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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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 */
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#include <key_buffer.h>
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#include <key_buffer.h>
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#include <futex.h>
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atomic_t keybuffer_futex = FUTEX_INITIALIZER;
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/** Clear key buffer.
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/** Clear key buffer.
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 */
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 */
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void keybuffer_free(keybuffer_t *keybuffer)
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void keybuffer_free(keybuffer_t *keybuffer)
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{
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{
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    futex_down(&keybuffer_futex);
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    keybuffer->head = 0;
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    keybuffer->tail = 0;
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    keybuffer->items = 0;
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    keybuffer->items = 0;
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    keybuffer->head = keybuffer->tail = keybuffer->items = 0;
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    futex_up(&keybuffer_futex);
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}
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}
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/** Key buffer initialization.
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/** Key buffer initialization.
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 *
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 *
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 */
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 */
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 * If buffer is full, character is ignored.
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 * If buffer is full, character is ignored.
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 * @param key code of stored key
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 * @param key code of stored key
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 */
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 */
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void keybuffer_push(keybuffer_t *keybuffer, char key)
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void keybuffer_push(keybuffer_t *keybuffer, char key)
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{
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{
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    futex_down(&keybuffer_futex);
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    if (keybuffer->items < KEYBUFFER_SIZE) {
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    if (keybuffer->items < KEYBUFFER_SIZE) {
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        keybuffer->fifo[keybuffer->tail] = key;
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        keybuffer->fifo[keybuffer->tail = (keybuffer->tail + 1) < keybuffer->items ? (keybuffer->tail + 1) : 0] = (key);
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        keybuffer->tail = (keybuffer->tail + 1) % KEYBUFFER_SIZE;
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        keybuffer->items++;
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        keybuffer->items++;
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    }
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    }
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    futex_up(&keybuffer_futex);
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}
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}
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/** Pop character from buffer.
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/** Pop character from buffer.
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 * @param c pointer to space where to store character from buffer.
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 * @param c pointer to space where to store character from buffer.
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 * @return zero on empty buffer, nonzero else
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 * @return zero on empty buffer, nonzero else
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 */
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 */
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int keybuffer_pop(keybuffer_t *keybuffer, char *c)
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int keybuffer_pop(keybuffer_t *keybuffer, char *c)
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{
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{
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    futex_down(&keybuffer_futex);
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    if (keybuffer->items > 0) {
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    if (keybuffer->items > 0) {
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        keybuffer->items--;
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        keybuffer->items--;
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        *c = keybuffer->fifo[keybuffer->head];
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        *c = keybuffer->fifo[keybuffer->head = (keybuffer->head + 1) < keybuffer->items ? (keybuffer->head + 1) : 0];
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        keybuffer->head = (keybuffer->head + 1) % KEYBUFFER_SIZE;
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        futex_up(&keybuffer_futex);
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        return 1;
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        return 1;
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    }
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    }
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    futex_up(&keybuffer_futex);
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    return 0;
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    return 0;
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}
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}
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