cosmopolitan/libc
Justine Tunney 2ec413b5a9
Fix bugs in poll(), select(), ppoll(), and pselect()
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.
2024-09-02 00:29:52 -07:00
..
calls Fix bugs in poll(), select(), ppoll(), and pselect() 2024-09-02 00:29:52 -07:00
crt Remove .internal from more header filenames 2024-08-04 12:52:25 -07:00
dlopen Delete superfluous function 2024-08-29 23:51:22 -07:00
elf Rerun clang-format on the repo (#1217) 2024-06-15 16:34:48 -04:00
fmt Make improvements 2024-09-01 01:27:47 -07:00
integral Release Cosmopolitan v3.8.0 2024-08-30 20:14:07 -07:00
intrin Fix bugs in poll(), select(), ppoll(), and pselect() 2024-09-02 00:29:52 -07:00
irq Remove .internal from more header filenames 2024-08-04 12:52:25 -07:00
isystem Fix bugs in poll(), select(), ppoll(), and pselect() 2024-09-02 00:29:52 -07:00
log Add VSCode settings 2024-08-25 11:02:31 -07:00
mem Make improvements 2024-09-01 01:27:47 -07:00
nexgen32e Make improvements 2024-09-01 01:27:47 -07:00
nt Fix the build 2024-08-26 16:44:05 -07:00
proc Fix bugs in poll(), select(), ppoll(), and pselect() 2024-09-02 00:29:52 -07:00
runtime Make improvements 2024-09-01 01:27:47 -07:00
sock Fix bugs in poll(), select(), ppoll(), and pselect() 2024-09-02 00:29:52 -07:00
stdio Fix printf funcs on memory pressure with floats (#1275) 2024-09-01 14:42:14 -07:00
str Make pthread mutex non-recursive 2024-09-01 02:05:17 -07:00
sysv Fix bugs in poll(), select(), ppoll(), and pselect() 2024-09-02 00:29:52 -07:00
testlib Make improvements 2024-09-01 01:27:47 -07:00
thread Fix bugs in poll(), select(), ppoll(), and pselect() 2024-09-02 00:29:52 -07:00
tinymath Import optimized routines changes to exp10 2024-08-15 18:37:33 -07:00
vga Remove .internal from more header filenames 2024-08-04 12:52:25 -07:00
x Get rid of some legacy code 2024-08-24 17:53:30 -07:00
ar.h Reduce header complexity 2023-11-28 14:39:42 -08:00
assert.h Add dontthrow attribute to most libc functions 2024-01-09 01:26:03 -08:00
atomic.h Optimize memory layout 2022-09-12 04:26:52 -07:00
BUILD.mk Upgrade to 2022-era LLVM LIBCXX 2024-05-27 02:12:27 -07:00
complex.h libc headers: make <complex.h> work, add struct ipv6_mreq (#1100) 2024-02-05 17:22:56 -05:00
cosmo.h Move LoadZipArgs() to cosmo.h 2024-08-17 12:06:27 -07:00
ctype.h Fix ctype.h and wctype.h 2024-07-21 15:54:17 -07:00
cxxabi.h libc: Fix __cxa_thread_atexit prototype (#1088) 2024-01-22 10:23:28 -08:00
dce.h Delete ASAN 2024-06-22 05:45:49 -07:00
dos.h Remove .internal from more header filenames 2024-08-04 12:52:25 -07:00
empty.s Do some basic build tuning 2023-05-10 04:20:46 -07:00
errno.h Make dlmalloc 2.4x faster for multithreading 2024-05-28 11:18:34 -07:00
imag.h Remove .internal from more header filenames 2024-08-04 12:52:25 -07:00
inttypes.h Fix issues for latest GCC toolchain 2023-10-11 14:54:42 -07:00
iso646.h Remove .internal from more header filenames 2024-08-04 12:52:25 -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.h Remove .internal from more header filenames 2024-08-04 12:52:25 -07:00
macho.h Remove .internal from more header filenames 2024-08-04 12:52:25 -07:00
macros.h Remove .internal from more header filenames 2024-08-04 12:52:25 -07:00
math.h Release Cosmopolitan v3.6.0 2024-07-23 03:28:19 -07:00
paths.h Embed cocmd.com interpreter for system() / open() 2022-10-02 15:29:57 -07:00
README.md
serialize.h Reduce header complexity 2023-11-28 14:39:42 -08:00
stdalign.h Remove .internal from more header filenames 2024-08-04 12:52:25 -07:00
stdbool.h Make improvements 2024-02-12 10:23:00 -08:00
stdckdint.h Reduce header complexity 2023-11-28 14:39:42 -08:00
stdlib.h Upgrade to 2022-era LLVM LIBCXX 2024-05-27 02:12:27 -07:00
temp.h Add dontthrow attribute to most libc functions 2024-01-09 01:26:03 -08:00
testlib-test.txt Fix some zipos directory related bugs 2023-09-19 02:30:42 -07:00
time.h Implement proper time zone support 2024-05-04 23:06:37 -07:00
unistd.h Put confstr() in unistd.h 2024-05-21 15:35:06 -07:00
utime.h Implement proper time zone support 2024-05-04 23:06:37 -07:00
wctype.h Fix ctype.h and wctype.h 2024-07-21 15:54:17 -07:00
zip.h Remove .internal from more header filenames 2024-08-04 12:52:25 -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.