dscale 0.5.1

A fast & deterministic simulation framework for benchmarking and testing distributed systems
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136

use std::cmp::Reverse;

use crate::{
    Jiffies, ProcessHandle,
    events::{Event, RankHandlerEvent, TimedEvent},

    global::{
        configuration::setup_local_configuration,
        local_access::{self, setup_local_access},
    },
    network::Network,
    random::Seed,
    runners::{RunStatus, SimulationRunner, common::RunnerCore, task::TaskResult},
};

pub(crate) struct SimpleRunner {
    core: RunnerCore,
    procs: Vec<Box<dyn ProcessHandle>>,
}

impl SimpleRunner {
    pub(crate) fn new(
        network: Network,
        time_budget: Jiffies,
        procs: Vec<Box<dyn ProcessHandle>>,
        seed: Seed,
    ) -> Self {
        for id in 0..procs.len() {
            setup_local_configuration(id, seed);
        }
        let (tx, _rx) = crossbeam_channel::unbounded::<TaskResult>();
        setup_local_access(seed, tx);
        Self {
            core: RunnerCore::new(network, time_budget, procs.len()),
            procs,
        }
    }

    pub(crate) fn seed_events(&mut self, events: Vec<Reverse<TimedEvent>>) {
        self.core.seed_events(events);
    }

    fn ensure_started(&mut self) {
        if self.core.mark_started() {
            for rank in 0..self.procs.len() {
                self.core.event_queue.push(Reverse(TimedEvent {
                    invocation_time: Jiffies(0),
                    event: Event::Handler(RankHandlerEvent::Start { rank }),
                }));
            }
        }
    }

    fn run_loop(&mut self, deadline: Jiffies, max_steps: Option<usize>) -> RunStatus {
        self.ensure_started();
        let mut steps = 0;
        loop {
            if let Some(k) = max_steps {
                if steps >= k {
                    return RunStatus::Completed { steps };
                }
            }
            if self.core.clock.now() >= self.core.time_budget {
                return RunStatus::BudgetExhausted { steps };
            }
            if self.core.clock.now() >= deadline {
                return RunStatus::Completed { steps };
            }
            match self.core.event_queue.pop() {
                None => return RunStatus::NoMoreEvents { steps },
                Some(event) => {
                    steps += self.step(event.0);
                }
            }
        }
    }

    fn step(&mut self, timed_event: TimedEvent) -> usize {
        self.core.advance_time(timed_event.invocation_time);
        match timed_event.event {
            Event::Fault(event) => {
                self.core.handle_fault_event(event);
                0 // Faults does not count in steps
            }
            Event::Handler(event) => {
                if let Some(ready) = self
                    .core
                    .handle_rank_handler_event(timed_event.invocation_time, event)
                {
                    self.dispatch(ready);
                    1
                } else {
                    0
                }
            }
        }
    }

    fn dispatch(&mut self, event: RankHandlerEvent) {
        local_access::prepare(event.target_rank(), self.core.clock.now());
        match event {
            RankHandlerEvent::Start { rank } => {
                self.procs[rank].on_start();
            }
            RankHandlerEvent::Network {
                source,
                target,
                message,
                ..
            } => {
                self.procs[target].on_message(source, message);
            }
            RankHandlerEvent::Timer { rank, id } => {
                self.procs[rank].on_timer(id);
            }
        }
        self.core.resolve_events(local_access::take_events());
    }
}

impl SimulationRunner for SimpleRunner {
    fn run_full_budget(&mut self) -> RunStatus {
        let status = self.run_loop(self.core.time_budget, None);
        self.core.progress_bar.finish();
        status
    }

    fn run_steps(&mut self, k: usize) -> RunStatus {
        self.run_loop(self.core.time_budget, Some(k))
    }

    fn run_sub_budget(&mut self, sub_budget: Jiffies) -> RunStatus {
        let deadline = self.core.clock.now() + sub_budget;
        self.run_loop(deadline, None)
    }
}