cosmopolitan/libc/calls/setitimer-nt.c
Justine Tunney 3e4fd4b0ad Add epoll and do more release readiness changes
This change also pays off some of the remaining technical debt with
stdio, file descriptors, and memory managemnt polyfills.
2020-11-28 12:01:51 -08:00

104 lines
4.3 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 │
│ │
│ 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/calls.h"
#include "libc/calls/internal.h"
#include "libc/calls/struct/itimerval.h"
#include "libc/conv/conv.h"
#include "libc/errno.h"
#include "libc/log/check.h"
#include "libc/nexgen32e/nexgen32e.h"
#include "libc/nt/files.h"
#include "libc/nt/runtime.h"
#include "libc/nt/synchronization.h"
#include "libc/nt/thread.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/itimer.h"
#include "libc/sysv/errfuns.h"
/**
* @fileoverview Heartbreaking polyfill for SIGALRM on NT.
*
* Threads are used to trigger the SIGALRM handler, which should
* hopefully be an unfancy function like this:
*
* void OnAlarm(int sig, struct siginfo *si, struct ucontext *uc) {
* g_alarmed = true;
* }
*
* This is needed because WIN32 provides no obvious solutions for
* interrupting i/o operations on the standard input handle.
*/
static struct ItimerNt {
int64_t ith;
uint32_t tid;
struct itimerval itv;
} g_itimernt;
static uint32_t ItimerWorker(void *arg) {
do {
if (!WaitForSingleObject(g_itimernt.ith, -1)) {
__winalarm(NULL, 0, 0);
}
} while (g_itimernt.ith && g_itimernt.tid == GetCurrentThreadId());
return 0;
}
textwindows int setitimer$nt(int which, const struct itimerval *newvalue,
struct itimerval *out_opt_oldvalue) {
int32_t period;
int64_t ith, duetime;
if (which != ITIMER_REAL) return einval();
if (newvalue) {
if (newvalue->it_value.tv_sec && newvalue->it_value.tv_usec) {
if (!(ith = CreateWaitableTimer(NULL, false, NULL))) {
return __winerr();
}
duetime = -(newvalue->it_value.tv_sec * HECTONANOSECONDS +
newvalue->it_value.tv_usec * 10);
period = newvalue->it_value.tv_sec * 1000 +
div1000int64(newvalue->it_value.tv_usec);
if (!period && newvalue->it_value.tv_usec) period = 1;
if (!SetWaitableTimer(ith, &duetime, period, NULL, NULL, false)) {
errno = GetLastError();
CloseHandle(ith);
return -1;
}
} else {
ith = 0;
}
if (g_itimernt.ith) {
CloseHandle(g_itimernt.ith);
g_itimernt.ith = 0;
}
} else {
ith = 0;
}
if (out_opt_oldvalue) {
memcpy(out_opt_oldvalue, &g_itimernt.itv, sizeof(struct itimerval));
}
if (ith) {
g_itimernt.ith = ith;
memcpy(&g_itimernt.itv, newvalue, sizeof(struct itimerval));
CloseHandle(
CreateThread(NULL, STACKSIZE, ItimerWorker, NULL, 0, &g_itimernt.tid));
}
return 0;
}