initial commit, 4.5 stable

thirdparty/sdl/thread/windows/SDL_syscond_cv.c

@@ -0,0 +1,226 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  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"
+
+#include "../generic/SDL_syscond_c.h"
+#include "SDL_sysmutex_c.h"
+
+typedef SDL_Condition *(*pfnSDL_CreateCondition)(void);
+typedef void (*pfnSDL_DestroyCondition)(SDL_Condition *);
+typedef void (*pfnSDL_SignalCondition)(SDL_Condition *);
+typedef void (*pfnSDL_BroadcastCondition)(SDL_Condition *);
+typedef bool (*pfnSDL_WaitConditionTimeoutNS)(SDL_Condition *, SDL_Mutex *, Sint64);
+
+typedef struct SDL_cond_impl_t
+{
+    pfnSDL_CreateCondition Create;
+    pfnSDL_DestroyCondition Destroy;
+    pfnSDL_SignalCondition Signal;
+    pfnSDL_BroadcastCondition Broadcast;
+    pfnSDL_WaitConditionTimeoutNS WaitTimeoutNS;
+} SDL_cond_impl_t;
+
+// Implementation will be chosen at runtime based on available Kernel features
+static SDL_cond_impl_t SDL_cond_impl_active = { 0 };
+
+/**
+ * Native Windows Condition Variable (SRW Locks)
+ */
+
+#ifndef CONDITION_VARIABLE_INIT
+#define CONDITION_VARIABLE_INIT \
+    {                           \
+        0                       \
+    }
+typedef struct CONDITION_VARIABLE
+{
+    PVOID Ptr;
+} CONDITION_VARIABLE, *PCONDITION_VARIABLE;
+#endif
+
+typedef VOID(WINAPI *pfnWakeConditionVariable)(PCONDITION_VARIABLE);
+typedef VOID(WINAPI *pfnWakeAllConditionVariable)(PCONDITION_VARIABLE);
+typedef BOOL(WINAPI *pfnSleepConditionVariableSRW)(PCONDITION_VARIABLE, PSRWLOCK, DWORD, ULONG);
+typedef BOOL(WINAPI *pfnSleepConditionVariableCS)(PCONDITION_VARIABLE, PCRITICAL_SECTION, DWORD);
+
+static pfnWakeConditionVariable pWakeConditionVariable = NULL;
+static pfnWakeAllConditionVariable pWakeAllConditionVariable = NULL;
+static pfnSleepConditionVariableSRW pSleepConditionVariableSRW = NULL;
+static pfnSleepConditionVariableCS pSleepConditionVariableCS = NULL;
+
+typedef struct SDL_cond_cv
+{
+    CONDITION_VARIABLE cond;
+} SDL_cond_cv;
+
+static SDL_Condition *SDL_CreateCondition_cv(void)
+{
+    // Relies on CONDITION_VARIABLE_INIT == 0.
+    return (SDL_Condition *)SDL_calloc(1, sizeof(SDL_cond_cv));
+}
+
+static void SDL_DestroyCondition_cv(SDL_Condition *cond)
+{
+    // There are no kernel allocated resources
+    SDL_free(cond);
+}
+
+static void SDL_SignalCondition_cv(SDL_Condition *_cond)
+{
+    SDL_cond_cv *cond = (SDL_cond_cv *)_cond;
+    pWakeConditionVariable(&cond->cond);
+}
+
+static void SDL_BroadcastCondition_cv(SDL_Condition *_cond)
+{
+    SDL_cond_cv *cond = (SDL_cond_cv *)_cond;
+    pWakeAllConditionVariable(&cond->cond);
+}
+
+static bool SDL_WaitConditionTimeoutNS_cv(SDL_Condition *_cond, SDL_Mutex *_mutex, Sint64 timeoutNS)
+{
+    SDL_cond_cv *cond = (SDL_cond_cv *)_cond;
+    DWORD timeout;
+    bool result;
+
+    if (timeoutNS < 0) {
+        timeout = INFINITE;
+    } else {
+        timeout = (DWORD)SDL_NS_TO_MS(timeoutNS);
+    }
+
+    if (SDL_mutex_impl_active.Type == SDL_MUTEX_SRW) {
+        SDL_mutex_srw *mutex = (SDL_mutex_srw *)_mutex;
+
+        if (mutex->count != 1 || mutex->owner != GetCurrentThreadId()) {
+            // Passed mutex is not locked or locked recursively"
+            return false;
+        }
+
+        // The mutex must be updated to the released state
+        mutex->count = 0;
+        mutex->owner = 0;
+
+        result = (pSleepConditionVariableSRW(&cond->cond, &mutex->srw, timeout, 0) == TRUE);
+
+        // The mutex is owned by us again, regardless of status of the wait
+        SDL_assert(mutex->count == 0 && mutex->owner == 0);
+        mutex->count = 1;
+        mutex->owner = GetCurrentThreadId();
+    } else {
+        SDL_mutex_cs *mutex = (SDL_mutex_cs *)_mutex;
+
+        SDL_assert(SDL_mutex_impl_active.Type == SDL_MUTEX_CS);
+
+        result = (pSleepConditionVariableCS(&cond->cond, &mutex->cs, timeout) == TRUE);
+    }
+
+    return result;
+}
+
+static const SDL_cond_impl_t SDL_cond_impl_cv = {
+    &SDL_CreateCondition_cv,
+    &SDL_DestroyCondition_cv,
+    &SDL_SignalCondition_cv,
+    &SDL_BroadcastCondition_cv,
+    &SDL_WaitConditionTimeoutNS_cv,
+};
+
+
+// Generic Condition Variable implementation using SDL_Mutex and SDL_Semaphore
+static const SDL_cond_impl_t SDL_cond_impl_generic = {
+    &SDL_CreateCondition_generic,
+    &SDL_DestroyCondition_generic,
+    &SDL_SignalCondition_generic,
+    &SDL_BroadcastCondition_generic,
+    &SDL_WaitConditionTimeoutNS_generic,
+};
+
+SDL_Condition *SDL_CreateCondition(void)
+{
+    if (!SDL_cond_impl_active.Create) {
+        const SDL_cond_impl_t *impl = NULL;
+
+        if (SDL_mutex_impl_active.Type == SDL_MUTEX_INVALID) {
+            // The mutex implementation isn't decided yet, trigger it
+            SDL_Mutex *mutex = SDL_CreateMutex();
+            if (!mutex) {
+                return NULL;
+            }
+            SDL_DestroyMutex(mutex);
+
+            SDL_assert(SDL_mutex_impl_active.Type != SDL_MUTEX_INVALID);
+        }
+
+        // Default to generic implementation, works with all mutex implementations
+        impl = &SDL_cond_impl_generic;
+        {
+            HMODULE kernel32 = GetModuleHandle(TEXT("kernel32.dll"));
+            if (kernel32) {
+                pWakeConditionVariable = (pfnWakeConditionVariable)GetProcAddress(kernel32, "WakeConditionVariable");
+                pWakeAllConditionVariable = (pfnWakeAllConditionVariable)GetProcAddress(kernel32, "WakeAllConditionVariable");
+                pSleepConditionVariableSRW = (pfnSleepConditionVariableSRW)GetProcAddress(kernel32, "SleepConditionVariableSRW");
+                pSleepConditionVariableCS = (pfnSleepConditionVariableCS)GetProcAddress(kernel32, "SleepConditionVariableCS");
+                if (pWakeConditionVariable && pWakeAllConditionVariable && pSleepConditionVariableSRW && pSleepConditionVariableCS) {
+                    // Use the Windows provided API
+                    impl = &SDL_cond_impl_cv;
+                }
+            }
+        }
+
+        SDL_copyp(&SDL_cond_impl_active, impl);
+    }
+    return SDL_cond_impl_active.Create();
+}
+
+void SDL_DestroyCondition(SDL_Condition *cond)
+{
+    if (cond) {
+        SDL_cond_impl_active.Destroy(cond);
+    }
+}
+
+void SDL_SignalCondition(SDL_Condition *cond)
+{
+    if (!cond) {
+        return;
+    }
+
+    SDL_cond_impl_active.Signal(cond);
+}
+
+void SDL_BroadcastCondition(SDL_Condition *cond)
+{
+    if (!cond) {
+        return;
+    }
+
+    SDL_cond_impl_active.Broadcast(cond);
+}
+
+bool SDL_WaitConditionTimeoutNS(SDL_Condition *cond, SDL_Mutex *mutex, Sint64 timeoutNS)
+{
+    if (!cond || !mutex) {
+        return true;
+    }
+
+    return SDL_cond_impl_active.WaitTimeoutNS(cond, mutex, timeoutNS);
+}

thirdparty/sdl/thread/windows/SDL_sysmutex.c

@@ -0,0 +1,238 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  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
+
+/**
+ * Mutex functions using the Win32 API
+ * There are two implementations available based on:
+ * - Critical Sections. Available on all OS versions since Windows XP.
+ * - Slim Reader/Writer Locks. Requires Windows 7 or newer.
+ * which are chosen at runtime.
+ */
+
+#include "SDL_sysmutex_c.h"
+
+// Implementation will be chosen at runtime based on available Kernel features
+SDL_mutex_impl_t SDL_mutex_impl_active = { 0 };
+
+/**
+ * Implementation based on Slim Reader/Writer (SRW) Locks for Win 7 and newer.
+ */
+
+typedef VOID(WINAPI *pfnInitializeSRWLock)(PSRWLOCK);
+typedef VOID(WINAPI *pfnReleaseSRWLockExclusive)(PSRWLOCK);
+typedef VOID(WINAPI *pfnAcquireSRWLockExclusive)(PSRWLOCK);
+typedef BOOLEAN(WINAPI *pfnTryAcquireSRWLockExclusive)(PSRWLOCK);
+static pfnInitializeSRWLock pInitializeSRWLock = NULL;
+static pfnReleaseSRWLockExclusive pReleaseSRWLockExclusive = NULL;
+static pfnAcquireSRWLockExclusive pAcquireSRWLockExclusive = NULL;
+static pfnTryAcquireSRWLockExclusive pTryAcquireSRWLockExclusive = NULL;
+
+static SDL_Mutex *SDL_CreateMutex_srw(void)
+{
+    SDL_mutex_srw *mutex = (SDL_mutex_srw *)SDL_calloc(1, sizeof(*mutex));
+    if (mutex) {
+        pInitializeSRWLock(&mutex->srw);
+    }
+    return (SDL_Mutex *)mutex;
+}
+
+static void SDL_DestroyMutex_srw(SDL_Mutex *mutex)
+{
+    // There are no kernel allocated resources
+    SDL_free(mutex);
+}
+
+static void SDL_LockMutex_srw(SDL_Mutex *_mutex) SDL_NO_THREAD_SAFETY_ANALYSIS  // clang doesn't know about NULL mutexes
+{
+    SDL_mutex_srw *mutex = (SDL_mutex_srw *)_mutex;
+    const DWORD this_thread = GetCurrentThreadId();
+
+    if (mutex->owner == this_thread) {
+        ++mutex->count;
+    } else {
+        /* The order of operations is important.
+           We set the locking thread id after we obtain the lock
+           so unlocks from other threads will fail.
+         */
+        pAcquireSRWLockExclusive(&mutex->srw);
+        SDL_assert(mutex->count == 0 && mutex->owner == 0);
+        mutex->owner = this_thread;
+        mutex->count = 1;
+    }
+}
+
+static bool SDL_TryLockMutex_srw(SDL_Mutex *_mutex)
+{
+    SDL_mutex_srw *mutex = (SDL_mutex_srw *)_mutex;
+    const DWORD this_thread = GetCurrentThreadId();
+    bool retval = true;
+
+    if (mutex->owner == this_thread) {
+        ++mutex->count;
+    } else {
+        if (pTryAcquireSRWLockExclusive(&mutex->srw) != 0) {
+            SDL_assert(mutex->count == 0 && mutex->owner == 0);
+            mutex->owner = this_thread;
+            mutex->count = 1;
+        } else {
+            retval = false;
+        }
+    }
+    return retval;
+}
+
+static void SDL_UnlockMutex_srw(SDL_Mutex *_mutex) SDL_NO_THREAD_SAFETY_ANALYSIS  // clang doesn't know about NULL mutexes
+{
+    SDL_mutex_srw *mutex = (SDL_mutex_srw *)_mutex;
+
+    if (mutex->owner == GetCurrentThreadId()) {
+        if (--mutex->count == 0) {
+            mutex->owner = 0;
+            pReleaseSRWLockExclusive(&mutex->srw);
+        }
+    } else {
+        SDL_assert(!"mutex not owned by this thread");  // undefined behavior...!
+    }
+}
+
+static const SDL_mutex_impl_t SDL_mutex_impl_srw = {
+    &SDL_CreateMutex_srw,
+    &SDL_DestroyMutex_srw,
+    &SDL_LockMutex_srw,
+    &SDL_TryLockMutex_srw,
+    &SDL_UnlockMutex_srw,
+    SDL_MUTEX_SRW,
+};
+
+/**
+ * Fallback Mutex implementation using Critical Sections (before Win 7)
+ */
+
+static SDL_Mutex *SDL_CreateMutex_cs(void)
+{
+    SDL_mutex_cs *mutex = (SDL_mutex_cs *)SDL_malloc(sizeof(*mutex));
+    if (mutex) {
+        // Initialize
+        // On SMP systems, a non-zero spin count generally helps performance
+        // This function always succeeds
+        (void)InitializeCriticalSectionAndSpinCount(&mutex->cs, 2000);
+    }
+    return (SDL_Mutex *)mutex;
+}
+
+static void SDL_DestroyMutex_cs(SDL_Mutex *mutex_)
+{
+    SDL_mutex_cs *mutex = (SDL_mutex_cs *)mutex_;
+    DeleteCriticalSection(&mutex->cs);
+    SDL_free(mutex);
+}
+
+static void SDL_LockMutex_cs(SDL_Mutex *mutex_) SDL_NO_THREAD_SAFETY_ANALYSIS  // clang doesn't know about NULL mutexes
+{
+    SDL_mutex_cs *mutex = (SDL_mutex_cs *)mutex_;
+    EnterCriticalSection(&mutex->cs);
+}
+
+static bool SDL_TryLockMutex_cs(SDL_Mutex *mutex_)
+{
+    SDL_mutex_cs *mutex = (SDL_mutex_cs *)mutex_;
+    return (TryEnterCriticalSection(&mutex->cs) == TRUE);
+}
+
+static void SDL_UnlockMutex_cs(SDL_Mutex *mutex_) SDL_NO_THREAD_SAFETY_ANALYSIS  // clang doesn't know about NULL mutexes
+{
+    SDL_mutex_cs *mutex = (SDL_mutex_cs *)mutex_;
+    LeaveCriticalSection(&mutex->cs);
+}
+
+static const SDL_mutex_impl_t SDL_mutex_impl_cs = {
+    &SDL_CreateMutex_cs,
+    &SDL_DestroyMutex_cs,
+    &SDL_LockMutex_cs,
+    &SDL_TryLockMutex_cs,
+    &SDL_UnlockMutex_cs,
+    SDL_MUTEX_CS,
+};
+
+/**
+ * Runtime selection and redirection
+ */
+
+SDL_Mutex *SDL_CreateMutex(void)
+{
+    if (!SDL_mutex_impl_active.Create) {
+        const SDL_mutex_impl_t *impl = &SDL_mutex_impl_cs;
+
+        // Try faster implementation for Windows 7 and newer
+        HMODULE kernel32 = GetModuleHandle(TEXT("kernel32.dll"));
+        if (kernel32) {
+            // Requires Vista:
+            pInitializeSRWLock = (pfnInitializeSRWLock)GetProcAddress(kernel32, "InitializeSRWLock");
+            pReleaseSRWLockExclusive = (pfnReleaseSRWLockExclusive)GetProcAddress(kernel32, "ReleaseSRWLockExclusive");
+            pAcquireSRWLockExclusive = (pfnAcquireSRWLockExclusive)GetProcAddress(kernel32, "AcquireSRWLockExclusive");
+            // Requires 7:
+            pTryAcquireSRWLockExclusive = (pfnTryAcquireSRWLockExclusive)GetProcAddress(kernel32, "TryAcquireSRWLockExclusive");
+            if (pInitializeSRWLock && pReleaseSRWLockExclusive && pAcquireSRWLockExclusive && pTryAcquireSRWLockExclusive) {
+                impl = &SDL_mutex_impl_srw;
+            }
+        }
+
+        // Copy instead of using pointer to save one level of indirection
+        SDL_copyp(&SDL_mutex_impl_active, impl);
+    }
+    return SDL_mutex_impl_active.Create();
+}
+
+void SDL_DestroyMutex(SDL_Mutex *mutex)
+{
+    if (mutex) {
+        SDL_mutex_impl_active.Destroy(mutex);
+    }
+}
+
+void SDL_LockMutex(SDL_Mutex *mutex)
+{
+    if (mutex) {
+        SDL_mutex_impl_active.Lock(mutex);
+    }
+}
+
+bool SDL_TryLockMutex(SDL_Mutex *mutex)
+{
+    bool result = true;
+
+    if (mutex) {
+        result = SDL_mutex_impl_active.TryLock(mutex);
+    }
+    return result;
+}
+
+void SDL_UnlockMutex(SDL_Mutex *mutex)
+{
+    if (mutex) {
+        SDL_mutex_impl_active.Unlock(mutex);
+    }
+}
+
+#endif // SDL_THREAD_WINDOWS

thirdparty/sdl/thread/windows/SDL_sysmutex_c.h

@@ -0,0 +1,73 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  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"
+
+#include "../../core/windows/SDL_windows.h"
+
+typedef SDL_Mutex *(*pfnSDL_CreateMutex)(void);
+typedef void (*pfnSDL_LockMutex)(SDL_Mutex *);
+typedef bool (*pfnSDL_TryLockMutex)(SDL_Mutex *);
+typedef void (*pfnSDL_UnlockMutex)(SDL_Mutex *);
+typedef void (*pfnSDL_DestroyMutex)(SDL_Mutex *);
+
+typedef enum
+{
+    SDL_MUTEX_INVALID = 0,
+    SDL_MUTEX_SRW,
+    SDL_MUTEX_CS,
+} SDL_MutexType;
+
+typedef struct SDL_mutex_impl_t
+{
+    pfnSDL_CreateMutex Create;
+    pfnSDL_DestroyMutex Destroy;
+    pfnSDL_LockMutex Lock;
+    pfnSDL_TryLockMutex TryLock;
+    pfnSDL_UnlockMutex Unlock;
+    // Needed by SDL_Condition:
+    SDL_MutexType Type;
+} SDL_mutex_impl_t;
+
+extern SDL_mutex_impl_t SDL_mutex_impl_active;
+
+#ifndef SRWLOCK_INIT
+#define SRWLOCK_INIT \
+    {                \
+        0            \
+    }
+typedef struct _SRWLOCK
+{
+    PVOID Ptr;
+} SRWLOCK, *PSRWLOCK;
+#endif
+
+typedef struct SDL_mutex_srw
+{
+    SRWLOCK srw;
+    // SRW Locks are not recursive, that has to be handled by SDL:
+    DWORD count;
+    DWORD owner;
+} SDL_mutex_srw;
+
+typedef struct SDL_mutex_cs
+{
+    CRITICAL_SECTION cs;
+} SDL_mutex_cs;

thirdparty/sdl/thread/windows/SDL_sysrwlock_srw.c

@@ -0,0 +1,231 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  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"
+
+/**
+ * Implementation based on Slim Reader/Writer (SRW) Locks for Win 7 and newer.
+ */
+
+// This header makes sure SRWLOCK is actually declared, even on ancient WinSDKs.
+#include "SDL_sysmutex_c.h"
+
+typedef VOID(WINAPI *pfnInitializeSRWLock)(PSRWLOCK);
+typedef VOID(WINAPI *pfnReleaseSRWLockShared)(PSRWLOCK);
+typedef VOID(WINAPI *pfnAcquireSRWLockShared)(PSRWLOCK);
+typedef BOOLEAN(WINAPI *pfnTryAcquireSRWLockShared)(PSRWLOCK);
+typedef VOID(WINAPI *pfnReleaseSRWLockExclusive)(PSRWLOCK);
+typedef VOID(WINAPI *pfnAcquireSRWLockExclusive)(PSRWLOCK);
+typedef BOOLEAN(WINAPI *pfnTryAcquireSRWLockExclusive)(PSRWLOCK);
+
+static pfnInitializeSRWLock pInitializeSRWLock = NULL;
+static pfnReleaseSRWLockShared pReleaseSRWLockShared = NULL;
+static pfnAcquireSRWLockShared pAcquireSRWLockShared = NULL;
+static pfnTryAcquireSRWLockShared  pTryAcquireSRWLockShared = NULL;
+static pfnReleaseSRWLockExclusive pReleaseSRWLockExclusive = NULL;
+static pfnAcquireSRWLockExclusive pAcquireSRWLockExclusive = NULL;
+static pfnTryAcquireSRWLockExclusive pTryAcquireSRWLockExclusive = NULL;
+
+typedef SDL_RWLock *(*pfnSDL_CreateRWLock)(void);
+typedef void (*pfnSDL_DestroyRWLock)(SDL_RWLock *);
+typedef void (*pfnSDL_LockRWLockForReading)(SDL_RWLock *);
+typedef void (*pfnSDL_LockRWLockForWriting)(SDL_RWLock *);
+typedef bool (*pfnSDL_TryLockRWLockForReading)(SDL_RWLock *);
+typedef bool (*pfnSDL_TryLockRWLockForWriting)(SDL_RWLock *);
+typedef void (*pfnSDL_UnlockRWLock)(SDL_RWLock *);
+
+typedef struct SDL_rwlock_impl_t
+{
+    pfnSDL_CreateRWLock Create;
+    pfnSDL_DestroyRWLock Destroy;
+    pfnSDL_LockRWLockForReading LockForReading;
+    pfnSDL_LockRWLockForWriting LockForWriting;
+    pfnSDL_TryLockRWLockForReading TryLockForReading;
+    pfnSDL_TryLockRWLockForWriting TryLockForWriting;
+    pfnSDL_UnlockRWLock Unlock;
+} SDL_rwlock_impl_t;
+
+// Implementation will be chosen at runtime based on available Kernel features
+static SDL_rwlock_impl_t SDL_rwlock_impl_active = { 0 };
+
+// rwlock implementation using Win7+ slim read/write locks (SRWLOCK)
+
+typedef struct SDL_rwlock_srw
+{
+    SRWLOCK srw;
+    SDL_ThreadID write_owner;
+} SDL_rwlock_srw;
+
+static SDL_RWLock *SDL_CreateRWLock_srw(void)
+{
+    SDL_rwlock_srw *rwlock = (SDL_rwlock_srw *)SDL_calloc(1, sizeof(*rwlock));
+    if (rwlock) {
+        pInitializeSRWLock(&rwlock->srw);
+    }
+    return (SDL_RWLock *)rwlock;
+}
+
+static void SDL_DestroyRWLock_srw(SDL_RWLock *_rwlock)
+{
+    SDL_rwlock_srw *rwlock = (SDL_rwlock_srw *) _rwlock;
+    // There are no kernel allocated resources
+    SDL_free(rwlock);
+}
+
+static void SDL_LockRWLockForReading_srw(SDL_RWLock *_rwlock) SDL_NO_THREAD_SAFETY_ANALYSIS  // clang doesn't know about NULL mutexes
+{
+    SDL_rwlock_srw *rwlock = (SDL_rwlock_srw *) _rwlock;
+    pAcquireSRWLockShared(&rwlock->srw);
+}
+
+static void SDL_LockRWLockForWriting_srw(SDL_RWLock *_rwlock) SDL_NO_THREAD_SAFETY_ANALYSIS  // clang doesn't know about NULL mutexes
+{
+    SDL_rwlock_srw *rwlock = (SDL_rwlock_srw *) _rwlock;
+    pAcquireSRWLockExclusive(&rwlock->srw);
+    rwlock->write_owner = SDL_GetCurrentThreadID();
+}
+
+static bool SDL_TryLockRWLockForReading_srw(SDL_RWLock *_rwlock)
+{
+    SDL_rwlock_srw *rwlock = (SDL_rwlock_srw *) _rwlock;
+    return pTryAcquireSRWLockShared(&rwlock->srw);
+}
+
+static bool SDL_TryLockRWLockForWriting_srw(SDL_RWLock *_rwlock)
+{
+    SDL_rwlock_srw *rwlock = (SDL_rwlock_srw *) _rwlock;
+    if (pTryAcquireSRWLockExclusive(&rwlock->srw)) {
+        rwlock->write_owner = SDL_GetCurrentThreadID();
+        return true;
+    } else {
+        return false;
+    }
+}
+
+static void SDL_UnlockRWLock_srw(SDL_RWLock *_rwlock) SDL_NO_THREAD_SAFETY_ANALYSIS  // clang doesn't know about NULL mutexes
+{
+    SDL_rwlock_srw *rwlock = (SDL_rwlock_srw *) _rwlock;
+    if (rwlock->write_owner == SDL_GetCurrentThreadID()) {
+        rwlock->write_owner = 0;
+        pReleaseSRWLockExclusive(&rwlock->srw);
+    } else {
+        pReleaseSRWLockShared(&rwlock->srw);
+    }
+}
+
+static const SDL_rwlock_impl_t SDL_rwlock_impl_srw = {
+    &SDL_CreateRWLock_srw,
+    &SDL_DestroyRWLock_srw,
+    &SDL_LockRWLockForReading_srw,
+    &SDL_LockRWLockForWriting_srw,
+    &SDL_TryLockRWLockForReading_srw,
+    &SDL_TryLockRWLockForWriting_srw,
+    &SDL_UnlockRWLock_srw
+};
+
+
+#include "../generic/SDL_sysrwlock_c.h"
+
+// Generic rwlock implementation using SDL_Mutex, SDL_Condition, and SDL_AtomicInt
+static const SDL_rwlock_impl_t SDL_rwlock_impl_generic = {
+    &SDL_CreateRWLock_generic,
+    &SDL_DestroyRWLock_generic,
+    &SDL_LockRWLockForReading_generic,
+    &SDL_LockRWLockForWriting_generic,
+    &SDL_TryLockRWLockForReading_generic,
+    &SDL_TryLockRWLockForWriting_generic,
+    &SDL_UnlockRWLock_generic
+};
+
+SDL_RWLock *SDL_CreateRWLock(void)
+{
+    if (!SDL_rwlock_impl_active.Create) {
+        // Default to generic implementation, works with all mutex implementations
+        const SDL_rwlock_impl_t *impl = &SDL_rwlock_impl_generic;
+        {
+            HMODULE kernel32 = GetModuleHandle(TEXT("kernel32.dll"));
+            if (kernel32) {
+                bool okay = true;
+                #define LOOKUP_SRW_SYM(sym) if (okay) { if ((p##sym = (pfn##sym)GetProcAddress(kernel32, #sym)) == NULL) { okay = false; } }
+                LOOKUP_SRW_SYM(InitializeSRWLock);
+                LOOKUP_SRW_SYM(ReleaseSRWLockShared);
+                LOOKUP_SRW_SYM(AcquireSRWLockShared);
+                LOOKUP_SRW_SYM(TryAcquireSRWLockShared);
+                LOOKUP_SRW_SYM(ReleaseSRWLockExclusive);
+                LOOKUP_SRW_SYM(AcquireSRWLockExclusive);
+                LOOKUP_SRW_SYM(TryAcquireSRWLockExclusive);
+                #undef LOOKUP_SRW_SYM
+                if (okay) {
+                    impl = &SDL_rwlock_impl_srw;  // Use the Windows provided API instead of generic fallback
+                }
+            }
+        }
+
+        SDL_copyp(&SDL_rwlock_impl_active, impl);
+    }
+    return SDL_rwlock_impl_active.Create();
+}
+
+void SDL_DestroyRWLock(SDL_RWLock *rwlock)
+{
+    if (rwlock) {
+        SDL_rwlock_impl_active.Destroy(rwlock);
+    }
+}
+
+void SDL_LockRWLockForReading(SDL_RWLock *rwlock) SDL_NO_THREAD_SAFETY_ANALYSIS  // clang doesn't know about NULL mutexes
+{
+    if (rwlock) {
+        SDL_rwlock_impl_active.LockForReading(rwlock);
+    }
+}
+
+void SDL_LockRWLockForWriting(SDL_RWLock *rwlock) SDL_NO_THREAD_SAFETY_ANALYSIS  // clang doesn't know about NULL mutexes
+{
+    if (rwlock) {
+        SDL_rwlock_impl_active.LockForWriting(rwlock);
+    }
+}
+
+bool SDL_TryLockRWLockForReading(SDL_RWLock *rwlock)
+{
+    bool result = true;
+    if (rwlock) {
+        result = SDL_rwlock_impl_active.TryLockForReading(rwlock);
+    }
+    return result;
+}
+
+bool SDL_TryLockRWLockForWriting(SDL_RWLock *rwlock)
+{
+    bool result = true;
+    if (rwlock) {
+        result = SDL_rwlock_impl_active.TryLockForWriting(rwlock);
+    }
+    return result;
+}
+
+void SDL_UnlockRWLock(SDL_RWLock *rwlock) SDL_NO_THREAD_SAFETY_ANALYSIS  // clang doesn't know about NULL mutexes
+{
+    if (rwlock) {
+        SDL_rwlock_impl_active.Unlock(rwlock);
+    }
+}
+

thirdparty/sdl/thread/windows/SDL_syssem.c

@@ -0,0 +1,351 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  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

thirdparty/sdl/thread/windows/SDL_systhread.c

@@ -0,0 +1,197 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  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
+
+// Win32 thread management routines for SDL
+
+#include "../SDL_thread_c.h"
+#include "../SDL_systhread.h"
+#include "SDL_systhread_c.h"
+
+#ifndef STACK_SIZE_PARAM_IS_A_RESERVATION
+#define STACK_SIZE_PARAM_IS_A_RESERVATION 0x00010000
+#endif
+
+#define SDL_DEBUGGER_NAME_EXCEPTION_CODE 0x406D1388
+
+typedef void (__cdecl * SDL_EndThreadExCallback) (unsigned retval);
+typedef uintptr_t (__cdecl * SDL_BeginThreadExCallback)
+                   (void *security, unsigned stacksize, unsigned (__stdcall *startaddr)(void *),
+                    void * arglist, unsigned initflag, unsigned *threadaddr);
+
+static DWORD RunThread(void *data)
+{
+    SDL_Thread *thread = (SDL_Thread *)data;
+    SDL_EndThreadExCallback pfnEndThread = (SDL_EndThreadExCallback)thread->endfunc;
+    SDL_RunThread(thread);
+    if (pfnEndThread) {
+        pfnEndThread(0);
+    }
+    return 0;
+}
+
+static DWORD WINAPI MINGW32_FORCEALIGN RunThreadViaCreateThread(LPVOID data)
+{
+    return RunThread(data);
+}
+
+static unsigned __stdcall MINGW32_FORCEALIGN RunThreadViaBeginThreadEx(void *data)
+{
+    return (unsigned)RunThread(data);
+}
+
+bool SDL_SYS_CreateThread(SDL_Thread *thread,
+                          SDL_FunctionPointer vpfnBeginThread,
+                          SDL_FunctionPointer vpfnEndThread)
+{
+    SDL_BeginThreadExCallback pfnBeginThread = (SDL_BeginThreadExCallback) vpfnBeginThread;
+
+    const DWORD flags = thread->stacksize ? STACK_SIZE_PARAM_IS_A_RESERVATION : 0;
+
+    // Save the function which we will have to call to clear the RTL of calling app!
+    thread->endfunc = vpfnEndThread;
+
+    // thread->stacksize == 0 means "system default", same as win32 expects
+    if (pfnBeginThread) {
+        unsigned threadid = 0;
+        thread->handle = (SYS_ThreadHandle)((size_t)pfnBeginThread(NULL, (unsigned int)thread->stacksize,
+                                                                   RunThreadViaBeginThreadEx,
+                                                                   thread, flags, &threadid));
+    } else {
+        DWORD threadid = 0;
+        thread->handle = CreateThread(NULL, thread->stacksize,
+                                      RunThreadViaCreateThread,
+                                      thread, flags, &threadid);
+    }
+    if (!thread->handle) {
+        return SDL_SetError("Not enough resources to create thread");
+    }
+    return true;
+}
+
+#pragma pack(push, 8)
+typedef struct tagTHREADNAME_INFO
+{
+    DWORD dwType;     // must be 0x1000
+    LPCSTR szName;    // pointer to name (in user addr space)
+    DWORD dwThreadID; // thread ID (-1=caller thread)
+    DWORD dwFlags;    // reserved for future use, must be zero
+} THREADNAME_INFO;
+#pragma pack(pop)
+
+static LONG NTAPI EmptyVectoredExceptionHandler(EXCEPTION_POINTERS *info)
+{
+    if (info != NULL && info->ExceptionRecord != NULL && info->ExceptionRecord->ExceptionCode == SDL_DEBUGGER_NAME_EXCEPTION_CODE) {
+        return EXCEPTION_CONTINUE_EXECUTION;
+    } else {
+        return EXCEPTION_CONTINUE_SEARCH;
+    }
+}
+
+typedef HRESULT(WINAPI *pfnSetThreadDescription)(HANDLE, PCWSTR);
+
+void SDL_SYS_SetupThread(const char *name)
+{
+    if (name) {
+        PVOID exceptionHandlerHandle;
+        static pfnSetThreadDescription pSetThreadDescription = NULL;
+        static HMODULE kernel32 = NULL;
+
+        if (!kernel32) {
+            kernel32 = GetModuleHandle(TEXT("kernel32.dll"));
+            if (kernel32) {
+                pSetThreadDescription = (pfnSetThreadDescription)GetProcAddress(kernel32, "SetThreadDescription");
+            }
+            if (!kernel32 || !pSetThreadDescription) {
+                HMODULE kernelBase = GetModuleHandle(TEXT("KernelBase.dll"));
+                if (kernelBase) {
+                    pSetThreadDescription = (pfnSetThreadDescription)GetProcAddress(kernelBase, "SetThreadDescription");
+                }
+            }
+        }
+
+        if (pSetThreadDescription) {
+            WCHAR *strw = WIN_UTF8ToStringW(name);
+            if (strw) {
+                pSetThreadDescription(GetCurrentThread(), strw);
+                SDL_free(strw);
+            }
+        }
+
+        /* Presumably some version of Visual Studio will understand SetThreadDescription(),
+           but we still need to deal with older OSes and debuggers. Set it with the arcane
+           exception magic, too. */
+
+        exceptionHandlerHandle = AddVectoredExceptionHandler(1, EmptyVectoredExceptionHandler);
+        if (exceptionHandlerHandle) {
+            THREADNAME_INFO inf;
+            // This magic tells the debugger to name a thread if it's listening.
+            SDL_zero(inf);
+            inf.dwType = 0x1000;
+            inf.szName = name;
+            inf.dwThreadID = (DWORD)-1;
+            inf.dwFlags = 0;
+
+            // The debugger catches this, renames the thread, continues on.
+            RaiseException(SDL_DEBUGGER_NAME_EXCEPTION_CODE, 0, sizeof(inf) / sizeof(ULONG_PTR), (const ULONG_PTR *)&inf);
+            RemoveVectoredExceptionHandler(exceptionHandlerHandle);
+        }
+    }
+}
+
+SDL_ThreadID SDL_GetCurrentThreadID(void)
+{
+    return (SDL_ThreadID)GetCurrentThreadId();
+}
+
+bool SDL_SYS_SetThreadPriority(SDL_ThreadPriority priority)
+{
+    int value;
+
+    if (priority == SDL_THREAD_PRIORITY_LOW) {
+        value = THREAD_PRIORITY_LOWEST;
+    } else if (priority == SDL_THREAD_PRIORITY_HIGH) {
+        value = THREAD_PRIORITY_HIGHEST;
+    } else if (priority == SDL_THREAD_PRIORITY_TIME_CRITICAL) {
+        value = THREAD_PRIORITY_TIME_CRITICAL;
+    } else {
+        value = THREAD_PRIORITY_NORMAL;
+    }
+    if (!SetThreadPriority(GetCurrentThread(), value)) {
+        return WIN_SetError("SetThreadPriority()");
+    }
+    return true;
+}
+
+void SDL_SYS_WaitThread(SDL_Thread *thread)
+{
+    WaitForSingleObjectEx(thread->handle, INFINITE, FALSE);
+    CloseHandle(thread->handle);
+}
+
+void SDL_SYS_DetachThread(SDL_Thread *thread)
+{
+    CloseHandle(thread->handle);
+}
+
+#endif // SDL_THREAD_WINDOWS

thirdparty/sdl/thread/windows/SDL_systhread_c.h

@@ -0,0 +1,30 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  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"
+
+#ifndef SDL_systhread_c_h_
+#define SDL_systhread_c_h_
+
+#include "../../core/windows/SDL_windows.h"
+
+typedef HANDLE SYS_ThreadHandle;
+
+#endif // SDL_systhread_c_h_

thirdparty/sdl/thread/windows/SDL_systls.c

@@ -0,0 +1,81 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  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
+
+#include "../../core/windows/SDL_windows.h"
+
+#include "../SDL_thread_c.h"
+
+static DWORD thread_local_storage = TLS_OUT_OF_INDEXES;
+static bool generic_local_storage = false;
+
+void SDL_SYS_InitTLSData(void)
+{
+    if (thread_local_storage == TLS_OUT_OF_INDEXES && !generic_local_storage) {
+        thread_local_storage = TlsAlloc();
+        if (thread_local_storage == TLS_OUT_OF_INDEXES) {
+            SDL_Generic_InitTLSData();
+            generic_local_storage = true;
+        }
+    }
+}
+
+SDL_TLSData *SDL_SYS_GetTLSData(void)
+{
+    if (generic_local_storage) {
+        return SDL_Generic_GetTLSData();
+    }
+
+    if (thread_local_storage != TLS_OUT_OF_INDEXES) {
+        return (SDL_TLSData *)TlsGetValue(thread_local_storage);
+    }
+    return NULL;
+}
+
+bool SDL_SYS_SetTLSData(SDL_TLSData *data)
+{
+    if (generic_local_storage) {
+        return SDL_Generic_SetTLSData(data);
+    }
+
+    if (!TlsSetValue(thread_local_storage, data)) {
+        return WIN_SetError("TlsSetValue()");
+    }
+    return true;
+}
+
+void SDL_SYS_QuitTLSData(void)
+{
+    if (generic_local_storage) {
+        SDL_Generic_QuitTLSData();
+        generic_local_storage = false;
+    } else {
+        if (thread_local_storage != TLS_OUT_OF_INDEXES) {
+            TlsFree(thread_local_storage);
+            thread_local_storage = TLS_OUT_OF_INDEXES;
+        }
+    }
+}
+
+#endif // SDL_THREAD_WINDOWS