/*-*- 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                              │
│                                                                              │
│ 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/bits/safemacros.internal.h"
#include "libc/calls/internal.h"
#include "libc/calls/kntprioritycombos.internal.h"
#include "libc/nt/process.h"
#include "libc/nt/runtime.h"
#include "libc/nt/thread.h"

static textwindows struct NtPriorityCombo findntprio(int nice) {
  size_t l, r, m;
  l = 0;
  r = kNtPriorityCombosLen;
  while (l < r) {
    m = (l + r) >> 1;
    if (kNtPriorityCombos[m].nice > nice) {
      r = m;
    } else {
      l = m + 1;
    }
  }
  return kNtPriorityCombos[max(0, l - 1)];
}

textwindows int sys_setpriority_nt(int nice) {
  uint32_t tier;
  struct NtPriorityCombo p;
  p = findntprio(nice);
  tier = 1 << (p.lg2tier - 1);
  if (SetPriorityClass(GetCurrentProcess(), tier) &&
      SetThreadPriority(GetCurrentThread(), p.wut)) {
    return p.nice;
  } else {
    return __winerr();
  }
}
