cosmopolitan/libc/runtime/memtrack.c

121 lines
4.8 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/assert.h"
#include "libc/dce.h"
#include "libc/macros.h"
#include "libc/runtime/memtrack.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
#include "libc/sysv/errfuns.h"
static void RemoveMemoryIntervals(struct MemoryIntervals *mm, int i, int n) {
assert(i >= 0);
assert(i + n <= mm->i);
memcpy(mm->p + i, mm->p + i + n,
(intptr_t)(mm->p + mm->i) - (intptr_t)(mm->p + i + n));
mm->i -= n;
}
static void CreateMemoryInterval(struct MemoryIntervals *mm, int i) {
assert(i >= 0);
assert(i <= mm->i);
assert(mm->i < ARRAYLEN(mm->p));
memmove(mm->p + i + 1, mm->p + i,
(intptr_t)(mm->p + mm->i) - (intptr_t)(mm->p + i));
++mm->i;
}
static int PunchHole(struct MemoryIntervals *mm, int x, int y, int i) {
if (mm->i == ARRAYLEN(mm->p)) return enomem();
CreateMemoryInterval(mm, i);
mm->p[i].y = x - 1;
mm->p[i + 1].x = y + 1;
return 0;
}
int ReleaseMemoryIntervals(struct MemoryIntervals *mm, int x, int y,
void wincb(struct MemoryIntervals *, int, int)) {
unsigned l, r;
assert(y >= x);
assert(AreMemoryIntervalsOk(mm));
if (!mm->i) return 0;
l = FindMemoryInterval(mm, x);
if (l == mm->i) return 0;
if (!l && y < mm->p[l].x) return 0;
if (y < mm->p[l].x) return 0;
r = FindMemoryInterval(mm, y);
if (r == mm->i || (r > l && y < mm->p[r].x)) --r;
assert(r >= l);
assert(x <= mm->p[r].y);
if (l == r && x > mm->p[l].x && y < mm->p[l].y) {
return PunchHole(mm, x, y, l);
}
if (x > mm->p[l].x && x <= mm->p[l].y) {
assert(y >= mm->p[l].y);
if (IsWindows()) return einval();
mm->p[l].y = x - 1;
assert(mm->p[l].x <= mm->p[l].y);
++l;
}
if (y >= mm->p[r].x && y < mm->p[r].y) {
assert(x <= mm->p[r].x);
if (IsWindows()) return einval();
mm->p[r].x = y + 1;
assert(mm->p[r].x <= mm->p[r].y);
--r;
}
if (l <= r) {
if (IsWindows() && wincb) {
wincb(mm, l, r);
}
RemoveMemoryIntervals(mm, l, r - l + 1);
}
return 0;
}
int TrackMemoryInterval(struct MemoryIntervals *mm, int x, int y, long h,
int prot, int flags) {
unsigned i;
assert(y >= x);
assert(AreMemoryIntervalsOk(mm));
i = FindMemoryInterval(mm, x);
if (i && x == mm->p[i - 1].y + 1 && h == mm->p[i - 1].h &&
prot == mm->p[i - 1].prot && flags == mm->p[i - 1].flags) {
mm->p[i - 1].y = y;
if (i < mm->i && y + 1 == mm->p[i].x && h == mm->p[i].h &&
prot == mm->p[i].prot && flags == mm->p[i].flags) {
mm->p[i - 1].y = mm->p[i].y;
RemoveMemoryIntervals(mm, i, 1);
}
} else if (i < mm->i && y + 1 == mm->p[i].x && h == mm->p[i].h &&
prot == mm->p[i].prot && flags == mm->p[i].flags) {
mm->p[i].x = x;
} else {
if (mm->i == ARRAYLEN(mm->p)) return enomem();
CreateMemoryInterval(mm, i);
mm->p[i].x = x;
mm->p[i].y = y;
mm->p[i].h = h;
mm->p[i].prot = prot;
mm->p[i].flags = flags;
}
return 0;
}