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cosmopolitan/libc/intrin/localtime_lock.c

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Initial import
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/*-*- 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 │
╞══════════════════════════════════════════════════════════════════════════════╡
Eliminate cyclic locks in runtime This change introduces a new deadlock detector for Cosmo's POSIX threads implementation. Error check mutexes will now track a DAG of nested locks and report EDEADLK when a deadlock is theoretically possible. These will occur rarely, but it's important for production hardening your code. You don't even need to change your mutexes to use the POSIX error check mode because `cosmocc -mdbg` will enable error checking on mutexes by default globally. When cycles are found, an error message showing your demangled symbols describing the strongly connected component are printed and then the SIGTRAP is raised, which means you'll also get a backtrace if you're using ShowCrashReports() too. This new error checker is so low-level and so pure that it's able to verify the relationships of every libc runtime lock, including those locks upon which the mutex implementation depends.
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│ Copyright 2024 Justine Alexandra Roberts Tunney │
Initial import
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│ │
Change license
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│ 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. │
Initial import
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│ │
Change license
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│ 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. │
Initial import
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╚─────────────────────────────────────────────────────────────────────────────*/
Allow user to override pthread mutex and cond
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#include "libc/thread/posixthread.internal.h"
Eliminate cyclic locks in runtime This change introduces a new deadlock detector for Cosmo's POSIX threads implementation. Error check mutexes will now track a DAG of nested locks and report EDEADLK when a deadlock is theoretically possible. These will occur rarely, but it's important for production hardening your code. You don't even need to change your mutexes to use the POSIX error check mode because `cosmocc -mdbg` will enable error checking on mutexes by default globally. When cycles are found, an error message showing your demangled symbols describing the strongly connected component are printed and then the SIGTRAP is raised, which means you'll also get a backtrace if you're using ShowCrashReports() too. This new error checker is so low-level and so pure that it's able to verify the relationships of every libc runtime lock, including those locks upon which the mutex implementation depends.
2024-12-17 04:51:27 +00:00
#include "third_party/tz/lock.h"
Initial import
2020-06-15 14:18:57 +00:00
Make fork() go 30% faster This change makes fork() go nearly as fast as sys_fork() on UNIX. As for Windows this change shaves about 4-5ms off fork() + wait() latency. This is accomplished by using WriteProcessMemory() from the parent process to setup the address space of a suspended process; it is better than a pipe
2025-01-01 12:59:38 +00:00
static pthread_mutex_t __localtime_lock_obj = PTHREAD_MUTEX_INITIALIZER;
Initial import
2020-06-15 14:18:57 +00:00
Eliminate cyclic locks in runtime This change introduces a new deadlock detector for Cosmo's POSIX threads implementation. Error check mutexes will now track a DAG of nested locks and report EDEADLK when a deadlock is theoretically possible. These will occur rarely, but it's important for production hardening your code. You don't even need to change your mutexes to use the POSIX error check mode because `cosmocc -mdbg` will enable error checking on mutexes by default globally. When cycles are found, an error message showing your demangled symbols describing the strongly connected component are printed and then the SIGTRAP is raised, which means you'll also get a backtrace if you're using ShowCrashReports() too. This new error checker is so low-level and so pure that it's able to verify the relationships of every libc runtime lock, including those locks upon which the mutex implementation depends.
2024-12-17 04:51:27 +00:00
void __localtime_lock(void) {
Allow user to override pthread mutex and cond
2024-12-24 05:57:52 +00:00
_pthread_mutex_lock(&__localtime_lock_obj);
Eliminate cyclic locks in runtime This change introduces a new deadlock detector for Cosmo's POSIX threads implementation. Error check mutexes will now track a DAG of nested locks and report EDEADLK when a deadlock is theoretically possible. These will occur rarely, but it's important for production hardening your code. You don't even need to change your mutexes to use the POSIX error check mode because `cosmocc -mdbg` will enable error checking on mutexes by default globally. When cycles are found, an error message showing your demangled symbols describing the strongly connected component are printed and then the SIGTRAP is raised, which means you'll also get a backtrace if you're using ShowCrashReports() too. This new error checker is so low-level and so pure that it's able to verify the relationships of every libc runtime lock, including those locks upon which the mutex implementation depends.
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}
void __localtime_unlock(void) {
Allow user to override pthread mutex and cond
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_pthread_mutex_unlock(&__localtime_lock_obj);
Improve cosmo's conformance to libc-test This change addresses various open source compatibility issues, so that we pass 313/411 of the tests in https://github.com/jart/libc-test where earlier today we were passing about 30/411 of them, due to header toil. Please note that Glibc only passes 341/411 so 313 today is pretty good! - Make the conformance of libc/isystem/ headers nearly perfect - Import more of the remaining math library routines from Musl - Fix inconsistencies with type signatures of calls like umask - Write tests for getpriority/setpriority which work great now - conform to `struct sockaddr *` on remaining socket functions - Import a bunch of uninteresting stdlib functions e.g. rand48 - Introduce readdir_r, scandir, pthread_kill, sigsetjmp, etc.. Follow the instructions in our `tool/scripts/cosmocc` toolchain to run these tests yourself. You use `make CC=cosmocc` on the test repository
2022-10-11 00:52:41 +00:00
}
Make fork() go 30% faster This change makes fork() go nearly as fast as sys_fork() on UNIX. As for Windows this change shaves about 4-5ms off fork() + wait() latency. This is accomplished by using WriteProcessMemory() from the parent process to setup the address space of a suspended process; it is better than a pipe
2025-01-01 12:59:38 +00:00
void __localtime_wipe(void) {
_pthread_mutex_wipe_np(&__localtime_lock_obj);
}
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