Envelope issues

[drdanz]

Being in the port and not associated to a message, the envelope has a few issues.

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• It is not clear which envelope is received when you call getEnvelope() if meanwhile the port received some other message. Is it the last one or the one associated to the last read?
• Is there a difference between Port and BufferedPort?
• What about if we are using a callback?
• What happens if a carrier modifier does not accept one message? Apparently the envelope is accepted anyway.

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• When 2 senders are connected to the same port, I suspect that there could be a race condition, and the envelope from one sender can be associated to the wrong message. For example

Console 1

> yarp read /r envelope
# yarp: Port /r active at tcp://192.168.99.1:10005

Console 2

> telnet 192.168.99.1 10005
# Trying 192.168.99.1...
# Connected to 192.168.99.1.
# Escape character is '^]'.
CONNECT /w1
# Welcome /w1
do envelope from w1

Console 1

# <nothing happens yet>

Console 3

> telnet 192.168.99.1 10005
# Trying 192.168.99.1...
# Connected to 192.168.99.1.
# Escape character is '^]'.
CONNECT /w2
# Welcome /w2
do envelope from w2

Console 1

# <nothing happens yet>

Console 2

message from w1

Console 1 --- RACE CONDITION

# envelope from w2 message from w1

Console 3

message from w2

Console 1 --- OK

# envelope from w2 message from w2

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• When a port receives some messages with the envelope and some without the envelope, the last received envelope will be associated to the messages without the envelope

Console 1

> yarp read /r envelope
# yarp: Port /r active at tcp://192.168.99.1:10005

Console 2

> telnet 192.168.99.1 10005
# Trying 192.168.99.1...
# Connected to 192.168.99.1.
# Escape character is '^]'.
CONNECT /w1
# Welcome /w1
do envelope1
message1

Console 1 --- OK

# envelope1 message1

Console 2

do
message2

Console 1 --- Envelope from the wrong message

# envelope1 message2