore_atom(Uint32 initial_value) -{ - SDL_sem_atom *sem; - - sem = (SDL_sem_atom *)SDL_malloc(sizeof(*sem)); - if (sem) { - sem->count = initial_value; - } - return (SDL_Semaphore *)sem; -} - -static void SDL_DestroySemaphore_atom(SDL_Semaphore *sem) -{ - SDL_free(sem); -} - -static bool SDL_WaitSemaphoreTimeoutNS_atom(SDL_Semaphore *_sem, Sint64 timeoutNS) -{ - SDL_sem_atom *sem = (SDL_sem_atom *)_sem; - LONG count; - Uint64 now; - Uint64 deadline; - DWORD timeout_eff; - - if (!sem) { - return true; - } - - if (timeoutNS == 0) { - count = sem->count; - if (count == 0) { - return false; - } - - if (InterlockedCompareExchange(&sem->count, count - 1, count) == count) { - return true; - } - - return false; - } - - if (timeoutNS < 0) { - for (;;) { - count = sem->count; - while (count == 0) { - if (!pWaitOnAddress(&sem->count, &count, sizeof(sem->count), INFINITE)) { - return false; - } - count = sem->count; - } - - if (InterlockedCompareExchange(&sem->count, count - 1, count) == count) { - return true; - } - } - } - - /** - * WaitOnAddress is subject to spurious and stolen wakeups so we - * need to recalculate the effective timeout before every wait - */ - now = SDL_GetTicksNS(); - deadline = now + timeoutNS; - - for (;;) { - count = sem->count; - // If no semaphore is available we need to wait - while (count == 0) { - now = SDL_GetTicksNS(); - if (deadline > now) { - timeout_eff = (DWORD)SDL_NS_TO_MS(deadline - now); - } else { - return false; - } - if (!pWaitOnAddress(&sem->count, &count, sizeof(count), timeout_eff)) { - return false; - } - count = sem->count; - } - - // Actually the semaphore is only consumed if this succeeds - // If it doesn't we need to do everything again - if (InterlockedCompareExchange(&sem->count, count - 1, count) == count) { - return true; - } - } -} - -static Uint32 SDL_GetSemaphoreValue_atom(SDL_Semaphore *_sem) -{ - SDL_sem_atom *sem = (SDL_sem_atom *)_sem; - - if (!sem) { - return 0; - } - - return (Uint32)sem->count; -} - -static void SDL_SignalSemaphore_atom(SDL_Semaphore *_sem) -{ - SDL_sem_atom *sem = (SDL_sem_atom *)_sem; - - if (!sem) { - return; - } - - InterlockedIncrement(&sem->count); - pWakeByAddressSingle(&sem->count); -} - -static const SDL_sem_impl_t SDL_sem_impl_atom = { - &SDL_CreateSemaphore_atom, - &SDL_DestroySemaphore_atom, - &SDL_WaitSemaphoreTimeoutNS_atom, - &SDL_GetSemaphoreValue_atom, - &SDL_SignalSemaphore_atom, -}; - -/** - * Fallback Semaphore implementation using Kernel Semaphores - */ - -typedef struct SDL_semaphore_kern -{ - HANDLE id; - LONG count; -} SDL_sem_kern; - -// Create a semaphore -static SDL_Semaphore *SDL_CreateSemaphore_kern(Uint32 initial_value) -{ - SDL_sem_kern *sem; - - // Allocate sem memory - sem = (SDL_sem_kern *)SDL_malloc(sizeof(*sem)); - if (sem) { - // Create the semaphore, with max value 32K - sem->id = CreateSemaphore(NULL, initial_value, 32 * 1024, NULL); - sem->count = initial_value; - if (!sem->id) { - SDL_SetError("Couldn't create semaphore"); - SDL_free(sem); - sem = NULL; - } - } - return (SDL_Semaphore *)sem; -} - -// Free the semaphore -static void SDL_DestroySemaphore_kern(SDL_Semaphore *_sem) -{ - SDL_sem_kern *sem = (SDL_sem_kern *)_sem; - if (sem) { - if (sem->id) { - CloseHandle(sem->id); - sem->id = 0; - } - SDL_free(sem); - } -} - -static bool SDL_WaitSemaphoreTimeoutNS_kern(SDL_Semaphore *_sem, Sint64 timeoutNS) -{ - SDL_sem_kern *sem = (SDL_sem_kern *)_sem; - DWORD dwMilliseconds; - - if (!sem) { - return true; - } - - if (timeoutNS < 0) { - dwMilliseconds = INFINITE; - } else { - dwMilliseconds = (DWORD)SDL_NS_TO_MS(timeoutNS); - } - switch (WaitForSingleObjectEx(sem->id, dwMilliseconds, FALSE)) { - case WAIT_OBJECT_0: - InterlockedDecrement(&sem->count); - return true; - default: - return false; - } -} - -// Returns the current count of the semaphore -static Uint32 SDL_GetSemaphoreValue_kern(SDL_Semaphore *_sem) -{ - SDL_sem_kern *sem = (SDL_sem_kern *)_sem; - if (!sem) { - return 0; - } - return (Uint32)sem->count; -} - -static void SDL_SignalSemaphore_kern(SDL_Semaphore *_sem) -{ - SDL_sem_kern *sem = (SDL_sem_kern *)_sem; - - if (!sem) { - return; - } - - /* Increase the counter in the first place, because - * after a successful release the semaphore may - * immediately get destroyed by another thread which - * is waiting for this semaphore. - */ - InterlockedIncrement(&sem->count); - if (ReleaseSemaphore(sem->id, 1, NULL) == FALSE) { - InterlockedDecrement(&sem->count); // restore - } -} - -static const SDL_sem_impl_t SDL_sem_impl_kern = { - &SDL_CreateSemaphore_kern, - &SDL_DestroySemaphore_kern, - &SDL_WaitSemaphoreTimeoutNS_kern, - &SDL_GetSemaphoreValue_kern, - &SDL_SignalSemaphore_kern, -}; - -/** - * Runtime selection and redirection - */ - -SDL_Semaphore *SDL_CreateSemaphore(Uint32 initial_value) -{ - if (!SDL_sem_impl_active.Create) { - // Default to fallback implementation - const SDL_sem_impl_t *impl = &SDL_sem_impl_kern; - - if (!SDL_GetHintBoolean(SDL_HINT_WINDOWS_FORCE_SEMAPHORE_KERNEL, false)) { - /* We already statically link to features from this Api - * Set (e.g. WaitForSingleObject). Dynamically loading - * API Sets is not explicitly documented but according to - * Microsoft our specific use case is legal and correct: - * https://github.com/microsoft/STL/pull/593#issuecomment-655799859 - */ - HMODULE synch120 = GetModuleHandle(TEXT("api-ms-win-core-synch-l1-2-0.dll")); - if (synch120) { - // Try to load required functions provided by Win 8 or newer - pWaitOnAddress = (pfnWaitOnAddress)GetProcAddress(synch120, "WaitOnAddress"); - pWakeByAddressSingle = (pfnWakeByAddressSingle)GetProcAddress(synch120, "WakeByAddressSingle"); - - if (pWaitOnAddress && pWakeByAddressSingle) { - impl = &SDL_sem_impl_atom; - } - } - } - - // Copy instead of using pointer to save one level of indirection - SDL_copyp(&SDL_sem_impl_active, impl); - } - return SDL_sem_impl_active.Create(initial_value); -} - -void SDL_DestroySemaphore(SDL_Semaphore *sem) -{ - SDL_sem_impl_active.Destroy(sem); -} - -bool SDL_WaitSemaphoreTimeoutNS(SDL_Semaphore *sem, Sint64 timeoutNS) -{ - return SDL_sem_impl_active.WaitTimeoutNS(sem, timeoutNS); -} - -Uint32 SDL_GetSemaphoreValue(SDL_Semaphore *sem) -{ - return SDL_sem_impl_active.Value(sem); -} - -void SDL_SignalSemaphore(SDL_Semaphore *sem) -{ - SDL_sem_impl_active.Signal(sem); -} - -#endif // SDL_THREAD_WINDOWS -- cgit v1.2.3