cosmopolitan/libc/calls/sigpending.c
Justine Tunney 0d74673213
Introduce interprocess signaling on Windows
This change gets rsync working without any warning or errors. On Windows
we now create a bunch of C:\var\sig\x\y.pid shared memory files, so sigs
can be delivered between processes. WinMain() creates this file when the
process starts. If the program links signaling system calls then we make
a thread at startup too, which allows asynchronous delivery each quantum
and cancelation points can spot these signals potentially faster on wait

See #1240
2024-09-19 03:02:13 -07:00

65 lines
3.2 KiB
C

/*-*- 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 │
╞══════════════════════════════════════════════════════════════════════════════╡
│ 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/sig.internal.h"
#include "libc/calls/struct/sigset.h"
#include "libc/calls/struct/sigset.internal.h"
#include "libc/dce.h"
#include "libc/intrin/atomic.h"
#include "libc/intrin/describeflags.h"
#include "libc/intrin/strace.h"
#include "libc/sysv/errfuns.h"
#include "libc/thread/tls.h"
/**
* Determines the blocked pending signals
*
* @param pending is where the bitset of pending signals is returned,
* which may not be null
* @return 0 on success, or -1 w/ errno
* @raise EFAULT if `pending` points to invalid memory
* @asyncsignalsafe
*/
int sigpending(sigset_t *pending) {
int rc;
if (!pending) {
rc = efault();
} else if (IsLinux() || IsNetbsd() || IsOpenbsd() || IsFreebsd() || IsXnu()) {
// 128 signals on NetBSD and FreeBSD, 64 on Linux, 32 on OpenBSD and XNU
uint64_t mem[2];
rc = sys_sigpending(mem, 8);
if (IsOpenbsd()) {
*pending = rc;
} else {
*pending = mem[0];
}
if (IsXnu() || IsOpenbsd()) {
*pending &= 0xffffffff;
}
rc = 0;
} else if (IsWindows()) {
*pending = atomic_load_explicit(__sig.process, memory_order_acquire) |
atomic_load_explicit(&__get_tls()->tib_sigpending,
memory_order_acquire);
rc = 0;
} else {
rc = enosys();
}
STRACE("sigpending([%s]) → %d% m", DescribeSigset(rc, pending), rc);
return rc;
}