use std::collections::HashSet;
use std::rc::Rc;
use std::sync::mpsc::Sender;
use byteorder::*;
use core::{EndpointId, Message};
use core::socket::{Protocol, Reply};
use core::endpoint::Pipe;
use core::context::Context;
use super::priolist::Priolist;
use super::pipes::PipeCollection;
use super::{Timeout, BUS};
use super::policy::{broadcast, fair_queue};
use io_error::*;
pub struct Bus {
inner: Inner,
state: Option<State>
}
enum State {
Idle,
Receiving(EndpointId, Timeout),
RecvOnHold(Timeout)
}
struct Inner {
reply_tx: Sender<Reply>,
pipes: PipeCollection,
bc: HashSet<EndpointId>,
fq: Priolist
}
impl Bus {
fn apply<F>(&mut self, ctx: &mut Context, transition: F) where F : FnOnce(State, &mut Context, &mut Inner) -> State {
if let Some(old_state) = self.state.take() {
#[cfg(debug_assertions)] let old_name = old_state.name();
let was_send_ready = self.is_send_ready();
let was_recv_ready = self.is_recv_ready();
let new_state = transition(old_state, ctx, &mut self.inner);
let is_send_ready = self.is_send_ready();
let is_recv_ready = self.is_recv_ready();
#[cfg(debug_assertions)] let new_name = new_state.name();
self.state = Some(new_state);
ctx.check_send_ready_change(was_send_ready, is_send_ready);
ctx.check_recv_ready_change(was_recv_ready, is_recv_ready);
#[cfg(debug_assertions)] debug!("[{:?}] switch from {} to {}", ctx, old_name, new_name);
}
}
}
impl From<Sender<Reply>> for Bus {
fn from(tx: Sender<Reply>) -> Bus {
Bus {
inner: Inner {
reply_tx: tx,
pipes: PipeCollection::new(),
bc: HashSet::new(),
fq: Priolist::new()
},
state: Some(State::Idle)
}
}
}
impl Protocol for Bus {
fn id(&self) -> u16 { BUS }
fn peer_id(&self) -> u16 { BUS }
fn add_pipe(&mut self, _: &mut Context, eid: EndpointId, pipe: Pipe) {
self.inner.add_pipe(eid, pipe)
}
fn remove_pipe(&mut self, ctx: &mut Context, eid: EndpointId) -> Option<Pipe> {
let was_send_ready = self.inner.is_send_ready();
let was_recv_ready = self.inner.is_recv_ready();
let pipe = self.inner.remove_pipe(eid);
let is_send_ready = self.inner.is_send_ready();
let is_recv_ready = self.inner.is_recv_ready();
if pipe.is_some() {
self.apply(ctx, |s, ctx, inner| s.on_pipe_removed(ctx, inner, eid));
}
ctx.check_send_ready_change(was_send_ready, is_send_ready);
ctx.check_recv_ready_change(was_recv_ready, is_recv_ready);
pipe
}
fn send(&mut self, ctx: &mut Context, msg: Message, timeout: Timeout) {
let (raw_msg, oid) = encode(msg);
self.apply(ctx, |s, ctx, inner| s.send(ctx, inner, Rc::new(raw_msg), oid, timeout))
}
fn on_send_ack(&mut self, ctx: &mut Context, eid: EndpointId) {
self.apply(ctx, |s, ctx, inner| s.on_send_ack(ctx, inner, eid))
}
fn on_send_timeout(&mut self, ctx: &mut Context) {
self.apply(ctx, |s, ctx, inner| s.on_send_timeout(ctx, inner))
}
fn on_send_ready(&mut self, ctx: &mut Context, eid: EndpointId) {
self.apply(ctx, |s, ctx, inner| s.on_send_ready(ctx, inner, eid))
}
fn on_send_not_ready(&mut self, ctx: &mut Context, eid: EndpointId) {
self.apply(ctx, |s, ctx, inner| s.on_send_not_ready(ctx, inner, eid))
}
fn recv(&mut self, ctx: &mut Context, timeout: Timeout) {
self.apply(ctx, |s, ctx, inner| s.recv(ctx, inner, timeout))
}
fn on_recv_ack(&mut self, ctx: &mut Context, eid: EndpointId, raw_msg: Message) {
let msg = decode(raw_msg, eid);
self.apply(ctx, |s, ctx, inner| s.on_recv_ack(ctx, inner, eid, msg))
}
fn on_recv_timeout(&mut self, ctx: &mut Context) {
self.apply(ctx, |s, ctx, inner| s.on_recv_timeout(ctx, inner))
}
fn on_recv_ready(&mut self, ctx: &mut Context, eid: EndpointId) {
self.apply(ctx, |s, ctx, inner| s.on_recv_ready(ctx, inner, eid))
}
fn on_recv_not_ready(&mut self, ctx: &mut Context, eid: EndpointId) {
self.apply(ctx, |s, ctx, inner| s.on_recv_not_ready(ctx, inner, eid))
}
fn is_send_ready(&self) -> bool {
self.inner.is_send_ready()
}
fn is_recv_ready(&self) -> bool {
self.inner.is_recv_ready()
}
fn close(&mut self, ctx: &mut Context) {
self.inner.close(ctx)
}
}
impl State {
#[cfg(debug_assertions)]
fn name(&self) -> &'static str {
match *self {
State::Idle => "Idle",
State::Receiving(..) => "Receiving",
State::RecvOnHold(..) => "RecvOnHold"
}
}
fn on_pipe_removed(self, ctx: &mut Context, inner: &mut Inner, eid: EndpointId) -> State {
match self {
State::Receiving(id, timeout) => {
if id == eid {
State::Idle.recv(ctx, inner, timeout)
} else {
State::Receiving(id, timeout)
}
},
any => any
}
}
fn send(self, ctx: &mut Context, inner: &mut Inner, msg: Rc<Message>, oid: Option<EndpointId>, timeout: Timeout) -> State {
inner.send(ctx, msg, oid, timeout);
self
}
fn on_send_ack(self, _: &mut Context, _: &mut Inner, _: EndpointId) -> State {
self
}
fn on_send_timeout(self, _: &mut Context, _: &mut Inner) -> State {
self
}
fn on_send_ready(self, ctx: &mut Context, inner: &mut Inner, eid: EndpointId) -> State {
inner.on_send_ready(ctx, eid);
self
}
fn on_send_not_ready(self, ctx: &mut Context, inner: &mut Inner, eid: EndpointId) -> State {
inner.on_send_not_ready(ctx, eid);
self
}
fn recv(self, ctx: &mut Context, inner: &mut Inner, timeout: Timeout) -> State {
inner.recv(ctx).map_or_else(
| | State::RecvOnHold(timeout),
|eid| State::Receiving(eid, timeout))
}
fn on_recv_ack(self, ctx: &mut Context, inner: &mut Inner, eid: EndpointId, msg: Message) -> State {
match self {
State::Receiving(id, timeout) => {
if id == eid {
inner.on_recv_ack(ctx, timeout, msg);
State::Idle
} else {
State::Receiving(id, timeout)
}
},
any => any
}
}
fn on_recv_timeout(self, _: &mut Context, inner: &mut Inner) -> State {
inner.on_recv_timeout();
State::Idle
}
fn on_recv_ready(self, ctx: &mut Context, inner: &mut Inner, eid: EndpointId) -> State {
inner.on_recv_ready(eid);
match self {
State::RecvOnHold(timeout) => State::Idle.recv(ctx, inner, timeout),
any => any
}
}
fn on_recv_not_ready(self, _: &mut Context, inner: &mut Inner, eid: EndpointId) -> State {
inner.on_recv_not_ready(eid);
self
}
}
impl Inner {
fn add_pipe(&mut self, eid: EndpointId, pipe: Pipe) {
self.fq.insert(eid, pipe.get_recv_priority());
self.pipes.insert(eid, pipe);
}
fn remove_pipe(&mut self, eid: EndpointId) -> Option<Pipe> {
self.bc.remove(&eid);
self.fq.remove(&eid);
self.pipes.remove(&eid)
}
fn send(&mut self, ctx: &mut Context, msg: Rc<Message>, oid: Option<EndpointId>, timeout: Timeout) {
if let Some(except) = oid {
if self.bc.contains(&except) {
self.send_to_all_except(ctx, msg, except);
} else {
self.send_to_all(ctx, msg);
}
} else {
self.send_to_all(ctx, msg);
}
let _ = self.reply_tx.send(Reply::Send);
if let Some(sched) = timeout {
ctx.cancel(sched);
}
}
fn send_to_all(&mut self, ctx: &mut Context, msg: Rc<Message>) {
broadcast::send_to_all(&mut self.bc, &mut self.pipes, ctx, msg)
}
fn send_to_all_except(&mut self, ctx: &mut Context, msg: Rc<Message>, except: EndpointId) {
broadcast::send_to_all_except(&mut self.bc, &mut self.pipes, ctx, msg, except)
}
fn on_send_ready(&mut self, _: &mut Context, eid: EndpointId) {
self.bc.insert(eid);
}
fn on_send_not_ready(&mut self, _: &mut Context, eid: EndpointId) {
self.bc.remove(&eid);
}
fn is_send_ready(&self) -> bool {
!self.bc.is_empty()
}
fn recv(&mut self, ctx: &mut Context) -> Option<EndpointId> {
fair_queue::recv(&mut self.fq, &mut self.pipes, ctx)
}
fn on_recv_ready(&mut self, eid: EndpointId) {
self.fq.activate(&eid)
}
fn on_recv_not_ready(&mut self, eid: EndpointId) {
self.fq.deactivate(&eid)
}
fn on_recv_ack(&self, ctx: &mut Context, timeout: Timeout, msg: Message) {
let _ = self.reply_tx.send(Reply::Recv(msg));
if let Some(sched) = timeout {
ctx.cancel(sched);
}
}
fn is_recv_ready(&self) -> bool {
self.fq.peek()
}
fn on_recv_timeout(&self) {
let error = timedout_io_error("Recv timed out");
let _ = self.reply_tx.send(Reply::Err(error));
}
fn close(&mut self, ctx: &mut Context) {
self.pipes.close_all(ctx)
}
}
fn decode(raw_msg: Message, eid: EndpointId) -> Message {
let originator: usize = eid.into();
let mut msg = raw_msg;
let mut originator_bytes: [u8; 4] = [0; 4];
BigEndian::write_u32(&mut originator_bytes[..], originator as u32);
msg.header.reserve(4);
msg.header.extend_from_slice(&originator_bytes);
msg
}
fn encode(msg: Message) -> (Message, Option<EndpointId>) {
if msg.get_header().len() < 4 {
return (msg, None);
}
let (mut header, body) = msg.split();
let remaining_header = header.split_off(4);
let originator = BigEndian::read_u32(&header) as usize;
let raw_msg = Message::from_header_and_body(remaining_header, body);
(raw_msg, Some(EndpointId::from(originator)))
}
#[cfg(test)]
mod tests {
use std::cell::RefCell;
use std::rc::Rc;
use std::sync::mpsc;
use core::{EndpointId, Message, Scheduled};
use core::socket::{Protocol, Reply};
use core::context::{Event};
use core::tests::*;
use super::*;
#[test]
fn when_send_succeeds_it_is_notified_and_timeout_is_cancelled() {
let (tx, rx) = mpsc::channel();
let mut bus = Bus::from(tx);
let ctx_sensor = Rc::new(RefCell::new(TestContextSensor::default()));
let mut ctx = TestContext::with_sensor(ctx_sensor.clone());
let msg = Message::new();
let timeout = Scheduled::from(0);
bus.send(&mut ctx, msg, Some(timeout));
let reply = rx.try_recv().expect("facade should have been sent a reply !");
let is_reply_ok = match reply {
Reply::Send => true,
_ => false
};
assert!(is_reply_ok);
let sensor = ctx_sensor.borrow();
sensor.assert_one_cancellation(timeout);
}
#[test]
fn send_broadcast_to_all_ready_pipes() {
let (tx, _) = mpsc::channel();
let mut bus = Bus::from(tx);
let ctx_sensor = Rc::new(RefCell::new(TestContextSensor::default()));
let mut ctx = TestContext::with_sensor(ctx_sensor.clone());
let eid1 = EndpointId::from(1);
let pipe1 = new_test_pipe(eid1);
let eid2 = EndpointId::from(2);
let pipe2 = new_test_pipe(eid2);
let eid3 = EndpointId::from(3);
let pipe3 = new_test_pipe(eid3);
bus.add_pipe(&mut ctx, eid1, pipe1);
bus.add_pipe(&mut ctx, eid2, pipe2);
bus.add_pipe(&mut ctx, eid3, pipe3);
bus.on_send_ready(&mut ctx, eid1);
bus.on_send_ready(&mut ctx, eid3);
bus.send(&mut ctx, Message::new(), None);
let sensor = ctx_sensor.borrow();
sensor.assert_send_to(eid1, 1);
sensor.assert_send_to(eid2, 0);
sensor.assert_send_to(eid3, 1);
}
#[test]
fn when_ready_pipe_list_becomes_not_empty_event_is_raised() {
let (tx, _) = mpsc::channel();
let mut bus = Bus::from(tx);
let ctx_sensor = Rc::new(RefCell::new(TestContextSensor::default()));
let mut ctx = TestContext::with_sensor(ctx_sensor.clone());
let eid1 = EndpointId::from(1);
let pipe1 = new_test_pipe(eid1);
let eid2 = EndpointId::from(2);
let pipe2 = new_test_pipe(eid2);
bus.add_pipe(&mut ctx, eid1, pipe1);
bus.add_pipe(&mut ctx, eid2, pipe2);
ctx_sensor.borrow().assert_no_event_raised();
bus.on_send_ready(&mut ctx, eid2);
let sensor = ctx_sensor.borrow();
let raised_evts = sensor.get_raised_events();
assert_eq!(1, raised_evts.len());
assert_eq!(Event::CanSend(true), raised_evts[0]);
}
#[test]
fn when_send_starts_event_is_raised() {
let (tx, _) = mpsc::channel();
let mut bus = Bus::from(tx);
let ctx_sensor = Rc::new(RefCell::new(TestContextSensor::default()));
let mut ctx = TestContext::with_sensor(ctx_sensor.clone());
let eid = EndpointId::from(1);
let pipe = new_test_pipe(eid);
bus.add_pipe(&mut ctx, eid, pipe);
bus.on_send_ready(&mut ctx, eid);
bus.send(&mut ctx, Message::new(), None);
let sensor = ctx_sensor.borrow();
let raised_evts = sensor.get_raised_events();
assert_eq!(2, raised_evts.len());
assert_eq!(Event::CanSend(true), raised_evts[0]);
assert_eq!(Event::CanSend(false), raised_evts[1]);
}
#[test]
fn when_recv_starts_event_is_raised() {
let (tx, _) = mpsc::channel();
let mut bus = Bus::from(tx);
let ctx_sensor = Rc::new(RefCell::new(TestContextSensor::default()));
let mut ctx = TestContext::with_sensor(ctx_sensor.clone());
let eid = EndpointId::from(1);
let pipe = new_test_pipe(eid);
bus.add_pipe(&mut ctx, eid, pipe);
bus.on_recv_ready(&mut ctx, eid);
bus.recv(&mut ctx, None);
bus.on_recv_ack(&mut ctx, eid, Message::new());
bus.on_recv_ready(&mut ctx, eid);
let sensor = ctx_sensor.borrow();
let raised_evts = sensor.get_raised_events();
assert_eq!(3, raised_evts.len());
assert_eq!(Event::CanRecv(true), raised_evts[0]);
assert_eq!(Event::CanRecv(false), raised_evts[1]);
assert_eq!(Event::CanRecv(true), raised_evts[2]);
}
#[test]
fn when_recv_ack_event_is_raised_if_there_is_another_pipe_ready() {
let (tx, _) = mpsc::channel();
let mut bus = Bus::from(tx);
let ctx_sensor = Rc::new(RefCell::new(TestContextSensor::default()));
let mut ctx = TestContext::with_sensor(ctx_sensor.clone());
let eid1 = EndpointId::from(1);
let pipe1 = new_test_pipe(eid1);
let eid2 = EndpointId::from(2);
let pipe2 = new_test_pipe(eid2);
bus.add_pipe(&mut ctx, eid1, pipe1);
bus.add_pipe(&mut ctx, eid2, pipe2);
bus.on_recv_ready(&mut ctx, eid1);
bus.recv(&mut ctx, None);
bus.on_recv_ready(&mut ctx, eid2);
bus.on_recv_ack(&mut ctx, eid1, Message::new());
let sensor = ctx_sensor.borrow();
let raised_evts = sensor.get_raised_events();
assert_eq!(3, raised_evts.len());
assert_eq!(Event::CanRecv(true), raised_evts[0]);
assert_eq!(Event::CanRecv(false), raised_evts[1]);
assert_eq!(Event::CanRecv(true), raised_evts[2]);
}
#[test]
fn when_send_ready_pipe_is_removed_event_is_raised() {
let (tx, _) = mpsc::channel();
let mut bus = Bus::from(tx);
let ctx_sensor = Rc::new(RefCell::new(TestContextSensor::default()));
let mut ctx = TestContext::with_sensor(ctx_sensor.clone());
let eid = EndpointId::from(5);
let pipe = new_test_pipe(eid);
bus.add_pipe(&mut ctx, eid, pipe);
assert_eq!(0, ctx_sensor.borrow().get_raised_events().len());
bus.on_send_ready(&mut ctx, eid);
assert_eq!(1, ctx_sensor.borrow().get_raised_events().len());
bus.remove_pipe(&mut ctx, eid);
assert_eq!(2, ctx_sensor.borrow().get_raised_events().len());
let sensor = ctx_sensor.borrow();
let raised_evts = sensor.get_raised_events();
assert_eq!(2, raised_evts.len());
assert_eq!(Event::CanSend(true), raised_evts[0]);
assert_eq!(Event::CanSend(false), raised_evts[1]);
}
#[test]
fn when_recv_ready_pipe_is_removed_event_is_raised() {
let (tx, _) = mpsc::channel();
let mut bus = Bus::from(tx);
let ctx_sensor = Rc::new(RefCell::new(TestContextSensor::default()));
let mut ctx = TestContext::with_sensor(ctx_sensor.clone());
let eid = EndpointId::from(5);
let pipe = new_test_pipe(eid);
bus.add_pipe(&mut ctx, eid, pipe);
bus.on_recv_ready(&mut ctx, eid);
bus.remove_pipe(&mut ctx, eid);
let sensor = ctx_sensor.borrow();
let raised_evts = sensor.get_raised_events();
assert_eq!(2, raised_evts.len());
assert_eq!(Event::CanRecv(true), raised_evts[0]);
assert_eq!(Event::CanRecv(false), raised_evts[1]);
}
}