Struct Clock

pub struct Clock { /* private fields */ }

A clock with optional coarse granularity.

Implementations

impl Clock

pub fn new(utc_offset: UtcOffset, cache_precision: Option<Precision>) -> Self

Creates a new Clock with the specified UtcOffset and (optional) cache Precision (see Clock::read).

Examples found in repository

examples/basic.rs (line 109)

fn main() {
    // read in an xml file whose path is given as a command line argument
    let args = std::env::args().collect::<Vec<_>>();
    if args.len() != 2 {
        panic!("usage: {} [xml file]", &args[0]);
    }
    let mut xml = String::new();
    std::fs::File::open(&args[1]).expect("failed to open file").read_to_string(&mut xml).expect("failed to read file");

    // create a new shared clock and start a thread that updates it at our desired interval
    let clock = Arc::new(Clock::new(UtcOffset::UTC, Some(Precision::Medium)));
    let clock_clone = clock.clone();
    std::thread::spawn(move || loop {
        std::thread::sleep(CLOCK_INTERVAL);
        clock_clone.update();
    });

    // create a custom config for the system - in this simple example we just implement the say/think blocks to print to stdout
    let config = Config::<C, StdSystem<C>> {
        request: None,
        command: Some(Rc::new(|_mc, key, command, _proc| match command {
            Command::Print { style: _, value } => {
                if let Some(value) = value {
                    println!("{value:?}");
                }
                key.complete(Ok(())); // any request that you handle must be completed - otherwise the calling process will hang forever
                CommandStatus::Handled
            }
            _ => CommandStatus::UseDefault { key, command }, // anything you don't handle should return the key and command to invoke the default behavior instead
        })),
    };

    // initialize our system with all the info we've put together
    let system = Rc::new(StdSystem::new_sync(CompactString::new(BASE_URL), None, config, clock.clone()));
    let mut env = get_running_project(&xml, system);

    // begin running the code - these are some helpers to make things more efficient in terms of memory and cpu resources
    let mut idle_sleeper = IdleAction::new(YIELDS_BEFORE_SLEEP, Box::new(|| std::thread::sleep(IDLE_SLEEP_TIME)));
    let mut next_collect = clock.read(Precision::Medium) + COLLECT_INTERVAL;
    loop {
        env.mutate(|mc, env| {
            let mut proj = env.proj.borrow_mut(mc);
            for _ in 0..1024 {
                // step the virtual machine forward by one bytecode instruction
                let res = proj.step(mc);
                if let ProjectStep::Error { error, proc } = &res {
                    // if we get an error, we can generate an error summary including a stack trace - here we just print out the result
                    let trace = ErrorSummary::extract(error, proc, &env.locs);
                    println!("error: {error:?}\ntrace: {trace:?}");
                }
                // this takes care of performing thread sleep if we get a bunch of no-ops from proj.step back to back
                idle_sleeper.consume(&res);
            }
        });
        // if it's time for us to do garbage collection, do it and reset the next collection time
        if clock.read(Precision::Low) >= next_collect {
            env.collect_all();
            next_collect = clock.read(Precision::Medium) + COLLECT_INTERVAL;
        }
    }
}

pub fn read(&self, precision: Precision) -> OffsetDateTime

Reads the current time with the specified level of precision. If caching was enabled by Clock::new, requests at or below the cache precision level will use the cached timestamp. In any other case, the real current time is fetched by Clock::update and the result is stored in the cache if caching is enabled.

Examples found in repository

examples/basic.rs (line 137)

fn main() {
    // read in an xml file whose path is given as a command line argument
    let args = std::env::args().collect::<Vec<_>>();
    if args.len() != 2 {
        panic!("usage: {} [xml file]", &args[0]);
    }
    let mut xml = String::new();
    std::fs::File::open(&args[1]).expect("failed to open file").read_to_string(&mut xml).expect("failed to read file");

    // create a new shared clock and start a thread that updates it at our desired interval
    let clock = Arc::new(Clock::new(UtcOffset::UTC, Some(Precision::Medium)));
    let clock_clone = clock.clone();
    std::thread::spawn(move || loop {
        std::thread::sleep(CLOCK_INTERVAL);
        clock_clone.update();
    });

    // create a custom config for the system - in this simple example we just implement the say/think blocks to print to stdout
    let config = Config::<C, StdSystem<C>> {
        request: None,
        command: Some(Rc::new(|_mc, key, command, _proc| match command {
            Command::Print { style: _, value } => {
                if let Some(value) = value {
                    println!("{value:?}");
                }
                key.complete(Ok(())); // any request that you handle must be completed - otherwise the calling process will hang forever
                CommandStatus::Handled
            }
            _ => CommandStatus::UseDefault { key, command }, // anything you don't handle should return the key and command to invoke the default behavior instead
        })),
    };

    // initialize our system with all the info we've put together
    let system = Rc::new(StdSystem::new_sync(CompactString::new(BASE_URL), None, config, clock.clone()));
    let mut env = get_running_project(&xml, system);

    // begin running the code - these are some helpers to make things more efficient in terms of memory and cpu resources
    let mut idle_sleeper = IdleAction::new(YIELDS_BEFORE_SLEEP, Box::new(|| std::thread::sleep(IDLE_SLEEP_TIME)));
    let mut next_collect = clock.read(Precision::Medium) + COLLECT_INTERVAL;
    loop {
        env.mutate(|mc, env| {
            let mut proj = env.proj.borrow_mut(mc);
            for _ in 0..1024 {
                // step the virtual machine forward by one bytecode instruction
                let res = proj.step(mc);
                if let ProjectStep::Error { error, proc } = &res {
                    // if we get an error, we can generate an error summary including a stack trace - here we just print out the result
                    let trace = ErrorSummary::extract(error, proc, &env.locs);
                    println!("error: {error:?}\ntrace: {trace:?}");
                }
                // this takes care of performing thread sleep if we get a bunch of no-ops from proj.step back to back
                idle_sleeper.consume(&res);
            }
        });
        // if it's time for us to do garbage collection, do it and reset the next collection time
        if clock.read(Precision::Low) >= next_collect {
            env.collect_all();
            next_collect = clock.read(Precision::Medium) + COLLECT_INTERVAL;
        }
    }
}

pub fn update(&self) -> OffsetDateTime

Reads the real world time and stores the result in the cache if caching was enabled by Clock::new.

Examples found in repository

examples/basic.rs (line 113)

fn main() {
    // read in an xml file whose path is given as a command line argument
    let args = std::env::args().collect::<Vec<_>>();
    if args.len() != 2 {
        panic!("usage: {} [xml file]", &args[0]);
    }
    let mut xml = String::new();
    std::fs::File::open(&args[1]).expect("failed to open file").read_to_string(&mut xml).expect("failed to read file");

    // create a new shared clock and start a thread that updates it at our desired interval
    let clock = Arc::new(Clock::new(UtcOffset::UTC, Some(Precision::Medium)));
    let clock_clone = clock.clone();
    std::thread::spawn(move || loop {
        std::thread::sleep(CLOCK_INTERVAL);
        clock_clone.update();
    });

    // create a custom config for the system - in this simple example we just implement the say/think blocks to print to stdout
    let config = Config::<C, StdSystem<C>> {
        request: None,
        command: Some(Rc::new(|_mc, key, command, _proc| match command {
            Command::Print { style: _, value } => {
                if let Some(value) = value {
                    println!("{value:?}");
                }
                key.complete(Ok(())); // any request that you handle must be completed - otherwise the calling process will hang forever
                CommandStatus::Handled
            }
            _ => CommandStatus::UseDefault { key, command }, // anything you don't handle should return the key and command to invoke the default behavior instead
        })),
    };

    // initialize our system with all the info we've put together
    let system = Rc::new(StdSystem::new_sync(CompactString::new(BASE_URL), None, config, clock.clone()));
    let mut env = get_running_project(&xml, system);

    // begin running the code - these are some helpers to make things more efficient in terms of memory and cpu resources
    let mut idle_sleeper = IdleAction::new(YIELDS_BEFORE_SLEEP, Box::new(|| std::thread::sleep(IDLE_SLEEP_TIME)));
    let mut next_collect = clock.read(Precision::Medium) + COLLECT_INTERVAL;
    loop {
        env.mutate(|mc, env| {
            let mut proj = env.proj.borrow_mut(mc);
            for _ in 0..1024 {
                // step the virtual machine forward by one bytecode instruction
                let res = proj.step(mc);
                if let ProjectStep::Error { error, proc } = &res {
                    // if we get an error, we can generate an error summary including a stack trace - here we just print out the result
                    let trace = ErrorSummary::extract(error, proc, &env.locs);
                    println!("error: {error:?}\ntrace: {trace:?}");
                }
                // this takes care of performing thread sleep if we get a bunch of no-ops from proj.step back to back
                idle_sleeper.consume(&res);
            }
        });
        // if it's time for us to do garbage collection, do it and reset the next collection time
        if clock.read(Precision::Low) >= next_collect {
            env.collect_all();
            next_collect = clock.read(Precision::Medium) + COLLECT_INTERVAL;
        }
    }
}