Skip to content

time: delay the cancellation of timers #7467

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom
Open
wants to merge 17 commits into
base: master
Choose a base branch
from
Open

time: delay the cancellation of timers #7467

wants to merge 17 commits into from
+1,638 −1,351

Conversation

ADD-SP
Copy link
Member

@ADD-SP ADD-SP commented Jul 19, 2025 •
edited
Loading

Review guide

Rationale for some technical decisions

Please checkout the inline PR comments I wrote.

Benchmarks

Script: https://gist.github.com/ADD-SP/5c9596972898e273f0824c73fe992f4d

@ADD-SP ADD-SP added A-tokio Area: The main tokio crate M-time Module: tokio/time T-performance Topic: performance and benchmarks R-loom-time-driver Run loom time driver tests on this PR R-loom-current-thread Run loom current-thread tests on this PR R-loom-multi-thread Run loom multi-thread tests on this PR labels Jul 19, 2025
@ADD-SP ADD-SP changed the title [WIP] [WIP] time: delayed cancellation of timers Jul 19, 2025
@ADD-SP ADD-SP force-pushed the add_sp/time-local-wheel branch 11 times, most recently from c2d5790 to d04c22f Compare July 19, 2025 13:19
@ADD-SP ADD-SP changed the title [WIP] time: delayed cancellation of timers [WIP] time: delay the cancellation of timers Jul 19, 2025
ADD-SP
ADD-SP commented Jul 19, 2025
View reviewed changes
tokio-util/tests/time_delay_queue.rs
@@ -522,43 +514,6 @@ async fn insert_after_ready_poll() {
assert_eq!("3", res[2]);
}

#[tokio::test]
async fn reset_later_after_slot_starts() {
Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Note

This test was removed because it was testing the behavior of tokio::runtime::time::entry::reset, which is removed in this PR.

ADD-SP
ADD-SP commented Jul 19, 2025
View reviewed changes
tokio-util/tests/time_delay_queue.rs
@@ -584,43 +539,6 @@ async fn reset_inserted_expired() {
assert_eq!(queue.len(), 0);
}

#[tokio::test]
async fn reset_earlier_after_slot_starts() {
Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Note

This test was removed because it was testing the behavior of tokio::runtime::time::entry::reset, which is removed in this PR.

ADD-SP
ADD-SP commented Jul 19, 2025
View reviewed changes
tokio-util/tests/time_delay_queue.rs
@@ -221,7 +219,7 @@ async fn reset_much_later() {

sleep(ms(20)).await;

assert!(queue.is_woken());
assert_ready_some!(poll!(queue));
Copy link
Member Author

@ADD-SP ADD-SP Jul 19, 2025 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Note

queue.reset_at resets inner Sleep, however, the new implementation will drop the inner timer and create a new one. So the waker will not be called, we have to poll manually.

ADD-SP
ADD-SP commented Jul 19, 2025
View reviewed changes
tokio-util/tests/time_delay_queue.rs
@@ -248,7 +246,7 @@ async fn reset_twice() {

sleep(ms(20)).await;

assert!(queue.is_woken());
assert_ready_some!(poll!(queue));
Copy link
Member Author

@ADD-SP ADD-SP Jul 19, 2025 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Note

queue.reset_at resets inner Sleep, however, the new implementation will drop the inner timer and create a new one. So the waker will not be called, we have to poll manually.

ADD-SP
ADD-SP commented Jul 19, 2025
View reviewed changes
tokio/src/runtime/scheduler/current_thread/mod.rs
Comment on lines +771 to +803
// runtime is shutting down
// OR waking up expired timers

// Track that a task was scheduled from **outside** of the runtime.
self.shared.scheduler_metrics.inc_remote_schedule_count();

// Schedule the task
self.shared.inject.push(task);
self.driver.unpark();
Copy link
Member Author

@ADD-SP ADD-SP Jul 19, 2025 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Note

Since the wheel is stored in the Core, the cx.core is None while waking up timers.

While we could store Option in Core, this would double the number of possible states in the local time subsystem, which isn't worth it.

ADD-SP
ADD-SP commented Jul 19, 2025
View reviewed changes
@ADD-SP ADD-SP force-pushed the add_sp/time-local-wheel branch 2 times, most recently from 695eea8 to e9255ee Compare July 20, 2025 08:21
@ADD-SP ADD-SP mentioned this pull request Jul 20, 2025
Closed
ADD-SP
ADD-SP commented Jul 20, 2025
View reviewed changes
tokio/src/util/mod.rs
@@ -41,7 +39,6 @@ mod wake_list;
feature = "fs",
feature = "rt",
feature = "signal",
feature = "time",
))]
pub(crate) use wake_list::WakeList;
Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Note

We no long use WakeList in the time subsystem.

ADD-SP
ADD-SP commented Jul 20, 2025
View reviewed changes
@ADD-SP ADD-SP force-pushed the add_sp/time-local-wheel branch 5 times, most recently from 4138c14 to a85b267 Compare August 10, 2025 13:20
ADD-SP added 16 commits August 10, 2025 21:20
@ADD-SP
add macro cfg_rt_and_time and cfg_rt_or_time
df7b272 
Signed-off-by: ADD-SP <[email protected]>
@ADD-SP
impl wheel::Entry
fcdf392 
Signed-off-by: ADD-SP <[email protected]>
@ADD-SP
remove global timer wheel
179cce0 
Signed-off-by: ADD-SP <[email protected]>
@ADD-SP
add local timer wheel to the current_thread scheduler
7959551 
Signed-off-by: ADD-SP <[email protected]>
@ADD-SP
add local timer wheel to the multi_thread scheduler
79e6e18 
Signed-off-by: ADD-SP <[email protected]>
@ADD-SP
remove tokio/src/runtime/time/entry.rs
4fdc79e 
Signed-off-by: ADD-SP <[email protected]>
@ADD-SP
impl tokio/src/runtime/time/timer.rs
4a66ce8 
Signed-off-by: ADD-SP <[email protected]>
@ADD-SP
adapt the impl of tokio::time::sleep
062e8fa 
Signed-off-by: ADD-SP <[email protected]>
@ADD-SP
adapt the impl of tokio::time::interval
e9503a4 
Signed-off-by: ADD-SP <[email protected]>
@ADD-SP
let current_thread scheduler process timers
3d2c0ac 
Signed-off-by: ADD-SP <[email protected]>
@ADD-SP
let multi_thread scheduler process timers
c4bad53 
Signed-off-by: ADD-SP <[email protected]>
@ADD-SP
remove the InsertError
97fb0f9 
Signed-off-by: ADD-SP <[email protected]>
@ADD-SP
fix tokio-util/tests/time_delay_queue.rs
a4615ee 
Signed-off-by: ADD-SP <[email protected]>
@ADD-SP
fix unused import wake_list::WakeList
34c59f9 
Signed-off-by: ADD-SP <[email protected]>
@ADD-SP
re-enable loom tests for timers
2b58b6f 
Signed-off-by: ADD-SP <[email protected]>
@ADD-SP
fix race conditions while operating on EntryHandle
91b9c91 
Signed-off-by: ADD-SP <[email protected]>
@ADD-SP ADD-SP force-pushed the add_sp/time-local-wheel branch 7 times, most recently from 5e59ce4 to 86a1e15 Compare August 10, 2025 14:52
@ADD-SP ADD-SP force-pushed the add_sp/time-local-wheel branch from 86a1e15 to b7692de Compare August 10, 2025 15:58
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Reviewers

@Darksonn Darksonn Darksonn left review comments

At least 1 approving review is required to merge this pull request.

Assignees
No one assigned
Labels
A-tokio Area: The main tokio crate M-time Module: tokio/time R-loom-current-thread Run loom current-thread tests on this PR R-loom-multi-thread Run loom multi-thread tests on this PR R-loom-time-driver Run loom time driver tests on this PR T-performance Topic: performance and benchmarks
Projects
None yet
Milestone
No milestone
Development

Successfully merging this pull request may close these issues.
2 participants
@ADD-SP @Darksonn