LinuxProcess: Start stdin relay after process start #478
+323
−41
Conversation
This file contains hidden or 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
Because we start piping stdin before process launch we can fill up the guest pipe buffer before the process even starts. We'd need some backpressure mechanism to handle this (register the other end with epoll and buffer some data etc.), but we should probably just start piping after the process is up and running. This change does exactly that, as well as stops holding the process mutex while draining stdin in the guest for `CloseStdin()`. This fixes issues where we try and write > pipe_buf bytes through stdin. Today this hangs.
jglogan
approved these changes
Jan 16, 2026
7 tasks
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
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Outdated suggestions cannot be applied.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.
Fixes #477
Because we start piping stdin before process launch we can fill up the guest pipe buffer before the process even starts. We'd need some backpressure mechanism to handle this and slow consumers (register the other end with epoll and buffer some data etc.), but we should probably just start piping after the process is up and running. This change does exactly that, as well as stops holding the process mutex while draining stdin in the guest for
CloseStdin().This fixes issues where we try and write > pipe_buf bytes through stdin. Today this hangs.