InterProcessComm

All Known Implementing Classes:

InterProcessComm_SocketImpl, MsgRecvCommFile
```
public interface InterProcessComm
```
This interface is the applicable interface to realize a communication between processes at the same processor board or between processes via network using UDP/IP. In generally, realization of this class is hardware-depended. An implementation with socket communications (using java.net.Socket*) exists. But the user can realize its own solutions based on this interface, at example with using dual port RAM-communication at system level.

Hint for Java4C-usage: In C this interface is existing too, see CRuntimeJavalike/Include/Ipc/InterProcessComm.h. For Java2C-translating the CRuntimeJavalike/stc/Ipc.stc file describes this class. This class is not translated by iteself.

Field Summary

Fields
Modifier and Type	Field and Description
`static boolean`	`receiverShouldbeBlocking` Mode of receiving, determined on open().
`static boolean`	`receiverShouldbePolling` Mode of receiving, determined on open().
`static int`	`version` version, history and license: 2012-08-22 Hartmut chg The constants `receiverShouldbeBlocking` /Polling should be boolean because the parameter of open is boolean.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`int`	`abortReceive()` Abort receiving function
`int`	`capacityToSendWithoutBlocking(int nrofBytesToSend)` Tests wether a next send is done without blocking.
`int`	`checkConnection()` Checks the connection.
`int`	`close()` Closes the mailbox, only to be called on shutdown of the application.
`Address_InterProcessComm`	`createAddress()` Creates an empty instance for a address information, especially for the sender.
`Address_InterProcessComm`	`createAddress(int p1, int p2)`
`Address_InterProcessComm`	`createAddress(java.lang.String address)`
`Address_InterProcessComm`	`createAddress(java.lang.String p1, int p2)`
`int`	`dataAvailable()` Tests wether data are available to receive.
`boolean`	`equals(Address_InterProcessComm address1P, Address_InterProcessComm address2P)` Compare the address to another address, returns true if it is the same address.
`int`	`flush()` Flushs send data to destination.
`void`	`freeData(byte[] data)` Relinguishes the data buffer, after it is evaluated.
`java.lang.String`	`getName()`
`Address_InterProcessComm`	`getOwnAddress()` Gets the own address of this interProcessComm, it are the receive parameters.
`byte[]`	`getSendBuffer(int len)` Gets a buffer for send.
`int`	`open(Address_InterProcessComm dstAddress, boolean shouldBlock)` Opens the Communication.
`byte[]`	`receive(int[] result, Address_InterProcessComm sender)` Receives a Datagram.
`byte[]`	`receiveData(int[] nrofBytes, byte[] buffer, Address_InterProcessComm sender)`
`int`	`send(byte[] data, int nBytes, Address_InterProcessComm addressee)` Sends Data.
`java.lang.String`	`translateErrorMsg(int nError)`

- Field Detail
  - version
```
static final int version
```
    version, history and license:
    - 2012-08-22 Hartmut chg The constants receiverShouldbeBlocking /Polling should be boolean because the parameter of open is boolean. The might be never used ?
    - 2011-01-05 Hartmut created
    Copyright/Copyleft: For this source the LGPL Lesser General Public License, published by the Free Software Foundation is valid. It means:
    1. You can use this source without any restriction for any desired purpose.
    2. You can redistribute copies of this source to everybody.
    3. Every user of this source, also the user of redistribute copies with or without payment, must accept this license for further using.
    4. But the LPGL ist not appropriate for a whole software product, if this source is only a part of them. It means, the user must publish this part of source, but don't need to publish the whole source of the own product.
    5. You can study and modify (improve) this source for own using or for redistribution, but you have to license the modified sources likewise under this LGPL Lesser General Public License. You mustn't delete this Copyright/Copyleft inscription in this source file.
    If you are intent to use this sources without publishing its usage, you can get a second license subscribing a special contract with the author.
    See Also:
    
    Constant Field Values
  - receiverShouldbeBlocking
```
static final boolean receiverShouldbeBlocking
```
    Mode of receiving, determined on open(). The receive()-call either blocks if no data are available (it should be called in an extra thread), or it returns a nullpointer, if no data are available. This is a polling manner.
    
    See Also:
    
    Constant Field Values
  - receiverShouldbePolling
```
static final boolean receiverShouldbePolling
```
    Mode of receiving, determined on open(). The receive()-call either blocks if no data are available (it should be called in an extra thread), or it returns a nullpointer, if no data are available. This is a polling manner.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - open
```
int open(Address_InterProcessComm dstAddress,
         boolean shouldBlock)
```
    Opens the Communication. Only called at startup.
    
    Parameters:
    
    dstAddress - The own address to which this interprocess-port is assigned. This address is also used when calling send() as information about the sender of the data.
    
    mode - true if the receiver can block if receivdata are not available but the connection is established. false then a call of receive(int[], Address_InterProcessComm) or receiveData(int[], byte[], Address_InterProcessComm) does never block. Use the receiverShouldbeBlocking or receiverShouldbePolling values.
    
    Returns:
    
    true if success, false if it failed. Use getReceiveErrorMsg() to detect the cause manually.
  - close
```
int close()
```
    Closes the mailbox, only to be called on shutdown of the application.
  - send
```
int send(byte[] data,
         int nBytes,
         Address_InterProcessComm addressee)
```
    Sends Data. The destination adress is defined on open. If a listener is associated with this class, the data will be forwarded to the users evaluation method defined in the implementation of the listener. So a evaluation may be execute directly without consideration of the users software and without consideration of the realization in this class. If no listener is associated, the data will be sent in the kind of realization of this class.
    
    Parameters:
    
    data - The data to be sent. The user should not touch the buffer after calling here.
    
    nBytes - The number of bytes to be send.
    
    addressee - The addressee, the receiver of the message. If it is a fix connection (TCP), then this parameter should be null. It isn't used. The addressee is given on #open(Address_InterProcessComm, int)-request.
    
    Returns:
    
    number of Bytes sent, if >=0. If <0 its an error code.
  - receive
```
byte[] receive(int[] result,
               Address_InterProcessComm sender)
```
    Receives a Datagram. This method blocks until a Datagram is received. If a Datagram is received, the content of the Datagram will copied into the appropriated buffer.
    
    Parameters:
    
    data - out:
    
    sender - Buffer for the sender of the message.
    
    result - result[0] = Nr of Bytes sendet, if >=0. If <0 its an error code.
    
    Returns:
    
    The reference to the buffer containing data. On error, the content of this reference is not valid, but the user must call relinguishData() with this reference .
  - receiveData
```
byte[] receiveData(int[] nrofBytes,
                   byte[] buffer,
                   Address_InterProcessComm sender)
```
    Parameters:
    
    nrofBytes -
    
    buffer -
    
    sender -
    
    Returns:
  - freeData
```
void freeData(byte[] data)
```
    Relinguishes the data buffer, after it is evaluated.
    
    Parameters:
    
    data - The buffer delivered from receive!
  - checkConnection
```
int checkConnection()
```
    Checks the connection. This is the alternativ method for polling instead of the callback methods errorConnection() and readyConnection().
    
    Returns:
    
    value less 0: error code, the connection is not available. If the value is >=0, the connection is established.
  - capacityToSendWithoutBlocking
```
int capacityToSendWithoutBlocking(int nrofBytesToSend)
```
    Tests wether a next send is done without blocking. If the transfer medium supports this test and it has a limited capacity, the method is helpfull to use. If the medium doesnot support such quest, the nrofBytes is returned. It means, it has a capacity. send is possible but it is not guarented that the send doesnot block.
    
    Returns:
    
    nrofBytes of capacity to send without blocking, but not greater than argument nrofBytesToSend. 0 if the next send call will be blocked. negativ value if any error.
  - dataAvailable
```
int dataAvailable()
```
    Tests wether data are available to receive. This is the alternativ method for polling instead of the callback methods dataAvailable() from the callback interface. This method can return 0 also if data are receiveable, if the implementation donot support such quest.
    
    Returns:
    
    value less 0: error code, the connection is not available. If the value is >0, data are available. If 0, no data are available.
  - abortReceive
```
int abortReceive()
```
    Abort receiving function
  - getName
```
java.lang.String getName()
```
  - getOwnAddress
```
Address_InterProcessComm getOwnAddress()
```
    Gets the own address of this interProcessComm, it are the receive parameters. The knowledge of receive address may be necessary at user level if the information about a other receive adress should be communicate to the partner. In most cases the partner knows the sender adress (back-info-argument of receive) from the implementation level, but in some cases (2-simplex-Ports TCP/UDP) the receive adress is the address getted here.
  - createAddress
```
Address_InterProcessComm createAddress()
```
    Creates an empty instance for a address information, especially for the sender.
    
    Returns:
    
    An empty new instance apropriate to the kind of communication.
  - createAddress
```
Address_InterProcessComm createAddress(int p1,
                                       int p2)
```
  - createAddress
```
Address_InterProcessComm createAddress(java.lang.String p1,
                                       int p2)
```
  - createAddress
```
Address_InterProcessComm createAddress(java.lang.String address)
```
  - equals
```
boolean equals(Address_InterProcessComm address1P,
               Address_InterProcessComm address2P)
```
    Compare the address to another address, returns true if it is the same address. This method can used to compare a known address with a sender address from InterProcessComm::receive().
    
    Parameters:
    
    address1 - The address to compare.
    
    address2 - The address to compare. return true if the addresses describes the same communication slot. On Pc that is the same IP-Address and the same port.
  - translateErrorMsg
```
java.lang.String translateErrorMsg(int nError)
```
  - flush
```
int flush()
```
    Flushs send data to destination.
  - getSendBuffer
```
byte[] getSendBuffer(int len)
```
    Gets a buffer for send.

Interface InterProcessComm

Field Summary

Method Summary

Field Detail

version

receiverShouldbeBlocking

receiverShouldbePolling

Method Detail

open

close

send

receive

receiveData

freeData

checkConnection

capacityToSendWithoutBlocking

dataAvailable

abortReceive

getName

getOwnAddress

createAddress

createAddress

createAddress

createAddress

equals

translateErrorMsg

flush

getSendBuffer