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#ifndef MYON_LEVELDATA_H_INCLUDED
#define MYON_LEVELDATA_H_INCLUDED
#include <stdatomic.h>
struct leveldata {
atomic_flag flag;
unsigned level;
bool read;
};
static inline unsigned leveldata_read(struct leveldata *data) {
while (atomic_flag_test_and_set_explicit(&data->flag, memory_order_acquire));
unsigned level = data->level;
data->read = true;
atomic_flag_clear_explicit(&data->flag, memory_order_release);
return level;
}
static inline void leveldata_update(struct leveldata *data, unsigned level) {
while (atomic_flag_test_and_set_explicit(&data->flag, memory_order_acquire));
if (data->read || (level > data->level)) data->level = level;
data->read = false;
atomic_flag_clear_explicit(&data->flag, memory_order_release);
}
static inline void leveldata_init(struct leveldata *data) {
*data = (struct leveldata) {0};
atomic_flag_clear_explicit(&data->flag, memory_order_relaxed);
}
#endif // MYON_LEVELDATA_H_INCLUDED
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