mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 19:43:32 +00:00
60 lines
3.1 KiB
C
60 lines
3.1 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/assert.h"
|
|
#include "libc/bits/weaken.h"
|
|
#include "libc/calls/internal.h"
|
|
#include "libc/calls/sig.internal.h"
|
|
#include "libc/calls/strace.internal.h"
|
|
#include "libc/calls/struct/sigaction.h"
|
|
#include "libc/dce.h"
|
|
#include "libc/intrin/lockcmpxchgp.h"
|
|
#include "libc/nexgen32e/threaded.h"
|
|
|
|
_Alignas(64) static int rlock;
|
|
|
|
// return 0 on success, or tid of other owner
|
|
static privileged inline int AcquireInterruptPollLock(void) {
|
|
// any thread can poll for interrupts
|
|
// but it's wasteful to have every single thread doing it
|
|
int me, owner = 0;
|
|
if (__threaded) {
|
|
me = gettid();
|
|
if (!_lockcmpxchgp(&rlock, &owner, me) && owner == me) {
|
|
owner = 0;
|
|
}
|
|
}
|
|
return owner;
|
|
}
|
|
|
|
static textwindows inline void ReleaseInterruptPollLock(void) {
|
|
int zero = 0;
|
|
__atomic_store(&rlock, &zero, __ATOMIC_RELAXED);
|
|
}
|
|
|
|
textwindows bool _check_interrupts(bool restartable, struct Fd *fd) {
|
|
bool res;
|
|
if (__time_critical) return false;
|
|
if (AcquireInterruptPollLock()) return false;
|
|
if (weaken(_check_sigalrm)) weaken(_check_sigalrm)();
|
|
if (weaken(_check_sigchld)) weaken(_check_sigchld)();
|
|
if (fd && weaken(_check_sigwinch)) weaken(_check_sigwinch)(fd);
|
|
res = weaken(__sig_check) && weaken(__sig_check)(restartable);
|
|
ReleaseInterruptPollLock();
|
|
return res;
|
|
}
|