cosmopolitan/libc
Justine Tunney 60cb435cb4
Implement pthread_atfork()
If threads are being used, then fork() will now acquire and release and
runtime locks so that fork() may be safely used from threads. This also
makes vfork() thread safe, because pthread mutexes will do nothing when
the process is a child of vfork(). More torture tests have been written
to confirm this all works like a charm. Additionally:

- Invent hexpcpy() api
- Rename nsync_malloc_() to kmalloc()
- Complete posix named semaphore implementation
- Make pthread_create() asynchronous signal safe
- Add rm, rmdir, and touch to command interpreter builtins
- Invent sigisprecious() and modify sigset functions to use it
- Add unit tests for posix_spawn() attributes and fix its bugs

One unresolved problem is the reclaiming of *NSYNC waiter memory in the
forked child processes, within apps which have threads waiting on locks
2022-10-16 12:25:13 -07:00
..
calls Implement pthread_atfork() 2022-10-16 12:25:13 -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 Make some foss compatibility improvements 2022-10-14 13:59:34 -07:00
intrin Implement pthread_atfork() 2022-10-16 12:25:13 -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 Implement pthread_atfork() 2022-10-16 12:25:13 -07:00
mem Implement pthread_atfork() 2022-10-16 12:25:13 -07:00
nexgen32e Improve cosmo's conformance to libc-test 2022-10-10 17:52:41 -07:00
nt Add posix semaphores support 2022-10-14 09:21:02 -07:00
runtime Implement pthread_atfork() 2022-10-16 12:25:13 -07:00
sock Greatly expand system() shell code features 2022-10-11 21:30:31 -07:00
stdio Implement pthread_atfork() 2022-10-16 12:25:13 -07:00
str Implement pthread_atfork() 2022-10-16 12:25:13 -07:00
stubs Clean up the TLS code 2022-09-10 11:49:13 -07:00
sysv Implement pthread_atfork() 2022-10-16 12:25:13 -07:00
testlib Implement pthread_atfork() 2022-10-16 12:25:13 -07:00
thread Implement pthread_atfork() 2022-10-16 12:25:13 -07:00
time Implement pthread_atfork() 2022-10-16 12:25:13 -07:00
tinymath Improve cosmo's conformance to libc-test 2022-10-10 17:52:41 -07:00
vga [metal] Allow more fine-grained control over page permissions (#663) 2022-10-12 11:07:11 -07:00
x Greatly expand system() shell code features 2022-10-11 21:30:31 -07:00
zipos Implement pthread_atfork() 2022-10-16 12:25:13 -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 Rename LINUX to _HOSTLINUX etc. to reduce clashes (#655) 2022-10-10 20:31:25 -07:00
disclaimer.inc Improve Libc by making Python work even better 2021-08-18 22:16:23 -07:00
dos.h Mold the redbean binary to minimize page faults 2021-05-03 12:14:13 -07:00
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 Perform some minor fixups 2021-03-16 22:19:51 -07:00
macho.internal.h Get Cosmopolitan into releasable state 2020-11-25 08:19:00 -08:00
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 Improve Libc by making Python work even better 2021-08-18 22:16:23 -07:00
notice.internal.h Add epoll and do more release readiness changes 2020-11-28 12:01:51 -08:00
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.