- Open flags (e.g. O_CREAT) are now constants
- Error numbers (e.g. EINVAL) are now constants
- Signal numbers (e.g. SIGINT) are now constants
- fcntl() file locks now work properly on Windows
- Significantly improve Windows path handling code
- Implement true vfork() on Windows and make fork() faster
- Implement scanf %[charset] support and improve conformance
- Introduce $COSMOSDRIVE so you can use Windows 11 dev drives
- Fix stdio seek/tell bug and make stdio locks faster and safer
- Change TLS ABI to use tlscc wrapper that inserts function calls
- Make malloc() faster on all platforms using new cosmo_shard() api
- Make malloc() fast like tcmalloc on Linux using restartable sequences
- Improve fsync() and fdatasync() polyfills so they abstract robustness
- Fix CLOCK_BOOTTIME and CLOCK_MONOTONIC on XNU so it reflects uptime
- Fix bugs in Windows overlapped code that could possibly cause crash
- Fix bugs in Windows signal code that could possibly cause crash
- Make symlinks with multiple components work right on Windows
- Add FreeBSD ELF note to remove SIGBUS issue and other quirks
- Support symlinks on Windows under non-administrator accounts
- Make kisdangerous() scalable by adding radix trie to mmap()
- Make large realloc() operations zero-cost on all platforms
- Fix bugs in readdir() on Windows where d_reclen wasn't set
- Make all system call wrappers memory safe (raises EFAULT)
- Fix bugs in poll() and select() on Windows with 64+ fds
- Fix bug in madvise() on Windows that could cause crash
- Support WUNTRACED, SIGSTOP, and SIGCONT on Windows
- Increase x86 image base from 0x400000 to 0x4200000
- Introduce -msysv and -mtinylinux flags to cosmocc
- Fix issues with siglongjmp() on XNU and NetBSD
- Make pthread_barrier_wait() work correctly
- Make clock_gettime() faster on FreeBSD ARM
- Support file mode bits better on Windows
- Improve performance of string libraries
- Raise EILSEQ when creating evil paths
- Fix std::terminate to not use malloc
- Modernize more c11 and c23 features
- Make pthread_once() exception safe
- Support RLIMIT_CPU on Windows
- Introduce HACL* cryptography
- Introduce cosmopolitan make
- Introduce fasterzip program
- Introduce open_memstream()
- Introduce dedupe program
- Introduce arc4random()
- Introduce f2fs support
You can now easily compile this program with non-cosmocc toolchains. The
glaring iconv() api usage mistake is now fixed. Restoring the terminal's
state on exit now works better. We try our best to limit the terminal to
80x24 cells.
This program was originally ported to Cosmopolitan before we had threads
so it was designed to use a single thread. That caused issues for people
with slower computers, like an Intel Core i5, where Gyarados would go so
slow that the audio would skip. I would also get audio skipping when the
terminal was put in full screen mode. Now we use two threads and smarter
timing, so NESEMU1 should go reliably fast on everyone's computer today.
When polling sockets poll() can now let you know about an event in about
10µs rather than 10ms. If you're not polling sockets then poll() reports
console events now in microseconds instead of milliseconds.
This change introduces comsoaudio v1. We're using a new strategy when it
comes to dynamic linking of dso files and building miniaudio device code
which I think will be fast and stable in the long run. You now have your
choice of reading/writing to the internal ring buffer abstraction or you
can specify a device-driven callback function instead. It's now possible
to not open the microphone when you don't need it since touching the mic
causes security popups to happen. The DLL is now built statically, so it
only needs to depend on kernel32. Our NES terminal emulator now uses the
cosmoaudio library and is confirmed to be working on Windows, Mac, Linux
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.
This change fixes an issue with all system calls ending with *at(), when
the caller passes `dirfd != AT_FDCWD` and an absolute path. It's because
the old code was turning paths like C:\bin\ls into \\C:\bin\ls\C:\bin\ls
after being converted from paths like /C/bin/ls. I noticed this when the
Emacs dired mode stopped working. It's unclear if it's a regression with
Cosmopolitan Libc or if this was introduced by the Emacs v29 upgrade. It
also impacted posix_spawn() for which a newly minted example now exists.
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.
So far I haven't found any way to run native Arm64 code on Windows Arm64
without using MSVC. When I build a PE binary from scratch that should be
a valid Windows Arm64 program, the OS refuses to run it. Possibly due to
requiring additional content like XML manifests or relocation or control
flow integrity data that isn't normally required on x64. I've also tried
using VirtualAlloc2() to JIT an Arm64 native function, but VirtualAlloc2
always fails with invalid parameter. I tried using MSVC to create an ARM
DLL that my x64 emulated program can link at runtime, to pass a function
pointer with ARM code, but LoadLibrary() rejects ARM DLLs as invalid exe
The only option left, is likely to write a new program like ape/ape-m1.c
which can be compiled by MSVC to load and run an AARCH64 ELF executable.
The emulated x64 binary would detect emulation using IsWow64Process2 and
then drop the loader executable in a temporary folder, and re-launch the
original executable, using the Arm64 segments of the cosmocc fat binary.
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.
The memory leak detector was crashing. When using gc() you shouldn't use
the CheckForMemoryLeaks() function from inside the same function, due to
how it runs the atexit handlers.
We now have a C++ red-black tree implementation that implements standard
template library compatible APIs while compiling 10x faster than libcxx.
It's not as beautiful as the red-black tree implementation in Plinko but
this will get the job done and the test proves it upholds all invariants
This change also restores CheckForMemoryLeaks() support and fixes a real
actual bug I discovered with Doug Lea's dlmalloc_inspect_all() function.
It hasn't been helpful enough to be justify the maintenance burden. What
actually does help is mprotect(), kprintf(), --ftrace and --strace which
can always be counted upon to work correctly. We aren't losing much with
this change. Support for ASAN on AARCH64 was never implemented. Applying
ASAN to the core libc runtimes was disabled many months ago. If there is
some way to have an ASAN runtime for user programs that is less invasive
we can potentially consider reintroducing support. But now is premature.
Actually Portable Executable now supports Android. Cosmo's old mmap code
required a 47 bit address space. The new implementation is very agnostic
and supports both smaller address spaces (e.g. embedded) and even modern
56-bit PML5T paging for x86 which finally came true on Zen4 Threadripper
Cosmopolitan no longer requires UNIX systems to observe the Windows 64kb
granularity; i.e. sysconf(_SC_PAGE_SIZE) will now report the host native
page size. This fixes a longstanding POSIX conformance issue, concerning
file mappings that overlap the end of file. Other aspects of conformance
have been improved too, such as the subtleties of address assignment and
and the various subtleties surrounding MAP_FIXED and MAP_FIXED_NOREPLACE
On Windows, mappings larger than 100 megabytes won't be broken down into
thousands of independent 64kb mappings. Support for MAP_STACK is removed
by this change; please use NewCosmoStack() instead.
Stack overflow avoidance is now being implemented using the POSIX thread
APIs. Please use GetStackBottom() and GetStackAddr(), instead of the old
error-prone GetStackAddr() and HaveStackMemory() APIs which are removed.
🚨 clang-format changes output per version!
This is with version 19.0.0. The modifications seem to be fixing the old
version’s errors - mainly involving omitted whitespace around binary ops
and inserted whitespace between goto labels and colons (if followed by a
curly brace.)
Also fixes a few mistakes made by e.g. someone (ahem) forgetting to pass
his ctl/string.h modifications through it.
We should add this to .git-blame-ignore-revs once we have its final hash
on master.
If pthread_create() is linked into the binary, then the cosmo runtime
will create an independent dlmalloc arena for each core. Whenever the
malloc() function is used it will index `g_heaps[sched_getcpu() / 2]`
to find the arena with the greatest hyperthread / numa locality. This
may be configured via an environment variable. For example if you say
`export COSMOPOLITAN_HEAP_COUNT=1` then you can restore the old ways.
Your process may be configured to have anywhere between 1 - 128 heaps
We need this revision because it makes multithreaded C++ applications
faster. For example, an HTTP server I'm working on that makes extreme
use of the STL went from 16k to 2000k requests per second, after this
change was made. To understand why, try out the malloc_test benchmark
which calls malloc() + realloc() in a loop across many threads, which
sees a a 250x improvement in process clock time and 200x on wall time
The tradeoff is this adds ~25ns of latency to individual malloc calls
compared to MODE=tiny, once the cosmo runtime has transitioned into a
fully multi-threaded state. If you don't need malloc() to be scalable
then cosmo provides many options for you. For starters the heap count
variable above can be set to put the process back in single heap mode
plus you can go even faster still, if you include tinymalloc.inc like
many of the programs in tool/build/.. are already doing since that'll
shave tens of kb off your binary footprint too. Theres also MODE=tiny
which is configured to use just 1 plain old dlmalloc arena by default
Another tradeoff is we need more memory now (except in MODE=tiny), to
track the provenance of memory allocation. This is so allocations can
be freely shared across threads, and because OSes can reschedule code
to different CPUs at any time.
Cosmo will now print C++ symbols correctly in --ftrace logs and
backtraces. Doing this required reducing the memory requirement
of the __demangle() function by 3x. This was accomplished using
16-bit indices and 16-bit malloc granularity. That puts a limit
on the longest symbol we can successfully decode, which I think
would be around 6553 characters long, given a 65536-byte buffer
We're now able to rewind the instruction pointer in x86 backtraces. This
helps ensure addr2line cannot print information about unrelated adjacent
code. I've restored -fno-schedule-insns2 in most cases because it really
does cause unpredictable breakage for backtraces.
We're now able to pretty print a C++ backtrace upon crashing in pretty
much any runtime execution scenario. The default pledge sandbox policy
on Linux is now to return EPERM. If you call pledge and have debugging
functions linked (e.g. GetSymbolTable) then the symbol table shall get
loaded before any security policy is put in place. This change updates
build/bootstrap/fixupobj too and fixes some other sneaky build errors.
Cosmopolitan now supports 104 time zones. They're embedded inside any
binary that links the localtime() function. Doing so adds about 100kb
to the binary size. This change also gets time zones working properly
on Windows for the first time. It's not needed to have /etc/localtime
exist on Windows, since we can get this information from WIN32. We're
also now updated to the latest version of Paul Eggert's TZ library.
The feenableexcept() and fedisableexcept() APIs are now provided which
let you detect when NaNs appear the moment it happens from anywhere in
your program. Tests have also been added for the mission critical math
functions expf() and erff(), whose perfect operation has been assured.
See examples/trapping.c to see how to use this powerful functionality.
Justin Tunney