qmk_firmware/platforms/synchronization_util.h

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// Copyright 2022 Stefan Kerkmann
// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once
#if defined(PLATFORM_SUPPORTS_SYNCHRONIZATION)
# if defined(SPLIT_KEYBOARD)
void split_shared_memory_lock(void);
void split_shared_memory_unlock(void);
# endif
#else
# if defined(SPLIT_KEYBOARD)
inline void split_shared_memory_lock(void){};
inline void split_shared_memory_unlock(void){};
# endif
#endif
/* GCCs cleanup attribute expects a function with one parameter, which is a
* pointer to a type compatible with the variable. As we don't want to expose
* the platforms internal mutex type this workaround with auto generated adapter
* function is defined */
#define QMK_DECLARE_AUTOUNLOCK_HELPERS(prefix) \
inline unsigned prefix##_autounlock_lock_helper(void) { \
prefix##_lock(); \
return 0; \
} \
\
inline void prefix##_autounlock_unlock_helper(unsigned* unused_guard) { \
prefix##_unlock(); \
}
/* Generate an out-of-line implementation in case the inline functions defined
* by the above macro don't actually get inlined. */
#define QMK_IMPLEMENT_AUTOUNLOCK_HELPERS(prefix) \
extern inline unsigned prefix##_autounlock_lock_helper(void); \
extern inline void prefix##_autounlock_unlock_helper(unsigned* unused_guard);
/* Convinience macro the automatically generate the correct RAII-style
* lock_autounlock function macro */
#define QMK_DECLARE_AUTOUNLOCK_CALL(prefix) unsigned prefix##_guard __attribute__((unused, cleanup(prefix##_autounlock_unlock_helper))) = prefix##_autounlock_lock_helper
#if defined(SPLIT_KEYBOARD)
QMK_DECLARE_AUTOUNLOCK_HELPERS(split_shared_memory)
/**
* @brief Acquire exclusive access to the split keyboard shared memory, by
* calling the platforms `split_shared_memory_lock()` function. The lock is
* automatically released by calling the platforms `split_shared_memory_unlock()`
* function. This happens when the block where
* `split_shared_memory_lock_autounlock()` is called in goes out of scope i.e.
* when the enclosing function returns.
*/
# define split_shared_memory_lock_autounlock QMK_DECLARE_AUTOUNLOCK_CALL(split_shared_memory)
#endif