5 files changed, 381 insertions, 0 deletions

diff --git a/contrib/SDL-3.2.8/src/thread/n3ds/SDL_sysmutex.c b/contrib/SDL-3.2.8/src/thread/n3ds/SDL_sysmutex.c
new file mode 100644
index 0000000..0abb9f5
--- /dev/null
+++ b/contrib/SDL-3.2.8/src/thread/n3ds/SDL_sysmutex.c
@@ -0,0 +1,67 @@
+/*
+  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_N3DS
+
+// An implementation of mutexes using libctru's RecursiveLock
+
+#include "SDL_sysmutex_c.h"
+
+SDL_Mutex *SDL_CreateMutex(void)
+{
+    SDL_Mutex *mutex = (SDL_Mutex *)SDL_malloc(sizeof(*mutex));
+    if (mutex) {
+        RecursiveLock_Init(&mutex->lock);
+    }
+    return mutex;
+}
+
+void SDL_DestroyMutex(SDL_Mutex *mutex)
+{
+    if (mutex) {
+        SDL_free(mutex);
+    }
+}
+
+void SDL_LockMutex(SDL_Mutex *mutex) SDL_NO_THREAD_SAFETY_ANALYSIS  // clang doesn't know about NULL mutexes
+{
+    if (mutex) {
+        RecursiveLock_Lock(&mutex->lock);
+    }
+}
+
+bool SDL_TryLockMutex(SDL_Mutex *mutex)
+{
+    if (mutex) {
+        return RecursiveLock_TryLock(&mutex->lock);
+    }
+    return true;
+}
+
+void SDL_UnlockMutex(SDL_Mutex *mutex) SDL_NO_THREAD_SAFETY_ANALYSIS // clang doesn't know about NULL mutexes
+{
+    if (mutex) {
+        RecursiveLock_Unlock(&mutex->lock);
+    }
+}
+
+#endif // SDL_THREAD_N3DS
diff --git a/contrib/SDL-3.2.8/src/thread/n3ds/SDL_sysmutex_c.h b/contrib/SDL-3.2.8/src/thread/n3ds/SDL_sysmutex_c.h
new file mode 100644
index 0000000..ddf8069
--- /dev/null
+++ b/contrib/SDL-3.2.8/src/thread/n3ds/SDL_sysmutex_c.h
@@ -0,0 +1,33 @@
+/*
+  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_sysmutex_c_h_
+#define SDL_sysmutex_c_h_
+
+#include <3ds.h>
+
+struct SDL_Mutex
+{
+    RecursiveLock lock;
+};
+
+#endif // SDL_sysmutex_c_h
diff --git a/contrib/SDL-3.2.8/src/thread/n3ds/SDL_syssem.c b/contrib/SDL-3.2.8/src/thread/n3ds/SDL_syssem.c
new file mode 100644
index 0000000..3207a2d
--- /dev/null
+++ b/contrib/SDL-3.2.8/src/thread/n3ds/SDL_syssem.c
@@ -0,0 +1,112 @@
+/*
+  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_N3DS
+
+// An implementation of semaphores using libctru's LightSemaphore
+
+#include <3ds.h>
+
+struct SDL_Semaphore
+{
+    LightSemaphore semaphore;
+};
+
+SDL_Semaphore *SDL_CreateSemaphore(Uint32 initial_value)
+{
+    SDL_Semaphore *sem;
+
+    if (initial_value > SDL_MAX_SINT16) {
+        SDL_SetError("Initial semaphore value too high for this platform");
+        return NULL;
+    }
+
+    sem = (SDL_Semaphore *)SDL_malloc(sizeof(*sem));
+    if (!sem) {
+        return NULL;
+    }
+
+    LightSemaphore_Init(&sem->semaphore, initial_value, SDL_MAX_SINT16);
+
+    return sem;
+}
+
+/* WARNING:
+   You cannot call this function when another thread is using the semaphore.
+*/
+void SDL_DestroySemaphore(SDL_Semaphore *sem)
+{
+    SDL_free(sem);
+}
+
+static bool WaitOnSemaphoreFor(SDL_Semaphore *sem, Sint64 timeoutNS)
+{
+    Uint64 stop_time = SDL_GetTicksNS() + timeoutNS;
+    while (SDL_GetTicksNS() < stop_time) {
+        if (LightSemaphore_TryAcquire(&sem->semaphore, 1) == 0) {
+            return true;
+        }
+        // 100 microseconds seems to be the sweet spot
+        SDL_DelayNS(SDL_US_TO_NS(100));
+    }
+
+    // If we failed, yield to avoid starvation on busy waits
+    SDL_DelayNS(1);
+    return false;
+}
+
+bool SDL_WaitSemaphoreTimeoutNS(SDL_Semaphore *sem, Sint64 timeoutNS)
+{
+    if (!sem) {
+        return true;
+    }
+
+    if (timeoutNS < 0) { // -1 == wait indefinitely.
+        LightSemaphore_Acquire(&sem->semaphore, 1);
+        return true;
+    }
+
+    if (LightSemaphore_TryAcquire(&sem->semaphore, 1) == 0) {
+        return true;
+    }
+
+    return WaitOnSemaphoreFor(sem, timeoutNS);
+}
+
+Uint32 SDL_GetSemaphoreValue(SDL_Semaphore *sem)
+{
+    if (!sem) {
+        return 0;
+    }
+    return sem->semaphore.current_count;
+}
+
+void SDL_SignalSemaphore(SDL_Semaphore *sem)
+{
+    if (sem) {
+        return;
+    }
+
+    LightSemaphore_Release(&sem->semaphore, 1);
+}
+
+#endif // SDL_THREAD_N3DS
diff --git a/contrib/SDL-3.2.8/src/thread/n3ds/SDL_systhread.c b/contrib/SDL-3.2.8/src/thread/n3ds/SDL_systhread.c
new file mode 100644
index 0000000..6bd826b
--- /dev/null
+++ b/contrib/SDL-3.2.8/src/thread/n3ds/SDL_systhread.c
@@ -0,0 +1,139 @@
+/*
+  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_N3DS
+
+// Thread management routines for SDL
+
+#include "../SDL_systhread.h"
+
+// N3DS has very limited RAM (128MB), so we set a low default thread stack size.
+#define N3DS_THREAD_STACK_SIZE_DEFAULT (80 * 1024)
+
+#define N3DS_THREAD_PRIORITY_LOW           0x3F /**< Minimum priority */
+#define N3DS_THREAD_PRIORITY_MEDIUM        0x2F /**< Slightly higher than main thread (0x30) */
+#define N3DS_THREAD_PRIORITY_HIGH          0x19 /**< High priority for non-video work */
+#define N3DS_THREAD_PRIORITY_TIME_CRITICAL 0x18 /**< Highest priority */
+
+static size_t GetStackSize(size_t requested_size);
+
+static void ThreadEntry(void *arg)
+{
+    SDL_RunThread((SDL_Thread *)arg);
+    threadExit(0);
+}
+
+
+bool SDL_SYS_CreateThread(SDL_Thread *thread,
+                          SDL_FunctionPointer pfnBeginThread,
+                          SDL_FunctionPointer pfnEndThread)
+{
+    s32 priority = 0x30;
+    int cpu = -1;
+    size_t stack_size = GetStackSize(thread->stacksize);
+
+    svcGetThreadPriority(&priority, CUR_THREAD_HANDLE);
+
+    // prefer putting audio thread on system core
+    if (thread->name && (SDL_strncmp(thread->name, "SDLAudioP", 9) == 0) && R_SUCCEEDED(APT_SetAppCpuTimeLimit(30))) {
+        cpu = 1;
+    }
+
+    thread->handle = threadCreate(ThreadEntry,
+                                  thread,
+                                  stack_size,
+                                  priority,
+                                  cpu,
+                                  false);
+
+    if (!thread->handle) {
+        return SDL_SetError("Couldn't create thread");
+    }
+
+    return true;
+}
+
+static size_t GetStackSize(size_t requested_size)
+{
+    if (requested_size == 0) {
+        return N3DS_THREAD_STACK_SIZE_DEFAULT;
+    }
+
+    return requested_size;
+}
+
+void SDL_SYS_SetupThread(const char *name)
+{
+    return;
+}
+
+SDL_ThreadID SDL_GetCurrentThreadID(void)
+{
+    u32 thread_ID = 0;
+    svcGetThreadId(&thread_ID, CUR_THREAD_HANDLE);
+    return (SDL_ThreadID)thread_ID;
+}
+
+bool SDL_SYS_SetThreadPriority(SDL_ThreadPriority sdl_priority)
+{
+    s32 svc_priority;
+    switch (sdl_priority) {
+    case SDL_THREAD_PRIORITY_LOW:
+        svc_priority = N3DS_THREAD_PRIORITY_LOW;
+        break;
+    case SDL_THREAD_PRIORITY_NORMAL:
+        svc_priority = N3DS_THREAD_PRIORITY_MEDIUM;
+        break;
+    case SDL_THREAD_PRIORITY_HIGH:
+        svc_priority = N3DS_THREAD_PRIORITY_HIGH;
+        break;
+    case SDL_THREAD_PRIORITY_TIME_CRITICAL:
+        svc_priority = N3DS_THREAD_PRIORITY_TIME_CRITICAL;
+        break;
+    default:
+        svc_priority = N3DS_THREAD_PRIORITY_MEDIUM;
+    }
+    if (svcSetThreadPriority(CUR_THREAD_HANDLE, svc_priority) < 0) {
+        return SDL_SetError("svcSetThreadPriority failed");
+    }
+    return true;
+}
+
+void SDL_SYS_WaitThread(SDL_Thread *thread)
+{
+    Result res = threadJoin(thread->handle, U64_MAX);
+
+    /*
+      Detached threads can be waited on, but should NOT be cleaned manually
+      as it would result in a fatal error.
+    */
+    if (R_SUCCEEDED(res) && SDL_GetThreadState(thread) != SDL_THREAD_DETACHED) {
+        threadFree(thread->handle);
+    }
+}
+
+void SDL_SYS_DetachThread(SDL_Thread *thread)
+{
+    threadDetach(thread->handle);
+}
+
+#endif // SDL_THREAD_N3DS
diff --git a/contrib/SDL-3.2.8/src/thread/n3ds/SDL_systhread_c.h b/contrib/SDL-3.2.8/src/thread/n3ds/SDL_systhread_c.h
new file mode 100644
index 0000000..d87d636
--- /dev/null
+++ b/contrib/SDL-3.2.8/src/thread/n3ds/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 <3ds.h>
+
+typedef Thread SYS_ThreadHandle;
+
+#endif // SDL_systhread_c_h_