mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-02-07 15:03:34 +00:00
4a6fd3d910
- fix rare thread exit race condition on openbsd - pthread_getattr_np() now supplies detached status - child threads may now pthread_join() the main thread - introduce sigandset(), sigorset(), and sigisemptyset() - introduce pthread_cleanup_push() and pthread_cleanup_pop()
38 lines
2.5 KiB
C
38 lines
2.5 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
|
|
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
|
|
╞══════════════════════════════════════════════════════════════════════════════╡
|
|
│ 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. │
|
|
╚─────────────────────────────────────────────────────────────────────────────*/
|
|
#include "libc/dce.h"
|
|
#include "libc/intrin/atomic.h"
|
|
#include "libc/thread/wait0.internal.h"
|
|
#include "third_party/nsync/futex.internal.h"
|
|
|
|
/**
|
|
* Blocks until memory location becomes zero.
|
|
*
|
|
* This is intended to be used on the child thread id, which is updated
|
|
* by the clone() system call when a thread terminates. We need this in
|
|
* order to know when it's safe to free a thread's stack. This function
|
|
* uses futexes on Linux, FreeBSD, OpenBSD, and Windows. On other
|
|
* platforms this uses polling with exponential backoff.
|
|
*/
|
|
void _wait0(const atomic_int *ctid) {
|
|
int x;
|
|
while ((x = atomic_load_explicit(ctid, memory_order_relaxed))) {
|
|
nsync_futex_wait_((int *)ctid, x, !IsWindows(), 0);
|
|
}
|
|
}
|