cosmopolitan/libc
Justine Tunney 2278327eba
Implement support for POSIX thread cancellations
This change makes some miracle modifications to the System Five system
call support, which lets us have safe, correct, and atomic handling of
thread cancellations. It all turned out to be cheaper than anticipated
because it wasn't necessary to modify the system call veneers. We were
able to encode the cancellability of each system call into the magnums
found in libc/sysv/syscalls.sh. Since cancellations are so waq, we are
also supporting a lovely Musl Libc mask feature for raising ECANCELED.
2022-11-04 01:04:43 -07:00
..
calls Implement support for POSIX thread cancellations 2022-11-04 01:04:43 -07:00
crt Rename LINUX to _HOSTLINUX etc. to reduce clashes (#655) 2022-10-10 20:31:25 -07:00
dns Improve cosmo's conformance to libc-test 2022-10-10 17:52:41 -07:00
elf Clean up some code 2022-08-20 12:32:51 -07:00
fmt Elevate Windows production worthiness 2022-10-13 13:44:41 -07:00
integral Rearrange code and make a faster sha256sum program 2022-11-02 23:19:16 -07:00
intrin Implement support for POSIX thread cancellations 2022-11-04 01:04:43 -07:00
isystem Implement pthread_atfork() 2022-10-16 12:25:13 -07:00
linux Add atomics to chibicc 2022-06-20 03:08:00 -07:00
log Add WSL to test fleet 2022-11-02 06:49:42 -07:00
mem Make fixes and improvements 2022-10-19 07:19:19 -07:00
nexgen32e Make fixes and improvements 2022-10-19 07:19:19 -07:00
nt Add WSL to test fleet 2022-11-02 06:49:42 -07:00
runtime Implement support for POSIX thread cancellations 2022-11-04 01:04:43 -07:00
sock Implement support for POSIX thread cancellations 2022-11-04 01:04:43 -07:00
stdio Implement support for POSIX thread cancellations 2022-11-04 01:04:43 -07:00
str Make fixes and improvements 2022-10-19 07:19:19 -07:00
stubs Clean up the TLS code 2022-09-10 11:49:13 -07:00
sysv Implement support for POSIX thread cancellations 2022-11-04 01:04:43 -07:00
testlib Make more threading improvements 2022-11-01 23:28:26 -07:00
thread Implement support for POSIX thread cancellations 2022-11-04 01:04:43 -07:00
time Make fixes and improvements 2022-10-19 07:19:19 -07:00
tinymath Improve cosmo's conformance to libc-test 2022-10-10 17:52:41 -07:00
vga Make more threading improvements 2022-11-01 23:28:26 -07:00
x Make more threading improvements 2022-11-01 23:28:26 -07:00
zipos Implement support for POSIX thread cancellations 2022-11-04 01:04:43 -07:00
assert.h Implement pthread_atfork() 2022-10-16 12:25:13 -07:00
atomic.h Optimize memory layout 2022-09-12 04:26:52 -07:00
complex.h Fix some more reported issues 2022-04-28 20:36:33 -07:00
dce.h Add WSL to test fleet 2022-11-02 06:49:42 -07:00
disclaimer.inc
dos.h
errno.h Add posix semaphores support 2022-10-14 09:21:02 -07:00
imag.h Improve cosmo's conformance to libc-test 2022-10-10 17:52:41 -07:00
inttypes.h Optimize memory layout 2022-09-12 04:26:52 -07:00
iso646.internal.h Add more missing C / C++ headers 2022-09-04 04:53:52 -07:00
libc.mk Add VGA support on bare metal (#588) 2022-09-06 18:41:08 -07:00
limits.h Improve cosmo's conformance to libc-test 2022-10-10 17:52:41 -07:00
literal.h Improve cosmo's conformance to libc-test 2022-10-10 17:52:41 -07:00
mach.h
macho.internal.h
macros.internal.h Enable CPU exception handling w/ IDT & TSS (#640) 2022-09-29 14:43:08 -07:00
math.h Improve cosmo's conformance to libc-test 2022-10-10 17:52:41 -07:00
notice.inc
notice.internal.h
paths.h Embed cocmd.com interpreter for system() / open() 2022-10-02 15:29:57 -07:00
README.md Reformat libc README.md (#437) 2022-06-21 07:50:42 -07:00
stdalign.internal.h Add more missing C / C++ headers 2022-09-04 04:53:52 -07:00
type2str.h Improve synchronization 2022-04-15 15:31:55 -07:00
zip.h Fold LIBC_BITS into LIBC_INTRIN 2022-08-11 12:13:18 -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.