func (r *RPC) openNewClient() {
ci, err := jsonrpc.Dial(r.network, r.dstServer, r.OnBrokenConnection)
if err != nil {
r.closeIfOpenNumZero(err)
return
}
r.mu.Lock()
defer r.mu.Unlock()
if r.closed {
ci.Close()
return
}
}
// return a connection(from idle conn lists or newly created) for rpc use
func (r *RPC) getConn() (nc *conn, err error) {
fmt.Printf("myrpc.RPC.getConn start:r(%+v)\n", *r)
defer func() { fmt.Printf("myrpc.RPC.getConn end:r(%+v),err(%+v)\n", *r, err) }()
r.mu.Lock()
if r.closed {
r.mu.Unlock()
return nil, errRPCClosed
}
if r.maxOpen > 0 && r.numOpen >= r.maxOpen && len(r.freeConn) == 0 {
// wait a free conn
req := make(chan connRequest, 1)
r.connRequests = append(r.connRequests, req)
r.mu.Unlock()
ret := <-req
return ret.rc, ret.err
}
for c := len(r.freeConn); c > 0; {
// get one from freeConn list
ci := r.freeConn[0]
r.freeConn = r.freeConn[1:]
fmt.Printf("myrpc.RPC.getConn get from r.freeConn:ci(%+v)\n", *ci)
// check if ci is closed already
if ci.isClosed() {
ci.Close() // Todo:close conn in r.mu.Unlock sucks, but is right here
r.numOpen--
c = len(r.freeConn)
continue
}
ci.inUse = true
r.mu.Unlock()
return ci, nil
}
// create a new connection
r.numOpen++
r.mu.Unlock()
ci, err := jsonrpc.Dial(r.network, r.dstServer, r.OnBrokenConnection)
if err != nil {
r.mu.Lock()
r.numOpen--
r.mu.Unlock()
// new creation failed, close if qualified
r.closeIfOpenNumZero(err)
return nil, err
}
fmt.Printf("myrpc.RPC.getConn create a new connection:r(%p),*r(%+v)\n", r, *r)
r.mu.Lock()
rc := &conn{
r: r,
ci: ci,
}
rc.inUse = true
r.mu.Unlock()
return rc, nil
}