typedef unsigned short int UINT16;
struct STRUCT {
  UINT16 uint16;
  int INT;
}
enum ENUM = { ... };

/* Shared Variables. */
struct STRUCT Shared_VariableA;
enum ENUM Shared_VariableB;

UINT16 GetVA () {
    pthread_mutex_lock( &_L_LOCK );
        UINT16 TMP = Shared_VariableA.uint16;
    pthread_mutex_lock( &_L_LOCK );
    return TMP;
}

void SetVA ( UINT16 in ) {
     pthread_mutex_lock( &_L_LOCK );
         Shared_VariableA.uint16 = in;
     pthread_mutex_lock( &_L_LOCK );
 }

/* Initialization. */
atomic_t uint16 = ATOMIC_INIT ( 0 );

UINT16 GetVA () {
         UINT16 TMP = atomic_read( &uint16 );  /* Force convert 'int' to UINT16 since atomic_read() returns an int (32 bits). */
        return TMP;
 }
 
 void SetVA ( UINT16 in ) {
       atomic_set( &uint16,in );
  }