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7fbb4fcb
by Rodrigo Mesquita at 2026-04-01T12:16:33+00:00
Bump default language edition to GHC2024
As per the accepted ghc-proposal#632
Fixes #26039
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5ae43275
by Peng Fan at 2026-04-01T19:01:06-04:00
NCG/LA64: add cmpxchg and xchg primops
And append some new instructions for LA664 uarch.
Apply fix to cmpxchg-prim by Andreas Klebinger.
Suggestions in https://gitlab.haskell.org/ghc/ghc/-/merge_requests/15515
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8f95534a
by Duncan Coutts at 2026-04-01T19:01:52-04:00
Remove signal-based ticker implementations
Fixes issue #27073
All supported platforms should work with the pthreads + nanosleep based
ticker implementation. This avoids all the problems with using signals.
In practice, all supported platforms were probably using the non-signal
tickers already, which is probably why we do not get lots of reports
about deadlocks and other weirdness: we were definately using functions
that are not async signal safe in the tick handler (such as fflush to
flussh the eventlog).
Only Solaris was explicitly using the timer_create ticker impl, and even
Solaris could probably use the pthreads one (if anyone cared: Solaris is
no longer a Teir 3 supported platform).
Plausibly the only supported platform that this will change will be AIX,
which should now use the pthreads impl.
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51b32b0d
by Duncan Coutts at 2026-04-01T19:01:52-04:00
Tidy up some timer/ticker comments elsewhere
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7562bcd7
by Duncan Coutts at 2026-04-01T19:01:52-04:00
Remove now-unused install_vtalrm_handler
Support function used by both of the signal-based ticker
implementations.
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6da127c7
by Duncan Coutts at 2026-04-01T19:01:52-04:00
No longer probe for timer_create in rts/configure
It was only used by the TimerCreate.c ticker impl.
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3fd490fa
by Duncan Coutts at 2026-04-01T19:01:53-04:00
Note that rtsTimerSignal is deprecated.
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63099b0f
by Simon Jakobi at 2026-04-01T19:02:39-04:00
Add perf test for #13960
Closes #13960.
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af3acc89
by Duncan Coutts at 2026-04-02T08:19:39+01:00
Add a rts posix FdWakup utility module
This will be used to implement wakeupIOManager for in-RTS I/O managers.
It provides a notification/wakeup mechanism using FDs, suitable for
situations when a thread is blocked on a set of fds anyway. It uses the
classic self-pipe trick, or equivalently eventfd on supported platforms.
This will initially be used to implement prompt interrupt or shutdown of
the posix ticker thread.
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0d466c40
by Duncan Coutts at 2026-04-02T08:19:39+01:00
Add prompt shutdown to the pthread ticker implementation.
The Linux timerfd ticker monitors a pipe which is used by exitTicker to
ensure a prompt wakeup and shutdown. The pthread ticker lacked this and
so would only exit at the next ticker wakeup (10ms by default).
This patch adds the same mechanism to the pthread ticker.
This changes the pthread ticker from waiting by using nanosleep() to
waiting using either ppoll() or select(), so that it can wait on both
a time and a file descriptor. On Linux at least, a test program to
compare the timing jitter of these APIs shows that using nanpsleep,
ppoll or select makes no statistical difference to the maximum or
average jitter.
This is a step towards unifying the posix ticker implementations, so
that we can have just one portable one (albeit with some limited cpp).
It is also a step towards using the ticker as part of a more general
implementation of wakeUpRts, since this will require a method to wake
the rts from a signal handler context (ctl-c handler).
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3e158b1e
by Duncan Coutts at 2026-04-02T08:19:39+01:00
Update ticker header commentary
It was antique and didn't apply even to the previous implementation, and
certainly not to the updated one.
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ebbfdf15
by Duncan Coutts at 2026-04-02T08:19:39+01:00
Remove the timerfd-based ticker implementation
There does not appear to be any remaining advantage on Linux to using
the timerfd ticker implementation over the portable one (using ppoll on
Linux for precise timing).
The eventfd implementation was originally added at a time when Linux was
still using a signal based implementation. So it made sense at the time.
See (closed) issue #10840.
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c6f8847c
by Duncan Coutts at 2026-04-02T08:19:39+01:00
Consolidate to a single posix ticker implementation
Previously we had four implementations, two using signals and two using
threads. Having just one should make behaviour more consistent between
platforms, and should make maintenance easier.