Make terminal ui binaries work well everywhere

Here's some screenshots of an emulator tui program that was compiled on
Linux, then scp'd it to Windows, Mac, and FreeBSD.

https://justine.storage.googleapis.com/blinkenlights-cmdexe.png
https://justine.storage.googleapis.com/blinkenlights-imac.png
https://justine.storage.googleapis.com/blinkenlights-freebsd.png
https://justine.storage.googleapis.com/blinkenlights-lisp.png

How is this even possible that we have a nontrivial ui binary that just
works on Mac, Windows, Linux, and BSD? Surely a first ever achievement.

Fixed many bugs. Bootstrapped John McCarthy's metacircular evaluator on
bare metal in half the size of Altair BASIC (about 2.5kb) and ran it in
emulator for fun and profit.
This commit is contained in:
Justine Tunney 2020-10-10 21:18:53 -07:00
parent 680daf1210
commit 9e3e985ae5
276 changed files with 7026 additions and 3790 deletions

73
libc/calls/setitimer.c Normal file
View file

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/*-*- 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
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
#include "libc/calls/internal.h"
#include "libc/calls/struct/itimerval.h"
#include "libc/dce.h"
#include "libc/sysv/errfuns.h"
#include "libc/time/time.h"
/**
* Schedules delivery of one-shot or intermittent interrupt signal, e.g.
*
* Raise SIGALRM every 1.5s:
*
* CHECK_NE(-1, sigaction(SIGALRM,
* &(struct sigaction){.sa_sigaction = missingno},
* NULL));
* CHECK_NE(-1, setitimer(ITIMER_REAL,
* &(const struct itimerval){{1, 500000}, {1, 500000}},
* NULL));
*
* Set single-shot 50ms timer callback to interrupt laggy connect():
*
* CHECK_NE(-1, sigaction(SIGALRM,
* &(struct sigaction){.sa_sigaction = missingno,
* .sa_flags = SA_RESETHAND},
* NULL));
* CHECK_NE(-1, setitimer(ITIMER_REAL,
* &(const struct itimerval){{0, 0}, {0, 50000}},
* NULL));
* if (connect(...) == -1 && errno == EINTR) { ... }
*
* Disarm timer:
*
* CHECK_NE(-1, setitimer(ITIMER_REAL, &(const struct itimerval){0}, NULL));
*
* Be sure to check for EINTR on your i/o calls, for best low latency.
*
* @param which can be ITIMER_REAL, ITIMER_VIRTUAL, etc.
* @param newvalue specifies the interval ({0,0} means one-shot) and
* duration ({0,0} means disarm) in microseconds [0,999999] and
* if this parameter is NULL, we'll polyfill getitimer() behavior
* @param out_opt_old may receive remainder of previous op (if any)
* @return 0 on success or -1 w/ errno
*/
int setitimer(int which, const struct itimerval *newvalue,
struct itimerval *out_opt_oldvalue) {
if (!IsWindows()) {
if (newvalue) {
return setitimer$sysv(which, newvalue, out_opt_oldvalue);
} else {
return getitimer$sysv(which, out_opt_oldvalue);
}
} else {
return setitimer$nt(which, newvalue, out_opt_oldvalue);
}
}