fdf_env/
test.rs

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1// Copyright 2025 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
5//! Helpers for writing tests using drivers and dispatchers
6
7use std::sync::{mpsc, Arc};
8
9use fdf::{CurrentDispatcher, OnDispatcher};
10
11use super::*;
12
13/// Runs the given closure under the a new root driver dispatcher. Use [`fdf::CurrentDispatcher`]
14/// to reference the dispatcher if needed.
15pub fn run_in_driver<T: Send + 'static>(name: &str, p: impl FnOnce() -> T + Send + 'static) -> T {
16    run_in_driver_raw(name, true, false, |tx| tx.send(p()).unwrap())
17}
18
19/// Runs the given closure under a new root driver dispatcher, with some additional options.
20/// Use [`fdf::CurrentDispatcher`] to reference the dispatcher if needed.
21pub fn run_in_driver_etc<T: Send + 'static>(
22    name: &str,
23    allow_thread_blocking: bool,
24    unsynchronized: bool,
25    p: impl FnOnce() -> T + Send + 'static,
26) -> T {
27    run_in_driver_raw(name, allow_thread_blocking, unsynchronized, |tx| tx.send(p()).unwrap())
28}
29
30/// Runs the given future to completion under the a new root driver dispatcher. Use
31/// [`fdf::CurrentDispatcher`] to reference the dispatcher if needed.
32pub fn spawn_in_driver<T: Send + 'static>(
33    name: &str,
34    p: impl Future<Output = T> + Send + 'static,
35) -> T {
36    run_in_driver_raw(name, true, false, |tx| {
37        CurrentDispatcher.spawn_task(async move { tx.send(p.await).unwrap() }).unwrap();
38    })
39}
40
41/// Runs the given future to completion under a new root driver dispatcher, with some additional
42/// options. Use [`fdf::CurrentDispatcher`] to reference the dispatcher if needed.
43pub fn spawn_in_driver_etc<T: Send + 'static>(
44    name: &str,
45    allow_thread_blocking: bool,
46    unsynchronized: bool,
47    p: impl Future<Output = T> + Send + 'static,
48) -> T {
49    run_in_driver_raw(name, allow_thread_blocking, unsynchronized, |tx| {
50        CurrentDispatcher.spawn_task(async move { tx.send(p.await).unwrap() }).unwrap();
51    })
52}
53
54fn run_in_driver_raw<T: Send + 'static>(
55    name: &str,
56    allow_thread_blocking: bool,
57    unsynchronized: bool,
58    p: impl FnOnce(mpsc::Sender<T>) + Send + 'static,
59) -> T {
60    let env = Arc::new(Environment::start(0).unwrap());
61    let env_clone = env.clone();
62
63    let (shutdown_tx, shutdown_rx) = mpsc::channel();
64    let driver_value: u32 = 0x1337;
65    let driver_value_ptr = &driver_value as *const u32;
66    let driver = env.new_driver(driver_value_ptr);
67    let dispatcher = DispatcherBuilder::new().name(name);
68    let dispatcher =
69        if allow_thread_blocking { dispatcher.allow_thread_blocking() } else { dispatcher };
70    let dispatcher = if unsynchronized { dispatcher.unsynchronized() } else { dispatcher };
71    let dispatcher = dispatcher.shutdown_observer(move |dispatcher| {
72        // We verify that the dispatcher has no tasks left queued in it,
73        // just because this is testing code.
74        assert!(!env_clone.dispatcher_has_queued_tasks(dispatcher.as_dispatcher_ref()));
75    });
76    let dispatcher = driver.new_dispatcher(dispatcher).unwrap();
77
78    let (finished_tx, finished_rx) = mpsc::channel();
79    dispatcher
80        .post_task_sync(move |_| {
81            p(finished_tx);
82        })
83        .unwrap();
84    let res = finished_rx.recv().unwrap();
85
86    driver.shutdown(move |driver| {
87        // SAFTEY: driver lives on the stack, it's safe to dereference it.
88        assert!(unsafe { *driver.0 } == 0x1337);
89        shutdown_tx.send(()).unwrap();
90    });
91
92    shutdown_rx.recv().unwrap();
93
94    res
95}
fdf_env/test.rs

fdf_env/
test.rs
