@startuml

title "Connection Pool Sequence Diagram"

actor User
control ConnectionPool as POOL
control ConnectionFactory as F
entity Connection as C

User -> POOL: getConnection(FTP)
POOL -> POOL: Check available
POOL -> F: newConnection(FTP)
F -> C: <<constructor call>>
C -> F: <<connection>>
F -> POOL: <<connection>>
POOL -> POOL: Increment used connection counts
POOL -> User: <<connection>>
User -> User: Do stuff with conn
User -> POOL: releaseConnection()



User -> POOL: getConnection(FTP)
POOL -> POOL: Check available
POOL -> User: <<connection>>
User -> User: Do stuff with conn
User -> POOL: releaseConnection()
POOL -> POOL: timeout connection



@enduml