- Every unit test now passes on Apple Silicon. The final piece of this
puzzle was porting our POSIX threads cancelation support, since that
works differently on ARM64 XNU vs. AMD64. Our semaphore support on
Apple Silicon is also superior now compared to AMD64, thanks to the
grand central dispatch library which lets *NSYNC locks go faster.
- The Cosmopolitan runtime is now more stable, particularly on Windows.
To do this, thread local storage is mandatory at all runtime levels,
and the innermost packages of the C library is no longer being built
using ASAN. TLS is being bootstrapped with a 128-byte TIB during the
process startup phase, and then later on the runtime re-allocates it
either statically or dynamically to support code using _Thread_local.
fork() and execve() now do a better job cooperating with threads. We
can now check how much stack memory is left in the process or thread
when functions like kprintf() / execve() etc. call alloca(), so that
ENOMEM can be raised, reduce a buffer size, or just print a warning.
- POSIX signal emulation is now implemented the same way kernels do it
with pthread_kill() and raise(). Any thread can interrupt any other
thread, regardless of what it's doing. If it's blocked on read/write
then the killer thread will cancel its i/o operation so that EINTR can
be returned in the mark thread immediately. If it's doing a tight CPU
bound operation, then that's also interrupted by the signal delivery.
Signal delivery works now by suspending a thread and pushing context
data structures onto its stack, and redirecting its execution to a
trampoline function, which calls SetThreadContext(GetCurrentThread())
when it's done.
- We're now doing a better job managing locks and handles. On NetBSD we
now close semaphore file descriptors in forked children. Semaphores on
Windows can now be canceled immediately, which means mutexes/condition
variables will now go faster. Apple Silicon semaphores can be canceled
too. We're now using Apple's pthread_yield() funciton. Apple _nocancel
syscalls are now used on XNU when appropriate to ensure pthread_cancel
requests aren't lost. The MbedTLS library has been updated to support
POSIX thread cancelations. See tool/build/runitd.c for an example of
how it can be used for production multi-threaded tls servers. Handles
on Windows now leak less often across processes. All i/o operations on
Windows are now overlapped, which means file pointers can no longer be
inherited across dup() and fork() for the time being.
- We now spawn a thread on Windows to deliver SIGCHLD and wakeup wait4()
which means, for example, that posix_spawn() now goes 3x faster. POSIX
spawn is also now more correct. Like Musl, it's now able to report the
failure code of execve() via a pipe although our approach favors using
shared memory to do that on systems that have a true vfork() function.
- We now spawn a thread to deliver SIGALRM to threads when setitimer()
is used. This enables the most precise wakeups the OS makes possible.
- The Cosmopolitan runtime now uses less memory. On NetBSD for example,
it turned out the kernel would actually commit the PT_GNU_STACK size
which caused RSS to be 6mb for every process. Now it's down to ~4kb.
On Apple Silicon, we reduce the mandatory upstream thread size to the
smallest possible size to reduce the memory overhead of Cosmo threads.
The examples directory has a program called greenbean which can spawn
a web server on Linux with 10,000 worker threads and have the memory
usage of the process be ~77mb. The 1024 byte overhead of POSIX-style
thread-local storage is now optional; it won't be allocated until the
pthread_setspecific/getspecific functions are called. On Windows, the
threads that get spawned which are internal to the libc implementation
use reserve rather than commit memory, which shaves a few hundred kb.
- sigaltstack() is now supported on Windows, however it's currently not
able to be used to handle stack overflows, since crash signals are
still generated by WIN32. However the crash handler will still switch
to the alt stack, which is helpful in environments with tiny threads.
- Test binaries are now smaller. Many of the mandatory dependencies of
the test runner have been removed. This ensures many programs can do a
better job only linking the the thing they're testing. This caused the
test binaries for LIBC_FMT for example, to decrease from 200kb to 50kb
- long double is no longer used in the implementation details of libc,
except in the APIs that define it. The old code that used long double
for time (instead of struct timespec) has now been thoroughly removed.
- ShowCrashReports() is now much tinier in MODE=tiny. Instead of doing
backtraces itself, it'll just print a command you can run on the shell
using our new `cosmoaddr2line` program to view the backtrace.
- Crash report signal handling now works in a much better way. Instead
of terminating the process, it now relies on SA_RESETHAND so that the
default SIG_IGN behavior can terminate the process if necessary.
- Our pledge() functionality has now been fully ported to AARCH64 Linux.
- compile.com now polyfills -march=native which gcc/clang removed
- Guarantee zero Windows code is linked into non-Windows binaries
- MODE=tinylinux binaries are now back to being as tiny as ~4kb
- Improve the runtime's stack allocation / alignment hack
- GitHub Actions now tests Linux modes for assurance
This change upgrades to the latest portcosmo gcc patch
6728fe1a25185560603ca312a8d4352af2a4e515 which lets us avoid needing to
define __tmpcosmo_FOO constants. We're now using an appropriate binutils
version for GCC 11. The older binutils sometimes wasn't able to print
backtraces, due to not being able to find a .debug_ranges section.
This is breaking change for /opt/cosmos libraries :'( due to this weird
"error: need linked-to section for --gc-sections" that pops up.
Please run `make clean` in the monorepo before rebuilding.
This change integrates e58abc1110b335a3341e8ad5821ad8e3880d9bb2 from
https://github.com/ahgamut/musl-cross-make/ which fixes the issues we
were having with our C language extension for symbolic constants. This
change also performs some code cleanup and bug fixes to getaddrinfo().
It's now possible to compile projects like ncurses, readline and python
without needing to patch anything upstream, except maybe a line or two.
Pretty soon it should be possible to build a Linux distro on Cosmo.
- Exhaustively document cancellation points
- Rename SIGCANCEL to SIGTHR just like BSDs
- Further improve POSIX thread cancellations
- Ensure asynchronous cancellations work correctly
- Elevate the quality of getrandom() and getentropy()
- Make futexes cancel correctly on OpenBSD 6.x and 7.x
- Add reboot.com and shutdown.com to examples directory
- Remove underscore prefix from awesome timespec_*() APIs
- Create assertions that help verify our cancellation points
- Remove bad timespec APIs (cmp generalizes eq/ne/gt/gte/lt/lte)
The ZIP filesystem has a breaking change. You now need to use /zip/ to
open() / opendir() / etc. assets within the ZIP structure of your APE
binary, instead of the previous convention of using zip: or zip! URIs.
This is needed because Python likes to use absolute paths, and having
ZIP paths encoded like URIs simply broke too many things.
Many more system calls have been updated to be able to operate on ZIP
files and file descriptors. In particular fcntl() and ioctl() since
Python would do things like ask if a ZIP file is a terminal and get
confused when the old implementation mistakenly said yes, because the
fastest way to guarantee native file descriptors is to dup(2). This
change also improves the async signal safety of zipos and ensures it
doesn't maintain any open file descriptors beyond that which the user
has opened.
This change makes a lot of progress towards adding magic numbers that
are specific to platforms other than Linux. The philosophy here is that,
if you use an operating system like FreeBSD, then you should be able to
take advantage of FreeBSD exclusive features, even if we don't polyfill
them on other platforms. For example, you can now open() a file with the
O_VERIFY flag. If your program runs on other platforms, then Cosmo will
automatically set O_VERIFY to zero. This lets you safely use it without
the need for #ifdef or ifstatements which detract from readability.
One of the blindspots of the ASAN memory hardening we use to offer Rust
like assurances has always been that memory passed to the kernel via
system calls (e.g. writev) can't be checked automatically since the
kernel wasn't built with MODE=asan. This change makes more progress
ensuring that each system call will verify the soundness of memory
before it's passed to the kernel. The code for doing these checks is
fast, particularly for buffers, where it can verify 64 bytes a cycle.
- Correct O_LOOP definition on NT
- Introduce program_executable_name
- Add ASAN guards to more system calls
- Improve termios compatibility with BSDs
- Fix bug in Windows auxiliary value encoding
- Add BSD and XNU specific errnos and open flags
- Add check to ensure build doesn't talk to internet
You can now use cosmopolitan.h with an ANSI C89 compiler like MSVC. The
Cosmopolitan codebase itself won't support being compiled that way. But
you can build objects that link against Cosmopolitan using any compiler
and you can furthermore use tools like IntelliSense that can't even GNU
See also #40
I wanted a tiny scriptable meltdown proof way to run userspace programs
and visualize how program execution impacts memory. It helps to explain
how things like Actually Portable Executable works. It can show you how
the GCC generated code is going about manipulating matrices and more. I
didn't feel fully comfortable with Qemu and Bochs because I'm not smart
enough to understand them. I wanted something like gVisor but with much
stronger levels of assurances. I wanted a single binary that'll run, on
all major operating systems with an embedded GPL barrier ZIP filesystem
that is tiny enough to transpile to JavaScript and run in browsers too.
https://justine.storage.googleapis.com/emulator625.mp4
