Merge commit 'dec0d4ec4153bf9fc2b78ae6c2df45b6ea8dde7a' as 'external/sdl/SDL'

external/sdl/SDL/src/thread/n3ds/SDL_systhread.c

@@ -0,0 +1,139 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2023 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 put a limit on thread stack size. */
+#define N3DS_THREAD_STACK_SIZE_MAX     (16 * 1024)
+#define N3DS_THREAD_STACK_SIZE_DEFAULT (4 * 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);
+}
+
+#ifdef SDL_PASSED_BEGINTHREAD_ENDTHREAD
+#error "SDL_PASSED_BEGINTHREAD_ENDTHREAD is not supported on N3DS"
+#endif
+
+int SDL_SYS_CreateThread(SDL_Thread *thread)
+{
+    s32 priority;
+    size_t stack_size = GetStackSize(thread->stacksize);
+    svcGetThreadPriority(&priority, CUR_THREAD_HANDLE);
+
+    thread->handle = threadCreate(ThreadEntry,
+                                  thread,
+                                  stack_size,
+                                  priority,
+                                  -1,
+                                  false);
+
+    if (thread->handle == NULL) {
+        return SDL_SetError("Couldn't create thread");
+    }
+
+    return 0;
+}
+
+static size_t GetStackSize(size_t requested_size)
+{
+    if (requested_size == 0) {
+        return N3DS_THREAD_STACK_SIZE_DEFAULT;
+    }
+
+    if (requested_size > N3DS_THREAD_STACK_SIZE_MAX) {
+        SDL_LogWarn(SDL_LOG_CATEGORY_SYSTEM,
+                    "Requested a thread size of %zu,"
+                    " falling back to the maximum supported of %zu\n",
+                    requested_size,
+                    N3DS_THREAD_STACK_SIZE_MAX);
+        requested_size = N3DS_THREAD_STACK_SIZE_MAX;
+    }
+    return requested_size;
+}
+
+void SDL_SYS_SetupThread(const char *name)
+{
+    return;
+}
+
+SDL_threadID SDL_ThreadID(void)
+{
+    u32 thread_ID = 0;
+    svcGetThreadId(&thread_ID, CUR_THREAD_HANDLE);
+    return (SDL_threadID)thread_ID;
+}
+
+int 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;
+    }
+    return (int)svcSetThreadPriority(CUR_THREAD_HANDLE, svc_priority);
+}
+
+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_AtomicGet(&thread->state) != SDL_THREAD_STATE_DETACHED) {
+        threadFree(thread->handle);
+    }
+}
+
+void SDL_SYS_DetachThread(SDL_Thread *thread)
+{
+    threadDetach(thread->handle);
+}
+
+#endif /* SDL_THREAD_N3DS */