winio: Fix Handle mode on inherited handles. #245
Merged
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
Collaborator
|
LGTM, though I can't claim I have a full understanding. Can you add a changelog entry about this? And does this warrant an immediate release, or should it be bundled with upcoming releases? |
Contributor
Author
Sure, will do!
I think that probably depends on if @mpickering thinks it can be included in the 9.4 release, otherwise no rush. |
Mistuke
force-pushed
the
wip/only-mark-non-inheritable-handles-as-overlapped
branch
from
97b0162 to
cc148bf
Compare
Contributor
Author
|
@snoyberg changelog added. looks like there no need for an immediate release, just merging should be enough and I'll be able to close the GHC ticket. thanks! |
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Outdated suggestions cannot be applied.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.
There's a small bug in the modes that we create handles with when we make inheritable handles.
We create both the input and output handles with
FILE_FLAG_OVERLAPPED.This is OK as long as the program being called is also not using IOCP. For the majority of the program
usually called this is the case and so we never noticed the bug in testing.
However when calling an application which is also using overlapped IO or uses the kernel low level
async APIs then the spawned application will misbehave because the operation would unexpectedly
become asynchronous. This is the case with any program using Microsoft VC++'s stdlibs to read pipes.
The fix is to only mark handles with
FILE_FLAG_OVERLAPPEDif they are not being inherited. That is,only make them asynchronous if we, the caller will be using them and not the callee.
Note that WINIO can handle synchronous handles as well, so even if some other part of the program
uses the synchronous handle it would still work correctly.
Fixes https://gitlab.haskell.org/ghc/ghc/-/issues/21610
/cc @bgamari