zecfoundation
/
zebra
mirror of https://github.com/ZcashFoundation/zebra.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

Document the behaviour of the `select!` macro

This commit is contained in:
teor 2021-03-27 14:54:21 +10:00 committed by Deirdre Connolly
parent 1c87372b03
commit 829a6f11c5
4 changed files with 10 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
tower-batch/src/worker.rs
View File

@ -143,6 +143,7 @@ where
}, },
Some(mut sleep) => { Some(mut sleep) => {
// Wait on either a new message or the batch timer. // Wait on either a new message or the batch timer.
// If both are ready, select! chooses one of them at random.
tokio::select! { tokio::select! {
maybe_msg = self.rx.recv() => match maybe_msg { maybe_msg = self.rx.recv() => match maybe_msg {
Some(msg) => { Some(msg) => {

2
zebrad/src/components/inbound/downloads.rs
View File

@ -223,6 +223,8 @@ where
.in_current_span(); .in_current_span();
let task = tokio::spawn(async move { let task = tokio::spawn(async move {
// TODO: if the verifier and cancel are both ready, which should we
// prefer? (Currently, select! chooses one at random.)
tokio::select! { tokio::select! {
_ = &mut cancel_rx => { _ = &mut cancel_rx => {
tracing::trace!("task cancelled prior to completion"); tracing::trace!("task cancelled prior to completion");

4
zebrad/src/components/sync/downloads.rs
View File

@ -149,6 +149,8 @@ where
let mut verifier = self.verifier.clone(); let mut verifier = self.verifier.clone();
let task = tokio::spawn( let task = tokio::spawn(
async move { async move {
// TODO: if the verifier and cancel are both ready, which should
// we prefer? (Currently, select! chooses one at random.)
let rsp = tokio::select! { let rsp = tokio::select! {
_ = &mut cancel_rx => { _ = &mut cancel_rx => {
tracing::trace!("task cancelled prior to download completion"); tracing::trace!("task cancelled prior to download completion");
@ -169,6 +171,8 @@ where
metrics::counter!("sync.downloaded.block.count", 1); metrics::counter!("sync.downloaded.block.count", 1);
let rsp = verifier.ready_and().await?.call(block); let rsp = verifier.ready_and().await?.call(block);
// TODO: if the verifier and cancel are both ready, which should
// we prefer? (Currently, select! chooses one at random.)
let verification = tokio::select! { let verification = tokio::select! {
_ = &mut cancel_rx => { _ = &mut cancel_rx => {
tracing::trace!("task cancelled prior to verification"); tracing::trace!("task cancelled prior to verification");

3
zebrad/src/components/tokio.rs
View File

@ -46,6 +46,8 @@ pub(crate) trait RuntimeRun {
impl RuntimeRun for Runtime { impl RuntimeRun for Runtime {
fn run(&mut self, fut: impl Future<Output = Result<(), Report>>) { fn run(&mut self, fut: impl Future<Output = Result<(), Report>>) {
let result = self.block_on(async move { let result = self.block_on(async move {
// If the run task and shutdown are both ready, select! chooses
// one of them at random.
tokio::select! { tokio::select! {
result = fut => result, result = fut => result,
_ = shutdown() => Ok(()), _ = shutdown() => Ok(()),
@ -68,6 +70,7 @@ mod imp {
use tracing::info; use tracing::info;
pub(super) async fn shutdown() { pub(super) async fn shutdown() {
// If both signals are received, select! chooses one of them at random.
tokio::select! { tokio::select! {
// SIGINT - Terminal interrupt signal. Typically generated by shells in response to Ctrl-C. // SIGINT - Terminal interrupt signal. Typically generated by shells in response to Ctrl-C.
() = sig(SignalKind::interrupt(), "SIGINT") => {} () = sig(SignalKind::interrupt(), "SIGINT") => {}