Changeset - 07b6378685f2
[Not reviewed]
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MH - 4 years ago 2021-11-12 20:02:26
contact@maxhenger.nl
Add forking to the AST walker
4 files changed with 48 insertions and 1 deletions:
0 comments (0 inline, 0 general)
src/protocol/ast.rs
Show inline comments
 
@@ -1280,49 +1280,49 @@ pub struct SynchronousStatement {
 
    pub body: BlockStatementId,
 
    pub end_sync: EndSynchronousStatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct EndSynchronousStatement {
 
    pub this: EndSynchronousStatementId,
 
    pub start_sync: SynchronousStatementId,
 
    // Phase 2: linker
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct ForkStatement {
 
    pub this: ForkStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "fork" keyword
 
    pub left_body: BlockStatementId,
 
    pub right_body: Option<BlockStatementId>,
 
    pub end_fork: EndForkStatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct EndForkStatement {
 
    pub this: EndForKStatementId,
 
    pub this: EndForkStatementId,
 
    pub start_fork: ForkStatementId,
 
    pub next: StatementId,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct ReturnStatement {
 
    pub this: ReturnStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "return" keyword
 
    pub expressions: Vec<ExpressionId>,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct GotoStatement {
 
    pub this: GotoStatementId,
 
    // Phase 1: parser
 
    pub span: InputSpan, // of the "goto" keyword
 
    pub label: Identifier,
 
    // Phase 2: linker
 
    pub target: Option<LabeledStatementId>,
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct NewStatement {
src/protocol/eval/executor.rs
Show inline comments
 
@@ -179,48 +179,49 @@ impl Frame {
 
            }
 
            Expression::Call(expr) => {
 
                for arg_expr_id in &expr.arguments {
 
                    self.expr_stack.push_back(ExprInstruction::PushValToFront);
 
                    self.serialize_expression(heap, *arg_expr_id);
 
                }
 
            },
 
            Expression::Variable(_expr) => {
 
                // No subexpressions
 
            }
 
        }
 
    }
 
}
 

	
 
type EvalResult = Result<EvalContinuation, EvalError>;
 

	
 
pub enum EvalContinuation {
 
    Stepping,
 
    Inconsistent,
 
    Terminal,
 
    SyncBlockStart,
 
    SyncBlockEnd,
 
    NewComponent(DefinitionId, i32, ValueGroup),
 
    NewChannel,
 
    NewFork,
 
    BlockFires(PortId),
 
    BlockGet(PortId),
 
    Put(PortId, Value),
 
}
 

	
 
// Note: cloning is fine, methinks. cloning all values and the heap regions then
 
// we end up with valid "pointers" to heap regions.
 
#[derive(Debug, Clone)]
 
pub struct Prompt {
 
    pub(crate) frames: Vec<Frame>,
 
    pub(crate) store: Store,
 
}
 

	
 
impl Prompt {
 
    pub fn new(_types: &TypeTable, heap: &Heap, def: DefinitionId, monomorph_idx: i32, args: ValueGroup) -> Self {
 
        let mut prompt = Self{
 
            frames: Vec::new(),
 
            store: Store::new(),
 
        };
 

	
 
        // Maybe do typechecking in the future?
 
        debug_assert!((monomorph_idx as usize) < _types.get_base_definition(&def).unwrap().definition.procedure_monomorphs().len());
 
        let new_frame = Frame::new(heap, def, monomorph_idx);
 
        let max_stack_size = new_frame.max_stack_size;
 
@@ -865,48 +866,75 @@ impl Prompt {
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Break(stmt) => {
 
                cur_frame.position = stmt.target.unwrap().upcast();
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Continue(stmt) => {
 
                cur_frame.position = stmt.target.unwrap().upcast();
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::Synchronous(stmt) => {
 
                cur_frame.position = stmt.body.upcast();
 

	
 
                Ok(EvalContinuation::SyncBlockStart)
 
            },
 
            Statement::EndSynchronous(stmt) => {
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::SyncBlockEnd)
 
            },
 
            Statement::Fork(stmt) => {
 
                if stmt.right_body.is_none() {
 
                    // No reason to fork
 
                    cur_frame.position = stmt.left_body.upcast();
 
                } else {
 
                    // Need to fork
 
                    if let Some(go_left) = ctx.get_fork() {
 
                        // Runtime has created a fork
 
                        if go_left {
 
                            cur_frame.position = stmt.left_body.upcast();
 
                        } else {
 
                            cur_frame.position = stmt.right_body.unwrap().upcast();
 
                        }
 
                    } else {
 
                        // Request the runtime to create a fork of the current
 
                        // branch
 
                        return Ok(EvalContinuation::NewFork);
 
                    }
 
                }
 

	
 
                Ok(EvalContinuation::Stepping)
 
            },
 
            Statement::EndFork(stmt) => {
 
                cur_frame.position = stmt.next;
 

	
 
                Ok(EvalContinuation::Stepping)
 
            }
 
            Statement::Return(_stmt) => {
 
                debug_assert!(heap[cur_frame.definition].is_function());
 
                debug_assert_eq!(cur_frame.expr_values.len(), 1, "expected one expr value for return statement");
 

	
 
                // The preceding frame has executed a call, so is expecting the
 
                // return expression on its expression value stack. Note that
 
                // we may be returning a reference to something on our stack,
 
                // so we need to read that value and clone it.
 
                let return_value = cur_frame.expr_values.pop_back().unwrap();
 
                let return_value = match return_value {
 
                    Value::Ref(value_id) => self.store.read_copy(value_id),
 
                    _ => return_value,
 
                };
 

	
 
                // Pre-emptively pop our stack frame
 
                self.frames.pop();
 

	
 
                // Clean up our section of the stack
 
                self.store.clear_stack(0);
 
                self.store.stack.truncate(self.store.cur_stack_boundary + 1);
 
                let prev_stack_idx = self.store.stack.pop().unwrap().as_stack_boundary();
 

	
 
                // TODO: Temporary hack for testing, remove at some point
 
                if self.frames.is_empty() {
src/protocol/mod.rs
Show inline comments
 
@@ -266,90 +266,94 @@ impl ProtocolDescription {
 
                        if !self.verify_same_type(expected, expected_idx + 1, arguments, element) {
 
                            return false;
 
                        }
 
                    }
 
                    return true;
 
                } else {
 
                    return false;
 
                }
 
            },
 
            CTP::Input => if let Value::Input(_) = argument { true } else { false },
 
            CTP::Output => if let Value::Output(_) = argument { true } else { false },
 
            CTP::Instance(_definition_id, _num_embedded) => {
 
                todo!("implement full type checking on user-supplied arguments");
 
                return false;
 
            },
 
        }
 
    }
 
}
 

	
 
// TODO: @temp Should just become a concrete thing that is passed in
 
pub trait RunContext {
 
    fn did_put(&mut self, port: PortId) -> bool;
 
    fn get(&mut self, port: PortId) -> Option<ValueGroup>; // None if still waiting on message
 
    fn fires(&mut self, port: PortId) -> Option<Value>; // None if not yet branched
 
    fn get_fork(&mut self) -> Option<bool>; // None if not yet forked
 
    fn get_channel(&mut self) -> Option<(Value, Value)>; // None if not yet prepared
 
}
 

	
 
#[derive(Debug)]
 
pub enum RunResult {
 
    // Can only occur outside sync blocks
 
    ComponentTerminated, // component has exited its procedure
 
    ComponentAtSyncStart,
 
    NewComponent(DefinitionId, i32, ValueGroup), // should also be possible inside sync
 
    NewChannel, // should also be possible inside sync
 
    // Can only occur inside sync blocks
 
    BranchInconsistent, // branch has inconsistent behaviour
 
    BranchMissingPortState(PortId), // branch doesn't know about port firing
 
    BranchMissingPortValue(PortId), // branch hasn't received message on input port yet
 
    BranchAtSyncEnd,
 
    BranchFork,
 
    BranchPut(PortId, ValueGroup),
 
}
 

	
 
impl ComponentState {
 
    pub(crate) fn run(&mut self, ctx: &mut impl RunContext, pd: &ProtocolDescription) -> RunResult {
 
        use EvalContinuation as EC;
 
        use RunResult as RR;
 

	
 
        loop {
 
            let step_result = self.prompt.step(&pd.types, &pd.heap, &pd.modules, ctx);
 
            match step_result {
 
                Err(reason) => {
 
                    // TODO: @temp
 
                    println!("Evaluation error:\n{}", reason);
 
                    todo!("proper error handling/bubbling up");
 
                },
 
                Ok(continuation) => match continuation {
 
                    // TODO: Probably want to remove this translation
 
                    EC::Stepping => continue,
 
                    EC::Inconsistent => return RR::BranchInconsistent,
 
                    EC::Terminal => return RR::ComponentTerminated,
 
                    EC::SyncBlockStart => return RR::ComponentAtSyncStart,
 
                    EC::SyncBlockEnd => return RR::BranchAtSyncEnd,
 
                    EC::NewComponent(definition_id, monomorph_idx, args) =>
 
                        return RR::NewComponent(definition_id, monomorph_idx, args),
 
                    EC::NewChannel =>
 
                        return RR::NewChannel,
 
                    EC::NewFork =>
 
                        return RR::BranchFork,
 
                    EC::BlockFires(port_id) => return RR::BranchMissingPortState(port_id),
 
                    EC::BlockGet(port_id) => return RR::BranchMissingPortValue(port_id),
 
                    EC::Put(port_id, value) => {
 
                        let value_group = ValueGroup::from_store(&self.prompt.store, &[value]);
 
                        return RR::BranchPut(port_id, value_group);
 
                    },
 
                }
 
            }
 
        }
 
    }
 
}
 

	
 
// TODO: @remove the old stuff
 
impl ComponentState {
 
    pub(crate) fn nonsync_run<'a: 'b, 'b>(
 
        &'a mut self,
 
        context: &'b mut NonsyncProtoContext<'b>,
 
        pd: &'a ProtocolDescription,
 
    ) -> NonsyncBlocker {
 
        let mut context = EvalContext::Nonsync(context);
 
        loop {
 
            let result = self.prompt.step(&pd.types, &pd.heap, &pd.modules, &mut context);
 
            match result {
 
                Err(err) => {
 
@@ -377,81 +381,83 @@ impl ComponentState {
 
                                _ => {}
 
                            }
 
                        }
 
                        for region in args.regions.iter() {
 
                            for arg in region {
 
                                match arg {
 
                                    Value::Output(port) => { moved_ports.insert(*port); },
 
                                    Value::Input(port) => { moved_ports.insert(*port); },
 
                                    _ => {},
 
                                }
 
                            }
 
                        }
 
                        let init_state = ComponentState { prompt: Prompt::new(&pd.types, &pd.heap, definition_id, monomorph_idx, args) };
 
                        context.new_component(moved_ports, init_state);
 
                        // Continue stepping
 
                        continue;
 
                    },
 
                    EvalContinuation::NewChannel => {
 
                        // Because of the way we emulate the old context for now, we can safely
 
                        // assume that this will never happen. The old context thingamajig always
 
                        // creates a channel, it never bubbles a "need to create a channel" message
 
                        // to the runtime
 
                        unreachable!();
 
                    },
 
                    EvalContinuation::NewFork => unreachable!(),
 
                    // Outside synchronous blocks, no fires/get/put happens
 
                    EvalContinuation::BlockFires(_) => unreachable!(),
 
                    EvalContinuation::BlockGet(_) => unreachable!(),
 
                    EvalContinuation::Put(_, _) => unreachable!(),
 
                },
 
            }
 
        }
 
    }
 

	
 
    pub(crate) fn sync_run<'a: 'b, 'b>(
 
        &'a mut self,
 
        context: &'b mut SyncProtoContext<'b>,
 
        pd: &'a ProtocolDescription,
 
    ) -> SyncBlocker {
 
        let mut context = EvalContext::Sync(context);
 
        loop {
 
            let result = self.prompt.step(&pd.types, &pd.heap, &pd.modules, &mut context);
 
            match result {
 
                Err(err) => {
 
                    println!("Evaluation error:\n{}", err);
 
                    panic!("proper error handling when component fails");
 
                },
 
                Ok(cont) => match cont {
 
                    EvalContinuation::Stepping => continue,
 
                    EvalContinuation::Inconsistent => return SyncBlocker::Inconsistent,
 
                    // First need to exit synchronous block before definition may end
 
                    EvalContinuation::Terminal => unreachable!(),
 
                    // No nested synchronous blocks
 
                    EvalContinuation::SyncBlockStart => unreachable!(),
 
                    EvalContinuation::SyncBlockEnd => return SyncBlocker::SyncBlockEnd,
 
                    // Not possible to create component in sync block
 
                    EvalContinuation::NewComponent(_, _, _) => unreachable!(),
 
                    EvalContinuation::NewChannel => unreachable!(),
 
                    EvalContinuation::NewFork => unreachable!(),
 
                    EvalContinuation::BlockFires(port) => {
 
                        return SyncBlocker::CouldntCheckFiring(port);
 
                    },
 
                    EvalContinuation::BlockGet(port) => {
 
                        return SyncBlocker::CouldntReadMsg(port);
 
                    },
 
                    EvalContinuation::Put(port, message) => {
 
                        let payload;
 
                        match message {
 
                            Value::Null => {
 
                                return SyncBlocker::Inconsistent;
 
                            },
 
                            Value::Message(heap_pos) => {
 
                                // Create a copy of the payload
 
                                let values = &self.prompt.store.heap_regions[heap_pos as usize].values;
 
                                let mut bytes = Vec::with_capacity(values.len());
 
                                for value in values {
 
                                    bytes.push(value.as_uint8());
 
                                }
 
                                payload = Payload(Arc::new(bytes));
 
                            }
 
                            _ => unreachable!(),
 
                        }
 
                        return SyncBlocker::PutMsg(port, payload);
 
@@ -503,48 +509,53 @@ impl RunContext for EvalContext<'_> {
 
        match self {
 
            EvalContext::None => unreachable!(),
 
            EvalContext::Nonsync(_) => unreachable!(),
 
            EvalContext::Sync(context) => {
 
                match context.is_firing(port) {
 
                    Some(did_fire) => Some(Value::Bool(did_fire)),
 
                    None => None,
 
                }
 
            }
 
        }
 
    }
 

	
 
    fn get_channel(&mut self) -> Option<(Value, Value)> {
 
        match self {
 
            EvalContext::None => unreachable!(),
 
            EvalContext::Nonsync(context) => {
 
                let [from, to] = context.new_port_pair();
 
                let from = Value::Output(from);
 
                let to = Value::Input(to);
 
                return Some((from, to));
 
            },
 
            EvalContext::Sync(_) => unreachable!(),
 
        }
 
    }
 

	
 
    fn get_fork(&mut self) -> Option<bool> {
 
        // Never actually used in the old runtime
 
        return None;
 
    }
 
}
 

	
 
// TODO: @remove once old runtime has disappeared
 
impl EvalContext<'_> {
 
    // fn random(&mut self) -> LongValue {
 
    //     match self {
 
    //         // EvalContext::None => unreachable!(),
 
    //         EvalContext::Nonsync(_context) => todo!(),
 
    //         EvalContext::Sync(_) => unreachable!(),
 
    //     }
 
    // }
 
    fn new_component(&mut self, moved_ports: HashSet<PortId>, init_state: ComponentState) -> () {
 
        match self {
 
            EvalContext::None => unreachable!(),
 
            EvalContext::Nonsync(context) => {
 
                context.new_component(moved_ports, init_state)
 
            }
 
            EvalContext::Sync(_) => unreachable!(),
 
        }
 
    }
 
    fn new_channel(&mut self) -> [Value; 2] {
 
        match self {
 
            EvalContext::None => unreachable!(),
 
            EvalContext::Nonsync(context) => {
src/protocol/parser/pass_validation_linking.rs
Show inline comments
 
@@ -393,48 +393,56 @@ impl Visitor for PassValidationLinking {
 
                "synchronous statements may only be used in primitive components"
 
            ));
 
        }
 

	
 
        // Synchronous statement implicitly moves to its block
 
        assign_then_erase_next_stmt!(self, ctx, id.upcast());
 

	
 
        let sync_body = ctx.heap[id].body;
 
        debug_assert!(self.in_sync.is_invalid());
 
        self.in_sync = id;
 
        self.visit_block_stmt_with_hint(ctx, sync_body, Some(id))?;
 
        assign_and_replace_next_stmt!(self, ctx, end_sync_id.upcast());
 

	
 
        self.in_sync = SynchronousStatementId::new_invalid();
 

	
 
        Ok(())
 
    }
 

	
 
    fn visit_fork_stmt(&mut self, ctx: &mut Ctx, id: ForkStatementId) -> VisitorResult {
 
        let fork_stmt = &ctx.heap[id];
 
        let end_fork_id = fork_stmt.end_fork;
 
        let left_body_id = fork_stmt.left_body;
 
        let right_body_id = fork_stmt.right_body;
 

	
 
        // Fork statements may only occur inside sync blocks
 
        if self.in_sync.is_invalid() {
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module().source, fork_stmt.span,
 
                "Forking may only occur inside sync blocks"
 
            ));
 
        }
 

	
 
        // Visit the respective bodies. Like the if statement, a fork statement
 
        // does not have a single static subsequent statement. It forks and then
 
        // each fork has a different next statement.
 
        assign_then_erase_next_stmt!(self, ctx, id.upcast());
 
        self.visit_block_stmt(ctx, left_body_id)?;
 
        assign_then_erase_next_stmt!(self, ctx, end_fork_id.upcast());
 

	
 
        if let Some(right_body_id) = right_body_id {
 
            self.visit_block_stmt(ctx, right_body_id)?;
 
            assign_then_erase_next_stmt!(self, ctx, end_fork_id.upcast());
 
        }
 

	
 
        self.prev_stmt = end_fork_id.upcast();
 
        Ok(())
 
    }
 

	
 
    fn visit_return_stmt(&mut self, ctx: &mut Ctx, id: ReturnStatementId) -> VisitorResult {
 
        // Check if "return" occurs within a function
 
        let stmt = &ctx.heap[id];
 
        if !self.def_type.is_function() {
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module().source, stmt.span,
 
                "return statements may only appear in function bodies"
 
            ));
0 comments (0 inline, 0 general)