initial commit, 4.5 stable

thirdparty/sdl/thread/SDL_thread.c

@@ -0,0 +1,584 @@
+/*
+  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"
+
+// System independent thread management routines for SDL
+
+#include "SDL_thread_c.h"
+#include "SDL_systhread.h"
+#include "../SDL_error_c.h"
+
+// The storage is local to the thread, but the IDs are global for the process
+
+static SDL_AtomicInt SDL_tls_allocated;
+static SDL_AtomicInt SDL_tls_id;
+
+void SDL_InitTLSData(void)
+{
+    SDL_SYS_InitTLSData();
+}
+
+void *SDL_GetTLS(SDL_TLSID *id)
+{
+    SDL_TLSData *storage;
+    int storage_index;
+
+    if (id == NULL) {
+        SDL_InvalidParamError("id");
+        return NULL;
+    }
+
+    storage_index = SDL_GetAtomicInt(id) - 1;
+    storage = SDL_SYS_GetTLSData();
+    if (!storage || storage_index < 0 || storage_index >= storage->limit) {
+        return NULL;
+    }
+    return storage->array[storage_index].data;
+}
+
+bool SDL_SetTLS(SDL_TLSID *id, const void *value, SDL_TLSDestructorCallback destructor)
+{
+    SDL_TLSData *storage;
+    int storage_index;
+
+    if (id == NULL) {
+        return SDL_InvalidParamError("id");
+    }
+
+    /* Make sure TLS is initialized.
+     * There's a race condition here if you are calling this from non-SDL threads
+     * and haven't called SDL_Init() on your main thread, but such is life.
+     */
+    SDL_InitTLSData();
+
+    // Get the storage index associated with the ID in a thread-safe way
+    storage_index = SDL_GetAtomicInt(id) - 1;
+    if (storage_index < 0) {
+        int new_id = (SDL_AtomicIncRef(&SDL_tls_id) + 1);
+
+        SDL_CompareAndSwapAtomicInt(id, 0, new_id);
+
+        /* If there was a race condition we'll have wasted an ID, but every thread
+         * will have the same storage index for this id.
+         */
+        storage_index = SDL_GetAtomicInt(id) - 1;
+    }
+
+    // Get the storage for the current thread
+    storage = SDL_SYS_GetTLSData();
+    if (!storage || storage_index >= storage->limit) {
+        unsigned int i, oldlimit, newlimit;
+        SDL_TLSData *new_storage;
+
+        oldlimit = storage ? storage->limit : 0;
+        newlimit = (storage_index + TLS_ALLOC_CHUNKSIZE);
+        new_storage = (SDL_TLSData *)SDL_realloc(storage, sizeof(*storage) + (newlimit - 1) * sizeof(storage->array[0]));
+        if (!new_storage) {
+            return false;
+        }
+        storage = new_storage;
+        storage->limit = newlimit;
+        for (i = oldlimit; i < newlimit; ++i) {
+            storage->array[i].data = NULL;
+            storage->array[i].destructor = NULL;
+        }
+        if (!SDL_SYS_SetTLSData(storage)) {
+            SDL_free(storage);
+            return false;
+        }
+        SDL_AtomicIncRef(&SDL_tls_allocated);
+    }
+
+    storage->array[storage_index].data = SDL_const_cast(void *, value);
+    storage->array[storage_index].destructor = destructor;
+    return true;
+}
+
+void SDL_CleanupTLS(void)
+{
+    SDL_TLSData *storage;
+
+    // Cleanup the storage for the current thread
+    storage = SDL_SYS_GetTLSData();
+    if (storage) {
+        int i;
+        for (i = 0; i < storage->limit; ++i) {
+            if (storage->array[i].destructor) {
+                storage->array[i].destructor(storage->array[i].data);
+            }
+        }
+        SDL_SYS_SetTLSData(NULL);
+        SDL_free(storage);
+        (void)SDL_AtomicDecRef(&SDL_tls_allocated);
+    }
+}
+
+void SDL_QuitTLSData(void)
+{
+    SDL_CleanupTLS();
+
+    if (SDL_GetAtomicInt(&SDL_tls_allocated) == 0) {
+        SDL_SYS_QuitTLSData();
+    } else {
+        // Some thread hasn't called SDL_CleanupTLS()
+    }
+}
+
+/* This is a generic implementation of thread-local storage which doesn't
+   require additional OS support.
+
+   It is not especially efficient and doesn't clean up thread-local storage
+   as threads exit.  If there is a real OS that doesn't support thread-local
+   storage this implementation should be improved to be production quality.
+*/
+
+typedef struct SDL_TLSEntry
+{
+    SDL_ThreadID thread;
+    SDL_TLSData *storage;
+    struct SDL_TLSEntry *next;
+} SDL_TLSEntry;
+
+static SDL_Mutex *SDL_generic_TLS_mutex;
+static SDL_TLSEntry *SDL_generic_TLS;
+
+void SDL_Generic_InitTLSData(void)
+{
+    if (!SDL_generic_TLS_mutex) {
+        SDL_generic_TLS_mutex = SDL_CreateMutex();
+    }
+}
+
+SDL_TLSData *SDL_Generic_GetTLSData(void)
+{
+    SDL_ThreadID thread = SDL_GetCurrentThreadID();
+    SDL_TLSEntry *entry;
+    SDL_TLSData *storage = NULL;
+
+    SDL_LockMutex(SDL_generic_TLS_mutex);
+    for (entry = SDL_generic_TLS; entry; entry = entry->next) {
+        if (entry->thread == thread) {
+            storage = entry->storage;
+            break;
+        }
+    }
+    SDL_UnlockMutex(SDL_generic_TLS_mutex);
+
+    return storage;
+}
+
+bool SDL_Generic_SetTLSData(SDL_TLSData *data)
+{
+    SDL_ThreadID thread = SDL_GetCurrentThreadID();
+    SDL_TLSEntry *prev, *entry;
+    bool result = true;
+
+    SDL_LockMutex(SDL_generic_TLS_mutex);
+    prev = NULL;
+    for (entry = SDL_generic_TLS; entry; entry = entry->next) {
+        if (entry->thread == thread) {
+            if (data) {
+                entry->storage = data;
+            } else {
+                if (prev) {
+                    prev->next = entry->next;
+                } else {
+                    SDL_generic_TLS = entry->next;
+                }
+                SDL_free(entry);
+            }
+            break;
+        }
+        prev = entry;
+    }
+    if (!entry && data) {
+        entry = (SDL_TLSEntry *)SDL_malloc(sizeof(*entry));
+        if (entry) {
+            entry->thread = thread;
+            entry->storage = data;
+            entry->next = SDL_generic_TLS;
+            SDL_generic_TLS = entry;
+        } else {
+            result = false;
+        }
+    }
+    SDL_UnlockMutex(SDL_generic_TLS_mutex);
+
+    return result;
+}
+
+void SDL_Generic_QuitTLSData(void)
+{
+    SDL_TLSEntry *entry;
+
+    // This should have been cleaned up by the time we get here
+    SDL_assert(!SDL_generic_TLS);
+    if (SDL_generic_TLS) {
+        SDL_LockMutex(SDL_generic_TLS_mutex);
+        for (entry = SDL_generic_TLS; entry; ) {
+            SDL_TLSEntry *next = entry->next;
+            SDL_free(entry->storage);
+            SDL_free(entry);
+            entry = next;
+        }
+        SDL_generic_TLS = NULL;
+        SDL_UnlockMutex(SDL_generic_TLS_mutex);
+    }
+
+    if (SDL_generic_TLS_mutex) {
+        SDL_DestroyMutex(SDL_generic_TLS_mutex);
+        SDL_generic_TLS_mutex = NULL;
+    }
+}
+
+// Non-thread-safe global error variable
+static SDL_error *SDL_GetStaticErrBuf(void)
+{
+    static SDL_error SDL_global_error;
+    static char SDL_global_error_str[128];
+    SDL_global_error.str = SDL_global_error_str;
+    SDL_global_error.len = sizeof(SDL_global_error_str);
+    return &SDL_global_error;
+}
+
+#ifndef SDL_THREADS_DISABLED
+static void SDLCALL SDL_FreeErrBuf(void *data)
+{
+    SDL_error *errbuf = (SDL_error *)data;
+
+    if (errbuf->str) {
+        errbuf->free_func(errbuf->str);
+    }
+    errbuf->free_func(errbuf);
+}
+#endif
+
+// Routine to get the thread-specific error variable
+SDL_error *SDL_GetErrBuf(bool create)
+{
+#ifdef SDL_THREADS_DISABLED
+    return SDL_GetStaticErrBuf();
+#else
+    static SDL_TLSID tls_errbuf;
+    SDL_error *errbuf;
+
+    errbuf = (SDL_error *)SDL_GetTLS(&tls_errbuf);
+    if (!errbuf) {
+        if (!create) {
+            return NULL;
+        }
+
+        /* Get the original memory functions for this allocation because the lifetime
+         * of the error buffer may span calls to SDL_SetMemoryFunctions() by the app
+         */
+        SDL_realloc_func realloc_func;
+        SDL_free_func free_func;
+        SDL_GetOriginalMemoryFunctions(NULL, NULL, &realloc_func, &free_func);
+
+        errbuf = (SDL_error *)realloc_func(NULL, sizeof(*errbuf));
+        if (!errbuf) {
+            return SDL_GetStaticErrBuf();
+        }
+        SDL_zerop(errbuf);
+        errbuf->realloc_func = realloc_func;
+        errbuf->free_func = free_func;
+        SDL_SetTLS(&tls_errbuf, errbuf, SDL_FreeErrBuf);
+    }
+    return errbuf;
+#endif // SDL_THREADS_DISABLED
+}
+
+static bool ThreadValid(SDL_Thread *thread)
+{
+    return SDL_ObjectValid(thread, SDL_OBJECT_TYPE_THREAD);
+}
+
+void SDL_RunThread(SDL_Thread *thread)
+{
+    void *userdata = thread->userdata;
+    int(SDLCALL *userfunc)(void *) = thread->userfunc;
+
+    int *statusloc = &thread->status;
+
+    // Perform any system-dependent setup - this function may not fail
+    SDL_SYS_SetupThread(thread->name);
+
+    // Get the thread id
+    thread->threadid = SDL_GetCurrentThreadID();
+
+    // Run the function
+    *statusloc = userfunc(userdata);
+
+    // Clean up thread-local storage
+    SDL_CleanupTLS();
+
+    // Mark us as ready to be joined (or detached)
+    if (!SDL_CompareAndSwapAtomicInt(&thread->state, SDL_THREAD_ALIVE, SDL_THREAD_COMPLETE)) {
+        // Clean up if something already detached us.
+        if (SDL_GetThreadState(thread) == SDL_THREAD_DETACHED) {
+            SDL_free(thread->name); // Can't free later, we've already cleaned up TLS
+            SDL_free(thread);
+        }
+    }
+}
+
+SDL_Thread *SDL_CreateThreadWithPropertiesRuntime(SDL_PropertiesID props,
+                              SDL_FunctionPointer pfnBeginThread,
+                              SDL_FunctionPointer pfnEndThread)
+{
+    // rather than check this in every backend, just make sure it's correct upfront. Only allow non-NULL if Windows, or Microsoft GDK.
+    #if !defined(SDL_PLATFORM_WINDOWS)
+    if (pfnBeginThread || pfnEndThread) {
+        SDL_SetError("_beginthreadex/_endthreadex not supported on this platform");
+        return NULL;
+    }
+    #endif
+
+    SDL_ThreadFunction fn = (SDL_ThreadFunction) SDL_GetPointerProperty(props, SDL_PROP_THREAD_CREATE_ENTRY_FUNCTION_POINTER, NULL);
+    const char *name = SDL_GetStringProperty(props, SDL_PROP_THREAD_CREATE_NAME_STRING, NULL);
+    const size_t stacksize = (size_t) SDL_GetNumberProperty(props, SDL_PROP_THREAD_CREATE_STACKSIZE_NUMBER, 0);
+    void *userdata = SDL_GetPointerProperty(props, SDL_PROP_THREAD_CREATE_USERDATA_POINTER, NULL);
+
+    if (!fn) {
+        SDL_SetError("Thread entry function is NULL");
+        return NULL;
+    }
+
+    SDL_InitMainThread();
+
+    SDL_Thread *thread = (SDL_Thread *)SDL_calloc(1, sizeof(*thread));
+    if (!thread) {
+        return NULL;
+    }
+    thread->status = -1;
+    SDL_SetAtomicInt(&thread->state, SDL_THREAD_ALIVE);
+
+    // Set up the arguments for the thread
+    if (name) {
+        thread->name = SDL_strdup(name);
+        if (!thread->name) {
+            SDL_free(thread);
+            return NULL;
+        }
+    }
+
+    thread->userfunc = fn;
+    thread->userdata = userdata;
+    thread->stacksize = stacksize;
+
+    SDL_SetObjectValid(thread, SDL_OBJECT_TYPE_THREAD, true);
+
+    // Create the thread and go!
+    if (!SDL_SYS_CreateThread(thread, pfnBeginThread, pfnEndThread)) {
+        // Oops, failed.  Gotta free everything
+        SDL_SetObjectValid(thread, SDL_OBJECT_TYPE_THREAD, false);
+        SDL_free(thread->name);
+        SDL_free(thread);
+        thread = NULL;
+    }
+
+    // Everything is running now
+    return thread;
+}
+
+SDL_Thread *SDL_CreateThreadRuntime(SDL_ThreadFunction fn,
+                 const char *name, void *userdata,
+                 SDL_FunctionPointer pfnBeginThread,
+                 SDL_FunctionPointer pfnEndThread)
+{
+    const SDL_PropertiesID props = SDL_CreateProperties();
+    SDL_SetPointerProperty(props, SDL_PROP_THREAD_CREATE_ENTRY_FUNCTION_POINTER, (void *) fn);
+    SDL_SetStringProperty(props, SDL_PROP_THREAD_CREATE_NAME_STRING, name);
+    SDL_SetPointerProperty(props, SDL_PROP_THREAD_CREATE_USERDATA_POINTER, userdata);
+    SDL_Thread *thread = SDL_CreateThreadWithPropertiesRuntime(props, pfnBeginThread, pfnEndThread);
+    SDL_DestroyProperties(props);
+    return thread;
+}
+
+// internal helper function, not in the public API.
+SDL_Thread *SDL_CreateThreadWithStackSize(SDL_ThreadFunction fn, const char *name, size_t stacksize, void *userdata)
+{
+    const SDL_PropertiesID props = SDL_CreateProperties();
+    SDL_SetPointerProperty(props, SDL_PROP_THREAD_CREATE_ENTRY_FUNCTION_POINTER, (void *) fn);
+    SDL_SetStringProperty(props, SDL_PROP_THREAD_CREATE_NAME_STRING, name);
+    SDL_SetPointerProperty(props, SDL_PROP_THREAD_CREATE_USERDATA_POINTER, userdata);
+    SDL_SetNumberProperty(props, SDL_PROP_THREAD_CREATE_STACKSIZE_NUMBER, (Sint64) stacksize);
+    SDL_Thread *thread = SDL_CreateThreadWithProperties(props);
+    SDL_DestroyProperties(props);
+    return thread;
+}
+
+SDL_ThreadID SDL_GetThreadID(SDL_Thread *thread)
+{
+    SDL_ThreadID id = 0;
+
+    if (thread) {
+        if (ThreadValid(thread)) {
+            id = thread->threadid;
+        }
+    } else {
+        id = SDL_GetCurrentThreadID();
+    }
+    return id;
+}
+
+const char *SDL_GetThreadName(SDL_Thread *thread)
+{
+    if (ThreadValid(thread)) {
+        return SDL_GetPersistentString(thread->name);
+    } else {
+        return NULL;
+    }
+}
+
+bool SDL_SetCurrentThreadPriority(SDL_ThreadPriority priority)
+{
+    return SDL_SYS_SetThreadPriority(priority);
+}
+
+void SDL_WaitThread(SDL_Thread *thread, int *status)
+{
+    if (!ThreadValid(thread)) {
+        if (status) {
+            *status = -1;
+        }
+        return;
+    }
+
+    SDL_SYS_WaitThread(thread);
+    if (status) {
+        *status = thread->status;
+    }
+    SDL_SetObjectValid(thread, SDL_OBJECT_TYPE_THREAD, false);
+    SDL_free(thread->name);
+    SDL_free(thread);
+}
+
+SDL_ThreadState SDL_GetThreadState(SDL_Thread *thread)
+{
+    if (!ThreadValid(thread)) {
+        return SDL_THREAD_UNKNOWN;
+    }
+
+    return (SDL_ThreadState)SDL_GetAtomicInt(&thread->state);
+}
+
+void SDL_DetachThread(SDL_Thread *thread)
+{
+    if (!ThreadValid(thread)) {
+        return;
+    }
+
+    // The thread may vanish at any time, it's no longer valid
+    SDL_SetObjectValid(thread, SDL_OBJECT_TYPE_THREAD, false);
+
+    // Grab dibs if the state is alive+joinable.
+    if (SDL_CompareAndSwapAtomicInt(&thread->state, SDL_THREAD_ALIVE, SDL_THREAD_DETACHED)) {
+        SDL_SYS_DetachThread(thread);
+    } else {
+        // all other states are pretty final, see where we landed.
+        SDL_ThreadState thread_state = SDL_GetThreadState(thread);
+        if (thread_state == SDL_THREAD_DETACHED) {
+            return; // already detached (you shouldn't call this twice!)
+        } else if (thread_state == SDL_THREAD_COMPLETE) {
+            SDL_WaitThread(thread, NULL); // already done, clean it up.
+        }
+    }
+}
+
+void SDL_WaitSemaphore(SDL_Semaphore *sem)
+{
+    SDL_WaitSemaphoreTimeoutNS(sem, -1);
+}
+
+bool SDL_TryWaitSemaphore(SDL_Semaphore *sem)
+{
+    return SDL_WaitSemaphoreTimeoutNS(sem, 0);
+}
+
+bool SDL_WaitSemaphoreTimeout(SDL_Semaphore *sem, Sint32 timeoutMS)
+{
+    Sint64 timeoutNS;
+
+    if (timeoutMS >= 0) {
+        timeoutNS = SDL_MS_TO_NS(timeoutMS);
+    } else {
+        timeoutNS = -1;
+    }
+    return SDL_WaitSemaphoreTimeoutNS(sem, timeoutNS);
+}
+
+void SDL_WaitCondition(SDL_Condition *cond, SDL_Mutex *mutex)
+{
+    SDL_WaitConditionTimeoutNS(cond, mutex, -1);
+}
+
+bool SDL_WaitConditionTimeout(SDL_Condition *cond, SDL_Mutex *mutex, Sint32 timeoutMS)
+{
+    Sint64 timeoutNS;
+
+    if (timeoutMS >= 0) {
+        timeoutNS = SDL_MS_TO_NS(timeoutMS);
+    } else {
+        timeoutNS = -1;
+    }
+    return SDL_WaitConditionTimeoutNS(cond, mutex, timeoutNS);
+}
+
+bool SDL_ShouldInit(SDL_InitState *state)
+{
+    while (SDL_GetAtomicInt(&state->status) != SDL_INIT_STATUS_INITIALIZED) {
+        if (SDL_CompareAndSwapAtomicInt(&state->status, SDL_INIT_STATUS_UNINITIALIZED, SDL_INIT_STATUS_INITIALIZING)) {
+            state->thread = SDL_GetCurrentThreadID();
+            return true;
+        }
+
+        // Wait for the other thread to complete transition
+        SDL_Delay(1);
+    }
+    return false;
+}
+
+bool SDL_ShouldQuit(SDL_InitState *state)
+{
+    while (SDL_GetAtomicInt(&state->status) != SDL_INIT_STATUS_UNINITIALIZED) {
+        if (SDL_CompareAndSwapAtomicInt(&state->status, SDL_INIT_STATUS_INITIALIZED, SDL_INIT_STATUS_UNINITIALIZING)) {
+            state->thread = SDL_GetCurrentThreadID();
+            return true;
+        }
+
+        // Wait for the other thread to complete transition
+        SDL_Delay(1);
+    }
+    return false;
+}
+
+void SDL_SetInitialized(SDL_InitState *state, bool initialized)
+{
+    SDL_assert(state->thread == SDL_GetCurrentThreadID());
+
+    if (initialized) {
+        SDL_SetAtomicInt(&state->status, SDL_INIT_STATUS_INITIALIZED);
+    } else {
+        SDL_SetAtomicInt(&state->status, SDL_INIT_STATUS_UNINITIALIZED);
+    }
+}
+