--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SDL3/SDL_atomic.h	Mon Jan 05 02:15:46 2026 -0500
@@ -0,0 +1,682 @@
+/*
+  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.
+*/
+
+/**
+ * # CategoryAtomic
+ *
+ * Atomic operations.
+ *
+ * IMPORTANT: If you are not an expert in concurrent lockless programming, you
+ * should not be using any functions in this file. You should be protecting
+ * your data structures with full mutexes instead.
+ *
+ * ***Seriously, here be dragons!***
+ *
+ * You can find out a little more about lockless programming and the subtle
+ * issues that can arise here:
+ * https://learn.microsoft.com/en-us/windows/win32/dxtecharts/lockless-programming
+ *
+ * There's also lots of good information here:
+ *
+ * - https://www.1024cores.net/home/lock-free-algorithms
+ * - https://preshing.com/
+ *
+ * These operations may or may not actually be implemented using processor
+ * specific atomic operations. When possible they are implemented as true
+ * processor specific atomic operations. When that is not possible the are
+ * implemented using locks that *do* use the available atomic operations.
+ *
+ * All of the atomic operations that modify memory are full memory barriers.
+ */
+
+#ifndef SDL_atomic_h_
+#define SDL_atomic_h_
+
+#include <SDL3/SDL_stdinc.h>
+#include <SDL3/SDL_platform_defines.h>
+
+#include <SDL3/SDL_begin_code.h>
+
+/* Set up for C function definitions, even when using C++ */
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * An atomic spinlock.
+ *
+ * The atomic locks are efficient spinlocks using CPU instructions, but are
+ * vulnerable to starvation and can spin forever if a thread holding a lock
+ * has been terminated. For this reason you should minimize the code executed
+ * inside an atomic lock and never do expensive things like API or system
+ * calls while holding them.
+ *
+ * They are also vulnerable to starvation if the thread holding the lock is
+ * lower priority than other threads and doesn't get scheduled. In general you
+ * should use mutexes instead, since they have better performance and
+ * contention behavior.
+ *
+ * The atomic locks are not safe to lock recursively.
+ *
+ * Porting Note: The spin lock functions and type are required and can not be
+ * emulated because they are used in the atomic emulation code.
+ */
+typedef int SDL_SpinLock;
+
+/**
+ * Try to lock a spin lock by setting it to a non-zero value.
+ *
+ * ***Please note that spinlocks are dangerous if you don't know what you're
+ * doing. Please be careful using any sort of spinlock!***
+ *
+ * \param lock a pointer to a lock variable.
+ * \returns true if the lock succeeded, false if the lock is already held.
+ *
+ * \threadsafety It is safe to call this function from any thread.
+ *
+ * \since This function is available since SDL 3.2.0.
+ *
+ * \sa SDL_LockSpinlock
+ * \sa SDL_UnlockSpinlock
+ */
+extern SDL_DECLSPEC bool SDLCALL SDL_TryLockSpinlock(SDL_SpinLock *lock);
+
+/**
+ * Lock a spin lock by setting it to a non-zero value.
+ *
+ * ***Please note that spinlocks are dangerous if you don't know what you're
+ * doing. Please be careful using any sort of spinlock!***
+ *
+ * \param lock a pointer to a lock variable.
+ *
+ * \threadsafety It is safe to call this function from any thread.
+ *
+ * \since This function is available since SDL 3.2.0.
+ *
+ * \sa SDL_TryLockSpinlock
+ * \sa SDL_UnlockSpinlock
+ */
+extern SDL_DECLSPEC void SDLCALL SDL_LockSpinlock(SDL_SpinLock *lock);
+
+/**
+ * Unlock a spin lock by setting it to 0.
+ *
+ * Always returns immediately.
+ *
+ * ***Please note that spinlocks are dangerous if you don't know what you're
+ * doing. Please be careful using any sort of spinlock!***
+ *
+ * \param lock a pointer to a lock variable.
+ *
+ * \threadsafety It is safe to call this function from any thread.
+ *
+ * \since This function is available since SDL 3.2.0.
+ *
+ * \sa SDL_LockSpinlock
+ * \sa SDL_TryLockSpinlock
+ */
+extern SDL_DECLSPEC void SDLCALL SDL_UnlockSpinlock(SDL_SpinLock *lock);
+
+
+#ifdef SDL_WIKI_DOCUMENTATION_SECTION
+
+/**
+ * Mark a compiler barrier.
+ *
+ * A compiler barrier prevents the compiler from reordering reads and writes
+ * to globally visible variables across the call.
+ *
+ * This macro only prevents the compiler from reordering reads and writes, it
+ * does not prevent the CPU from reordering reads and writes. However, all of
+ * the atomic operations that modify memory are full memory barriers.
+ *
+ * \threadsafety Obviously this macro is safe to use from any thread at any
+ *               time, but if you find yourself needing this, you are probably
+ *               dealing with some very sensitive code; be careful!
+ *
+ * \since This macro is available since SDL 3.2.0.
+ */
+#define SDL_CompilerBarrier() DoCompilerSpecificReadWriteBarrier()
+
+#elif defined(_MSC_VER) && (_MSC_VER > 1200) && !defined(__clang__)
+void _ReadWriteBarrier(void);
+#pragma intrinsic(_ReadWriteBarrier)
+#define SDL_CompilerBarrier()   _ReadWriteBarrier()
+#elif (defined(__GNUC__) && !defined(SDL_PLATFORM_EMSCRIPTEN)) || (defined(__SUNPRO_C) && (__SUNPRO_C >= 0x5120))
+/* This is correct for all CPUs when using GCC or Solaris Studio 12.1+. */
+#define SDL_CompilerBarrier()   __asm__ __volatile__ ("" : : : "memory")
+#elif defined(__WATCOMC__)
+extern __inline void SDL_CompilerBarrier(void);
+#pragma aux SDL_CompilerBarrier = "" parm [] modify exact [];
+#else
+#define SDL_CompilerBarrier()   \
+{ SDL_SpinLock _tmp = 0; SDL_LockSpinlock(&_tmp); SDL_UnlockSpinlock(&_tmp); }
+#endif
+
+/**
+ * Insert a memory release barrier (function version).
+ *
+ * Please refer to SDL_MemoryBarrierRelease for details. This is a function
+ * version, which might be useful if you need to use this functionality from a
+ * scripting language, etc. Also, some of the macro versions call this
+ * function behind the scenes, where more heavy lifting can happen inside of
+ * SDL. Generally, though, an app written in C/C++/etc should use the macro
+ * version, as it will be more efficient.
+ *
+ * \threadsafety Obviously this function is safe to use from any thread at any
+ *               time, but if you find yourself needing this, you are probably
+ *               dealing with some very sensitive code; be careful!
+ *
+ * \since This function is available since SDL 3.2.0.
+ *
+ * \sa SDL_MemoryBarrierRelease
+ */
+extern SDL_DECLSPEC void SDLCALL SDL_MemoryBarrierReleaseFunction(void);
+
+/**
+ * Insert a memory acquire barrier (function version).
+ *
+ * Please refer to SDL_MemoryBarrierRelease for details. This is a function
+ * version, which might be useful if you need to use this functionality from a
+ * scripting language, etc. Also, some of the macro versions call this
+ * function behind the scenes, where more heavy lifting can happen inside of
+ * SDL. Generally, though, an app written in C/C++/etc should use the macro
+ * version, as it will be more efficient.
+ *
+ * \threadsafety Obviously this function is safe to use from any thread at any
+ *               time, but if you find yourself needing this, you are probably
+ *               dealing with some very sensitive code; be careful!
+ *
+ * \since This function is available since SDL 3.2.0.
+ *
+ * \sa SDL_MemoryBarrierAcquire
+ */
+extern SDL_DECLSPEC void SDLCALL SDL_MemoryBarrierAcquireFunction(void);
+
+
+#ifdef SDL_WIKI_DOCUMENTATION_SECTION
+
+/**
+ * Insert a memory release barrier (macro version).
+ *
+ * Memory barriers are designed to prevent reads and writes from being
+ * reordered by the compiler and being seen out of order on multi-core CPUs.
+ *
+ * A typical pattern would be for thread A to write some data and a flag, and
+ * for thread B to read the flag and get the data. In this case you would
+ * insert a release barrier between writing the data and the flag,
+ * guaranteeing that the data write completes no later than the flag is
+ * written, and you would insert an acquire barrier between reading the flag
+ * and reading the data, to ensure that all the reads associated with the flag
+ * have completed.
+ *
+ * In this pattern you should always see a release barrier paired with an
+ * acquire barrier and you should gate the data reads/writes with a single
+ * flag variable.
+ *
+ * For more information on these semantics, take a look at the blog post:
+ * http://preshing.com/20120913/acquire-and-release-semantics
+ *
+ * This is the macro version of this functionality; if possible, SDL will use
+ * compiler intrinsics or inline assembly, but some platforms might need to
+ * call the function version of this, SDL_MemoryBarrierReleaseFunction to do
+ * the heavy lifting. Apps that can use the macro should favor it over the
+ * function.
+ *
+ * \threadsafety Obviously this macro is safe to use from any thread at any
+ *               time, but if you find yourself needing this, you are probably
+ *               dealing with some very sensitive code; be careful!
+ *
+ * \since This macro is available since SDL 3.2.0.
+ *
+ * \sa SDL_MemoryBarrierAcquire
+ * \sa SDL_MemoryBarrierReleaseFunction
+ */
+#define SDL_MemoryBarrierRelease() SDL_MemoryBarrierReleaseFunction()
+
+/**
+ * Insert a memory acquire barrier (macro version).
+ *
+ * Please see SDL_MemoryBarrierRelease for the details on what memory barriers
+ * are and when to use them.
+ *
+ * This is the macro version of this functionality; if possible, SDL will use
+ * compiler intrinsics or inline assembly, but some platforms might need to
+ * call the function version of this, SDL_MemoryBarrierAcquireFunction, to do
+ * the heavy lifting. Apps that can use the macro should favor it over the
+ * function.
+ *
+ * \threadsafety Obviously this macro is safe to use from any thread at any
+ *               time, but if you find yourself needing this, you are probably
+ *               dealing with some very sensitive code; be careful!
+ *
+ * \since This macro is available since SDL 3.2.0.
+ *
+ * \sa SDL_MemoryBarrierRelease
+ * \sa SDL_MemoryBarrierAcquireFunction
+ */
+#define SDL_MemoryBarrierAcquire() SDL_MemoryBarrierAcquireFunction()
+
+#elif defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))
+#define SDL_MemoryBarrierRelease()   __asm__ __volatile__ ("lwsync" : : : "memory")
+#define SDL_MemoryBarrierAcquire()   __asm__ __volatile__ ("lwsync" : : : "memory")
+#elif defined(__GNUC__) && defined(__aarch64__)
+#define SDL_MemoryBarrierRelease()   __asm__ __volatile__ ("dmb ish" : : : "memory")
+#define SDL_MemoryBarrierAcquire()   __asm__ __volatile__ ("dmb ish" : : : "memory")
+#elif defined(__GNUC__) && defined(__arm__)
+#if 0 /* defined(SDL_PLATFORM_LINUX) || defined(SDL_PLATFORM_ANDROID) */
+/* Information from:
+   https://chromium.googlesource.com/chromium/chromium/+/trunk/base/atomicops_internals_arm_gcc.h#19
+
+   The Linux kernel provides a helper function which provides the right code for a memory barrier,
+   hard-coded at address 0xffff0fa0
+*/
+typedef void (*SDL_KernelMemoryBarrierFunc)();
+#define SDL_MemoryBarrierRelease()  ((SDL_KernelMemoryBarrierFunc)0xffff0fa0)()
+#define SDL_MemoryBarrierAcquire()  ((SDL_KernelMemoryBarrierFunc)0xffff0fa0)()
+#else
+#if defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7EM__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) || defined(__ARM_ARCH_8A__)
+#define SDL_MemoryBarrierRelease()   __asm__ __volatile__ ("dmb ish" : : : "memory")
+#define SDL_MemoryBarrierAcquire()   __asm__ __volatile__ ("dmb ish" : : : "memory")
+#elif defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6T2__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__)
+#ifdef __thumb__
+/* The mcr instruction isn't available in thumb mode, use real functions */
+#define SDL_MEMORY_BARRIER_USES_FUNCTION
+#define SDL_MemoryBarrierRelease()   SDL_MemoryBarrierReleaseFunction()
+#define SDL_MemoryBarrierAcquire()   SDL_MemoryBarrierAcquireFunction()
+#else
+#define SDL_MemoryBarrierRelease()   __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 5" : : "r"(0) : "memory")
+#define SDL_MemoryBarrierAcquire()   __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 5" : : "r"(0) : "memory")
+#endif /* __thumb__ */
+#else
+#define SDL_MemoryBarrierRelease()   __asm__ __volatile__ ("" : : : "memory")
+#define SDL_MemoryBarrierAcquire()   __asm__ __volatile__ ("" : : : "memory")
+#endif /* SDL_PLATFORM_LINUX || SDL_PLATFORM_ANDROID */
+#endif /* __GNUC__ && __arm__ */
+#else
+#if (defined(__SUNPRO_C) && (__SUNPRO_C >= 0x5120))
+/* This is correct for all CPUs on Solaris when using Solaris Studio 12.1+. */
+#include <mbarrier.h>
+#define SDL_MemoryBarrierRelease()  __machine_rel_barrier()
+#define SDL_MemoryBarrierAcquire()  __machine_acq_barrier()
+#else
+/* This is correct for the x86 and x64 CPUs, and we'll expand this over time. */
+#define SDL_MemoryBarrierRelease()  SDL_CompilerBarrier()
+#define SDL_MemoryBarrierAcquire()  SDL_CompilerBarrier()
+#endif
+#endif
+
+/* "REP NOP" is PAUSE, coded for tools that don't know it by that name. */
+#ifdef SDL_WIKI_DOCUMENTATION_SECTION
+
+/**
+ * A macro to insert a CPU-specific "pause" instruction into the program.
+ *
+ * This can be useful in busy-wait loops, as it serves as a hint to the CPU as
+ * to the program's intent; some CPUs can use this to do more efficient
+ * processing. On some platforms, this doesn't do anything, so using this
+ * macro might just be a harmless no-op.
+ *
+ * Note that if you are busy-waiting, there are often more-efficient
+ * approaches with other synchronization primitives: mutexes, semaphores,
+ * condition variables, etc.
+ *
+ * \threadsafety This macro is safe to use from any thread.
+ *
+ * \since This macro is available since SDL 3.2.0.
+ */
+#define SDL_CPUPauseInstruction() DoACPUPauseInACompilerAndArchitectureSpecificWay
+
+#elif (defined(__GNUC__) || defined(__clang__)) && (defined(__i386__) || defined(__x86_64__))
+    #define SDL_CPUPauseInstruction() __asm__ __volatile__("pause\n")  /* Some assemblers can't do REP NOP, so go with PAUSE. */
+#elif (defined(__arm__) && defined(__ARM_ARCH) && __ARM_ARCH >= 7) || defined(__aarch64__)
+    #define SDL_CPUPauseInstruction() __asm__ __volatile__("yield" ::: "memory")
+#elif (defined(__powerpc__) || defined(__powerpc64__))
+    #define SDL_CPUPauseInstruction() __asm__ __volatile__("or 27,27,27");
+#elif (defined(__riscv) && __riscv_xlen == 64)
+    #define SDL_CPUPauseInstruction() __asm__ __volatile__(".insn i 0x0F, 0, x0, x0, 0x010");
+#elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))
+    #define SDL_CPUPauseInstruction() _mm_pause()  /* this is actually "rep nop" and not a SIMD instruction. No inline asm in MSVC x86-64! */
+#elif defined(_MSC_VER) && (defined(_M_ARM) || defined(_M_ARM64))
+    #define SDL_CPUPauseInstruction() __yield()
+#elif defined(__WATCOMC__) && defined(__386__)
+    extern __inline void SDL_CPUPauseInstruction(void);
+    #pragma aux SDL_CPUPauseInstruction = ".686p" ".xmm2" "pause"
+#else
+    #define SDL_CPUPauseInstruction()
+#endif
+
+
+/**
+ * A type representing an atomic integer value.
+ *
+ * This can be used to manage a value that is synchronized across multiple
+ * CPUs without a race condition; when an app sets a value with
+ * SDL_SetAtomicInt all other threads, regardless of the CPU it is running on,
+ * will see that value when retrieved with SDL_GetAtomicInt, regardless of CPU
+ * caches, etc.
+ *
+ * This is also useful for atomic compare-and-swap operations: a thread can
+ * change the value as long as its current value matches expectations. When
+ * done in a loop, one can guarantee data consistency across threads without a
+ * lock (but the usual warnings apply: if you don't know what you're doing, or
+ * you don't do it carefully, you can confidently cause any number of
+ * disasters with this, so in most cases, you _should_ use a mutex instead of
+ * this!).
+ *
+ * This is a struct so people don't accidentally use numeric operations on it
+ * directly. You have to use SDL atomic functions.
+ *
+ * \since This struct is available since SDL 3.2.0.
+ *
+ * \sa SDL_CompareAndSwapAtomicInt
+ * \sa SDL_GetAtomicInt
+ * \sa SDL_SetAtomicInt
+ * \sa SDL_AddAtomicInt
+ */
+typedef struct SDL_AtomicInt { int value; } SDL_AtomicInt;
+
+/**
+ * Set an atomic variable to a new value if it is currently an old value.
+ *
+ * ***Note: If you don't know what this function is for, you shouldn't use
+ * it!***
+ *
+ * \param a a pointer to an SDL_AtomicInt variable to be modified.
+ * \param oldval the old value.
+ * \param newval the new value.
+ * \returns true if the atomic variable was set, false otherwise.
+ *
+ * \threadsafety It is safe to call this function from any thread.
+ *
+ * \since This function is available since SDL 3.2.0.
+ *
+ * \sa SDL_GetAtomicInt
+ * \sa SDL_SetAtomicInt
+ */
+extern SDL_DECLSPEC bool SDLCALL SDL_CompareAndSwapAtomicInt(SDL_AtomicInt *a, int oldval, int newval);
+
+/**
+ * Set an atomic variable to a value.
+ *
+ * This function also acts as a full memory barrier.
+ *
+ * ***Note: If you don't know what this function is for, you shouldn't use
+ * it!***
+ *
+ * \param a a pointer to an SDL_AtomicInt variable to be modified.
+ * \param v the desired value.
+ * \returns the previous value of the atomic variable.
+ *
+ * \threadsafety It is safe to call this function from any thread.
+ *
+ * \since This function is available since SDL 3.2.0.
+ *
+ * \sa SDL_GetAtomicInt
+ */
+extern SDL_DECLSPEC int SDLCALL SDL_SetAtomicInt(SDL_AtomicInt *a, int v);
+
+/**
+ * Get the value of an atomic variable.
+ *
+ * ***Note: If you don't know what this function is for, you shouldn't use
+ * it!***
+ *
+ * \param a a pointer to an SDL_AtomicInt variable.
+ * \returns the current value of an atomic variable.
+ *
+ * \threadsafety It is safe to call this function from any thread.
+ *
+ * \since This function is available since SDL 3.2.0.
+ *
+ * \sa SDL_SetAtomicInt
+ */
+extern SDL_DECLSPEC int SDLCALL SDL_GetAtomicInt(SDL_AtomicInt *a);
+
+/**
+ * Add to an atomic variable.
+ *
+ * This function also acts as a full memory barrier.
+ *
+ * ***Note: If you don't know what this function is for, you shouldn't use
+ * it!***
+ *
+ * \param a a pointer to an SDL_AtomicInt variable to be modified.
+ * \param v the desired value to add.
+ * \returns the previous value of the atomic variable.
+ *
+ * \threadsafety It is safe to call this function from any thread.
+ *
+ * \since This function is available since SDL 3.2.0.
+ *
+ * \sa SDL_AtomicDecRef
+ * \sa SDL_AtomicIncRef
+ */
+extern SDL_DECLSPEC int SDLCALL SDL_AddAtomicInt(SDL_AtomicInt *a, int v);
+
+#ifndef SDL_AtomicIncRef
+
+/**
+ * Increment an atomic variable used as a reference count.
+ *
+ * ***Note: If you don't know what this macro is for, you shouldn't use it!***
+ *
+ * \param a a pointer to an SDL_AtomicInt to increment.
+ * \returns the previous value of the atomic variable.
+ *
+ * \threadsafety It is safe to call this macro from any thread.
+ *
+ * \since This macro is available since SDL 3.2.0.
+ *
+ * \sa SDL_AtomicDecRef
+ */
+#define SDL_AtomicIncRef(a)    SDL_AddAtomicInt(a, 1)
+#endif
+
+#ifndef SDL_AtomicDecRef
+
+/**
+ * Decrement an atomic variable used as a reference count.
+ *
+ * ***Note: If you don't know what this macro is for, you shouldn't use it!***
+ *
+ * \param a a pointer to an SDL_AtomicInt to decrement.
+ * \returns true if the variable reached zero after decrementing, false
+ *          otherwise.
+ *
+ * \threadsafety It is safe to call this macro from any thread.
+ *
+ * \since This macro is available since SDL 3.2.0.
+ *
+ * \sa SDL_AtomicIncRef
+ */
+#define SDL_AtomicDecRef(a)    (SDL_AddAtomicInt(a, -1) == 1)
+#endif
+
+/**
+ * A type representing an atomic unsigned 32-bit value.
+ *
+ * This can be used to manage a value that is synchronized across multiple
+ * CPUs without a race condition; when an app sets a value with
+ * SDL_SetAtomicU32 all other threads, regardless of the CPU it is running on,
+ * will see that value when retrieved with SDL_GetAtomicU32, regardless of CPU
+ * caches, etc.
+ *
+ * This is also useful for atomic compare-and-swap operations: a thread can
+ * change the value as long as its current value matches expectations. When
+ * done in a loop, one can guarantee data consistency across threads without a
+ * lock (but the usual warnings apply: if you don't know what you're doing, or
+ * you don't do it carefully, you can confidently cause any number of
+ * disasters with this, so in most cases, you _should_ use a mutex instead of
+ * this!).
+ *
+ * This is a struct so people don't accidentally use numeric operations on it
+ * directly. You have to use SDL atomic functions.
+ *
+ * \since This struct is available since SDL 3.2.0.
+ *
+ * \sa SDL_CompareAndSwapAtomicU32
+ * \sa SDL_GetAtomicU32
+ * \sa SDL_SetAtomicU32
+ */
+typedef struct SDL_AtomicU32 { Uint32 value; } SDL_AtomicU32;
+
+/**
+ * Set an atomic variable to a new value if it is currently an old value.
+ *
+ * ***Note: If you don't know what this function is for, you shouldn't use
+ * it!***
+ *
+ * \param a a pointer to an SDL_AtomicU32 variable to be modified.
+ * \param oldval the old value.
+ * \param newval the new value.
+ * \returns true if the atomic variable was set, false otherwise.
+ *
+ * \threadsafety It is safe to call this function from any thread.
+ *
+ * \since This function is available since SDL 3.2.0.
+ *
+ * \sa SDL_GetAtomicU32
+ * \sa SDL_SetAtomicU32
+ */
+extern SDL_DECLSPEC bool SDLCALL SDL_CompareAndSwapAtomicU32(SDL_AtomicU32 *a, Uint32 oldval, Uint32 newval);
+
+/**
+ * Set an atomic variable to a value.
+ *
+ * This function also acts as a full memory barrier.
+ *
+ * ***Note: If you don't know what this function is for, you shouldn't use
+ * it!***
+ *
+ * \param a a pointer to an SDL_AtomicU32 variable to be modified.
+ * \param v the desired value.
+ * \returns the previous value of the atomic variable.
+ *
+ * \threadsafety It is safe to call this function from any thread.
+ *
+ * \since This function is available since SDL 3.2.0.
+ *
+ * \sa SDL_GetAtomicU32
+ */
+extern SDL_DECLSPEC Uint32 SDLCALL SDL_SetAtomicU32(SDL_AtomicU32 *a, Uint32 v);
+
+/**
+ * Get the value of an atomic variable.
+ *
+ * ***Note: If you don't know what this function is for, you shouldn't use
+ * it!***
+ *
+ * \param a a pointer to an SDL_AtomicU32 variable.
+ * \returns the current value of an atomic variable.
+ *
+ * \threadsafety It is safe to call this function from any thread.
+ *
+ * \since This function is available since SDL 3.2.0.
+ *
+ * \sa SDL_SetAtomicU32
+ */
+extern SDL_DECLSPEC Uint32 SDLCALL SDL_GetAtomicU32(SDL_AtomicU32 *a);
+
+/**
+ * Add to an atomic variable.
+ *
+ * This function also acts as a full memory barrier.
+ *
+ * ***Note: If you don't know what this function is for, you shouldn't use
+ * it!***
+ *
+ * \param a a pointer to an SDL_AtomicU32 variable to be modified.
+ * \param v the desired value to add or subtract.
+ * \returns the previous value of the atomic variable.
+ *
+ * \threadsafety It is safe to call this function from any thread.
+ *
+ * \since This function is available since SDL 3.4.0.
+ */
+extern SDL_DECLSPEC Uint32 SDLCALL SDL_AddAtomicU32(SDL_AtomicU32 *a, int v);
+
+/**
+ * Set a pointer to a new value if it is currently an old value.
+ *
+ * ***Note: If you don't know what this function is for, you shouldn't use
+ * it!***
+ *
+ * \param a a pointer to a pointer.
+ * \param oldval the old pointer value.
+ * \param newval the new pointer value.
+ * \returns true if the pointer was set, false otherwise.
+ *
+ * \threadsafety It is safe to call this function from any thread.
+ *
+ * \since This function is available since SDL 3.2.0.
+ *
+ * \sa SDL_CompareAndSwapAtomicInt
+ * \sa SDL_GetAtomicPointer
+ * \sa SDL_SetAtomicPointer
+ */
+extern SDL_DECLSPEC bool SDLCALL SDL_CompareAndSwapAtomicPointer(void **a, void *oldval, void *newval);
+
+/**
+ * Set a pointer to a value atomically.
+ *
+ * ***Note: If you don't know what this function is for, you shouldn't use
+ * it!***
+ *
+ * \param a a pointer to a pointer.
+ * \param v the desired pointer value.
+ * \returns the previous value of the pointer.
+ *
+ * \threadsafety It is safe to call this function from any thread.
+ *
+ * \since This function is available since SDL 3.2.0.
+ *
+ * \sa SDL_CompareAndSwapAtomicPointer
+ * \sa SDL_GetAtomicPointer
+ */
+extern SDL_DECLSPEC void * SDLCALL SDL_SetAtomicPointer(void **a, void *v);
+
+/**
+ * Get the value of a pointer atomically.
+ *
+ * ***Note: If you don't know what this function is for, you shouldn't use
+ * it!***
+ *
+ * \param a a pointer to a pointer.
+ * \returns the current value of a pointer.
+ *
+ * \threadsafety It is safe to call this function from any thread.
+ *
+ * \since This function is available since SDL 3.2.0.
+ *
+ * \sa SDL_CompareAndSwapAtomicPointer
+ * \sa SDL_SetAtomicPointer
+ */
+extern SDL_DECLSPEC void * SDLCALL SDL_GetAtomicPointer(void **a);
+
+/* Ends C function definitions when using C++ */
+#ifdef __cplusplus
+}
+#endif
+
+#include <SDL3/SDL_close_code.h>
+
+#endif /* SDL_atomic_h_ */