async_io: adapt self-pipe trick to Windows #8044
Merged
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
rgrinberg
approved these changes
Jun 26, 2023
My understanding is that it is not that it doesn't work, but rather that the semantics of pipes on Windows do not match exactly those of Linux and the emulation in
Thanks, will add. I also want to wait to see if by chance this PR also fixes #8043. |
Signed-off-by: nojebar <[email protected]>
Signed-off-by: Nicolás Ojeda Bär <[email protected]>
nojb
force-pushed
the
async_io_self_pipe_win32
branch
from
e477b72
to
58fb66c
Compare
|
@emillon if there is a bug fix release 3.8.3 this should be in it. |
emillon
pushed a commit
to emillon/dune
that referenced
this pull request
Jun 27, 2023
Signed-off-by: Nicolás Ojeda Bär <[email protected]>
emillon
pushed a commit
to emillon/dune
that referenced
this pull request
Jun 27, 2023
Signed-off-by: Nicolás Ojeda Bär <[email protected]>
emillon
added a commit
that referenced
this pull request
Jun 27, 2023
* async_io: adapt self-pipe trick to Windows (#8044) Signed-off-by: Nicolás Ojeda Bär <[email protected]> * Update CHANGES.md Signed-off-by: Etienne Millon <[email protected]> --------- Signed-off-by: Nicolás Ojeda Bär <[email protected]> Signed-off-by: Etienne Millon <[email protected]> Co-authored-by: Nicolás Ojeda Bär <[email protected]>
emillon
added a commit
to emillon/opam-repository
that referenced
this pull request
Jun 27, 2023
CHANGES: - Fix deadlock on Windows (ocaml/dune#8044, @nojb) - When using `sendfile` to copy files on Linux, fall back to the portable version if it fails at runtime for some reason (NFS, etc). (ocaml/dune#8049, fixes ocaml/dune#8041, @emillon)
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.
The Dune RPC server uses the "self-pipe trick" to interrupt
Unix.select. Unfortunately, on Windows, pipes cannot be passed to the nativeselectsystem call, which means thatUnix.selectfalls back to a complicated emulation using threads to poll for data on the pipe. This, plus the fact that pipes are always blocking, seem to be causing some deadlock somewhere which makes the RPC server hang under certain circumstances.This PR proposes an alternative form of the self-pipe trick using a self-connected UDP socket. The advantages is that no pipes are involved, so only the native
selectcall is used byUnix.select, completely bypassing all the complexity of the emulation and the associated blocking pipes.