func NewRandomUnreliableTransport(f trace.Frame, nok, ndrop int, expa, expb time.Duration) *Transport {
return NewTransport(f, func(f0, f1 trace.Frame, a0, a1 net.Addr) (net.Conn, net.Conn) {
nok, ndrop := rand.Intn(nok+1), rand.Intn(ndrop+1)
nok = max(nok, 1)
f.Printf("TRANSPORT PROFILE NOK=%d, NDROP=%d", nok, ndrop)
return NewSievePipe(f0, f1, a0, a1, nok, ndrop, expa, expb)
})
}
func NewTransport(frame trace.Frame, sub *codec.Transport) *Transport {
t := &Transport{
frame: frame,
sub: sub,
Dialer: NewDialer(frame.Refine("dialer"), sub),
}
frame.Bind(t)
return t
}
// NewBuffer creates a new buffer with limit m.
func NewBuffer(frame trace.Frame, m int) *Buffer {
b := &Buffer{
wch: make(chan struct{}, m+1), // +1 for the final EOF, so it does not block
// The capacity of rch is chosen so that writers to rch will never block.
rch: make(chan struct{}, 4*m+2),
}
frame.Bind(b)
b.Frame = frame
for i := 0; i < m; i++ {
b.wch <- struct{}{}
}
return b
}
// NewSievePipe returns the two net.Conn endpoints of a new bi-directional drop tail pipe.
func NewSievePipe(f0, f1 trace.Frame, a0, a1 net.Addr, nok, ndrop int, expa, expb time.Duration) (p, q net.Conn) {
a, b := NewHalfConn(f0), NewHalfConn(f1)
ax, bx, xa, xb := newChan(), newChan(), newChan(), newChan()
axk, bxk := newBackChan(), newBackChan()
a.RecvFrom(xa, a1)
b.RecvFrom(xb, a0)
a.SendTo(ax, axk, a0)
b.SendTo(bx, bxk, a1)
ab, ba := StartSieve(f0.Refine("sieve"), f1.Refine("sieve"), ax, bx, xa, xb, axk, bxk, nok, ndrop, expa, expb)
a.in, a.out = ba, ab
b.in, b.out = ab, ba
return a, b
}
func testWrite(fr trace.Frame, t *testing.T, c *Conn, ready chan<- int) {
defer func() {
ready <- 1
}()
for i := 0; i < N; i++ {
if err := c.Write([]byte{byte(i), byte(i + 1), byte(i + 2)}); err != nil {
t.Errorf("write (%s)", err)
failNow()
}
fr.Printf("WROTE %d/%d", i+1, N)
}
if err := c.Close(); err != nil {
t.Fatalf("write-side close (%s)", err)
failNow()
}
fr.Printf("CLOSED WRITE")
}
func (a *Conn) Start(frame trace.Frame, id chainID, addr net.Addr, linker linker, scrb func()) {
frame.Bind(a)
a.frame = frame
a.scrb = scrb
a.id = id
a.addr = addr
a.linker = linker
a.cascade = MakeCascade(frame)
// A buffer size 1 on rch, helps remove a deadlock in the TestConn.
// Essentially it ensures that Read and Write (on two ends of a
// connection) cannot deadlock each other when a successful Write also
// requires a stitch. We throw in a couple of extra buffer spaces to
// prevent any potential deadlock between Read and Kill.
a.rch = make(chan interface{}, 3)
a.kch = make(chan struct{})
go a.readLoop()
}
func testRead(fr trace.Frame, t *testing.T, c *Conn, ready chan<- int) {
defer func() {
ready <- 1
}()
for i := 0; i < N; i++ {
q, err := c.Read()
if err != nil {
t.Fatalf("read (%s)", err)
failNow()
}
z := []byte{byte(i), byte(i + 1), byte(i + 2)}
if !reflect.DeepEqual(q, z) {
t.Fatalf("expecting %#v, got %#v", z, q)
failNow()
}
fr.Printf("READ %d/%d", i+1, N)
}
if err := c.Close(); err != nil {
t.Fatalf("read-side close (%s)", err)
failNow()
}
fr.Printf("CLOSED READ")
}
func NewConn(frame trace.Frame, under *chain.Conn) *Conn {
// Only 1 needed in readLoop; get 3 just to be safe
rch := make(chan interface{}, 3)
// Capacity 1 (below) unblocks writeSync, invoked in readLoop right after a connection stitch
// stitch is received, racing with a user write waiting on waitForLink.
// In particular, if execUserWrite is waiting on waitForLink, it would prevent readLoop from
// moving on to adopt the new connection.
sch := make(chan *control, 1)
// Abort channel
ach := make(chan struct{})
// User-facing Conn
c := &Conn{
frame: frame,
sub: under,
rch: rch,
ach: ach,
bfr: NewBuffer(frame.Refine("buffer"), MemoryCap),
}
c.frame.Bind(c)
// readConn
rc := &readConn{
frame: frame.Refine("R∞"),
sub: c.sub,
rch: rch,
sch: sch,
ach: ach,
bfr: c.bfr,
}
rc.frame.Bind(rc)
go rc.loop()
// writeConn
wc := &writeConn{
frame: frame.Refine("W∞"),
sub: c.sub,
bfr: c.bfr,
sch: sch,
}
wc.frame.Bind(wc)
go wc.loop()
return c
}
func NewListener(frame trace.Frame, sub *codec.Listener) *Listener {
l := &Listener{frame: frame, sub: sub}
frame.Bind(l)
return l
}
func NewUnreliableTransport(f trace.Frame, nok, ndrop int, expa, expb time.Duration) *Transport {
return NewTransport(f, func(f0, f1 trace.Frame, a0, a1 net.Addr) (net.Conn, net.Conn) {
f.Printf("TRANSPORT PROFILE NOK=%d, NDROP=%d", nok, ndrop)
return NewSievePipe(f0, f1, a0, a1, nok, ndrop, expa, expb)
})
}