Set current_time to absolute system time to prevent drift #171
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
CuddlyBunion341
commented
Feb 4, 2025
| fn update_internal_state(&mut self, duration: Duration) -> Result<(), NetcodeError> { | ||
| self.current_time += duration; | ||
| fn update_internal_state(&mut self) -> Result<(), NetcodeError> { | ||
| self.current_time = SystemTime::now().duration_since(SystemTime::UNIX_EPOCH).unwrap(); |
There was a problem hiding this comment.
This is probably not the best approach.
Instead there should be some method to synchronize the clocks.
Otherwise it is not possible to set a custom delay.
There was a problem hiding this comment.
Perhaps the current_time should be synchronized every so often by passing in a special duration.
CuddlyBunion341
force-pushed
the
fix-time-drift-on-update
branch
from
4f23740 to
e9258be
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Prevent current time update from drifting
Current setup
The current_time gets updated by a fixed amount every system tick. This is error prone especially for long running sessions, like described in #157.
Proposal
Instead of having the delay be updated by an relative amount, the current_time should be set to an absolute value in order to prevent a drift of the internal clock.
In addition to setting the current_time at the beginning of the session, the current_time should be updated on every tick accordingly.
Problems / Considerations
Alternatives
auto_syncwhich periodically updates the client and server time to current system time, to avoid drifting.