cosmopolitan/libc/calls/sigsuspend.c
Justine Tunney 0c5dd7b342
Make improvements
- Improved async signal safety of read() particularly for longjmp()
- Started adding cancel cleanup handlers for locks / etc on Windows
- Make /dev/tty work better particularly for uses like `foo | less`
- Eagerly read console input into a linked list, so poll can signal
- Fix some libc definitional bugs, which configure scripts detected
2023-09-21 07:30:39 -07:00

84 lines
3.6 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 2020 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/calls/cp.internal.h"
#include "libc/calls/internal.h"
#include "libc/calls/sig.internal.h"
#include "libc/calls/struct/sigset.h"
#include "libc/calls/struct/sigset.internal.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/intrin/asan.internal.h"
#include "libc/intrin/strace.internal.h"
#include "libc/nt/synchronization.h"
#include "libc/sysv/consts/sig.h"
#include "libc/sysv/errfuns.h"
/**
* Blocks until SIG ∉ MASK is delivered to thread.
*
* This temporarily replaces the signal mask until a signal that it
* doesn't contain is delivered.
*
* @param ignore is a bitset of signals to block temporarily, which if
* NULL is equivalent to passing an empty signal set
* @return -1 w/ EINTR (or possibly EFAULT)
* @cancellationpoint
* @asyncsignalsafe
* @norestart
*/
int sigsuspend(const sigset_t *ignore) {
int rc;
const sigset_t *arg;
sigset_t save, mask = {0};
BEGIN_CANCELLATION_POINT;
if (IsAsan() && ignore && !__asan_is_valid(ignore, sizeof(*ignore))) {
rc = efault();
} else if (IsXnu() || IsOpenbsd()) {
// openbsd and xnu only support 32 signals
// they use a register calling convention for sigsuspend
if (ignore) {
arg = (sigset_t *)(uintptr_t)(*(uint32_t *)ignore);
} else {
arg = 0;
}
rc = sys_sigsuspend(arg, 8);
} else if (IsLinux() || IsFreebsd() || IsNetbsd() || IsWindows()) {
if (ignore) {
arg = ignore;
} else {
arg = &mask;
}
if (!IsWindows()) {
rc = sys_sigsuspend(arg, 8);
} else {
__sig_mask(SIG_SETMASK, arg, &save);
while (!(rc = _check_interrupts(0))) {
if ((rc = __pause_thread(__SIG_SIG_INTERVAL_MS))) break;
}
__sig_mask(SIG_SETMASK, &save, 0);
}
} else {
rc = enosys();
}
END_CANCELLATION_POINT;
STRACE("sigsuspend(%s) → %d% m", DescribeSigset(0, ignore), rc);
return rc;
}