mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 19:43:32 +00:00
3f0bcdc3ef
- Exhaustively document cancellation points - Rename SIGCANCEL to SIGTHR just like BSDs - Further improve POSIX thread cancellations - Ensure asynchronous cancellations work correctly - Elevate the quality of getrandom() and getentropy() - Make futexes cancel correctly on OpenBSD 6.x and 7.x - Add reboot.com and shutdown.com to examples directory - Remove underscore prefix from awesome timespec_*() APIs - Create assertions that help verify our cancellation points - Remove bad timespec APIs (cmp generalizes eq/ne/gt/gte/lt/lte)
104 lines
4.3 KiB
C
104 lines
4.3 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/calls/calls.h"
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#include "libc/calls/cp.internal.h"
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#include "libc/calls/internal.h"
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#include "libc/calls/sig.internal.h"
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#include "libc/calls/struct/sigset.h"
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#include "libc/calls/struct/sigset.internal.h"
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#include "libc/dce.h"
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#include "libc/intrin/asan.internal.h"
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#include "libc/intrin/describeflags.internal.h"
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#include "libc/intrin/strace.internal.h"
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#include "libc/log/backtrace.internal.h"
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#include "libc/nt/errors.h"
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#include "libc/nt/synchronization.h"
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#include "libc/sysv/consts/sig.h"
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#include "libc/sysv/errfuns.h"
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/**
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* Blocks until SIG ∉ MASK is delivered to thread.
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*
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* This temporarily replaces the signal mask until a signal that it
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* doesn't contain is delivered.
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*
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* @param ignore is a bitset of signals to block temporarily, which if
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* NULL is equivalent to passing an empty signal set
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* @return -1 w/ EINTR (or possibly EFAULT)
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* @cancellationpoint
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* @asyncsignalsafe
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* @norestart
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*/
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int sigsuspend(const sigset_t *ignore) {
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int rc;
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long ms, totoms;
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sigset_t save, *arg, mask = {0};
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STRACE("sigsuspend(%s) → ...", DescribeSigset(0, ignore));
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BEGIN_CANCELLATION_POINT;
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if (IsAsan() && ignore && !__asan_is_valid(ignore, sizeof(*ignore))) {
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rc = efault();
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} else if (IsXnu() || IsOpenbsd()) {
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// openbsd and xnu only support 32 signals
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// they use a register calling convention for sigsuspend
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if (ignore) {
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arg = (sigset_t *)(uintptr_t)(*(uint32_t *)ignore);
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} else {
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arg = 0;
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}
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rc = sys_sigsuspend(arg, 8);
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} else if (IsLinux() || IsFreebsd() || IsNetbsd() || IsWindows()) {
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if (ignore) {
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arg = ignore;
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} else {
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arg = &mask;
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}
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if (!IsWindows()) {
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rc = sys_sigsuspend(arg, 8);
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} else {
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__sig_mask(SIG_SETMASK, arg, &save);
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ms = 0;
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totoms = 0;
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do {
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if ((rc = _check_interrupts(false, g_fds.p))) {
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break;
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}
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if (SleepEx(__SIG_POLLING_INTERVAL_MS, true) == kNtWaitIoCompletion) {
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POLLTRACE("IOCP EINTR");
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continue;
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}
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#if defined(SYSDEBUG) && defined(_POLLTRACE)
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ms += __SIG_POLLING_INTERVAL_MS;
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if (ms >= __SIG_LOGGING_INTERVAL_MS) {
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totoms += ms, ms = 0;
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POLLTRACE("... sigsuspending for %'lums...", totoms);
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}
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#endif
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} while (1);
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__sig_mask(SIG_SETMASK, &save, 0);
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}
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} else {
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// TODO(jart): sigsuspend metal support
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rc = enosys();
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}
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END_CANCELLATION_POINT;
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STRACE("...sigsuspend → %d% m", rc);
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return rc;
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}
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