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cosmopolitan/libc/thread/pthread_cond_init.c

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Make mutex calling code 10x tinier Calls to lock/unlock functions are now NOPs by default. The first time clone() is called, they get turned into CALL instructions. Doing this caused funcctions like fputc() to shrink from 85 bytes to 45+4 bytes. Since the ANSI solution of `(__threaded && lock())` inlines os much superfluous binary content into functions all over the place.
2022-06-13 02:33:42 +00:00
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
Reduce makefile dependencies by 10% The includes in libc/calls/calls.h have now been refactored so that functions with struct parameters are declared in libc/calls/struct/
2022-06-09 03:01:28 +00:00
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
Make recursive mutexes faster Recursive mutexes now go as fast as normal mutexes. The tradeoff is they are no longer safe to use in signal handlers. However you can still have signal safe mutexes if you set your mutex to both recursive and pshared. You can also make functions that use recursive mutexes signal safe using sigprocmask to ensure recursion doesn't happen due to any signal handler The impact of this change is that, on Windows, many functions which edit the file descriptor table rely on recursive mutexes, e.g. open(). If you develop your app so it uses pread() and pwrite() then your app should go very fast when performing a heavily multithreaded and contended workload For example, when scaling to 40+ cores, *NSYNC mutexes can go as much as 1000x faster (in CPU time) than the naive recursive lock implementation. Now recursive will use *NSYNC under the hood when it's possible to do so
2024-09-10 05:07:03 +00:00
#include "libc/dce.h"
Introduce pthread_condattr_setclock() This is one of the few POSIX APIs that was missing. It lets you choose a monotonic clock for your condition variables. This might improve perf on some platforms. It might also grant more flexibility with NTP configs. I know Qt is one project that believes it needs this. To introduce this, I needed to change some the *NSYNC APIs, to support passing a clock param. There's also new benchmarks, demonstrating Cosmopolitan's supremacy over many libc implementations when it comes to mutex performance. Cygwin has an alarmingly bad pthread_mutex_t implementation. It is so bad that they would have been significantly better off if they'd used naive spinlocks.
2024-09-03 06:37:50 +00:00
#include "libc/sysv/consts/clock.h"
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 09:56:25 +00:00
#include "libc/thread/thread.h"
Reduce makefile dependencies by 10% The includes in libc/calls/calls.h have now been refactored so that functions with struct parameters are declared in libc/calls/struct/
2022-06-09 03:01:28 +00:00
Make mutex calling code 10x tinier Calls to lock/unlock functions are now NOPs by default. The first time clone() is called, they get turned into CALL instructions. Doing this caused funcctions like fputc() to shrink from 85 bytes to 45+4 bytes. Since the ANSI solution of `(__threaded && lock())` inlines os much superfluous binary content into functions all over the place.
2022-06-13 02:33:42 +00:00
/**
Introduce pthread_condattr_setclock() This is one of the few POSIX APIs that was missing. It lets you choose a monotonic clock for your condition variables. This might improve perf on some platforms. It might also grant more flexibility with NTP configs. I know Qt is one project that believes it needs this. To introduce this, I needed to change some the *NSYNC APIs, to support passing a clock param. There's also new benchmarks, demonstrating Cosmopolitan's supremacy over many libc implementations when it comes to mutex performance. Cygwin has an alarmingly bad pthread_mutex_t implementation. It is so bad that they would have been significantly better off if they'd used naive spinlocks.
2024-09-03 06:37:50 +00:00
* Initializes condition variable.
Implement POSIX threads API
2022-09-05 15:26:03 +00:00
*
* @param attr may be null
Make mutex calling code 10x tinier Calls to lock/unlock functions are now NOPs by default. The first time clone() is called, they get turned into CALL instructions. Doing this caused funcctions like fputc() to shrink from 85 bytes to 45+4 bytes. Since the ANSI solution of `(__threaded && lock())` inlines os much superfluous binary content into functions all over the place.
2022-06-13 02:33:42 +00:00
* @return 0 on success, or error number on failure
*/
Make futexes cancellable by pthreads
2022-11-05 01:19:05 +00:00
errno_t pthread_cond_init(pthread_cond_t *cond,
const pthread_condattr_t *attr) {
Use *NSYNC for POSIX threads locking APIs Condition variables, barriers, and r/w locks now work very well.
2022-09-11 18:02:07 +00:00
*cond = (pthread_cond_t){0};
Introduce pthread_condattr_setclock() This is one of the few POSIX APIs that was missing. It lets you choose a monotonic clock for your condition variables. This might improve perf on some platforms. It might also grant more flexibility with NTP configs. I know Qt is one project that believes it needs this. To introduce this, I needed to change some the *NSYNC APIs, to support passing a clock param. There's also new benchmarks, demonstrating Cosmopolitan's supremacy over many libc implementations when it comes to mutex performance. Cygwin has an alarmingly bad pthread_mutex_t implementation. It is so bad that they would have been significantly better off if they'd used naive spinlocks.
2024-09-03 06:37:50 +00:00
if (attr) {
cond->_pshared = attr->_pshared;
cond->_clock = attr->_clock;
}
Add pthread attributes and other libc functions
2022-09-07 12:23:44 +00:00
return 0;
Make mutex calling code 10x tinier Calls to lock/unlock functions are now NOPs by default. The first time clone() is called, they get turned into CALL instructions. Doing this caused funcctions like fputc() to shrink from 85 bytes to 45+4 bytes. Since the ANSI solution of `(__threaded && lock())` inlines os much superfluous binary content into functions all over the place.
2022-06-13 02:33:42 +00:00
}
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