Fix race condition and improve performance of rmw_wait #203
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
With the current code in rmw_wait, there is a race between the time when we check whether we should wait, and whether an event comes in. If we've determined we should wait, and an event comes in (and does cv.notify()) *before* we start waiting, then we won't wake up until the timeout. This commit fixes that by taking a mutex across *all* of rmw_wait(). This means that if an event comes in while we are holding the mutex, it will actually cause us to never go to sleep. This fixes the race. While we are in here, we notice that we can improve performance by just having a single lock in the context that everything uses. This allows us to skip the entire attach/detach dance, getting rid of one of the 3 loops in rmw_wait. Signed-off-by: Chris Lalancette <[email protected]>
Signed-off-by: Yadunund <[email protected]>
Closed
|
It turns out that this way of doing things is not really feasible, given the design of Because of that, I'm going to close out this PR. #205 is the start of a series of PRs that should fix this in a different way. |
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Outdated suggestions cannot be applied.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.
No description provided.