* ucontext_t ptr is 8-byte aligned instead of 16-byte aligned which @alignCast() expects
* Retrieve pc address from ucontext_t since unwind_state is null
* Work around __mcontext_data being written incorrectly by the kernel
Textual PTX is just assembly language like any other. And if we do ever add
support for emitting PTX object files after reverse engineering the bytecode
format, we'd be emitting ELF files like the CUDA toolchain. So there's really no
need for a special ObjectFormat tag here, nor linker code that treats it as a
distinct format.
For C code the macros SIGRTMIN and SIGRTMAX provide these values. In
practice what looks like a constant is actually provided by a libc call.
So the Zig implementations are explicitly function calls.
glibc (and Musl) export a run-time minimum "real-time" signal number,
based on how many signals are reserved for internal implementation details
(generally threading). In practice, on Linux, sigrtmin() is 35 on glibc
with the older LinuxThread and 34 with the newer NPTL-based
implementation. Musl always returns 35. The maximum "real-time" signal
number is NSIG - 1 (64 on most Linux kernels, but 128 on MIPS).
When not linking a C Library, Zig can report the full range of "rt"
signals (none are reserved by Zig).
Fixes#21189
There were several bugs with the synchronization here; most notably an
ABA problem which was causing #21663. I fixed that and some other
issues, and took the opportunity to get rid of the `.seq_cst` orderings
from this file. I'm at least relatively sure my new orderings are correct.
Co-authored-by: achan1989 <achan1989@gmail.com>
Resolves: #21663
Dunno why the MIPS signal numbers are different, or why Zig had them
already special cased, but wrong.
We have the technology to test these constants. We should use it.
All the existing code that manipulates `ucontext_t` expects there to be a
glibc-compatible sigmask (1024-bit). The `ucontext_t` struct need to be
cleaned up so the glibc-dependent format is only used when linking
glibc/musl library, but that is a more involved change.
In practice, no Zig code looks at the sigset field contents, so it just
needs to be the right size.
By returning an initialized sigset (instead of taking the set as an output
parameter), these functions can be used to directly initialize the `mask`
parameter of a `Sigaction` instance.
