cosmopolitan/libc
Justine Tunney 791f79fcb3
Make improvements
- 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.
2023-10-08 08:59:53 -07:00
..
calls Make improvements 2023-10-08 08:59:53 -07:00
crt Implement thread cancellation for aarch64 2023-09-07 08:48:38 -07:00
dns Make improvements 2023-10-08 08:59:53 -07:00
elf Make improvements 2023-09-18 21:04:47 -07:00
fmt Delete non-standard broken strtonum() function 2023-10-04 08:20:06 -07:00
integral Make improvements 2023-10-08 08:59:53 -07:00
intrin Make improvements 2023-10-08 08:59:53 -07:00
isystem Make improvements 2023-10-08 08:59:53 -07:00
log Make improvements 2023-10-08 08:59:53 -07:00
mem Make improvements 2023-10-03 06:17:16 -07:00
nexgen32e Use CLK_TCK for clock_nanosleep() spin threshold 2023-10-03 17:26:29 -07:00
nt Make improvements 2023-10-08 08:59:53 -07:00
proc Make improvements 2023-10-08 08:59:53 -07:00
runtime Make improvements 2023-10-08 08:59:53 -07:00
sock Make improvements 2023-10-08 08:59:53 -07:00
stdio Make improvements 2023-10-08 08:59:53 -07:00
str Make improvements 2023-10-08 08:59:53 -07:00
sysv Make improvements 2023-10-08 08:59:53 -07:00
testlib Make improvements 2023-10-08 08:59:53 -07:00
thread Make improvements 2023-10-08 08:59:53 -07:00
time Make improvements 2023-10-08 08:59:53 -07:00
tinymath Reduce mandatory stack rss by 256kb 2023-09-07 04:33:01 -07:00
vga [metal] Fix video mode filtering & frame buffer ref-counting (#889) 2023-09-06 03:41:07 -07:00
x Make improvements 2023-10-08 08:59:53 -07:00
ar.h Rewrite Cosmopolitan Ar 2023-07-02 10:19:16 -07:00
assert.h Make greenbean web server better 2023-09-07 03:44:50 -07:00
atomic.h
complex.h Port a lot more code to AARCH64 2023-05-14 09:37:26 -07:00
cosmo.h Invent systemvpe() function 2023-08-09 00:27:55 -07:00
dce.h Replace COSMO define with _COSMO_SOURCE 2023-08-13 20:55:04 -07:00
disclaimer.inc
dos.internal.h Introduce #include <cosmo.h> to toolchain users 2023-06-09 18:03:05 -07:00
empty.s Do some basic build tuning 2023-05-10 04:20:46 -07:00
errno.h Make improvements 2023-09-18 21:04:47 -07:00
imag.internal.h Remove evil constants from cosmopolitan.h 2022-12-17 00:42:45 -08:00
inttypes.h Fix inttypes.h FAST16 macros to have a correct definition (#791) 2023-03-29 00:19:40 -07:00
iso646.internal.h
libc.mk Make improvements 2023-09-18 21:04:47 -07:00
limits.h Make improvements 2023-10-08 08:59:53 -07:00
literal.h Get GNU MPFR and MPC tests to pass 2023-08-21 15:05:10 -07:00
mach.internal.h Introduce #include <cosmo.h> to toolchain users 2023-06-09 18:03:05 -07:00
macho.internal.h Fiddle around with Mach-O 2023-05-20 04:13:49 -07:00
macros.internal.h Make improvements 2023-10-03 06:17:16 -07:00
math.h Get GNU MPFR and MPC tests to pass 2023-08-21 15:05:10 -07:00
notice.inc
notice.internal.h
paths.h
README.md
stdalign.internal.h
stdbool.h Make fatcosmocc good enough to build ncurses 6.4 2023-08-12 22:30:05 -07:00
stdckdint.h Perform inconsequential code cleanup 2023-08-07 20:24:50 -07:00
temp.h Overhaul process spawning 2023-09-10 08:17:44 -07:00
testlib-test.txt Fix some zipos directory related bugs 2023-09-19 02:30:42 -07:00
type2str.h Improve new C23 checked arithmetic feature 2023-06-16 15:32:18 -07:00
zip.internal.h Revert "Rewrite ZipOS" 2023-10-03 14:40:03 -07:00

Cosmopolitan Standard Library

This directory defines static archives defining functions, like printf(), mmap(), win32, etc. Please note that the Cosmopolitan build configuration doesn't link any C/C++ library dependencies by default, so you still have the flexibility to choose the one provided by your system. If you'd prefer Cosmopolitan, just add $(LIBC) and $(CRT) to your linker arguments.

Your library is compromised of many bite-sized static archives. We use the checkdeps tool to guarantee that the contents of the archives are organized in a logical way that's easy to use with or without our makefile infrastructure, since there's no cyclic dependencies.

The Cosmopolitan Library exports only the most stable canonical system calls for all supported operating systems, regardless of which platform is used for compilation. We polyfill many of the APIs, e.g. read(), write() so they work consistently everywhere while other apis, e.g. CreateWindowEx(), might only work on one platform, in which case they become no-op functions on others.

Cosmopolitan polyfill wrappers will usually use the dollar sign naming convention, so they may be bypassed when necessary. This same convention is used when multiple implementations of string library and other performance-critical function are provided to allow Cosmopolitan to go fast on both old and newer computers.

We take an approach to configuration that relies heavily on the compiler's dead code elimination pass (libc/dce.h). Most of the code is written so that, for example, folks not wanting support for OpenBSD can flip a bit in SUPPORT_VECTOR and that code will be omitted from the build. The same is true for builds that are tuned using -march=native which effectively asks the library to not include runtime support hooks for x86 processors older than what you use.

Please note that, unlike Cygwin or MinGW, Cosmopolitan does not achieve broad support by bolting on a POSIX emulation layer. We do nothing more than (in most cases) stateless API translations that get you 90% of the way there in a fast lightweight manner. We therefore can't address some of the subtle differences, such as the nuances of absolute paths on Windows. Our approach could be compared to something more along the lines of, "the Russians just used a pencil to write in space", versus spending millions researching a pen like NASA.