org.jgroups.stack
Class Retransmitter
java.lang.Object
org.jgroups.stack.Retransmitter
public class Retransmitter
extends java.lang.Object
Maintains a pool of sequence numbers of messages that need to be retransmitted. Messages
are aged and retransmission requests sent according to age (linear backoff used). If a
TimeScheduler instance is given to the constructor, it will be used, otherwise Reransmitter
will create its own. The retransmit timeouts have to be set first thing after creating an instance.
The add()
method adds a range of sequence numbers of messages to be retransmitted. The
remove()
method removes a sequence number again, cancelling retransmission requests for it.
Whenever a message needs to be retransmitted, the RetransmitCommand.retransmit()
method is called.
It can be used e.g. by an ack-based scheme (e.g. AckSenderWindow) to retransmit a message to the receiver, or
by a nak-based scheme to send a retransmission request to the sender of the missing message.
void | add(long first_seqno, long last_seqno) - Add the given range [first_seqno, last_seqno] in the list of
entries eligible for retransmission.
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static void | main(String[] args)
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void | remove(long seqno) - Remove the given sequence number from the list of seqnos eligible
for retransmission.
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void | reset() - Reset the retransmitter: clear all msgs and cancel all the
respective tasks
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void | setRetransmitTimeouts(long[] timeouts)
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void | stop() - Stop the rentransmition and clear all pending msgs.
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String | toString()
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log
protected static Log log
Retransmitter
public Retransmitter(Address sender,
Retransmitter.RetransmitCommand cmd)
Create a new Retransmitter associated with the given sender address
sender
- the address from which retransmissions are expected or to which retransmissions are sentcmd
- the retransmission callback reference
Retransmitter
public Retransmitter(Address sender,
Retransmitter.RetransmitCommand cmd,
TimeScheduler sched)
Create a new Retransmitter associated with the given sender address
sender
- the address from which retransmissions are expected or to which retransmissions are sentcmd
- the retransmission callback referencesched
- retransmissions scheduler
add
public void add(long first_seqno,
long last_seqno)
Add the given range [first_seqno, last_seqno] in the list of
entries eligible for retransmission. If first_seqno > last_seqno,
then the range [last_seqno, first_seqno] is added instead
If retransmitter thread is suspended, wake it up
TODO:
Does not check for duplicates !
main
public static void main(String[] args)
remove
public void remove(long seqno)
Remove the given sequence number from the list of seqnos eligible
for retransmission. If there are no more seqno intervals in the
respective entry, cancel the entry from the retransmission
scheduler and remove it from the pending entries
reset
public void reset()
Reset the retransmitter: clear all msgs and cancel all the
respective tasks
setRetransmitTimeouts
public void setRetransmitTimeouts(long[] timeouts)
stop
public void stop()
Stop the rentransmition and clear all pending msgs.
If this retransmitter has been provided an externally managed
scheduler, then just clear all msgs and the associated tasks, else
stop the scheduler. In this case the method blocks until the
scheduler's thread is dead. Only the owner of the scheduler should
stop it.
toString
public String toString()
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