import jpos.JposConst;
import jpos.JposException;
import org.apache.log4j.Logger;
-import de.javapos.example.ThreadSafe;
import de.javapos.example.queue.JposEventListener;
/**
* @author
*
*/
-public class KeyBoardDeviceLinux implements BaseKeyBoardDriver {
+public class KeyBoardDeviceLinux implements BaseKeyBoardDriver, Runnable {
private static final Logger logger = Logger.getLogger(KeyBoardDeviceLinux.class);
//value EV_KEY from include/linux/input.h
private static final int EV_KEY = 1;
}
/**
- * Not thread-safe.
- * This method just works in the following cases:
- * 1. Several processes trying to claim the device. Just one will own the device and the another
- * receive a nice exception.
- * 2. Several threads in the same Java process trying to claim the device. If the class loader is the same for
- * both threads for sure one will lock and the another one receive an OverlappingFileLockException.
- * This method probably is not going to work in this case:
- * 1. Several threads in the same Java process with different class loaders. The java.nio classes must be in the
- * same class loader, otherwise (I have not tested it) the threads are not going to realize the file was previously locked
- * because the FileLock implementation is using static fields in order to find out if the file was locked before.
- * See: SharedFileLockTable in FileChannelImpl where the static classes are being used. By the way, since Java 5.0
- * it is system-wide but in 1.4 it was not. The doubt is with different class loaders for each thread... Is this "system-wide"
- * implementation going to work? I do not think so.
- * Just one more thing: sun.nio.ch.disableSystemWideOverlappingFileLockCheck system property must be false or
- * it must not exist. see: FileChannelImpl.isSharedFileLockTable
+ * Not thread-safe.!!!!!
*/
@Override
public void claim(int time) throws JposException {
if (time == -1) {
try {
+ //This method is not aware interrupt. :(
lock = this.fileChannelLock.lock();
//I do not like catching RunTimeExceptions but I have no choice...
} catch (OverlappingFileLockException e) {
- //¿esta cosa se entera si hay otra instancia de esta clase manejada desde otro thread?
- //otro open del mismo archivo devuelve un file descriptor distinto. ¿Cómo Java se enteraría
- //de que otro hilo que creó otra instancia de esta clase KeyBoardDeviceLinux está intentando bloquear
- //el mismo archivo?
- //WOW Java sí se entera si creo dos instancias de esta clase desde varios hilos y ambos
- //intentan bloquear el mismo archivo incluso aunque los file descriptor sean distintos.
- //Usa un objecto llamado FileKey.java que contiene entre otras cosas 2 campos: st_dev y st_ino
- //esos campos los consigue con FileKey.init que llama a fstat64!!!! WOWOWOWOWOW
- //así incluso si tenemos 2 instancias del objecto KeyBoardDeviceLinux usadas por 2 hilos distintos podemos
- //saber si el hilo fue bloqueado ya.
- //CON ESTA IMPLEMENTACION SOLO SALTARIA OverlappingFileLockException SI OTRO HILO CREA UNA NUEVA
- //INSTANCIA DE ESTA CLASE E INTENTA HACER UN claim. CON HILOS USANDO LA MISMA INSTANCIA DE LA CLASE
- //DEBERIAN VER LA PROPIEDAD isClaimed A TRUE Y POR TANTO NUNCA LLEGARIAN AQUI.
- throw new JposException(JposConst.JPOS_E_CLAIMED, "Some thread from this process already claimed this device.",e);
+ logger.warn("Concurrent access in claim method not supported without synchronization.", e);
} catch (IOException e) {
throw new JposException(JposConst.JPOS_E_CLAIMED, "Error while trying to claim device.",e);
}
}
//I do not like catching RunTimeExceptions but I have no choice...
} catch (OverlappingFileLockException e) {
- throw new JposException(JposConst.JPOS_E_CLAIMED, "Some thread from this process already claimed this device.",e);
+ logger.warn("Concurrent access in claim method not supported without synchronization.", e);
} catch (IOException e) {
throw new JposException(JposConst.JPOS_E_CLAIMED, "Error while trying to claim device.",e);
}
if (lock == null) {
throw new JposException(JposConst.JPOS_E_TIMEOUT, "Timeout while trying to claim device.", null);
}
- else {
- this.lock = lock;
- }
+ }
+
+ if (lock != null) {
+ //Just when concurrent access without synchronization (this method is not tread-safe) you could see
+ //null value. claim does not support concurrent access in itself anyway I take counter measures in case
+ //of someone forgets it.
+ this.lock = lock;
+ this.isClaimed = true;
}
}
+ /**
+ * Not thread-safe.!!!!!
+ */
@Override
public void release() throws JposException {
- this.isClaimed = false;
-
+ if (!this.isClaimed) {
+ return;
+ }
+
if (this.lock != null) {
try {
//SI LLAMO A ESTO PERO FALLO AL INTENTAR LOCK NO CIERRO NI LIBERO EL LOCK REALIZADO
//DESDE OTRO HILO :)
this.lock.release();
} catch (IOException e) {
- //NO PUEDO LLAMAR A ESTO AQUI PORQUE ME METO EN UN BUCLE INFERNAL
throw new JposException(JposConst.JPOSERR, "Error when releasing the keyboard file lock",e);
}
}
if (this.fileChannelLock != null) {
try {
- //NO HAY PROBLEMA EN LLAMAR A ESTO, CADA HILO CIERRA SU fd. CADA HILO TIENE
- //SU PROPIO file descriptor QUE ES LO QUE CIERRA :)
this.fileChannelLock.close();
this.fileChannelLock = null;
} catch (IOException e) {
- //NO PUEDO LLAMAR A ESTO AQUI PORQUE ME METO EN UN BUCLE INFERNAL
throw new JposException(JposConst.JPOSERR, "Error when closing the keyboard file lock", e);
}
}
+
+ this.isClaimed = false;
}
@Override
} catch (FileNotFoundException e) {
throw new JposException(JposConst.JPOS_E_NOHARDWARE, "Device not found.",e);
}
- this.thread = new Thread (new HardwareLoop(this.device, this.eventListener), "KeyBoardDeviceLinux-Thread");
+ this.thread = new Thread (this, "KeyBoardDeviceLinux-Thread");
this.thread.setUncaughtExceptionHandler(new DriverHWUncaughtExceptionHandler());
this.thread.start();
}
public void device(String device) {
this.deviceName = device;
}
-
-
- @ThreadSafe
- private class HardwareLoop implements Runnable {
- private final DataInputStream device;
- private final JposEventListener eventListener;
-
- private HardwareLoop (DataInputStream device, JposEventListener eventListener) {
- this.device = device;
- this.eventListener = eventListener;
- }
-
- @Override
- public void run() {
- //OS 64 bits
- byte []buffer = new byte[24];
- short code = 0;
- short type = 0;
- int value = 0;
- int ch1 = 0;
- int ch2 = 0;
- int ch3 = 0;
- int ch4 = 0;
+ @Override
+ public void run() {
+ //OS 64 bits
+ byte []buffer = new byte[24];
+ short code = 0;
+ short type = 0;
+ int value = 0;
+ int ch1 = 0;
+ int ch2 = 0;
+ int ch3 = 0;
+ int ch4 = 0;
+
+ try {
+ while (true) {
+ //using command: evtest /dev/input/event4
+ //It is not clear hear but I am using sun.nio.ch.FileChannelImpl.read(ByteBuffer ) method which throws
+ //exception (java.nio.channels.ClosedByInterruptException) when the thread is interrupted
+ //see: Thread.interrupt(), sun.nio.ch.FileChannelImpl.read(ByteBuffer) and
+ //java.nio.channels.spi.AbstractInterruptibleChannel.begin() methods
+ //Basically before getting in an I/O operation that might block indefinitely the begin method implements
+ //the Thread.blocker field. This field is used when running the method Thread.interrupt(). The blocker
+ //implementation closes the file descriptor, so the I/0 operation throws an IOException (closed file)
+ //In the finally block of the sun.nio.ch.FileChannelImpl.read(ByteBuffer) method we can find the
+ //java.nio.channels.spi.AbstractInterruptibleChannel.end(boolean) method which throws the java.nio.channels.ClosedByInterruptException
+ //We are losing the IOException (because the file was closed by the blocker implementation) but indeed
+ //the reality is that we are getting out of the I/O blocking operation because we interrupted the running thread.
+ this.device.readFully(buffer);
+
+ ch1 = buffer[19];
+ ch2 = buffer[18];
+ code = (short)((ch1 << 8) + (ch2 << 0));
+
+ ch1 = buffer[17];
+ ch2 = buffer[16];
+ type = (short)((ch1 << 8) + (ch2 << 0));
+
+
+ ch1 = buffer[23];
+ ch2 = buffer[22];;
+ ch3 = buffer[21];
+ ch4 = buffer[20];
+ value = ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + (ch4 << 0));
+
+ if (type == KeyBoardDeviceLinux.EV_KEY) {
+ this.eventListener.inputAvailable(code);
+ logger.debug("Captured key " + "type: " + type + " code: " + code + " value: " + value);
+
+ if (KeyBoardDeviceLinux.this.autoDisable) {
+ //CERRAR this.device.close(); NO SE COMO HACER ESTO CORRECTAMENTE :(
+ break;
+ }
+ }
+ }
+ } catch (EOFException e) {
+ logger.error("Something went really bad. Impossible end of file while reading keyboard device!!!!", e);
+ } catch (IOException e) {
+ //We reach this code because the thread was interrupted (disable) or because there was an I/O error
+ //logger.debug or logger.error if it was an error I am not going to log it... :/
+ logger.debug("Finished KeyBoardDeviceLinux Thread", e);
+ } finally {
try {
- while (true) {
- //using command: evtest /dev/input/event4
- //It is not clear hear but I am using sun.nio.ch.FileChannelImpl.read(ByteBuffer ) method which throws
- //exception (java.nio.channels.ClosedByInterruptException) when the thread is interrupted
- //see: Thread.interrupt(), sun.nio.ch.FileChannelImpl.read(ByteBuffer) and
- //java.nio.channels.spi.AbstractInterruptibleChannel.begin() methods
- //Basically before getting in an I/O operation that might block indefinitely the begin method implements
- //the Thread.blocker field. This field is used when running the method Thread.interrupt(). The blocker
- //implementation closes the file descriptor, so the I/0 operation throws an IOException (closed file)
- //In the finally block of the sun.nio.ch.FileChannelImpl.read(ByteBuffer) method we can find the
- //java.nio.channels.spi.AbstractInterruptibleChannel.end(boolean) method which throws the java.nio.channels.ClosedByInterruptException
- //We are losing the IOException (because the file was closed by the blocker implementation) but indeed
- //the reality is that we are getting out of the I/O blocking operation because we interrupted the running thread.
- this.device.readFully(buffer);
-
- ch1 = buffer[19];
- ch2 = buffer[18];
- code = (short)((ch1 << 8) + (ch2 << 0));
-
- ch1 = buffer[17];
- ch2 = buffer[16];
- type = (short)((ch1 << 8) + (ch2 << 0));
-
-
- ch1 = buffer[23];
- ch2 = buffer[22];;
- ch3 = buffer[21];
- ch4 = buffer[20];
- value = ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + (ch4 << 0));
-
- if (type == KeyBoardDeviceLinux.EV_KEY) {
- this.eventListener.inputAvailable(code);
- logger.debug("Captured key " + "type: " + type + " code: " + code + " value: " + value);
-
- if (KeyBoardDeviceLinux.this.autoDisable) {
- //CERRAR this.device.close(); NO SE COMO HACER ESTO CORRECTAMENTE :(
- break;
- }
- }
- }
- } catch (EOFException e) {
- logger.error("Something went really bad. Impossible end of file while reading keyboard device!!!!", e);
- } catch (IOException e) {
- //We reach this code because the thread was interrupted (disable) or because there was an I/O error
- //logger.debug or logger.error if it was an error I am not going to log it... :/
- logger.debug("Finished KeyBoardDeviceLinux Thread", e);
- } finally {
- try {
- this.device.close();
- //SI EL HILO MUERE ¿DEBERÍA DEJAR EL ESTADO DEL DISPOSITIVO LOGICO JAVAPOS
- //EN UN MODO CONSISTENTE?
- //liberar el LOCK SI EL HILO MUERE DE FORMA INESPERADA????
- //¿como moriria este hilo de forma inesperada?? por ejemplo por RunTimeException
- //¿Como hago saber a la aplicacion que este hilo murio de forma inesperada por RunTimeException y el teclado
- //ha dejado de funcionar... Si el teclado deja de funcionar no sería mejor parar toda la aplicacion y ver
- //que pasa...
- } catch (IOException e1) {
- logger.warn("Something went wrong while closing the channel",e1);
- }
+ this.device.close();
+ //SI EL HILO MUERE ¿DEBERÍA DEJAR EL ESTADO DEL DISPOSITIVO LOGICO JAVAPOS
+ //EN UN MODO CONSISTENTE?
+ //liberar el LOCK SI EL HILO MUERE DE FORMA INESPERADA????
+ //¿como moriria este hilo de forma inesperada?? por ejemplo por RunTimeException
+ //¿Como hago saber a la aplicacion que este hilo murio de forma inesperada por RunTimeException y el teclado
+ //ha dejado de funcionar... Si el teclado deja de funcionar no sería mejor parar toda la aplicacion y ver
+ //que pasa...
+ } catch (IOException e1) {
+ logger.warn("Something went wrong while closing the channel",e1);
}
}
}
projects / JavaForFun / commitdiff