Commit graph

16 commits

Author SHA1 Message Date
Justine Tunney
fadb64a2bf
Introduce pthread_rwlock_try{rd,wr}lock
This also changes recursive mutexes to favor cpu over scheduler yield.
2023-10-31 22:13:08 -07:00
Justine Tunney
a359de7893
Get rid of kmalloc()
This changes *NSYNC to allocate waiters on the stack so our locks don't
need to depend on dynamic memory. This make our runtiem simpler, and it
also fixes bugs with thread cancellation support.
2023-09-11 21:56:00 -07:00
Justine Tunney
0d748ad58e
Fix warnings
This change fixes Cosmopolitan so it has fewer opinions about compiler
warnings. The whole repository had to be cleaned up to be buildable in
-Werror -Wall mode. This lets us benefit from things like strict const
checking. Some actual bugs might have been caught too.
2023-09-01 20:50:18 -07:00
Justine Tunney
a4b6803556
Fix recursive locks when tid is huge
It turns out Linux may assign thread ids that are much larger than
previously thought. We now have fewer bits of depth so we can have
bigger tids.
2023-01-03 05:01:00 -08:00
Justine Tunney
c7a8cd21e9
Improve system call wrappers
This change improves copy_file_range(), sendfile(), splice(), openpty(),
closefrom(), close_range(), fadvise() and posix_fadvise() in addition to
writing tests that confirm things like errno and seeking behavior across
platforms. We now less aggressively polyfill behavior with some of these
functions when the platform support isn't available. Please see:

https://justine.lol/cosmopolitan/functions.html
2022-09-19 15:06:25 -07:00
Justine Tunney
654ceaba7d
Clean up threading code some more 2022-09-13 20:17:34 -07:00
Justine Tunney
6f7d0cb1c3
Pay off more technical debt
This makes breaking changes to add underscores to many non-standard
function names provided by the c library. MODE=tiny is now tinier and
we now use smaller locks that are better for tiny apps in this mode.
Some headers have been renamed to be in the same folder as the build
package, so it'll be easier to know which build dependency is needed.
Certain old misguided interfaces have been removed. Intel intrinsics
headers are now listed in libc/isystem (but not in the amalgamation)
to help further improve open source compatibility. Header complexity
has also been reduced. Lastly, more shell scripts are now available.
2022-09-12 23:36:56 -07:00
Justine Tunney
b5cb71ab84
Use *NSYNC for POSIX threads locking APIs
Condition variables, barriers, and r/w locks now work very well.
2022-09-11 11:04:50 -07:00
Justine Tunney
cfcf5918bc
Rewrite recursive mutex code 2022-09-10 09:18:52 -07:00
Justine Tunney
155b378a39
Tidy up the threading implementation
The organization of the source files is now much more rational.
Old experiments that didn't work out are now deleted. Naming of
things like files is now more intuitive.
2022-09-10 02:56:25 -07:00
Justine Tunney
4339d9f15e
Add pthread attributes and other libc functions 2022-09-07 05:28:32 -07:00
Justine Tunney
7ff0ea8c13
Make pthread mutexes more scalable
pthread_mutex_lock() now uses a better algorithm which goes much faster
in multithreaded environments that have lock contention. This comes at
the cost of adding some fixed-cost overhead to mutex invocations. That
doesn't matter for Cosmopolitan because our core libraries all encode
locking operations as NOP instructions when in single-threaded mode.
Overhead only applies starting the moment you first call clone().
2022-09-05 15:57:51 -07:00
Justine Tunney
05b8f82371 Fold LIBC_BITS into LIBC_INTRIN 2022-08-11 12:13:18 -07:00
Justine Tunney
c06ffd458c Write some lock contention tests 2022-06-16 09:06:09 -07:00
Justine Tunney
8cdec62f5b Apply even more fixups
- Finish cleaning up the stdio unlocked APIs
- Make __cxa_finalize() properly thread safe
- Don't log locks if threads aren't being used
- Add some more mutex guards to places using _mmi
- Specific lock names now appear in the --ftrace logs
- Fix mkdeps.com generating invalid Makefiles sometimes
- Simplify and fix bugs in the test runner infrastructure
- Fix issue where sometimes some functions wouldn't be logged
2022-06-12 11:57:00 -07:00
Justine Tunney
c260345e06 Make locks more reliable
This change switches most of the core locks to be re-entrant, in order
to reduce the chance of deadlocking code that does, clever things with
asynchronous signal handlers. This change implements it it in pthreads
so we're one step closer to having a standardized threading primitives
2022-06-11 02:07:20 -07:00