Files
tokio/tokio-process/src/lib.rs
T

845 lines
27 KiB
Rust

#![doc(html_root_url = "https://docs.rs/tokio-process/0.3.0-alpha.1")]
#![warn(
missing_debug_implementations,
missing_docs,
rust_2018_idioms,
unreachable_pub
)]
#![doc(test(no_crate_inject, attr(deny(rust_2018_idioms))))]
#![feature(async_await)]
//! An implementation of asynchronous process management for Tokio.
//!
//! This crate provides a `CommandExt` trait to enhance the functionality of the
//! `Command` type in the standard library. The three methods provided by this
//! trait mirror the "spawning" methods in the standard library. The
//! `CommandExt` trait in this crate, though, returns "future aware" types that
//! interoperate with Tokio. The asynchronous process support is provided
//! through signal handling on Unix and system APIs on Windows.
//!
//! # Examples
//!
//! Here's an example program which will spawn `echo hello world` and then wait
//! for it complete.
//!
//! ```no_run
//! #![feature(async_await)]
//!
//! use std::process::Command;
//! use tokio_process::CommandExt;
//!
//! #[tokio::main]
//! async fn main() -> Result<(), Box<dyn std::error::Error>> {
//! // Use the standard library's `Command` type to build a process and
//! // then execute it via the `CommandExt` trait.
//! let child = Command::new("echo").arg("hello").arg("world")
//! .spawn_async();
//!
//! // Make sure our child succeeded in spawning and process the result
//! let future = child.expect("failed to spawn");
//!
//! // Await until the future (and the command) completes
//! let status = future.await?;
//! println!("the command exited with: {}", status);
//! Ok(())
//! }
//! ```
//!
//! Next, let's take a look at an example where we not only spawn `echo hello
//! world` but we also capture its output.
//!
//! ```no_run
//! #![feature(async_await)]
//!
//! use std::process::Command;
//! use tokio_process::CommandExt;
//!
//! #[tokio::main]
//! async fn main() -> Result<(), Box<dyn std::error::Error>> {
//! // Like above, but use `output_async` which returns a future instead of
//! // immediately returning the `Child`.
//! let output = Command::new("echo").arg("hello").arg("world")
//! .output_async();
//!
//! let output = output.await?;
//!
//! assert!(output.status.success());
//! assert_eq!(output.stdout, b"hello world\n");
//! Ok(())
//! }
//! ```
//!
//! We can also read input line by line.
//!
//! ```no_run
//! #![feature(async_await)]
//!
//! use futures_util::stream::StreamExt;
//! use std::process::{Command, Stdio};
//! use tokio::codec::{FramedRead, LinesCodec};
//! use tokio_process::CommandExt;
//!
//! #[tokio::main]
//! async fn main() -> Result<(), Box<dyn std::error::Error>> {
//! let mut cmd = Command::new("cat");
//!
//! // Specify that we want the command's standard output piped back to us.
//! // By default, standard input/output/error will be inherited from the
//! // current process (for example, this means that standard input will
//! // come from the keyboard and standard output/error will go directly to
//! // the terminal if this process is invoked from the command line).
//! cmd.stdout(Stdio::piped());
//!
//! let mut child = cmd.spawn_async()
//! .expect("failed to spawn command");
//!
//! let stdout = child.stdout().take()
//! .expect("child did not have a handle to stdout");
//!
//! let mut reader = FramedRead::new(stdout, LinesCodec::new());
//!
//! // Ensure the child process is spawned in the runtime so it can
//! // make progress on its own while we await for any output.
//! tokio::spawn(async {
//! let status = child.await
//! .expect("child process encountered an error");
//!
//! println!("child status was: {}", status);
//! });
//!
//! while let Some(line) = reader.next().await {
//! println!("Line: {}", line?);
//! }
//!
//! Ok(())
//! }
//! ```
//!
//! # Caveats
//!
//! While similar to the standard library, this crate's `Child` type differs
//! importantly in the behavior of `drop`. In the standard library, a child
//! process will continue running after the instance of `std::process::Child`
//! is dropped. In this crate, however, because `tokio_process::Child` is a
//! future of the child's `ExitStatus`, a child process is terminated if
//! `tokio_process::Child` is dropped. The behavior of the standard library can
//! be regained with the `Child::forget` method.
#[cfg(unix)]
#[macro_use]
extern crate lazy_static;
#[cfg(unix)]
#[macro_use]
extern crate log;
use std::io;
use std::process::{Command, ExitStatus, Output, Stdio};
use futures_core::future::TryFuture;
use futures_util::future;
use futures_util::future::FutureExt;
use futures_util::try_future::TryFutureExt;
use kill::Kill;
use std::fmt;
use std::future::Future;
use std::pin::Pin;
use std::task::Context;
use std::task::Poll;
use tokio_io::{AsyncRead, AsyncReadExt, AsyncWrite};
use tokio_reactor::Handle;
#[path = "unix/mod.rs"]
#[cfg(unix)]
mod imp;
#[path = "windows.rs"]
#[cfg(windows)]
mod imp;
mod kill;
/// Extensions provided by this crate to the `Command` type in the standard
/// library.
///
/// This crate primarily enhances the standard library's `Command` type with
/// asynchronous capabilities. The currently three blocking functions in the
/// standard library, `spawn`, `status`, and `output`, all have asynchronous
/// versions through this trait.
///
/// Note that the `Child` type spawned is specific to this crate, and that the
/// I/O handles created from this crate are all asynchronous as well (differing
/// from their `std` counterparts).
pub trait CommandExt {
/// Executes the command as a child process, returning a handle to it.
///
/// By default, stdin, stdout and stderr are inherited from the parent.
///
/// This method will spawn the child process synchronously and return a
/// handle to a future-aware child process. The `Child` returned implements
/// `Future` itself to acquire the `ExitStatus` of the child, and otherwise
/// the `Child` has methods to acquire handles to the stdin, stdout, and
/// stderr streams.
///
/// All I/O this child does will be associated with the current default
/// event loop.
fn spawn_async(&mut self) -> io::Result<Child> {
self.spawn_async_with_handle(&Handle::default())
}
/// Executes the command as a child process, returning a handle to it.
///
/// By default, stdin, stdout and stderr are inherited from the parent.
///
/// This method will spawn the child process synchronously and return a
/// handle to a future-aware child process. The `Child` returned implements
/// `Future` itself to acquire the `ExitStatus` of the child, and otherwise
/// the `Child` has methods to acquire handles to the stdin, stdout, and
/// stderr streams.
///
/// The `handle` specified to this method must be a handle to a valid event
/// loop, and all I/O this child does will be associated with the specified
/// event loop.
fn spawn_async_with_handle(&mut self, handle: &Handle) -> io::Result<Child>;
/// Executes a command as a child process, waiting for it to finish and
/// collecting its exit status.
///
/// By default, stdin, stdout and stderr are inherited from the parent.
///
/// The `StatusAsync` future returned will resolve to the `ExitStatus`
/// type in the standard library representing how the process exited. If
/// any input/output handles are set to a pipe then they will be immediately
/// closed after the child is spawned.
///
/// All I/O this child does will be associated with the current default
/// event loop.
///
/// If the `StatusAsync` future is dropped before the future resolves, then
/// the child will be killed, if it was spawned.
///
/// # Errors
///
/// This function will return an error immediately if the child process
/// cannot be spawned. Otherwise errors obtained while waiting for the child
/// are returned through the `StatusAsync` future.
fn status_async(&mut self) -> io::Result<StatusAsync> {
self.status_async_with_handle(&Handle::default())
}
/// Executes a command as a child process, waiting for it to finish and
/// collecting its exit status.
///
/// By default, stdin, stdout and stderr are inherited from the parent.
///
/// The `StatusAsync` future returned will resolve to the `ExitStatus`
/// type in the standard library representing how the process exited. If
/// any input/output handles are set to a pipe then they will be immediately
/// closed after the child is spawned.
///
/// The `handle` specified must be a handle to a valid event loop, and all
/// I/O this child does will be associated with the specified event loop.
///
/// If the `StatusAsync` future is dropped before the future resolves, then
/// the child will be killed, if it was spawned.
///
/// # Errors
///
/// This function will return an error immediately if the child process
/// cannot be spawned. Otherwise errors obtained while waiting for the child
/// are returned through the `StatusAsync` future.
fn status_async_with_handle(&mut self, handle: &Handle) -> io::Result<StatusAsync>;
/// Executes the command as a child process, waiting for it to finish and
/// collecting all of its output.
///
/// > **Note**: this method, unlike the standard library, will
/// > unconditionally configure the stdout/stderr handles to be pipes, even
/// > if they have been previously configured. If this is not desired then
/// > the `spawn_async` method should be used in combination with the
/// > `wait_with_output` method on child.
///
/// This method will return a future representing the collection of the
/// child process's stdout/stderr. The `OutputAsync` future will resolve to
/// the `Output` type in the standard library, containing `stdout` and
/// `stderr` as `Vec<u8>` along with an `ExitStatus` representing how the
/// process exited.
///
/// All I/O this child does will be associated with the current default
/// event loop.
///
/// If the `OutputAsync` future is dropped before the future resolves, then
/// the child will be killed, if it was spawned.
fn output_async(&mut self) -> OutputAsync {
self.output_async_with_handle(&Handle::default())
}
/// Executes the command as a child process, waiting for it to finish and
/// collecting all of its output.
///
/// > **Note**: this method, unlike the standard library, will
/// > unconditionally configure the stdout/stderr handles to be pipes, even
/// > if they have been previously configured. If this is not desired then
/// > the `spawn_async` method should be used in combination with the
/// > `wait_with_output` method on child.
///
/// This method will return a future representing the collection of the
/// child process's stdout/stderr. The `OutputAsync` future will resolve to
/// the `Output` type in the standard library, containing `stdout` and
/// `stderr` as `Vec<u8>` along with an `ExitStatus` representing how the
/// process exited.
///
/// The `handle` specified must be a handle to a valid event loop, and all
/// I/O this child does will be associated with the specified event loop.
///
/// If the `OutputAsync` future is dropped before the future resolves, then
/// the child will be killed, if it was spawned.
fn output_async_with_handle(&mut self, handle: &Handle) -> OutputAsync;
}
struct SpawnedChild {
child: imp::Child,
stdin: Option<imp::ChildStdin>,
stdout: Option<imp::ChildStdout>,
stderr: Option<imp::ChildStderr>,
}
impl CommandExt for Command {
fn spawn_async_with_handle(&mut self, handle: &Handle) -> io::Result<Child> {
imp::spawn_child(self, handle).map(|spawned_child| Child {
child: ChildDropGuard::new(spawned_child.child),
stdin: spawned_child.stdin.map(|inner| ChildStdin { inner }),
stdout: spawned_child.stdout.map(|inner| ChildStdout { inner }),
stderr: spawned_child.stderr.map(|inner| ChildStderr { inner }),
})
}
fn status_async_with_handle(&mut self, handle: &Handle) -> io::Result<StatusAsync> {
self.spawn_async_with_handle(handle).map(|mut child| {
// Ensure we close any stdio handles so we can't deadlock
// waiting on the child which may be waiting to read/write
// to a pipe we're holding.
child.stdin.take();
child.stdout.take();
child.stderr.take();
StatusAsync { inner: child }
})
}
fn output_async_with_handle(&mut self, handle: &Handle) -> OutputAsync {
self.stdout(Stdio::piped());
self.stderr(Stdio::piped());
let inner =
future::ready(self.spawn_async_with_handle(handle)).and_then(Child::wait_with_output);
OutputAsync {
inner: inner.boxed(),
}
}
}
/// A drop guard which ensures the child process is killed on drop to maintain
/// the contract of dropping a Future leads to "cancellation".
#[derive(Debug)]
struct ChildDropGuard<T: Kill> {
inner: T,
kill_on_drop: bool,
}
impl<T: Kill> ChildDropGuard<T> {
fn new(inner: T) -> Self {
Self {
inner,
kill_on_drop: true,
}
}
fn forget(&mut self) {
self.kill_on_drop = false;
}
}
impl<T: Kill> Kill for ChildDropGuard<T> {
fn kill(&mut self) -> io::Result<()> {
let ret = self.inner.kill();
if ret.is_ok() {
self.kill_on_drop = false;
}
ret
}
}
impl<T: Kill> Drop for ChildDropGuard<T> {
fn drop(&mut self) {
if self.kill_on_drop {
drop(self.kill());
}
}
}
impl<T: TryFuture + Kill + Unpin> Future for ChildDropGuard<T> {
type Output = Result<T::Ok, T::Error>;
fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
let ret = Pin::new(&mut self.inner).try_poll(cx);
if let Poll::Ready(Ok(_)) = ret {
// Avoid the overhead of trying to kill a reaped process
self.kill_on_drop = false;
}
ret
}
}
/// Representation of a child process spawned onto an event loop.
///
/// This type is also a future which will yield the `ExitStatus` of the
/// underlying child process. A `Child` here also provides access to information
/// like the OS-assigned identifier and the stdio streams.
///
/// > **Note**: The behavior of `drop` on a child in this crate is *different
/// > than the behavior of the standard library*. If a `tokio_process::Child` is
/// > dropped before the process finishes then the process will be terminated.
/// > In the standard library, however, the process continues executing. This is
/// > done because futures in general take `drop` as a sign of cancellation, and
/// > this `Child` is itself a future. If you'd like to run a process in the
/// > background, though, you may use the `forget` method.
#[must_use = "futures do nothing unless polled"]
#[derive(Debug)]
pub struct Child {
child: ChildDropGuard<imp::Child>,
stdin: Option<ChildStdin>,
stdout: Option<ChildStdout>,
stderr: Option<ChildStderr>,
}
impl Child {
/// Returns the OS-assigned process identifier associated with this child.
pub fn id(&self) -> u32 {
self.child.inner.id()
}
/// Forces the child to exit.
///
/// This is equivalent to sending a SIGKILL on unix platforms.
pub fn kill(&mut self) -> io::Result<()> {
self.child.kill()
}
/// Returns a handle for writing to the child's stdin, if it has been
/// captured
pub fn stdin(&mut self) -> &mut Option<ChildStdin> {
&mut self.stdin
}
/// Returns a handle for writing to the child's stdout, if it has been
/// captured
pub fn stdout(&mut self) -> &mut Option<ChildStdout> {
&mut self.stdout
}
/// Returns a handle for writing to the child's stderr, if it has been
/// captured
pub fn stderr(&mut self) -> &mut Option<ChildStderr> {
&mut self.stderr
}
/// Returns a future that will resolve to an `Output`, containing the exit
/// status, stdout, and stderr of the child process.
///
/// The returned future will simultaneously waits for the child to exit and
/// collect all remaining output on the stdout/stderr handles, returning an
/// `Output` instance.
///
/// The stdin handle to the child process, if any, will be closed before
/// waiting. This helps avoid deadlock: it ensures that the child does not
/// block waiting for input from the parent, while the parent waits for the
/// child to exit.
///
/// By default, stdin, stdout and stderr are inherited from the parent. In
/// order to capture the output into this `Output` it is necessary to create
/// new pipes between parent and child. Use `stdout(Stdio::piped())` or
/// `stderr(Stdio::piped())`, respectively, when creating a `Command`.
pub fn wait_with_output(mut self) -> WaitWithOutput {
drop(self.stdin().take());
let stdout_val = self.stdout.take();
let stderr_val = self.stderr.take();
let stdout_fut = async {
match stdout_val {
Some(mut io) => {
let mut vec = Vec::new();
AsyncReadExt::read_to_end(&mut io, &mut vec).await?;
Ok(vec)
}
None => Ok(Vec::new()),
}
};
let stderr_fut = async {
match stderr_val {
Some(mut io) => {
let mut vec = Vec::new();
AsyncReadExt::read_to_end(&mut io, &mut vec).await?;
Ok(vec)
}
None => Ok(Vec::new()),
}
};
WaitWithOutput {
inner: futures_util::try_future::try_join3(stdout_fut, stderr_fut, self)
.and_then(|(stdout, stderr, status)| {
future::ok(Output {
status,
stdout,
stderr,
})
})
.boxed(),
}
}
/// Drop this `Child` without killing the underlying process.
///
/// Normally a `Child` is killed if it's still alive when dropped, but this
/// method will ensure that the child may continue running once the `Child`
/// instance is dropped.
///
/// > **Note**: this method may leak OS resources depending on your platform.
/// > To ensure resources are eventually cleaned up, consider sending the
/// > `Child` instance into an event loop as an alternative to this method.
///
/// ```no_run
/// # #![feature(async_await)]
/// # use std::process::Command;
/// # use tokio_process::CommandExt;
///
/// # #[tokio::main]
/// # async fn main() {
/// let child = Command::new("echo").arg("hello").arg("world")
/// .spawn_async()
/// .expect("failed to spawn");
///
/// tokio::spawn(async {
/// let _ = child.await;
/// });
/// # }
pub fn forget(mut self) {
self.child.forget();
}
}
impl Future for Child {
type Output = io::Result<ExitStatus>;
fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
Pin::new(&mut self.child).poll(cx)
}
}
/// Future returned from the `Child::wait_with_output` method.
///
/// This future will resolve to the standard library's `Output` type which
/// contains the exit status, stdout, and stderr of a child process.
#[must_use = "futures do nothing unless polled"]
pub struct WaitWithOutput {
inner: Pin<Box<dyn Future<Output = io::Result<Output>> + Send>>,
}
impl fmt::Debug for WaitWithOutput {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt.debug_struct("WaitWithOutput")
.field("inner", &"..")
.finish()
}
}
impl Future for WaitWithOutput {
type Output = io::Result<Output>;
fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
Pin::new(&mut self.inner).poll(cx)
}
}
/// Future returned by the `CommandExt::status_async` method.
///
/// This future is used to conveniently spawn a child and simply wait for its
/// exit status. This future will resolves to the `ExitStatus` type in the
/// standard library.
#[must_use = "futures do nothing unless polled"]
#[derive(Debug)]
pub struct StatusAsync {
inner: Child,
}
impl Future for StatusAsync {
type Output = io::Result<ExitStatus>;
fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
Pin::new(&mut self.inner).poll(cx)
}
}
/// Future returned by the `CommandExt::output_async` method.
///
/// This future is mostly equivalent to spawning a process and then calling
/// `wait_with_output` on it internally. This can be useful to simply spawn a
/// process, collecting all of its output and its exit status.
#[must_use = "futures do nothing unless polled"]
pub struct OutputAsync {
inner: Pin<Box<dyn Future<Output = io::Result<Output>> + Send>>,
}
impl fmt::Debug for OutputAsync {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt.debug_struct("OutputAsync")
.field("inner", &"..")
.finish()
}
}
impl Future for OutputAsync {
type Output = io::Result<Output>;
fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
Pin::new(&mut self.inner).poll(cx)
}
}
/// The standard input stream for spawned children.
///
/// This type implements the `AsyncWrite` trait to pass data to the stdin handle of
/// handle of a child process asynchronously.
#[derive(Debug)]
pub struct ChildStdin {
inner: imp::ChildStdin,
}
/// The standard output stream for spawned children.
///
/// This type implements the `AsyncRead` trait to read data from the stdout
/// handle of a child process asynchronously.
#[derive(Debug)]
pub struct ChildStdout {
inner: imp::ChildStdout,
}
/// The standard error stream for spawned children.
///
/// This type implements the `AsyncRead` trait to read data from the stderr
/// handle of a child process asynchronously.
#[derive(Debug)]
pub struct ChildStderr {
inner: imp::ChildStderr,
}
impl AsyncWrite for ChildStdin {
fn poll_write(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8],
) -> Poll<io::Result<usize>> {
Pin::new(&mut self.inner).poll_write(cx, buf)
}
fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
Pin::new(&mut self.inner).poll_flush(cx)
}
fn poll_shutdown(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
Pin::new(&mut self.inner).poll_shutdown(cx)
}
}
impl AsyncRead for ChildStdout {
fn poll_read(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8],
) -> Poll<io::Result<usize>> {
Pin::new(&mut self.inner).poll_read(cx, buf)
}
}
impl AsyncRead for ChildStderr {
fn poll_read(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8],
) -> Poll<io::Result<usize>> {
Pin::new(&mut self.inner).poll_read(cx, buf)
}
}
#[cfg(unix)]
mod sys {
use super::{ChildStderr, ChildStdin, ChildStdout};
use std::os::unix::io::{AsRawFd, RawFd};
impl AsRawFd for ChildStdin {
fn as_raw_fd(&self) -> RawFd {
self.inner.get_ref().as_raw_fd()
}
}
impl AsRawFd for ChildStdout {
fn as_raw_fd(&self) -> RawFd {
self.inner.get_ref().as_raw_fd()
}
}
impl AsRawFd for ChildStderr {
fn as_raw_fd(&self) -> RawFd {
self.inner.get_ref().as_raw_fd()
}
}
}
#[cfg(windows)]
mod sys {
use super::{ChildStderr, ChildStdin, ChildStdout};
use std::os::windows::io::{AsRawHandle, RawHandle};
impl AsRawHandle for ChildStdin {
fn as_raw_handle(&self) -> RawHandle {
self.inner.get_ref().as_raw_handle()
}
}
impl AsRawHandle for ChildStdout {
fn as_raw_handle(&self) -> RawHandle {
self.inner.get_ref().as_raw_handle()
}
}
impl AsRawHandle for ChildStderr {
fn as_raw_handle(&self) -> RawHandle {
self.inner.get_ref().as_raw_handle()
}
}
}
#[cfg(test)]
mod test {
use super::ChildDropGuard;
use crate::kill::Kill;
use futures_util::future::FutureExt;
use std::future::Future;
use std::io;
use std::pin::Pin;
use std::task::Context;
use std::task::Poll;
struct Mock {
num_kills: usize,
num_polls: usize,
poll_result: Poll<Result<(), ()>>,
}
impl Mock {
fn new() -> Self {
Self::with_result(Poll::Pending)
}
fn with_result(result: Poll<Result<(), ()>>) -> Self {
Self {
num_kills: 0,
num_polls: 0,
poll_result: result,
}
}
}
impl Kill for Mock {
fn kill(&mut self) -> io::Result<()> {
self.num_kills += 1;
Ok(())
}
}
impl Future for Mock {
type Output = Result<(), ()>;
fn poll(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Self::Output> {
let inner = Pin::get_mut(self);
inner.num_polls += 1;
inner.poll_result
}
}
#[test]
fn kills_on_drop() {
let mut mock = Mock::new();
{
let guard = ChildDropGuard::new(&mut mock);
drop(guard);
}
assert_eq!(1, mock.num_kills);
assert_eq!(0, mock.num_polls);
}
#[test]
fn no_kill_if_already_killed() {
let mut mock = Mock::new();
{
let mut guard = ChildDropGuard::new(&mut mock);
let _ = guard.kill();
drop(guard);
}
assert_eq!(1, mock.num_kills);
assert_eq!(0, mock.num_polls);
}
#[test]
fn no_kill_if_reaped() {
let mut mock_pending = Mock::with_result(Poll::Pending);
let mut mock_reaped = Mock::with_result(Poll::Ready(Ok(())));
let mut mock_err = Mock::with_result(Poll::Ready(Err(())));
let waker = futures_util::task::noop_waker();
let mut context = Context::from_waker(&waker);
{
let mut guard = ChildDropGuard::new(&mut mock_pending);
let _ = guard.poll_unpin(&mut context);
let mut guard = ChildDropGuard::new(&mut mock_reaped);
let _ = guard.poll_unpin(&mut context);
let mut guard = ChildDropGuard::new(&mut mock_err);
let _ = guard.poll_unpin(&mut context);
}
assert_eq!(1, mock_pending.num_kills);
assert_eq!(1, mock_pending.num_polls);
assert_eq!(0, mock_reaped.num_kills);
assert_eq!(1, mock_reaped.num_polls);
assert_eq!(1, mock_err.num_kills);
assert_eq!(1, mock_err.num_polls);
}
#[test]
fn no_kill_on_forget() {
let mut mock = Mock::new();
{
let mut guard = ChildDropGuard::new(&mut mock);
guard.forget();
drop(guard);
}
assert_eq!(0, mock.num_kills);
assert_eq!(0, mock.num_polls);
}
}