The way to use double linked lists, is to remove all the things you want
to work on, insert them into a new list on the stack. Then once you have
all the work items, you release the lock, do your work, and then lock it
again, to add the shelled out items back to a global freelist.
This fixes a regression in mmap(MAP_FIXED) on Windows caused by a recent
revision. This change also fixes ZipOS so it no longer needs a MAP_FIXED
mapping to open files from the PKZIP store. The memory mapping mutex was
implemented incorrectly earlier which meant that ftrace and strace could
cause cause crashes. This lock and other recursive mutexes are rewritten
so that it should be provable that recursive mutexes in cosmopolitan are
asynchronous signal safe.
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.
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
This change fixes a bug where exiting a crash signal handler on Windows
after adding the signal to uc_sigmask, but not correcting the CPU state
would cause the signal handler to loop infinitely, causing process hang
Another issue is that very tiny programs, that don't link posix signals
would not have their SIGILL / SIGSEGV / etc. status reported to Cosmo's
bash shell when terminating on crash. That's fixed by a tiny handler in
WinMain() that knows how to map WIN32 crash codes to the POSIX flavors.
Microsoft caused some very gentle breakages for Cosmopolitan. They
removed the version information from the PEB which caused uname to
report WINDOWS 0.0.0. We should have called GetVersionExW but that
doesn't really exist anymore either. Windows policy is now to give
whatever version we used in ape/ape.S. Windows8 has been EOL since
2023-01-10 so lets avoid our modern executables being relegated to
legacy infrastructure. Requiring Windows 10+ going forward lets us
remove runtime compatibility bloat from the codebase. Further note
Cosmopolitan maintains a Windows Vista branch on GitHub, so anyone
preferring the older versions, can still have a future with Cosmo.
Another neat thing this fixes is UTF-8 support in the console. The
changes Microsoft made broke the if statement that enabled UTF8 in
terminals. This explains why bug reports had broken arrows. In the
future this should be less of an issue, since the PEB code is gone
which means we more strictly conform to only Microsoft's WIN32 API
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.
It's now possible to safely print C++ backtraces from signal handlers.
This symbol demangler doesn't need malloc, tls, or even static memory.
Additionally, this change makes it 2x faster and adds test cases. It's
almost as performant and accurate as the libcxxabi implementation now.
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.
Commit bc6c183 introduced a bunch of discrepancies between what files
look like in the repo and what clang-format says they should look like.
However, there were already a few discrepancies prior to that. Most of
these discrepancies seemed to be unintentional, but a few of them were
load-bearing (e.g., a #include that violated header ordering needing
something to have been #defined by a 'later' #include.)
I opted to take what I hope is a relatively smooth-brained approach: I
reverted the .clang-format change, ran clang-format on the whole repo,
reapplied the .clang-format change, reran clang-format again, and then
reverted the commit that contained the first run. Thus the full effect
of this PR should only be to apply the changed formatting rules to the
repo, and from skimming the results, this seems to be the case.
My work can be checked by applying the short, manual commits, and then
rerunning the command listed in the autogenerated commits (those whose
messages I have prefixed auto:) and seeing if your results agree.
It might be that the other diffs should be fixed at some point but I'm
leaving that aside for now.
fd '\.c(c|pp)?$' --print0| xargs -0 clang-format -i
Previously, the atomic store looked like it was happening while the
struct's memory was still poisoned. I was unable to observe any issues
with this, but this change seems to make the code more obviously correct
(at the cost of a redundant atomic store to zeroed space in case the map
needed to be extended.)
Now that these functions are behind _COSMO_SOURCE there's no reason for
having the ugly underscore anymore. To use these functions, you need to
pass -mcosmo to cosmocc.
The WIN32 CreateProcess() function does not require an .exe or .com
suffix in order to spawn an executable. Now that we have Cosmo bash
we're no longer so dependent on the cmd.exe prompt.
Sometimes we need to interact with code that wasn't compiled using
`-fno-omit-frame-pointer`. For example, if a function pointer gets
passed and called by a foreign function, linked by cosmo_dlopen().
Function call tracing will now detect backtrace pointer corruption
and simply reduce the indentation level back to zero, as a result.
This change upgrades to GCC 12.3 and GNU binutils 2.42. The GNU linker
appears to have changed things so that only a single de-duplicated str
table is present in the binary, and it gets placed wherever the linker
wants, regardless of what the linker script says. To cope with that we
need to stop using .ident to embed licenses. As such, this change does
significant work to revamp how third party licenses are defined in the
codebase, using `.section .notice,"aR",@progbits`.
This new GCC 12.3 toolchain has support for GNU indirect functions. It
lets us support __target_clones__ for the first time. This is used for
optimizing the performance of libc string functions such as strlen and
friends so far on x86, by ensuring AVX systems favor a second codepath
that uses VEX encoding. It shaves some latency off certain operations.
It's a useful feature to have for scientific computing for the reasons
explained by the test/libcxx/openmp_test.cc example which compiles for
fifteen different microarchitectures. Thanks to the upgrades, it's now
also possible to use newer instruction sets, such as AVX512FP16, VNNI.
Cosmo now uses the %gs register on x86 by default for TLS. Doing it is
helpful for any program that links `cosmo_dlopen()`. Such programs had
to recompile their binaries at startup to change the TLS instructions.
That's not great, since it means every page in the executable needs to
be faulted. The work of rewriting TLS-related x86 opcodes, is moved to
fixupobj.com instead. This is great news for MacOS x86 users, since we
previously needed to morph the binary every time for that platform but
now that's no longer necessary. The only platforms where we need fixup
of TLS x86 opcodes at runtime are now Windows, OpenBSD, and NetBSD. On
Windows we morph TLS to point deeper into the TIB, based on a TlsAlloc
assignment, and on OpenBSD/NetBSD we morph %gs back into %fs since the
kernels do not allow us to specify a value for the %gs register.
OpenBSD users are now required to use APE Loader to run Cosmo binaries
and assimilation is no longer possible. OpenBSD kernel needs to change
to allow programs to specify a value for the %gs register, or it needs
to stop marking executable pages loaded by the kernel as mimmutable().
This release fixes __constructor__, .ctor, .init_array, and lastly the
.preinit_array so they behave the exact same way as glibc.
We no longer use hex constants to define math.h symbols like M_PI.
- Introduce portable sched_getcpu() api
- Support GCC's __target_clones__ feature
- Make fma() go faster on x86 in default mode
- Remove some asan checks from core libraries
- WinMain() now ensures $HOME and $USER are defined
- Let OpenMP be usable via cosmocc
- Let libunwind be usable via cosmocc
- Make X86_HAVE(AVXVNNI) work correctly
- Avoid using MAP_GROWSDOWN on qemu-aarch64
- Introduce in6addr_any and in6addr_loopback
- Have thread stacks use MAP_GROWSDOWN by default
- Ask OpenMP to not use filesystem to manage threads
- Make NI_MAXHOST and NI_MAXSERV available w/o _GNU_SOURCE
If you install qemu-user from apt then glibc links a lot of address
space bloat that causes pthread_create() to ENOMEM (a.k.a. EAGAIN).
Boosting the virtual memory quota from 512m to 2048m will hopefully
future proof the build for the future, as Linux distros get fatter.
Please note this only applies to MODE=aarch64 on x86_64 builds when
you're using QEMU from Debian/Ubuntu rather than installing the one
cosmo provides in third_party/qemu/qemu-aarch64.gz. This change may
also be useful to people who are using the host compiler toolchain.
Renaming gc() to _gc() was a mistake since the better thing to do is put
it behind the _COSMO_SOURCE macro. We need this change because I haven't
wanted to use my amazing garbage collector ever since we renamed it. You
now need to define _COSMO_SOURCE yourself when using amalgamation header
and cosmocc users need to pass the -mcosmo flag to get the gc() function
Some other issues relating to cancelation have been fixed along the way.
We're also now putting cosmocc in a folder named `.cosmocc` so it can be
more safely excluded by grep --exclude-dir=.cosmocc --exclude-dir=o etc.
* third_party: Add libcxxabi
Added libcxxabi from LLVM 17.0.6
The library implements the Itanium C++ exception handling ABI.
* third_party/libcxxabi: Enable __cxa_thread_atexit
Enable `__cxa_thread_atexit` from libcxxabi.
`__cxa_thread_atexit_impl` is still implemented by the cosmo libc.
The original `__cxa_thread_atexit` has been removed.
* third_party/libcxx: Build with exceptions
Build libcxx with exceptions enabled.
- Removed `_LIBCPP_NO_EXCEPTIONS` from `__config`.
- Switched the exception implementation to `libcxxabi`. These two files
are taken from the same `libcxx` version as mentioned in `README.cosmo`.
- Removed `new_handler_fallback` in favor of `libcxxabi` implementation.
- Enable `-fexceptions` and `-frtti` for `libcxx`.
- Removed `THIRD_PARTY_LIBCXX` dependency from `libcxxabi` and
`libunwind`. These libraries do not use any runtime `libcxx` functions,
just headers.
* libc: Remove remaining redundant cxa functions
- `__cxa_pure_virtual` in `libcxxabi` is also a stub similar to the
existing one.
- `__cxa_guard_*` from `libcxxabi` is used instead of the ones from
Android.
Now there should be no more duplicate implementations.
`__cxa_thread_atexit_impl`, `__cxa_atexit`, and related supporting
functions, are still left to other libraries as in `libcxxabi`.
`libcxxabi` is also now added to `cosmopolitan.a` to make up for the
removed functions.
Affected in-tree libraries (`third_party/double-conversion`) have been
updated.
If cosmo_dlopen() is linked on AMD64 then the runtime will switch to
using %gs for thread-local storage. This eliminates the need for the
imported symbol trampoline. It's now safer to pass function pointers
back and forth with imported libraries. Your program gets recompiled
at runtime to make it happen and the overhead is a few milliseconds.
* Reorder Launch arguments, pass aarch64 os
Third and fourth arguments are now identical between cosmo and Launch.
By passing sp as argument 4, we save a bit of register juggling.
Fourth argument (os) is now always passed by the loader on aarch64. It
is not yet processed by cosmo. Pushing this change separately, as the
cosmo side turns out to be somewhat more involved.
* cosmo2 receives os from loader
FreeBSD aarch64 now traps early rather than pretending to be Linux.
o/aarch64/examples/env.com still works on Linux and Xnu.
Somehow or another, I previously had missed `BUILD.mk` files.
In the process I found a few straggler cases where the modeline was
different from the file, including one very involved manual fix where a
file had been treated like it was ts=2 and ts=8 on separate occasions.
The commit history in the PR shows the gory details; the BUILD.mk was
automated, everything else was mostly manual.
The ape loader now passes the program executable name directly as a
register. `x2` is used on aarch64, `%rdx` on x86_64. This is passed
as the third argument to `cosmo()` (M1) or `Launch` (non-M1) and is
assigned to the global `__program_executable_name`.
`GetProgramExecutableName` now returns this global's value, setting
it if it is initially null. `InitProgramExecutableName` first tries
exotic, secure methods: `KERN_PROC_PATHNAME` on FreeBSD/NetBSD, and
`/proc` on Linux. If those produce a reasonable response (i.e., not
`"/usr/bin/ape"`, which happens with the loader before this change),
that is used. Otherwise, if `issetugid()`, the empty string is used.
Otherwise, the old argv/envp parsing code is run.
The value returned from the loader is always the full absolute path
of the binary to be executed, having passed through `realpath`. For
the non-M1 loader, this necessitated writing `RealPath`, which uses
`readlinkat` of `"/proc/self/fd/[progfd]"` on Linux, `F_GETPATH` on
Xnu, and the `__realpath` syscall on OpenBSD. On FreeBSD/NetBSD, it
punts to `GetProgramExecutableName`, which is secure on those OSes.
With the loader, all platforms now have a secure program executable
name. With no loader or an old loader, everything still works as it
did, but setuid/setgid is not supported if the insecure pathfinding
code would have been needed.
Fixes#991.
At least in neovim, `│vi:` is not recognized as a modeline because it
has no preceding whitespace. After fixing this, opening a file yields
an error because `net` is not an option. (`noet`, however, is.)
* Better refcounting
Cribbed from [Rust Arc][1] and the [Boost docs][2]:
"""
Increasing the reference counter can always be done with
memory_order_relaxed: New references to an object can only be formed
from an existing reference, and passing an existing reference from one
thread to another must already provide any required synchronization.
It is important to enforce any possible access to the object in one
thread (through an existing reference) to happen before deleting the
object in a different thread. This is achieved by a "release" operation
after dropping a reference (any access to the object through this
reference must obviously happened before), and an "acquire" operation
before deleting the object.
It would be possible to use memory_order_acq_rel for the fetch_sub
operation, but this results in unneeded "acquire" operations when the
reference counter does not yet reach zero and may impose a performance
penalty.
"""
[1] https://moshg.github.io/rust-std-ja/src/alloc/arc.rs.html
[2] https://www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html
* Make ZiposHandle's pos atomic
Implements a somewhat stronger guarantee than POSIX specifies: reads and
seeks are atomic. They may be arbitrarily reordered between threads, but
each one happens all the way and leaves the fd in a consistent state.
This is achieved by "locking" pos in __zipos_read by storing SIZE_MAX to
pos during the operation, so only one can be in-flight at a time. Seeks,
on the other hand, just update pos in one go, and rerun if it changed in
the meantime.
I used `LIKELY` / `UNLIKELY` to pessimize the concurrent case; hopefully
that buys back some performance.
* Implement __zipos_dup
Makes ZiposHandle reference-counted by an `rc` field in a union with its
freelist `next` pointer. The functions `__zipos_free` and `__zipos_keep`
function as incref/decref for it. Adds `__zipos_postdup` to fix metadata
on file descriptors after dup-like operations, and adds zipos support to
`sys_dup_nt` + `sys_close_nt`.
* Remove noop __zipos_postdup
rc is never a zipos file because it is always a previously unused file
descriptor. fd is never a zipos file because that case has been handled
above by __zipos_fcntl.
- Introduce MAP_JIT which is zero on other platforms
- Invent __jit_begin() and __jit_end() which wrap Apple's APIs
- Runtime dispatch to sys_icache_invalidate() in __clear_cache()
- Use good ELF technique in cosmo_dlopen()
- Make strerror() conform more to other libc impls
- Introduce __clear_cache() and use it in cosmo_dlopen()
- Remove libc/fmt/fmt.h header (trying to kill off LIBC_FMT)
* [metal] Ensure DF is clear when calling C from exception handler
* [metal] Mark some internal routines and declarations as `@internal`
* [metal] Fix crash under UEFI when command line string is NULL
* [metal] Fix argc & argv[] setting, & VM page freeing, for UEFI
Part of the memory occupied by the argv[] contents was
erroneously used for page tables & then later erroneously
freed. The symptom was that argv[0] would show up as an
empty string ("").
We now have an `#include <cxxabi.h>` header which defines all the APIs
Cosmopolitan's implemented so far. The `cosmocc` README.md file is now
greatly expanded with documentation.
Our makefile generator now accepts badly formatted include lines. It's
now more hermetic with better error checking in the cosmo repo, and it
can be configured to not be hermetic at all.
wait4() is now solid enough to run `make -j100` on Windows. You can now
use MSG_DONTWAIT on Windows. There was a handle leak in accept() that's
been fixed. Our WIN32 overlapped i/o code has been simplified. Priority
class now inherits into subprocesses, so the verynice command will work
and the signal mask will now be inherited by execve() and posix_spawn()
Every program built using Cosmopolitan is statically-linked. However
there are some cases, e.g. GUIs and video drivers, where linking the
host platform libraries is desirable. So what we do in such cases is
launch a stub executable using the host platform's libc, and longjmp
back into this executable. The stub executable passes back to us the
platform-specific dlopen() implementation, which we shall then wrap.
Here's the list of platforms that are supported so far:
- x86-64 Linux w/ Glibc
- x86-64 Linux w/ Musl Libc
- x86-64 FreeBSD
- x86-64 Windows
- aarch64 Linux w/ Glibc
- aarch64 MacOS
What this means is your Cosmo programs can call foreign functions on
your host operating system. However, it's important to note that any
foreign library you link won't have the ability to call functions in
your Cosmopolitan program. For example it's now technically possible
that Lua can load a module, however that almost certainly won't work
since the Lua module won't have access to Cosmo's Lua API.
Kudos to @jacereda for figuring out how to do this.
* [metal] Add a uprintf() routine, for non-emergency boot logging
* [metal] _Really_ push forward timing of VGA TTY initialization
* [metal] Do something useful with uprintf()
* [metal] Locate some ACPI tables, for later hardware detection
Specifically the code now tries to find the ACPI RSDP,
RSDT/XSDT, FADT, & MADT tables, whether in legacy BIOS
bootup mode or in a UEFI bootup. These are useful for
figuring out how to (re)enable asynchronous interrupts
in legacy 8259 PIC mode.
- You can now run `make -j8 toolchain` on Windows
- You can now run `make -j` on MacOS ARM64 and BSD OSes
- You can now use our Emacs dev environment on MacOS/Windows
- Fix bug where the x16 register was being corrupted by --ftrace
- The programs under build/bootstrap/ are updated as fat binaries
- The Makefile now explains how to download cosmocc-0.0.12 toolchain
- The build scripts under bin/ now support "cosmo" branded toolchains
- stat() now goes faster on Windows (shaves 100ms off `make` latency)
- Code cleanup and added review on the Windows signal checking code
- posix_spawnattr_setrlimit() now works around MacOS ARM64 bugs
- Landlock Make now favors posix_spawn() on non-Linux/OpenBSD
- posix_spawn() now has better --strace logging on Windows
- fstatat() can now avoid EACCES in more cases on Windows
- fchmod() can now change the readonly bit on Windows
GNU Make on Windows now appears to be working reliably. This change also
fixes a bug where, after fork the Windows thread handle wasn't reset and
that caused undefined behavior using SetThreadContext() with our signals
This change gets GNU grep working. What caused it to not work, is it
wouldn't write to an output file descriptor when its dev/ino equaled
/dev/null's. So now we invent special dev/ino values for these files
- On Windows connect() can now be interrupted by a signal; connect() w/
O_NONBLOCK will now raise EINPROGRESS; and connect() with SO_SNDTIMEO
will raise ETIMEDOUT after the interval has elapsed.
- We now get the AcceptEx(), ConnectEx(), and TransmitFile() functions
from the WIN32 API the officially blessed way, using WSAIoctl().
- Do nothing on Windows when fsync() is called on a directory handle.
This was raising EACCES earlier becaues GENERIC_WRITE is required on
the handle. It's possible to FlushFileBuffers() a directory handle if
it's opened with write access but MSDN doesn't document what it does.
If you have any idea, please let us know!
- Prefer manual reset event objects for read() and write() on Windows.
- Do some code cleanup on our dlmalloc customizations.
- Fix errno type error in Windows blocking routines.
- Make the futex polyfill simpler and faster.
This change deletes mkfifo() so that GNU Make on Windows will work in
parallel mode using its pipe-based implementation. There's an example
called greenbean2 now, which shows how to build a scalable web server
for Windows with 10k+ threads. The accuracy of clock_nanosleep is now
significantly improved on Linux.
- We now serialize the file descriptor table when spawning / executing
processes on Windows. This means you can now inherit more stuff than
just standard i/o. It's needed by bash, which duplicates the console
to file descriptor #255. We also now do a better job serializing the
environment variables, so you're less likely to encounter E2BIG when
using your bash shell. We also no longer coerce environ to uppercase
- execve() on Windows now remotely controls its parent process to make
them spawn a replacement for itself. Then it'll be able to terminate
immediately once the spawn succeeds, without having to linger around
for the lifetime as a shell process for proxying the exit code. When
process worker thread running in the parent sees the child die, it's
given a handle to the new child, to replace it in the process table.
- execve() and posix_spawn() on Windows will now provide CreateProcess
an explicit handle list. This allows us to remove handle locks which
enables better fork/spawn concurrency, with seriously correct thread
safety. Other codebases like Go use the same technique. On the other
hand fork() still favors the conventional WIN32 inheritence approach
which can be a little bit messy, but is *controlled* by guaranteeing
perfectly clean slates at both the spawning and execution boundaries
- sigset_t is now 64 bits. Having it be 128 bits was a mistake because
there's no reason to use that and it's only supported by FreeBSD. By
using the system word size, signal mask manipulation on Windows goes
very fast. Furthermore @asyncsignalsafe funcs have been rewritten on
Windows to take advantage of signal masking, now that it's much more
pleasant to use.
- All the overlapped i/o code on Windows has been rewritten for pretty
good signal and cancelation safety. We're now able to ensure overlap
data structures are cleaned up so long as you don't longjmp() out of
out of a signal handler that interrupted an i/o operation. Latencies
are also improved thanks to the removal of lots of "busy wait" code.
Waits should be optimal for everything except poll(), which shall be
the last and final demon we slay in the win32 i/o horror show.
- getrusage() on Windows is now able to report RUSAGE_CHILDREN as well
as RUSAGE_SELF, thanks to aggregation in the process manager thread.
It's now possible to use sigaltstack() to recover from stack overflows
on Windows. Several bugs in sigaltstack() have been fixed, for all our
supported platforms. There's a newer better example showing how to use
this, along with three independent unit tests just to further showcase
the various techniques.
The `cat` command now works properly, when run by itself on the bash
command prompt. It's working beautifully so far, and is only missing
a few keystrokes for clearing words and lines. Definitely works more
well than the one that ships with WIN32 :-)
Thanks to @autumnjolitz (in #876) the Cosmopolitan codebase is now
acquainted with Apple's outstanding ulock system calls which offer
something much closer to futexes than Grand Central Dispatch which
wasn't quite as good, since its wait function can't be interrupted
by signals (therefore necessitating a busy loop) and it also needs
semaphore objects to be created and freed. Even though ulock is an
internal Apple API, strictly speaking, the benefits of futexes are
so great that it's worth the risk for now especially since we have
the GCD implementation still as a quick escape hatch if it changes
Here's why this change is important for x86 XNU users. Cosmo has a
suboptimal polyfill when the operating system doesn't offer an API
that let's us implement futexes properly. Sadly we had to use that
on X86 XNU until now. The polyfill works using clock_nanosleep, to
poll the futex in a busy loop with exponential backoff. On XNU x86
clock_nanosleep suffers from us not being able to use a fast clock
gettime implementation, which had a compounding effect that's made
the polyfill function even more poorly. On X86 XNU we also need to
polyfill sched_yield() using select(), which made things even more
troublesome. Now that we have futexes we don't have any busy loops
anymore for both condition variables and thread joining so optimal
performance is attained. To demonstrate, consider these benchmarks
Before:
$ ./lockscale_test.com -b
consumed 38.8377 seconds real time and
0.087131 seconds cpu time
After:
$ ./lockscale_test.com -b
consumed 0.007955 seconds real time and
0.011515 seconds cpu time
Fixes#876
This reverts commit b01282e23e. Some tests
are broken. It's not clear how it'll impact metal yet. Let's revisit the
memory optimization benefits of this change again sometime soon.
This reduces the virtual memory usage of Emacs for me by 30%. We now
have a simpler implementation that uses read(), rather mmap()ing the
whole executable.
- This change fixes a bug that allowed unbuffered printf() output (to
streams like stderr) to be truncated. This regression was introduced
some time between now and the last release.
- POSIX specifies all functions as thread safe by default. This change
works towards cleaning up our use of the @threadsafe / @threadunsafe
documentation annotations to reflect that. The goal is (1) to use
@threadunsafe to document functions which POSIX say needn't be thread
safe, and (2) use @threadsafe to document functions that we chose to
implement as thread safe even though POSIX didn't mandate it.
- Tidy up the clock_gettime() implementation. We're now trying out a
cleaner approach to system call support that aims to maintain the
Linux errno convention as long as possible. This also fixes bugs that
existed previously, where the vDSO errno wasn't being translated
properly. The gettimeofday() system call is now a wrapper for
clock_gettime(), which reduces bloat in apps that use both.
- The recently-introduced improvements to the execute bit on Windows has
had bugs fixed. access(X_OK) on a directory on Windows now succeeds.
fstat() will now perform the MZ/#! ReadFile() operation correctly.
- Windows.h is no longer included in libc/isystem/, because it confused
PCRE's build system into thinking Cosmopolitan is a WIN32 platform.
Cosmo's Windows.h polyfill was never even really that good, since it
only defines a subset of the subset of WIN32 APIs that Cosmo defines.
- The setlongerjmp() / longerjmp() APIs are removed. While they're nice
APIs that are superior to the standardized setjmp / longjmp functions,
they weren't superior enough to not be dead code in the monorepo. If
you use these APIs, please file an issue and they'll be restored.
- The .com appending magic has now been removed from APE Loader.
- Improved async signal safety of read() particularly for longjmp()
- Started adding cancel cleanup handlers for locks / etc on Windows
- Make /dev/tty work better particularly for uses like `foo | less`
- Eagerly read console input into a linked list, so poll can signal
- Fix some libc definitional bugs, which configure scripts detected
This change removes our use of ENABLE_VIRTUAL_TERMINAL_INPUT (which
isn't very good) in favor of having read() translate Windows Console
input events to ANSI/XTERM sequences by hand. This makes it possible to
capture important keystrokes (e.g. ctrl-space) that weren't possible
before. Most importantly this change also removes the stdin/sigwinch
worker threads, which never really worked that well. Interactive TTY
sessions will now work reliably when a Cosmo process spawns or forks
another Cosmo process, e.g. unbourne.com launching emacs.com.
