mirror of
https://github.com/wolfpld/tracy.git
synced 2024-11-10 10:41:50 +00:00
114 lines
3.1 KiB
C++
114 lines
3.1 KiB
C++
/* sort.c -- Sort without allocating memory
|
|
Copyright (C) 2012-2020 Free Software Foundation, Inc.
|
|
Written by Ian Lance Taylor, Google.
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions are
|
|
met:
|
|
|
|
(1) Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
|
|
(2) Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in
|
|
the documentation and/or other materials provided with the
|
|
distribution.
|
|
|
|
(3) The name of the author may not be used to
|
|
endorse or promote products derived from this software without
|
|
specific prior written permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
|
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
|
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
|
|
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
|
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
|
|
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
|
|
IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
POSSIBILITY OF SUCH DAMAGE. */
|
|
|
|
#include "config.h"
|
|
|
|
#include <stddef.h>
|
|
#include <sys/types.h>
|
|
|
|
#include "backtrace.hpp"
|
|
#include "internal.hpp"
|
|
|
|
namespace tracy
|
|
{
|
|
|
|
/* The GNU glibc version of qsort allocates memory, which we must not
|
|
do if we are invoked by a signal handler. So provide our own
|
|
sort. */
|
|
|
|
static void
|
|
swap (char *a, char *b, size_t size)
|
|
{
|
|
size_t i;
|
|
|
|
for (i = 0; i < size; i++, a++, b++)
|
|
{
|
|
char t;
|
|
|
|
t = *a;
|
|
*a = *b;
|
|
*b = t;
|
|
}
|
|
}
|
|
|
|
void
|
|
backtrace_qsort (void *basearg, size_t count, size_t size,
|
|
int (*compar) (const void *, const void *))
|
|
{
|
|
char *base = (char *) basearg;
|
|
size_t i;
|
|
size_t mid;
|
|
|
|
tail_recurse:
|
|
if (count < 2)
|
|
return;
|
|
|
|
/* The symbol table and DWARF tables, which is all we use this
|
|
routine for, tend to be roughly sorted. Pick the middle element
|
|
in the array as our pivot point, so that we are more likely to
|
|
cut the array in half for each recursion step. */
|
|
swap (base, base + (count / 2) * size, size);
|
|
|
|
mid = 0;
|
|
for (i = 1; i < count; i++)
|
|
{
|
|
if ((*compar) (base, base + i * size) > 0)
|
|
{
|
|
++mid;
|
|
if (i != mid)
|
|
swap (base + mid * size, base + i * size, size);
|
|
}
|
|
}
|
|
|
|
if (mid > 0)
|
|
swap (base, base + mid * size, size);
|
|
|
|
/* Recurse with the smaller array, loop with the larger one. That
|
|
ensures that our maximum stack depth is log count. */
|
|
if (2 * mid < count)
|
|
{
|
|
backtrace_qsort (base, mid, size, compar);
|
|
base += (mid + 1) * size;
|
|
count -= mid + 1;
|
|
goto tail_recurse;
|
|
}
|
|
else
|
|
{
|
|
backtrace_qsort (base + (mid + 1) * size, count - (mid + 1),
|
|
size, compar);
|
|
count = mid;
|
|
goto tail_recurse;
|
|
}
|
|
}
|
|
|
|
}
|