While we have always licked glibc and musl libc on gnu/systemd sadly the
Apple Libc implementation of pthread_mutex_t is better than ours. It may
be due to how the XNU kernel and M2 microprocessor are in league when it
comes to scheduling processes and the NSYNC behavior is being penalized.
We can solve this by leaning more heavily on ulock using Drepper's algo.
It's kind of ironic that Linux's official mutexes work terribly on Linux
but almost as good as Apple Libc if used on MacOS.
poll() and select() now delegate to ppoll() and pselect() for assurances
that both polyfill implementations are correct and well-tested. Poll now
polyfills XNU and BSD quirks re: the hanndling of POLLNVAL and the other
similar status flags. This change resolves a misunderstanding concerning
how select(exceptfds) is intended to map to POLPRI. We now use E2BIG for
bouncing requests that exceed the 64 handle limit on Windows. With pipes
and consoles on Windows our poll impl will now report POLLHUP correctly.
Issues with Windows path generation have been fixed. For example, it was
problematic on Windows to say: posix_spawn_file_actions_addchdir_np("/")
due to the need to un-UNC paths in some additional places. Calling fstat
on UNC style volume path handles will now work. posix_spawn now supports
simulating the opening of /dev/null and other special paths on Windows.
Cosmopolitan no longer defines epoll(). I think wepoll is a nice project
for using epoll() on Windows socket handles. However we need generalized
file descriptor support to make epoll() for Windows work well enough for
inclusion in a C library. It's also not worth having epoll() if we can't
get it to work on XNU and BSD OSes which provide different abstractions.
Even epoll() on Linux isn't that great of an abstraction since it's full
of footguns. Last time I tried to get it to be useful I had little luck.
Considering how long it took to get poll() and select() to be consistent
across platforms, we really have no business claiming to have epoll too.
While it'd be nice to have fully implemented, the only software that use
epoll() are event i/o libraries used by things like nodejs. Event i/o is
not the best paradigm for handling i/o; threads make so much more sense.
Cosmopolitan's printf-family functions will currently crash if one tries
formatting a floating point number with a larger precision (large enough
that gdtoa attempts to allocate memory to format the number) while under
memory pressure (i.e. when malloc fails) because gdtoa fails to check if
malloc fails.
The added tests (which would previously crash under cosmopolitan without
this patch) show how to reproduce the issue.
This patch fixes this, and adds the aforementioned tests.
- wcsstr() is now linearly complex
- strstr16() is now linearly complex
- strstr() is now vectorized on aarch64 (10x)
- strstr() now uses KMP on pathological cases
- memmem() is now vectorized on aarch64 (10x)
- memmem() now uses KMP on pathological cases
- Disable shared_ptr::owner_before until fixed
- Make iswlower(), iswupper() consistent with glibc
- Remove figure space from iswspace() implementation
- Include line and paragraph separator in iswcntrl()
- Use Musl wcwidth(), iswalpha(), iswpunct(), towlower(), towupper()
This change switches c++ exception handling from sjlj to standard dwarf.
It's needed because clang for aarch64 doesn't support sjlj. It turns out
that libunwind had a bare-metal configuration that made this easy to do.
This change gets the new experimental cosmocc -mclang flag in a state of
working so well that it can now be used to build all of llamafile and it
goes 3x faster in terms of build latency, without trading away any perf.
The int_fast16_t and int_fast32_t types are now always defined as 32-bit
in the interest of having more abi consistency between cosmocc -mgcc and
-mclang mode.
This is believed to fix a crash, that's possible in nsync_waiter_free_()
when you call pthread_cond_timedwait(), or nsync_cv_wait_with_deadline()
where an assertion can fail. Thanks ipv4.games for helping me find this!
It turns out sched_getcpu() didn't work on many platforms. So the system
call now has tests and is well documented. We now employ new workarounds
on platforms where it isn't supported in our malloc() implementation. It
was previously the case that malloc() was only scalable on Linux/Windows
for x86-64. Now the other platforms are scalable too.
We now have implement all of Musl's localization code, the same way that
Musl implements localization. You may need setlocale(LC_ALL, "C.UTF-8"),
just in case anything stops working as expected.
This change makes a second pass, at fixing the errno issue with libcxx's
filesystem code. Previously, 89.01% of LLVM's test suite was passing and
now 98.59% of their tests pass. Best of all, it's now possible for Clang
to be built as a working APE binary that can to compile the Cosmopolitan
repository. Please note it has only been vetted so far for some objects,
and more work would obviously need to be done in cosmo, to fix warnings.
This change solves an issue where many threads attempting to spawn forks
at once would cause fork() performance to degrade with the thread count.
Things got real nasty on NetBSD, which slowed down the whole test fleet,
because there's no vfork() and we're forced to use fork() in our server.
threads count task
1 1062 fork+exit+wait
2 668 fork+exit+wait
4 66 fork+exit+wait
8 19 fork+exit+wait
16 22 fork+exit+wait
32 16 fork+exit+wait
Things are now much less bad on NetBSD, but not great, since it does not
have futexes; we rely on its semaphore file descriptors to do conditions
threads count task
1 1085 fork+exit+wait
2 842 fork+exit+wait
4 532 fork+exit+wait
8 400 fork+exit+wait
16 276 fork+exit+wait
32 66 fork+exit+wait
With OpenBSD which also lacks vfork(), things were just as bad as NetBSD
threads count task
1 584 fork+exit+wait
2 687 fork+exit+wait
4 206 fork+exit+wait
8 24 fork+exit+wait
16 33 fork+exit+wait
32 26 fork+exit+wait
But since OpenBSD has futexes fork() works terrifically thanks to *NSYNC
threads count task
1 525 fork+exit+wait
2 580 fork+exit+wait
4 451 fork+exit+wait
8 479 fork+exit+wait
16 408 fork+exit+wait
32 373 fork+exit+wait
This issue would most likely only manifest itself, when pthread_atfork()
callers manage to slip a spin lock into the outermost position of fork's
list of locks. Since fork() is very slow, a spin lock can be devastating
Needless to say vfork() rules and anyone who says differently is kidding
themselves. Look at what a FreeBSD 14.1 virtual machine with equal specs
can do over the course of three hundred milliseconds.
threads count task
1 2559 vfork+exit+wait
2 5389 vfork+exit+wait
4 34933 vfork+exit+wait
8 43273 vfork+exit+wait
16 49648 vfork+exit+wait
32 40247 vfork+exit+wait
So it's a shame that so few OSes support vfork(). It creates an unsavory
situation, where someone wanting to build a server that spawns processes
would be better served to not use threads and favor a multiprocess model
The cosmocc.zip toolchain will now include four builds of the libcosmo.a
runtime libraries. You can pass the -mdbg flag if you want to debug your
cosmopolitan runtime. You can pass the -moptlinux flag if you don't want
windows code lurking in your binary. See tool/cosmocc/README.md for more
details on how these flags may be used and their important implications.
- NetBSD should now have faster synchronization
- POSIX barriers may now be shared across processes
- An edge case with memory map tracking has been fixed
- Grand Central Dispatch is no longer used on MacOS ARM64
- POSIX mutexes in normal mode now use futexes across processes
Cosmopolitan now supports mremap(), which is only supported on Linux and
NetBSD. First, it allows memory mappings to be relocated without copying
them; this can dramatically speed up data structures like std::vector if
the array size grows larger than 256kb. The mremap() system call is also
10x faster than munmap() when shrinking large memory mappings.
There's now two functions, getpagesize() and getgransize() which help to
write portable code that uses mmap(MAP_FIXED). Alternative sysconf() may
be called with our new _SC_GRANSIZE. The madvise() system call now has a
better wrapper with improved documentation.
It's now possible to create thousands of thousands of sparse independent
memory mappings, without any slowdown. The memory manager is better with
tracking memory protection now, particularly on Windows in a precise way
that can be restored during fork(). You now have the highest quality mem
manager possible. It's even better than some OSes like XNU, where mmap()
is implemented as an O(n) operation which means sadly things aren't much
improved over there. With this change the llamafile HTTP server endpoint
at /tokenize with a prompt of 50 tokens is now able to handle 2.6m r/sec
This change reduces o/tiny/examples/life from 44kb to 24kb in size since
it avoids linking mmap() when unnecessary. This is important, to helping
cosmo not completely lose touch with its roots.
The Cosmopolitan Compiler Collection now includes the following programs
- `ar.ape` is a faster alternative to `ar rcsD` for creating determistic
static archives. It's ~10x faster than GNU because it isn't quadratic.
It'll even outperform LLVM ar by 2x, thanks to writev/copy_file_range.
- `sha256sum.ape` is a faster alternative to the `sha256sum` command. It
goes 2x faster since it leverages vectorized assembly implementations.
- `resymbol` is a brand new program we invented, like objcopy, that lets
you rename all the global symbols in a .o file to have a new suffix or
prefix. In the future, this will be used by cosmocc automatically when
building -O3 math kernels, that need to be vectorized for all hardware
- `gzip.ape` is a faster version of the `gzip` command, that is included
by most Linux distros. It gains better performance using Chromium Zlib
which, once again, includes highly optimized assembly, that Mark Adler
won't merge into the official MS-DOS compatible zlib codebase.
- `cocmd` is the cosmopolitan shell. It can function as a faster `sh -c`
alternative than bash and dash as the `SHELL = /opt/cosmocc/bin/cocmd`
at the top of your Makefile. Please note you should be using the cosmo
fork of GNU make (already included), since normal make won't recognize
this as a bourne-compatible shell and remove the execve() optimization
which makes things slower. In some ways that's true. This doesn't have
a complete POSIX shell implementation. However it's enough for cosmo's
mono repo. It also implements faster behaviors in some respects.
The following programs are also introduced, which aren't as interesting.
The main reason why they're here is so Cosmopolitan's mono repo shall be
able to remove build/bootstrap/ in future editions. That way we can keep
build utilities better up to date, without bloating the git history much
- `chmod.ape` for hermeticity
- `cp.ape` for hermeticity
- `echo.ape` for hermeticity
- `objbincopy` is an objcopy-like tool that's used to build ape loader
- `package.ape` is used for strict dependency checking of object graph
- `rm.ape` for hermeticity
- `touch.ape` for hermeticity
