Changeset - 93081320c9fa
[Not reviewed]
0 6 0
mh - 3 years ago 2022-03-23 11:25:13
contact@maxhenger.nl
Introduce trait for components
6 files changed with 78 insertions and 54 deletions:
0 comments (0 inline, 0 general)
src/runtime2/component/component.rs
Show inline comments
 
use crate::protocol::eval::EvalError;
 
use crate::runtime2::*;
 
use super::CompCtx;
 

	
 
pub enum CompScheduling {
 
    Immediate,
 
    Requeue,
 
    Sleep,
 
    Exit,
 
}
 

	
 
/// Generic representation of a component (as viewed by a scheduler).
 
pub(crate) trait Component {
 
    fn handle_message(sched_ctx: &mut SchedulerCtx, comp_ctx: &mut CompCtx, message: Message);
 
    fn run(sched_ctx: &mut SchedulerCtx, comp_ctx: &mut CompCtx) -> CompScheduling;
 
    /// Called if the component is created by another component and the messages
 
    /// are being transferred between the two.
 
    fn adopt_message(&mut self, comp_ctx: &mut CompCtx, message: DataMessage);
 

	
 
    /// Called if the component receives a new message. The component is
 
    /// responsible for deciding where that messages goes.
 
    fn handle_message(&mut self, sched_ctx: &mut SchedulerCtx, comp_ctx: &mut CompCtx, message: Message);
 

	
 
    /// Called if the component's routine should be executed. The return value
 
    /// can be used to indicate when the routine should be run again.
 
    fn run(&mut self, sched_ctx: &mut SchedulerCtx, comp_ctx: &mut CompCtx) -> Result<CompScheduling, EvalError>;
 
}
 
\ No newline at end of file
src/runtime2/component/component_pdl.rs
Show inline comments
 
use crate::random::Random;
 
use crate::protocol::*;
 
use crate::protocol::ast::ProcedureDefinitionId;
 
use crate::protocol::eval::{
 
    PortId as EvalPortId, Prompt,
 
    ValueGroup, Value,
 
    EvalContinuation, EvalResult, EvalError
 
};
 

	
 
use crate::runtime2::scheduler::SchedulerCtx;
 
use crate::runtime2::communication::*;
 

	
 
use super::component::CompScheduling;
 
use super::component::*;
 
use super::component_context::*;
 
use super::control_layer::*;
 
use super::consensus::Consensus;
 

	
 
pub enum ExecStmt {
 
    CreatedChannel((Value, Value)),
 
    PerformedPut,
 
    PerformedGet(ValueGroup),
 
    PerformedSelectWait(u32),
 
    None,
 
}
 

	
 
impl ExecStmt {
 
    fn take(&mut self) -> ExecStmt {
 
        let mut value = ExecStmt::None;
 
        std::mem::swap(self, &mut value);
 
        return value;
 
    }
 

	
 
    fn is_none(&self) -> bool {
 
        match self {
 
            ExecStmt::None => return true,
 
            _ => return false,
 
        }
 
    }
 
}
 

	
 
pub struct ExecCtx {
 
    stmt: ExecStmt,
 
}
 

	
 
impl RunContext for ExecCtx {
 
    fn performed_put(&mut self, _port: EvalPortId) -> bool {
 
        match self.stmt.take() {
 
            ExecStmt::None => return false,
 
            ExecStmt::PerformedPut => return true,
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn performed_get(&mut self, _port: EvalPortId) -> Option<ValueGroup> {
 
        match self.stmt.take() {
 
            ExecStmt::None => return None,
 
            ExecStmt::PerformedGet(value) => return Some(value),
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn fires(&mut self, _port: EvalPortId) -> Option<Value> {
 
        todo!("remove fires")
 
    }
 

	
 
    fn performed_fork(&mut self) -> Option<bool> {
 
        todo!("remove fork")
 
    }
 

	
 
    fn created_channel(&mut self) -> Option<(Value, Value)> {
 
        match self.stmt.take() {
 
            ExecStmt::None => return None,
 
            ExecStmt::CreatedChannel(ports) => return Some(ports),
 
            _ => unreachable!(),
 
        }
 
    }
 

	
 
    fn performed_select_wait(&mut self) -> Option<u32> {
 
        match self.stmt.take() {
 
            ExecStmt::None => return None,
 
            ExecStmt::PerformedSelectWait(selected_case) => Some(selected_case),
 
            _v => unreachable!(),
 
        }
 
    }
 
}
 

	
 
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
 
pub(crate) enum Mode {
 
    NonSync, // not in sync mode
 
    Sync, // in sync mode, can interact with other components
 
    SyncEnd, // awaiting a solution, i.e. encountered the end of the sync block
 
    BlockedGet, // blocked because we need to receive a message on a particular port
 
    BlockedPut, // component is blocked because the port is blocked
 
    BlockedSelect, // waiting on message to complete the select statement
 
    StartExit, // temporary state: if encountered then we start the shutdown process
 
    BusyExit, // temporary state: waiting for Acks for all the closed ports
 
    Exit, // exiting: shutdown process started, now waiting until the reference count drops to 0
 
}
 

	
 
impl Mode {
 
    fn is_in_sync_block(&self) -> bool {
 
        use Mode::*;
 

	
 
        match self {
 
            Sync | SyncEnd | BlockedGet | BlockedPut | BlockedSelect => true,
 
            NonSync | StartExit | BusyExit | Exit => false,
 
        }
 
    }
 
}
 
@@ -150,391 +150,403 @@ impl SelectState {
 
    /// return an error
 
    fn register_select_case_port(&mut self, comp_ctx: &CompCtx, case_index: u32, _port_index: u32, port_id: PortId) -> Result<(), PortId> {
 
        // Retrieve case and port handle
 
        self.ensure_at_case(case_index);
 
        let cur_case = &mut self.cases[case_index as usize];
 
        let port_handle = comp_ctx.get_port_handle(port_id);
 
        debug_assert_eq!(cur_case.involved_ports.len(), _port_index as usize);
 

	
 
        // Make sure port wasn't added before, we disallow having the same port
 
        // in the same select guard twice.
 
        if cur_case.involved_ports.contains(&port_handle) {
 
            return Err(port_id);
 
        }
 

	
 
        cur_case.involved_ports.push(port_handle);
 
        return Ok(());
 
    }
 

	
 
    /// Notification that all ports have been registered and we should now wait
 
    /// until the appropriate messages have come in.
 
    fn handle_select_waiting_point(&mut self, inbox: &InboxMain, comp_ctx: &CompCtx) -> SelectDecision {
 
        if self.num_cases != self.next_case {
 
            // This happens when there are >=1 select cases written at the end
 
            // of the select block.
 
            self.ensure_at_case(self.num_cases - 1);
 
        }
 

	
 
        return self.has_decision(inbox, comp_ctx);
 
    }
 

	
 
    fn handle_updated_inbox(&mut self, inbox: &InboxMain, comp_ctx: &CompCtx) -> SelectDecision {
 
        return self.has_decision(inbox, comp_ctx);
 
    }
 

	
 
    /// Internal helper, pushes empty cases inbetween last case and provided new
 
    /// case index.
 
    fn ensure_at_case(&mut self, new_case_index: u32) {
 
        // Push an empty case for all intermediate cases that were not
 
        // registered with a port.
 
        debug_assert!(new_case_index >= self.next_case && new_case_index < self.num_cases);
 
        for _ in self.next_case..new_case_index + 1 {
 
            self.cases.push(SelectCase{ involved_ports: Vec::new() });
 
        }
 
        self.next_case = new_case_index + 1;
 
    }
 

	
 
    /// Checks if a decision can be reached
 
    fn has_decision(&mut self, inbox: &InboxMain, comp_ctx: &CompCtx) -> SelectDecision {
 
        self.candidates_workspace.clear();
 
        if self.cases.is_empty() {
 
            // If there are no cases then we can immediately reach a "bogus
 
            // decision".
 
            return SelectDecision::Case(0);
 
        }
 

	
 
        // Need to check for valid case
 
        'case_loop: for (case_index, case) in self.cases.iter().enumerate() {
 
            for port_handle in case.involved_ports.iter().copied() {
 
                let port_index = comp_ctx.get_port_index(port_handle);
 
                if inbox[port_index].is_none() {
 
                    // Condition not satisfied
 
                    continue 'case_loop;
 
                }
 
            }
 

	
 
            // If here then the case guard is satisfied
 
            self.candidates_workspace.push(case_index);
 
        }
 

	
 
        if self.candidates_workspace.is_empty() {
 
            return SelectDecision::None;
 
        } else {
 
            let candidate_index = self.random.get_u64() as usize % self.candidates_workspace.len();
 
            return SelectDecision::Case(self.candidates_workspace[candidate_index] as u32);
 
        }
 
    }
 
}
 

	
 
pub(crate) struct CompPDL {
 
    pub mode: Mode,
 
    pub mode_port: PortId, // when blocked on a port
 
    pub mode_value: ValueGroup, // when blocked on a put
 
    select: SelectState,
 
    pub prompt: Prompt,
 
    pub control: ControlLayer,
 
    pub consensus: Consensus,
 
    pub sync_counter: u32,
 
    pub exec_ctx: ExecCtx,
 
    // TODO: Temporary field, simulates future plans of having one storage place
 
    //  reserved per port.
 
    // Should be same length as the number of ports. Corresponding indices imply
 
    // message is intended for that port.
 
    pub inbox_main: InboxMain,
 
    pub inbox_backup: Vec<DataMessage>,
 
}
 

	
 
impl CompPDL {
 
    pub(crate) fn new(initial_state: Prompt, num_ports: usize) -> Self {
 
        let mut inbox_main = Vec::new();
 
        inbox_main.reserve(num_ports);
 
        for _ in 0..num_ports {
 
            inbox_main.push(None);
 
        }
 

	
 
        return Self{
 
            mode: Mode::NonSync,
 
            mode_port: PortId::new_invalid(),
 
            mode_value: ValueGroup::default(),
 
            select: SelectState::new(),
 
            prompt: initial_state,
 
            control: ControlLayer::default(),
 
            consensus: Consensus::new(),
 
            sync_counter: 0,
 
            exec_ctx: ExecCtx{
 
                stmt: ExecStmt::None,
 
            },
 
            inbox_main,
 
            inbox_backup: Vec::new(),
 
impl Component for CompPDL {
 
    fn adopt_message(&mut self, comp_ctx: &mut CompCtx, message: DataMessage) {
 
        let port_handle = comp_ctx.get_port_handle(message.data_header.target_port);
 
        let port_index = comp_ctx.get_port_index(port_handle);
 
        if self.inbox_main[port_index].is_none() {
 
            self.inbox_main[port_index] = Some(message);
 
        } else {
 
            self.inbox_backup.push(message);
 
        }
 
    }
 

	
 
    pub(crate) fn handle_message(&mut self, sched_ctx: &mut SchedulerCtx, comp_ctx: &mut CompCtx, mut message: Message) {
 
    fn handle_message(&mut self, sched_ctx: &mut SchedulerCtx, comp_ctx: &mut CompCtx, mut message: Message) {
 
        sched_ctx.log(&format!("handling message: {:#?}", message));
 
        if let Some(new_target) = self.control.should_reroute(&mut message) {
 
            let mut target = sched_ctx.runtime.get_component_public(new_target);
 
            target.send_message(sched_ctx, message, false); // not waking up: we schedule once we've received all PortPeerChanged Acks
 
            let _should_remove = target.decrement_users();
 
            debug_assert!(_should_remove.is_none());
 
            return;
 
        }
 

	
 
        match message {
 
            Message::Data(message) => {
 
                self.handle_incoming_data_message(sched_ctx, comp_ctx, message);
 
            },
 
            Message::Control(message) => {
 
                self.handle_incoming_control_message(sched_ctx, comp_ctx, message);
 
            },
 
            Message::Sync(message) => {
 
                self.handle_incoming_sync_message(sched_ctx, comp_ctx, message);
 
            }
 
        }
 
    }
 

	
 
    // -------------------------------------------------------------------------
 
    // Running component and handling changes in global component state
 
    // -------------------------------------------------------------------------
 

	
 
    pub(crate) fn run(&mut self, sched_ctx: &mut SchedulerCtx, comp_ctx: &mut CompCtx) -> Result<CompScheduling, EvalError> {
 
    fn run(&mut self, sched_ctx: &mut SchedulerCtx, comp_ctx: &mut CompCtx) -> Result<CompScheduling, EvalError> {
 
        use EvalContinuation as EC;
 

	
 
        sched_ctx.log(&format!("Running component (mode: {:?})", self.mode));
 

	
 
        // Depending on the mode don't do anything at all, take some special
 
        // actions, or fall through and run the PDL code.
 
        match self.mode {
 
            Mode::NonSync | Mode::Sync | Mode::BlockedSelect => {
 
                // continue and run PDL code
 
            },
 
            Mode::SyncEnd | Mode::BlockedGet | Mode::BlockedPut => {
 
                return Ok(CompScheduling::Sleep);
 
            }
 
            Mode::StartExit => {
 
                self.handle_component_exit(sched_ctx, comp_ctx);
 
                return Ok(CompScheduling::Immediate);
 
            },
 
            Mode::BusyExit => {
 
                if self.control.has_acks_remaining() {
 
                    return Ok(CompScheduling::Sleep);
 
                } else {
 
                    self.mode = Mode::Exit;
 
                    return Ok(CompScheduling::Exit);
 
                }
 
            },
 
            Mode::Exit => {
 
                return Ok(CompScheduling::Exit);
 
            }
 
        }
 

	
 
        let run_result = self.execute_prompt(&sched_ctx)?;
 

	
 
        match run_result {
 
            EC::Stepping => unreachable!(), // execute_prompt runs until this is no longer returned
 
            EC::BranchInconsistent | EC::NewFork | EC::BlockFires(_) => todo!("remove these"),
 
            // Results that can be returned in sync mode
 
            EC::SyncBlockEnd => {
 
                debug_assert_eq!(self.mode, Mode::Sync);
 
                self.handle_sync_end(sched_ctx, comp_ctx);
 
                return Ok(CompScheduling::Immediate);
 
            },
 
            EC::BlockGet(port_id) => {
 
                debug_assert_eq!(self.mode, Mode::Sync);
 
                debug_assert!(self.exec_ctx.stmt.is_none());
 

	
 
                let port_id = port_id_from_eval(port_id);
 
                let port_handle = comp_ctx.get_port_handle(port_id);
 
                let port_index = comp_ctx.get_port_index(port_handle);
 
                if let Some(message) = &self.inbox_main[port_index] {
 
                    // Check if we can actually receive the message
 
                    if self.consensus.try_receive_data_message(sched_ctx, comp_ctx, message) {
 
                        // Message was received. Make sure any blocked peers and
 
                        // pending messages are handled.
 
                        let message = self.inbox_main[port_index].take().unwrap();
 
                        self.handle_received_data_message(sched_ctx, comp_ctx, port_handle);
 

	
 
                        self.exec_ctx.stmt = ExecStmt::PerformedGet(message.content);
 
                        return Ok(CompScheduling::Immediate);
 
                    } else {
 
                        todo!("handle sync failure due to message deadlock");
 
                        return Ok(CompScheduling::Sleep);
 
                    }
 
                } else {
 
                    // We need to wait
 
                    self.mode = Mode::BlockedGet;
 
                    self.mode_port = port_id;
 
                    return Ok(CompScheduling::Sleep);
 
                }
 
            },
 
            EC::Put(port_id, value) => {
 
                debug_assert_eq!(self.mode, Mode::Sync);
 
                sched_ctx.log(&format!("Putting value {:?}", value));
 
                let port_id = port_id_from_eval(port_id);
 
                let port_handle = comp_ctx.get_port_handle(port_id);
 
                let port_info = comp_ctx.get_port(port_handle);
 
                if port_info.state.is_blocked() {
 
                    self.mode = Mode::BlockedPut;
 
                    self.mode_port = port_id;
 
                    self.mode_value = value;
 
                    self.exec_ctx.stmt = ExecStmt::PerformedPut; // prepare for when we become unblocked
 
                    return Ok(CompScheduling::Sleep);
 
                } else {
 
                    self.send_data_message_and_wake_up(sched_ctx, comp_ctx, port_handle, value);
 
                    self.exec_ctx.stmt = ExecStmt::PerformedPut;
 
                    return Ok(CompScheduling::Immediate);
 
                }
 
            },
 
            EC::SelectStart(num_cases, _num_ports) => {
 
                debug_assert_eq!(self.mode, Mode::Sync);
 
                self.select.handle_select_start(num_cases);
 
                return Ok(CompScheduling::Requeue);
 
            },
 
            EC::SelectRegisterPort(case_index, port_index, port_id) => {
 
                debug_assert_eq!(self.mode, Mode::Sync);
 
                let port_id = port_id_from_eval(port_id);
 
                if let Err(_err) = self.select.register_select_case_port(comp_ctx, case_index, port_index, port_id) {
 
                    todo!("handle registering a port multiple times");
 
                }
 
                return Ok(CompScheduling::Immediate);
 
            },
 
            EC::SelectWait => {
 
                debug_assert_eq!(self.mode, Mode::Sync);
 
                let select_decision = self.select.handle_select_waiting_point(&self.inbox_main, comp_ctx);
 
                if let SelectDecision::Case(case_index) = select_decision {
 
                    // Reached a conclusion, so we can continue immediately
 
                    self.exec_ctx.stmt = ExecStmt::PerformedSelectWait(case_index);
 
                    self.mode = Mode::Sync;
 
                    return Ok(CompScheduling::Immediate);
 
                } else {
 
                    // No decision yet
 
                    self.mode = Mode::BlockedSelect;
 
                    return Ok(CompScheduling::Sleep);
 
                }
 
            },
 
            // Results that can be returned outside of sync mode
 
            EC::ComponentTerminated => {
 
                self.mode = Mode::StartExit; // next call we'll take care of the exit
 
                return Ok(CompScheduling::Immediate);
 
            },
 
            EC::SyncBlockStart => {
 
                debug_assert_eq!(self.mode, Mode::NonSync);
 
                self.handle_sync_start(sched_ctx, comp_ctx);
 
                return Ok(CompScheduling::Immediate);
 
            },
 
            EC::NewComponent(definition_id, type_id, arguments) => {
 
                debug_assert_eq!(self.mode, Mode::NonSync);
 
                self.create_component_and_transfer_ports(
 
                    sched_ctx, comp_ctx,
 
                    definition_id, type_id, arguments
 
                );
 
                return Ok(CompScheduling::Requeue);
 
            },
 
            EC::NewChannel => {
 
                debug_assert_eq!(self.mode, Mode::NonSync);
 
                debug_assert!(self.exec_ctx.stmt.is_none());
 
                let channel = comp_ctx.create_channel();
 
                self.exec_ctx.stmt = ExecStmt::CreatedChannel((
 
                    Value::Output(port_id_to_eval(channel.putter_id)),
 
                    Value::Input(port_id_to_eval(channel.getter_id))
 
                ));
 
                self.inbox_main.push(None);
 
                self.inbox_main.push(None);
 
                return Ok(CompScheduling::Immediate);
 
            }
 
        }
 
    }
 
}
 

	
 
impl CompPDL {
 
    pub(crate) fn new(initial_state: Prompt, num_ports: usize) -> Self {
 
        let mut inbox_main = Vec::new();
 
        inbox_main.reserve(num_ports);
 
        for _ in 0..num_ports {
 
            inbox_main.push(None);
 
        }
 

	
 
        return Self{
 
            mode: Mode::NonSync,
 
            mode_port: PortId::new_invalid(),
 
            mode_value: ValueGroup::default(),
 
            select: SelectState::new(),
 
            prompt: initial_state,
 
            control: ControlLayer::default(),
 
            consensus: Consensus::new(),
 
            sync_counter: 0,
 
            exec_ctx: ExecCtx{
 
                stmt: ExecStmt::None,
 
            },
 
            inbox_main,
 
            inbox_backup: Vec::new(),
 
        }
 
    }
 

	
 
    // -------------------------------------------------------------------------
 
    // Running component and handling changes in global component state
 
    // -------------------------------------------------------------------------
 

	
 
    fn execute_prompt(&mut self, sched_ctx: &SchedulerCtx) -> EvalResult {
 
        let mut step_result = EvalContinuation::Stepping;
 
        while let EvalContinuation::Stepping = step_result {
 
            step_result = self.prompt.step(
 
                &sched_ctx.runtime.protocol.types, &sched_ctx.runtime.protocol.heap,
 
                &sched_ctx.runtime.protocol.modules, &mut self.exec_ctx,
 
            )?;
 
        }
 

	
 
        return Ok(step_result)
 
    }
 

	
 
    fn handle_sync_start(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx) {
 
        sched_ctx.log("Component starting sync mode");
 
        self.consensus.notify_sync_start(comp_ctx);
 
        for message in self.inbox_main.iter() {
 
            if let Some(message) = message {
 
                self.consensus.handle_new_data_message(comp_ctx, message);
 
            }
 
        }
 
        debug_assert_eq!(self.mode, Mode::NonSync);
 
        self.mode = Mode::Sync;
 
    }
 

	
 
    /// Handles end of sync. The conclusion to the sync round might arise
 
    /// immediately (and be handled immediately), or might come later through
 
    /// messaging. In any case the component should be scheduled again
 
    /// immediately
 
    fn handle_sync_end(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx) {
 
        sched_ctx.log("Component ending sync mode (now waiting for solution)");
 
        let decision = self.consensus.notify_sync_end(sched_ctx, comp_ctx);
 
        self.mode = Mode::SyncEnd;
 
        self.handle_sync_decision(sched_ctx, comp_ctx, decision);
 
    }
 

	
 
    /// Handles decision from the consensus round. This will cause a change in
 
    /// the internal `Mode`, such that the next call to `run` can take the
 
    /// appropriate next steps.
 
    fn handle_sync_decision(&mut self, sched_ctx: &SchedulerCtx, _comp_ctx: &mut CompCtx, decision: SyncRoundDecision) {
 
        sched_ctx.log(&format!("Handling sync decision: {:?} (in mode {:?})", decision, self.mode));
 
        let is_success = match decision {
 
            SyncRoundDecision::None => {
 
                // No decision yet
 
                return;
 
            },
 
            SyncRoundDecision::Solution => true,
 
            SyncRoundDecision::Failure => false,
 
        };
 

	
 
        // If here then we've reached a decision
 
        debug_assert_eq!(self.mode, Mode::SyncEnd);
 
        if is_success {
 
            self.mode = Mode::NonSync;
 
            self.consensus.notify_sync_decision(decision);
 
        } else {
 
            self.mode = Mode::StartExit;
 
        }
 
    }
 

	
 
    fn handle_component_exit(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx) {
 
        sched_ctx.log("Component exiting");
 
        debug_assert_eq!(self.mode, Mode::StartExit);
 
        self.mode = Mode::BusyExit;
 

	
 
        // Doing this by index, then retrieving the handle is a bit rediculous,
 
        // but Rust is being Rust with its borrowing rules.
 
        for port_index in 0..comp_ctx.num_ports() {
 
            let port = comp_ctx.get_port_by_index_mut(port_index);
 
            if port.state == PortState::Closed {
 
                // Already closed, or in the process of being closed
 
                continue;
 
            }
 

	
 
            // Mark as closed
 
            let port_id = port.self_id;
 
            port.state = PortState::Closed;
 

	
 
            // Notify peer of closing
 
            let port_handle = comp_ctx.get_port_handle(port_id);
 
            let (peer, message) = self.control.initiate_port_closing(port_handle, comp_ctx);
 
            let peer_info = comp_ctx.get_peer(peer);
 
            peer_info.handle.send_message(sched_ctx, Message::Control(message), true);
 
        }
 
    }
 

	
 
    // -------------------------------------------------------------------------
 
    // Handling messages
 
    // -------------------------------------------------------------------------
 

	
 
    fn send_data_message_and_wake_up(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &CompCtx, source_port_handle: LocalPortHandle, value: ValueGroup) {
 
        let port_info = comp_ctx.get_port(source_port_handle);
 
        let peer_handle = comp_ctx.get_peer_handle(port_info.peer_comp_id);
 
        let peer_info = comp_ctx.get_peer(peer_handle);
 
        let annotated_message = self.consensus.annotate_data_message(comp_ctx, port_info, value);
 
        peer_info.handle.send_message(sched_ctx, Message::Data(annotated_message), true);
 
@@ -786,240 +798,239 @@ impl CompPDL {
 
            creator_id: PortId,
 
            created_handle: LocalPortHandle,
 
            created_id: PortId,
 
        }
 
        let mut port_id_pairs = Vec::new();
 

	
 
        let reservation = sched_ctx.runtime.start_create_pdl_component();
 
        let mut created_ctx = CompCtx::new(&reservation);
 

	
 
        // Take all the ports ID that are in the `args` (and currently belong to
 
        // the creator component) and translate them into new IDs that are
 
        // associated with the component we're about to create
 
        let mut arg_iter = ValueGroupIter::new(&mut arguments);
 
        while let Some(port_reference) = arg_iter.next() {
 
            // Create port entry for new component
 
            let creator_port_id = port_reference.id;
 
            let creator_port_handle = creator_ctx.get_port_handle(creator_port_id);
 
            let creator_port = creator_ctx.get_port(creator_port_handle);
 
            let created_port_handle = created_ctx.add_port(
 
                creator_port.peer_comp_id, creator_port.peer_port_id,
 
                creator_port.kind, creator_port.state
 
            );
 
            let created_port = created_ctx.get_port(created_port_handle);
 
            let created_port_id = created_port.self_id;
 

	
 
            port_id_pairs.push(PortPair{
 
                creator_handle: creator_port_handle,
 
                creator_id: creator_port_id,
 
                created_handle: created_port_handle,
 
                created_id: created_port_id,
 
            });
 

	
 
            // Modify value in arguments (bit dirty, but double vec in ValueGroup causes lifetime issues)
 
            let arg_value = if let Some(heap_pos) = port_reference.heap_pos {
 
                &mut arg_iter.group.regions[heap_pos][port_reference.index]
 
            } else {
 
                &mut arg_iter.group.values[port_reference.index]
 
            };
 
            match arg_value {
 
                Value::Input(id) => *id = port_id_to_eval(created_port_id),
 
                Value::Output(id) => *id = port_id_to_eval(created_port_id),
 
                _ => unreachable!(),
 
            }
 
        }
 

	
 
        // For each transferred port pair set their peer components to the
 
        // correct values. This will only change the values for the ports of
 
        // the new component.
 
        let mut created_component_has_remote_peers = false;
 

	
 
        for pair in port_id_pairs.iter() {
 
            let creator_port_info = creator_ctx.get_port(pair.creator_handle);
 
            let created_port_info = created_ctx.get_port_mut(pair.created_handle);
 

	
 
            if created_port_info.peer_comp_id == creator_ctx.id {
 
                // Port peer is owned by the creator as well
 
                let created_peer_port_index = port_id_pairs
 
                    .iter()
 
                    .position(|v| v.creator_id == creator_port_info.peer_port_id);
 
                match created_peer_port_index {
 
                    Some(created_peer_port_index) => {
 
                        // Peer port moved to the new component as well. So
 
                        // adjust IDs appropriately.
 
                        let peer_pair = &port_id_pairs[created_peer_port_index];
 
                        created_port_info.peer_port_id = peer_pair.created_id;
 
                        created_port_info.peer_comp_id = reservation.id();
 
                        todo!("either add 'self peer', or remove that idea from Ctx altogether")
 
                    },
 
                    None => {
 
                        // Peer port remains with creator component.
 
                        created_port_info.peer_comp_id = creator_ctx.id;
 
                        created_ctx.add_peer(pair.created_handle, sched_ctx, creator_ctx.id, None);
 
                    }
 
                }
 
            } else {
 
                // Peer is a different component. We'll deal with sending the
 
                // appropriate messages later
 
                let peer_handle = creator_ctx.get_peer_handle(created_port_info.peer_comp_id);
 
                let peer_info = creator_ctx.get_peer(peer_handle);
 
                created_ctx.add_peer(pair.created_handle, sched_ctx, peer_info.id, Some(&peer_info.handle));
 
                created_component_has_remote_peers = true;
 
            }
 
        }
 

	
 
        // We'll now actually turn our reservation for a new component into an
 
        // actual component. Note that we initialize it as "not sleeping" as
 
        // its initial scheduling might be performed based on `Ack`s in response
 
        // to message exchanges between remote peers.
 
        let prompt = Prompt::new(
 
            &sched_ctx.runtime.protocol.types, &sched_ctx.runtime.protocol.heap,
 
            definition_id, type_id, arguments,
 
        );
 
        let component = CompPDL::new(prompt, port_id_pairs.len());
 
        let (created_key, component) = sched_ctx.runtime.finish_create_pdl_component(
 
            reservation, component, created_ctx, false,
 
        );
 
        let created_ctx = &component.ctx;
 

	
 
        // Now modify the creator's ports: remove every transferred port and
 
        // potentially remove the peer component. Here is also where we will
 
        // transfer messages in the main inbox.
 
        // potentially remove the peer component.
 
        for pair in port_id_pairs.iter() {
 
            // Remove peer if appropriate
 
            let creator_port_info = creator_ctx.get_port(pair.creator_handle);
 
            let creator_port_index = creator_ctx.get_port_index(pair.creator_handle);
 
            let creator_peer_comp_id = creator_port_info.peer_comp_id;
 
            creator_ctx.remove_peer(sched_ctx, pair.creator_handle, creator_peer_comp_id, false);
 
            creator_ctx.remove_port(pair.creator_handle);
 

	
 
            // Transfer any messages
 
            let created_port_index = created_ctx.get_port_index(pair.created_handle);
 
            let created_port_info = created_ctx.get_port(pair.created_handle);
 
            debug_assert!(component.code.inbox_main[created_port_index].is_none());
 
            if let Some(mut message) = self.inbox_main.remove(creator_port_index) {
 
                message.data_header.target_port = pair.created_id;
 
                component.code.inbox_main[created_port_index] = Some(message);
 
                component.component.adopt_message(&mut component.ctx, message)
 
            }
 

	
 
            let mut message_index = 0;
 
            while message_index < self.inbox_backup.len() {
 
                let message = &self.inbox_backup[message_index];
 
                if message.data_header.target_port == pair.creator_id {
 
                    // transfer message
 
                    let mut message = self.inbox_backup.remove(message_index);
 
                    message.data_header.target_port = pair.created_id;
 
                    component.code.inbox_backup.push(message);
 
                    component.component.adopt_message(&mut component.ctx, message);
 
                } else {
 
                    message_index += 1;
 
                }
 
            }
 

	
 
            // Handle potential channel between creator and created component
 
            let created_port_info = component.ctx.get_port(pair.created_handle);
 

	
 
            if created_port_info.peer_comp_id == creator_ctx.id {
 
                let peer_port_handle = creator_ctx.get_port_handle(created_port_info.peer_port_id);
 
                let peer_port_info = creator_ctx.get_port_mut(peer_port_handle);
 
                peer_port_info.peer_comp_id = created_ctx.id;
 
                peer_port_info.peer_comp_id = component.ctx.id;
 
                peer_port_info.peer_port_id = created_port_info.self_id;
 
                creator_ctx.add_peer(peer_port_handle, sched_ctx, created_ctx.id, None);
 
                creator_ctx.add_peer(peer_port_handle, sched_ctx, component.ctx.id, None);
 
            }
 
        }
 

	
 
        // By now all ports have been transferred. We'll now do any of the setup
 
        // for rerouting/messaging
 
        // By now all ports and messages have been transferred. If there are any
 
        // peers that need to be notified about this new component, then we
 
        // initiate the protocol that will notify everyone here.
 
        if created_component_has_remote_peers {
 
            let created_ctx = &component.ctx;
 
            let schedule_entry_id = self.control.add_schedule_entry(created_ctx.id);
 
            for pair in port_id_pairs.iter() {
 
                let port_info = created_ctx.get_port(pair.created_handle);
 
                if port_info.peer_comp_id != creator_ctx.id && port_info.peer_comp_id != created_ctx.id {
 
                    let message = self.control.add_reroute_entry(
 
                        creator_ctx.id, port_info.peer_port_id, port_info.peer_comp_id,
 
                        pair.creator_id, pair.created_id, created_ctx.id,
 
                        schedule_entry_id
 
                    );
 
                    let peer_handle = created_ctx.get_peer_handle(port_info.peer_comp_id);
 
                    let peer_info = created_ctx.get_peer(peer_handle);
 
                    peer_info.handle.send_message(sched_ctx, message, true);
 
                }
 
            }
 
        } else {
 
            // Peer can be scheduled immediately
 
            sched_ctx.runtime.enqueue_work(created_key);
 
        }
 
    }
 
}
 

	
 
#[inline]
 
fn port_id_from_eval(port_id: EvalPortId) -> PortId {
 
    return PortId(port_id.id);
 
}
 

	
 
#[inline]
 
fn port_id_to_eval(port_id: PortId) -> EvalPortId {
 
    return EvalPortId{ id: port_id.0 };
 
}
 

	
 
/// Recursively goes through the value group, attempting to find ports.
 
/// Duplicates will only be added once.
 
pub(crate) fn find_ports_in_value_group(value_group: &ValueGroup, ports: &mut Vec<PortId>) {
 
    // Helper to check a value for a port and recurse if needed.
 
    fn find_port_in_value(group: &ValueGroup, value: &Value, ports: &mut Vec<PortId>) {
 
        match value {
 
            Value::Input(port_id) | Value::Output(port_id) => {
 
                // This is an actual port
 
                let cur_port = PortId(port_id.id);
 
                for prev_port in ports.iter() {
 
                    if *prev_port == cur_port {
 
                        // Already added
 
                        return;
 
                    }
 
                }
 

	
 
                ports.push(cur_port);
 
            },
 
            Value::Array(heap_pos) |
 
            Value::Message(heap_pos) |
 
            Value::String(heap_pos) |
 
            Value::Struct(heap_pos) |
 
            Value::Union(_, heap_pos) => {
 
                // Reference to some dynamic thing which might contain ports,
 
                // so recurse
 
                let heap_region = &group.regions[*heap_pos as usize];
 
                for embedded_value in heap_region {
 
                    find_port_in_value(group, embedded_value, ports);
 
                }
 
            },
 
            _ => {}, // values we don't care about
 
        }
 
    }
 

	
 
    // Clear the ports, then scan all the available values
 
    ports.clear();
 
    for value in &value_group.values {
 
        find_port_in_value(value_group, value, ports);
 
    }
 
}
 

	
 
struct ValueGroupIter<'a> {
 
    group: &'a mut ValueGroup,
 
    heap_stack: Vec<(usize, usize)>,
 
    index: usize,
 
}
 

	
 
impl<'a> ValueGroupIter<'a> {
 
    fn new(group: &'a mut ValueGroup) -> Self {
 
        return Self{ group, heap_stack: Vec::new(), index: 0 }
 
    }
 
}
 

	
 
struct ValueGroupPortRef {
 
    id: PortId,
 
    heap_pos: Option<usize>, // otherwise: on stack
 
    index: usize,
 
}
 

	
 
impl<'a> Iterator for ValueGroupIter<'a> {
 
    type Item = ValueGroupPortRef;
 

	
 
    fn next(&mut self) -> Option<Self::Item> {
 
        // Enter loop that keeps iterating until a port is found
 
        loop {
src/runtime2/component/mod.rs
Show inline comments
 
mod component_pdl;
 
mod component_context;
 
mod control_layer;
 
mod consensus;
 
mod component;
 

	
 
pub(crate) use component_pdl::{CompPDL, CompScheduling};
 
pub(crate) use component::{Component, CompScheduling};
 
pub(crate) use component_pdl::{CompPDL};
 
pub(crate) use component_context::CompCtx;
 
pub(crate) use control_layer::{ControlId};
 

	
 
use super::scheduler::*;
 
use super::runtime::*;
 

	
 
/// If the component is sleeping, then that flag will be atomically set to
 
/// false. If we're the ones that made that happen then we add it to the work
 
/// queue.
 
pub(crate) fn wake_up_if_sleeping(sched_ctx: &SchedulerCtx, comp_id: CompId, handle: &CompHandle) {
 
    use std::sync::atomic::Ordering;
 

	
 
    let should_wake_up = handle.sleeping
 
        .compare_exchange(true, false, Ordering::AcqRel, Ordering::Acquire)
 
        .is_ok();
 

	
 
    if should_wake_up {
 
        let comp_key = unsafe{ comp_id.upgrade() };
 
        sched_ctx.runtime.enqueue_work(comp_key);
 
    }
 
}
 
\ No newline at end of file
src/runtime2/mod.rs
Show inline comments
 
mod store;
 
mod runtime;
 
mod component;
 
mod communication;
 
mod scheduler;
 
#[cfg(test)] mod tests;
 

	
 
pub use runtime::Runtime;
 
pub(crate) use scheduler::SchedulerCtx;
 
pub(crate) use communication::Message;
 
\ No newline at end of file
 
pub(crate) use communication::{Message, ControlMessage, SyncMessage, DataMessage};
 
\ No newline at end of file
src/runtime2/runtime.rs
Show inline comments
 
use std::sync::{Arc, Mutex, Condvar};
 
use std::sync::atomic::{AtomicU32, AtomicBool, Ordering};
 
use std::collections::VecDeque;
 

	
 
use crate::protocol::*;
 

	
 
use super::communication::Message;
 
use super::component::{wake_up_if_sleeping, CompPDL, CompCtx};
 
use super::component::{Component, wake_up_if_sleeping, CompPDL, CompCtx};
 
use super::store::{ComponentStore, ComponentReservation, QueueDynMpsc, QueueDynProducer};
 
use super::scheduler::*;
 

	
 
// -----------------------------------------------------------------------------
 
// Component
 
// -----------------------------------------------------------------------------
 

	
 
/// Key to a component. Type system somewhat ensures that there can only be one
 
/// of these. Only with a key one may retrieve privately-accessible memory for
 
/// a component. Practically just a generational index, like `CompId` is.
 
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
 
pub(crate) struct CompKey(pub u32);
 

	
 
impl CompKey {
 
    pub(crate) fn downgrade(&self) -> CompId {
 
        return CompId(self.0);
 
    }
 
}
 

	
 
/// Generational ID of a component
 
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
 
pub struct CompId(pub u32);
 

	
 
impl CompId {
 
    pub(crate) fn new_invalid() -> CompId {
 
        return CompId(u32::MAX);
 
    }
 

	
 
    /// Upgrade component ID to component key. Unsafe because the caller needs
 
    /// to make sure that only one component key can exist at a time (to ensure
 
    /// a component can only be scheduled/executed by one thread).
 
    pub(crate) unsafe fn upgrade(&self) -> CompKey {
 
        return CompKey(self.0);
 
    }
 
}
 

	
 
/// Handle to a component that is being created.
 
pub(crate) struct CompReserved {
 
    reservation: ComponentReservation,
 
}
 

	
 
impl CompReserved {
 
    pub(crate) fn id(&self) -> CompId {
 
        return CompId(self.reservation.index)
 
    }
 
}
 

	
 
/// Private fields of a component, may only be modified by a single thread at
 
/// a time.
 
/// Representation of a runtime component. Contains the bookkeeping variables
 
/// for the schedulers, the publicly accessible fields, and the private fields
 
/// that should only be accessed by the thread running the component's routine.
 
pub(crate) struct RuntimeComp {
 
    pub public: CompPublic,
 
    pub code: CompPDL,
 
    pub component: Box<dyn Component>,
 
    pub ctx: CompCtx,
 
    pub inbox: QueueDynMpsc<Message>,
 
    pub exiting: bool,
 
}
 

	
 
/// Should contain everything that is accessible in a thread-safe manner
 
// TODO: Do something about the `num_handles` thing. This needs to be a bit more
 
//  "foolproof" to lighten the mental burden of using the `num_handles`
 
//  variable.
 
pub(crate) struct CompPublic {
 
    pub sleeping: AtomicBool,
 
    pub num_handles: AtomicU32, // manually modified (!)
 
    inbox: QueueDynProducer<Message>,
 
}
 

	
 
/// Handle to public part of a component. Would be nice if we could
 
/// automagically manage the `num_handles` counter. But when it reaches zero we
 
/// need to manually remove the handle from the runtime. So we just have debug
 
/// code to make sure this actually happens.
 
pub(crate) struct CompHandle {
 
    target: *const CompPublic,
 
    id: CompId, // TODO: @Remove after debugging
 
    #[cfg(debug_assertions)] decremented: bool,
 
}
 

	
 
impl CompHandle {
 
    fn new(id: CompId, public: &CompPublic) -> CompHandle {
 
        let handle = CompHandle{
 
            target: public,
 
            id,
 
            #[cfg(debug_assertions)] decremented: false,
 
        };
 
        handle.increment_users();
 
        return handle;
 
    }
 

	
 
    pub(crate) fn send_message(&self, sched_ctx: &SchedulerCtx, message: Message, try_wake_up: bool) {
 
        sched_ctx.log(&format!("Sending message to [c:{:03}, wakeup:{}]: {:?}", self.id.0, try_wake_up, message));
 
        self.inbox.push(message);
 
        if try_wake_up {
 
            wake_up_if_sleeping(sched_ctx, self.id, self);
 
        }
 
    }
 

	
 
    fn increment_users(&self) {
 
        let old_count = self.num_handles.fetch_add(1, Ordering::AcqRel);
 
        debug_assert!(old_count > 0); // because we should never be able to retrieve a handle when the component is (being) destroyed
 
    }
 

	
 
    /// Returns the `CompKey` to the component if it should be destroyed
 
    pub(crate) fn decrement_users(&mut self) -> Option<CompKey> {
 
        dbg_code!(assert!(!self.decremented, "illegal to 'decrement_users' twice"));
 
        let old_count = self.num_handles.fetch_sub(1, Ordering::AcqRel);
 
        let new_count = old_count - 1;
 
        dbg_code!(self.decremented = true);
 
        if new_count == 0 {
 
            return Some(unsafe{ self.id.upgrade() });
 
        }
 

	
 
        return None;
 
    }
 
}
 

	
 
impl Clone for CompHandle {
 
    fn clone(&self) -> Self {
 
        dbg_code!(assert!(!self.decremented, "illegal to clone after 'decrement_users'"));
 
        self.increment_users();
 
        return CompHandle{
 
            target: self.target,
 
            id: self.id,
 
            #[cfg(debug_assertions)] decremented: false,
 
        };
 
    }
 
}
 

	
 
impl std::ops::Deref for CompHandle {
 
    type Target = CompPublic;
 

	
 
    fn deref(&self) -> &Self::Target {
 
        dbg_code!(assert!(!self.decremented)); // cannot access if control is relinquished
 
        return unsafe{ &*self.target };
 
    }
 
}
 

	
 
impl Drop for CompHandle {
 
    fn drop(&mut self) {
 
        dbg_code!(assert!(self.decremented, "need call to 'decrement_users' before dropping"));
 
    }
 
}
 

	
 
// -----------------------------------------------------------------------------
 
// Runtime
 
// -----------------------------------------------------------------------------
 

	
 
pub struct Runtime {
 
    pub(crate) inner: Arc<RuntimeInner>,
 
    threads: Vec<std::thread::JoinHandle<()>>,
 
}
 

	
 
impl Runtime {
 
    // TODO: debug_logging should be removed at some point
 
    pub fn new(num_threads: u32, debug_logging: bool, protocol_description: ProtocolDescription) -> Runtime {
 
        assert!(num_threads > 0, "need a thread to perform work");
 
        let runtime_inner = Arc::new(RuntimeInner {
 
            protocol: protocol_description,
 
            components: ComponentStore::new(128),
 
            work_queue: Mutex::new(VecDeque::with_capacity(128)),
 
            work_condvar: Condvar::new(),
 
            active_elements: AtomicU32::new(1),
 
        });
 
        let mut runtime = Runtime {
 
            inner: runtime_inner,
 
            threads: Vec::with_capacity(num_threads as usize),
 
        };
 

	
 
        for thread_index in 0..num_threads {
 
            let mut scheduler = Scheduler::new(runtime.inner.clone(), thread_index, debug_logging);
 
            let thread_handle = std::thread::spawn(move || {
 
                scheduler.run();
 
            });
 

	
 
            runtime.threads.push(thread_handle);
 
        }
 

	
 
        return runtime;
 
    }
 

	
 
    pub fn create_component(&self, module_name: &[u8], routine_name: &[u8]) -> Result<(), ComponentCreationError> {
 
        use crate::protocol::eval::ValueGroup;
 
        let prompt = self.inner.protocol.new_component(
 
            module_name, routine_name,
 
            ValueGroup::new_stack(Vec::new())
 
        )?;
 
        let reserved = self.inner.start_create_pdl_component();
 
        let ctx = CompCtx::new(&reserved);
 
        let (key, _) = self.inner.finish_create_pdl_component(reserved, CompPDL::new(prompt, 0), ctx, false);
 
        self.inner.enqueue_work(key);
 

	
 
        return Ok(())
 
    }
 
}
 

	
 
impl Drop for Runtime {
 
    fn drop(&mut self) {
 
        self.inner.decrement_active_components();
 
        for handle in self.threads.drain(..) {
 
            handle.join().expect("join scheduler thread");
 
        }
 
    }
 
}
 

	
 
/// Memory that is maintained by "the runtime". In practice it is maintained by
 
/// multiple schedulers, and this serves as the common interface to that memory.
 
pub(crate) struct RuntimeInner {
 
    pub protocol: ProtocolDescription,
 
    components: ComponentStore<RuntimeComp>,
 
    work_queue: Mutex<VecDeque<CompKey>>,
 
    work_condvar: Condvar,
 
    active_elements: AtomicU32, // active components and APIs (i.e. component creators)
 
}
 

	
 
impl RuntimeInner {
 
    // Scheduling and retrieving work
 

	
 
    pub(crate) fn take_work(&self) -> Option<CompKey> {
 
        let mut lock = self.work_queue.lock().unwrap();
 
        while lock.is_empty() && self.active_elements.load(Ordering::Acquire) != 0 {
 
            lock = self.work_condvar.wait(lock).unwrap();
 
        }
 

	
 
        // We have work, or the schedulers should exit.
 
        return lock.pop_front();
 
    }
 

	
 
    pub(crate) fn enqueue_work(&self, key: CompKey) {
 
        let mut lock = self.work_queue.lock().unwrap();
 
        lock.push_back(key);
 
        self.work_condvar.notify_one();
 
    }
 

	
 
    // Creating/destroying components
 

	
 
    pub(crate) fn start_create_pdl_component(&self) -> CompReserved {
 
        self.increment_active_components();
 
        let reservation = self.components.reserve();
 
        return CompReserved{ reservation };
 
    }
 

	
 
    pub(crate) fn finish_create_pdl_component(
 
    pub(crate) fn finish_create_pdl_component<C: 'static + Component>(
 
        &self, reserved: CompReserved,
 
        component: CompPDL, mut context: CompCtx, initially_sleeping: bool,
 
        component: C, mut context: CompCtx, initially_sleeping: bool,
 
    ) -> (CompKey, &mut RuntimeComp) {
 
        let inbox_queue = QueueDynMpsc::new(16);
 
        let inbox_producer = inbox_queue.producer();
 

	
 
        let _id = reserved.id();
 
        context.id = reserved.id();
 
        let component = RuntimeComp {
 
            public: CompPublic{
 
                sleeping: AtomicBool::new(initially_sleeping),
 
                num_handles: AtomicU32::new(1), // the component itself acts like a handle
 
                inbox: inbox_producer,
 
            },
 
            code: component,
 
            component: Box::new(component),
 
            ctx: context,
 
            inbox: inbox_queue,
 
            exiting: false,
 
        };
 

	
 
        let index = self.components.submit(reserved.reservation, component);
 
        debug_assert_eq!(index, _id.0);
 
        let component = self.components.get_mut(index);
 

	
 
        return (CompKey(index), component);
 
    }
 

	
 
    pub(crate) fn get_component(&self, key: CompKey) -> &mut RuntimeComp {
 
        let component = self.components.get_mut(key.0);
 
        return component;
 
    }
 

	
 
    pub(crate) fn get_component_public(&self, id: CompId) -> CompHandle {
 
        let component = self.components.get(id.0);
 
        return CompHandle::new(id, &component.public);
 
    }
 

	
 
    pub(crate) fn destroy_component(&self, key: CompKey) {
 
        dbg_code!({
 
            let component = self.get_component(key);
 
            debug_assert!(component.exiting);
 
            debug_assert_eq!(component.public.num_handles.load(Ordering::Acquire), 0);
 
        });
 
        self.decrement_active_components();
 
        self.components.destroy(key.0);
 
    }
 

	
 
    // Tracking number of active interfaces and the active components
 

	
 
    #[inline]
 
    fn increment_active_components(&self) {
 
        let _old_val = self.active_elements.fetch_add(1, Ordering::AcqRel);
 
        debug_assert!(_old_val > 0); // can only create a component from a API/component, so can never be 0.
 
    }
 

	
 
    fn decrement_active_components(&self) {
 
        let old_val = self.active_elements.fetch_sub(1, Ordering::AcqRel);
 
        debug_assert!(old_val > 0); // something wrong with incr/decr logic
 
        let new_val = old_val - 1;
 
        if new_val == 0 {
 
            // Just to be sure, in case the last thing that gets destroyed is an
 
            // API instead of a thread.
 
            let _lock = self.work_queue.lock();
 
            self.work_condvar.notify_all();
 
        }
 
    }
 
}
src/runtime2/scheduler.rs
Show inline comments
 
use std::sync::Arc;
 
use std::sync::atomic::Ordering;
 

	
 
use super::component::*;
 
use super::runtime::*;
 

	
 
/// Data associated with a scheduler thread
 
pub(crate) struct Scheduler {
 
    runtime: Arc<RuntimeInner>,
 
    scheduler_id: u32,
 
    debug_logging: bool,
 
}
 

	
 
pub(crate) struct SchedulerCtx<'a> {
 
    pub runtime: &'a RuntimeInner,
 
    pub id: u32,
 
    pub comp: u32,
 
    pub logging_enabled: bool,
 
}
 

	
 
impl<'a> SchedulerCtx<'a> {
 
    pub fn new(runtime: &'a RuntimeInner, id: u32, logging_enabled: bool) -> Self {
 
        return Self {
 
            runtime,
 
            id,
 
            comp: 0,
 
            logging_enabled,
 
        }
 
    }
 

	
 
    pub(crate) fn log(&self, text: &str) {
 
        if self.logging_enabled {
 
            println!("[s:{:02}, c:{:03}] {}", self.id, self.comp, text);
 
        }
 
    }
 
}
 

	
 
impl Scheduler {
 
    // public interface to thread
 

	
 
    pub fn new(runtime: Arc<RuntimeInner>, scheduler_id: u32, debug_logging: bool) -> Self {
 
        return Scheduler{ runtime, scheduler_id, debug_logging }
 
    }
 

	
 
    pub fn run(&mut self) {
 
        let mut scheduler_ctx = SchedulerCtx::new(&*self.runtime, self.scheduler_id, self.debug_logging);
 

	
 
        'run_loop: loop {
 
            // Wait until we have something to do (or need to quit)
 
            let comp_key = self.runtime.take_work();
 
            if comp_key.is_none() {
 
                break 'run_loop;
 
            }
 

	
 
            let comp_key = comp_key.unwrap();
 
            let component = self.runtime.get_component(comp_key);
 
            scheduler_ctx.comp = comp_key.0;
 

	
 
            // Run the component until it no longer indicates that it needs to
 
            // be re-executed immediately.
 
            let mut new_scheduling = CompScheduling::Immediate;
 
            while let CompScheduling::Immediate = new_scheduling {
 
                while let Some(message) = component.inbox.pop() {
 
                    component.code.handle_message(&mut scheduler_ctx, &mut component.ctx, message);
 
                    component.component.handle_message(&mut scheduler_ctx, &mut component.ctx, message);
 
                }
 
                new_scheduling = component.code.run(&mut scheduler_ctx, &mut component.ctx).expect("TODO: Handle error");
 
                new_scheduling = component.component.run(&mut scheduler_ctx, &mut component.ctx).expect("TODO: Handle error");
 
            }
 

	
 
            // Handle the new scheduling
 
            match new_scheduling {
 
                CompScheduling::Immediate => unreachable!(),
 
                CompScheduling::Requeue => { self.runtime.enqueue_work(comp_key); },
 
                CompScheduling::Sleep => { self.mark_component_as_sleeping(comp_key, component); },
 
                CompScheduling::Exit => { self.mark_component_as_exiting(&scheduler_ctx, component); }
 
            }
 
        }
 
    }
 

	
 
    // local utilities
 

	
 
    /// Marks component as sleeping, if after marking itself as sleeping the
 
    /// inbox contains messages then the component will be immediately
 
    /// rescheduled. After calling this function the component should not be
 
    /// executed anymore.
 
    fn mark_component_as_sleeping(&self, key: CompKey, component: &mut RuntimeComp) {
 
        debug_assert_eq!(key.downgrade(), component.ctx.id); // make sure component matches key
 
        debug_assert_eq!(component.public.sleeping.load(Ordering::Acquire), false); // we're executing it, so it cannot be sleeping
 

	
 
        component.public.sleeping.store(true, Ordering::Release);
 
        if component.inbox.can_pop() {
 
            let should_reschedule = component.public.sleeping
 
                .compare_exchange(true, false, Ordering::AcqRel, Ordering::Relaxed)
 
                .is_ok();
 

	
 
            if should_reschedule {
 
                self.runtime.enqueue_work(key);
 
            }
 
        }
 
    }
 

	
 
    /// Marks the component as exiting by removing the reference it holds to
 
    /// itself. Afterward the component will enter "normal" sleeping mode (if it
 
    /// has not yet been destroyed)
 
    fn mark_component_as_exiting(&self, sched_ctx: &SchedulerCtx, component: &mut RuntimeComp) {
 
        // If we didn't yet decrement our reference count, do so now
 
        let comp_key = unsafe{ component.ctx.id.upgrade() };
 

	
 
        if !component.exiting {
 
            component.exiting = true;
 

	
 
            let old_count = component.public.num_handles.fetch_sub(1, Ordering::AcqRel);
 
            let new_count = old_count - 1;
 
            if new_count == 0 {
 
                sched_ctx.runtime.destroy_component(comp_key);
 
                return;
 
            }
 
        }
 

	
 
        // Enter "regular" sleeping mode
 
        self.mark_component_as_sleeping(comp_key, component);
 
    }
 
}
 
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