2020-06-15 14:18:57 +00:00
|
|
|
/*-*- 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 │
|
|
|
|
|
│ │
|
2020-12-28 01:18:44 +00:00
|
|
|
│ 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. │
|
2020-06-15 14:18:57 +00:00
|
|
|
│ │
|
2020-12-28 01:18:44 +00:00
|
|
|
│ 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. │
|
2020-06-15 14:18:57 +00:00
|
|
|
╚─────────────────────────────────────────────────────────────────────────────*/
|
|
|
|
|
#include "libc/calls/calls.h"
|
|
|
|
|
#include "libc/calls/struct/sigaction.h"
|
|
|
|
|
#include "libc/str/str.h"
|
|
|
|
|
#include "libc/sysv/consts/sig.h"
|
|
|
|
|
#include "libc/x/x.h"
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* Installs handler for kernel interrupt, e.g.:
|
|
|
|
|
*
|
2020-12-26 10:09:07 +00:00
|
|
|
* onctrlc(sig) { exit(128+sig); }
|
|
|
|
|
* CHECK_NE(-1, xsigaction(SIGINT, onctrlc, SA_RESETHAND, 0, 0));
|
2020-06-15 14:18:57 +00:00
|
|
|
*
|
|
|
|
|
* @param sig can be SIGINT, SIGTERM, etc.
|
|
|
|
|
* @param handler is SIG_DFL, SIG_IGN, or a pointer to a 0≤arity≤3
|
|
|
|
|
* callback function passed (sig, siginfo_t *, ucontext_t *).
|
|
|
|
|
* @param flags can have SA_RESETHAND, SA_RESTART, SA_SIGINFO, etc.
|
|
|
|
|
* @param mask is 1ul«SIG₁[…|1ul«SIGₙ] bitset to block in handler
|
|
|
|
|
* @param old optionally receives previous handler
|
|
|
|
|
* @return 0 on success, or -1 w/ errno
|
|
|
|
|
* @see libc/sysv/consts.sh
|
|
|
|
|
* @asyncsignalsafe
|
|
|
|
|
*/
|
|
|
|
|
int xsigaction(int sig, void *handler, uint64_t flags, uint64_t mask,
|
|
|
|
|
struct sigaction *old) {
|
|
|
|
|
/* This API is superior to sigaction() because (1) it offers feature
|
|
|
|
|
parity; (2) compiler emits 1/3rd as much binary code at call-site;
|
|
|
|
|
and (3) it removes typing that just whines without added saftey. */
|
|
|
|
|
struct sigaction sa;
|
|
|
|
|
memset(&sa, 0, sizeof(sa));
|
|
|
|
|
sa.sa_handler = handler;
|
|
|
|
|
sa.sa_flags = flags;
|
|
|
|
|
memcpy(&sa.sa_mask, &mask, sizeof(mask));
|
|
|
|
|
return sigaction(sig, &sa, old);
|
|
|
|
|
}
|
