use futex directly instead of via syscall on OpenBSD #1621
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
sprunk
reviewed
Jul 27, 2024
rts/System/Platform/Linux/Futex.cpp
Outdated
| syscall(SYS_futex, &mtx, FUTEX_WAIT_PRIVATE, 2, NULL, NULL, 0); | ||
| #else | ||
| futex(&mtx, FUTEX_WAIT, 2, NULL, NULL); |
There was a problem hiding this comment.
not _PRIVATE on the FIUTEX constant?
There was a problem hiding this comment.
I didn't use _PRIVATE because it's not documented in our man page, but I see that these constants are also defined in sys/futex.h. I'll do a build with the _PRIVATE parts and if that works, I'll change it!
There was a problem hiding this comment.
changed it to _PRIVATE futex flags
sprunk
approved these changes
Jul 31, 2024
sprunk
reviewed
Jul 31, 2024
rts/System/Platform/Linux/Futex.cpp
Outdated
Comment on lines
36
to
40
| #ifndef __OpenBSD__ | ||
| syscall(SYS_futex, &mtx, FUTEX_WAIT_PRIVATE, 2, NULL, NULL, 0); | ||
| #else | ||
| futex(&mtx, FUTEX_WAIT_PRIVATE, 2, NULL, NULL); | ||
| #endif |
There was a problem hiding this comment.
Perhaps this pattern could be extracted to a function? So somewhere above there would be
static inline void do_futex (uint32_t *mtx, uint32_t value)
{
#ifndef __OpenBSD__
syscall(SYS_futex, mtx, FUTEX_WAIT_PRIVATE, value, NULL, NULL, 0);
#else
futex(mtx, FUTEX_WAIT_PRIVATE, value, NULL, NULL);
#endif
}And this would become just
Suggested change
| #ifndef __OpenBSD__ | |
| syscall(SYS_futex, &mtx, FUTEX_WAIT_PRIVATE, 2, NULL, NULL, 0); | |
| #else | |
| futex(&mtx, FUTEX_WAIT_PRIVATE, 2, NULL, NULL); | |
| #endif | |
| do_futex(&mtx, 2); |
There was a problem hiding this comment.
that makes sense indeed. Will be easier to read/maintain. I'll rebase to do it this 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.
This is necessary for building on OpenBSD (and currently used in the OpenBSD port of recoil). syscall entry point was removed from OpenBSD in 2023 for security reasons and the recommended way is use of the specific syscall as in this diff.