sampler/
lib.rs

1// Copyright 2020 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use crate::config::SamplerConfig;
6use anyhow::{Context, Error};
7use argh::FromArgs;
8use fuchsia_component::client::connect_to_protocol;
9use fuchsia_component::server::ServiceFs;
10use fuchsia_inspect::health::Reporter;
11use fuchsia_inspect::{self as inspect};
12use futures::{StreamExt, TryStreamExt};
13use log::{info, warn};
14use sampler_component_config::Config as ComponentConfig;
15use {fidl_fuchsia_hardware_power_statecontrol as reboot, fuchsia_async as fasync};
16
17mod config;
18mod diagnostics;
19mod executor;
20
21/// The name of the subcommand and the logs-tag.
22pub const PROGRAM_NAME: &str = "sampler";
23
24/// Arguments used to configure sampler.
25#[derive(Debug, Default, FromArgs, PartialEq)]
26#[argh(subcommand, name = "sampler")]
27pub struct Args {}
28
29pub async fn main() -> Result<(), Error> {
30    // Serve inspect.
31    let inspector = inspect::component::inspector();
32    let _inspect_server_task =
33        inspect_runtime::publish(inspector, inspect_runtime::PublishOptions::default());
34
35    let mut service_fs = ServiceFs::new();
36    service_fs.take_and_serve_directory_handle()?;
37    fasync::Task::spawn(async move {
38        service_fs.collect::<()>().await;
39    })
40    .detach();
41
42    // Starting service.
43    inspect::component::health().set_starting_up();
44
45    let sampler_config = SamplerConfig::new(ComponentConfig::take_from_startup_handle())?;
46
47    // Create endpoint for the reboot watcher register.
48    let (reboot_watcher_client, reboot_watcher_request_stream) =
49        fidl::endpoints::create_request_stream::<reboot::RebootWatcherMarker>();
50
51    {
52        // Let the transient connection fall out of scope once we've passed the client
53        // end to our callback server.
54        let reboot_watcher_register =
55            connect_to_protocol::<reboot::RebootMethodsWatcherRegisterMarker>()
56                .context("Connect to Reboot watcher register")?;
57
58        reboot_watcher_register
59            .register_watcher(reboot_watcher_client)
60            .await
61            .context("Providing the reboot register with callback channel.")?;
62    }
63
64    let sampler_executor = executor::SamplerExecutor::new(sampler_config).await?;
65
66    // Trigger the project samplers and returns a TaskCancellation struct used to trigger
67    // reboot shutdown of sampler.
68    let task_canceller = sampler_executor.execute();
69
70    inspect::component::health().set_ok();
71    reboot_watcher(reboot_watcher_request_stream, task_canceller).await;
72    Ok(())
73}
74
75async fn reboot_watcher(
76    mut stream: reboot::RebootWatcherRequestStream,
77    task_canceller: executor::TaskCancellation,
78) {
79    if let Some(reboot::RebootWatcherRequest::OnReboot { options: _, responder }) =
80        stream.try_next().await.unwrap_or_else(|err| {
81            // If the channel closed for some reason, we can just let Sampler keep running
82            // until component manager kills it.
83            warn!("Reboot callback channel closed: {:?}", err);
84            None
85        })
86    {
87        task_canceller.perform_reboot_cleanup().await;
88
89        // acknowledge reboot notification to unblock before timeout.
90        responder
91            .send()
92            .unwrap_or_else(|err| warn!("Acking the reboot register failed: {:?}", err));
93
94        info!("Sampler has been halted due to reboot. Goodbye.");
95    } else {
96        // The reboot watcher channel somehow died. There's no reason to
97        // clean ourselves up early, might as well just run until the component
98        // manager tells us to stop or all tasks finish.
99        task_canceller.run_without_cancellation().await;
100        info!("All Sampler tasks have finished running. Goodbye.");
101    }
102}
sampler/lib.rs

sampler/
lib.rs
