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100 lines
2.6 KiB
C
100 lines
2.6 KiB
C
/* simulate `sbrk' with an array in .bss, for `unexec' support for Cygwin;
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complete rewrite of xemacs Cygwin `unexec' code
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Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc.
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This file is part of GNU Emacs.
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GNU Emacs is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU Emacs is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU Emacs; see the file COPYING. If not, write to
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the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
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Boston, MA 02110-1301, USA. */
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#include <config.h>
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#include <stdio.h>
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#include "lisp.h"
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#include <unistd.h>
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#define STATIC_HEAP_SIZE (12 * 1024 * 1024)
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int debug_sheap = 0;
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#define BLOCKSIZE 4096
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char bss_sbrk_buffer[STATIC_HEAP_SIZE];
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char *bss_sbrk_ptr;
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int bss_sbrk_did_unexec;
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void *
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bss_sbrk (ptrdiff_t request_size)
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{
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if (!bss_sbrk_ptr)
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{
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bss_sbrk_ptr = bss_sbrk_buffer;
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#ifdef CYGWIN
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sbrk (BLOCKSIZE); /* force space for fork to work */
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#endif
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}
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if (!(int) request_size)
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{
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return (bss_sbrk_ptr);
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}
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else if (bss_sbrk_ptr + (int) request_size < bss_sbrk_buffer)
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{
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printf
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("attempt to free too much: avail %d used %d failed request %d\n",
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STATIC_HEAP_SIZE, bss_sbrk_ptr - bss_sbrk_buffer,
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(int) request_size);
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exit (-1);
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return 0;
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}
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else if (bss_sbrk_ptr + (int) request_size >
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bss_sbrk_buffer + STATIC_HEAP_SIZE)
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{
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printf ("static heap exhausted: avail %d used %d failed request %d\n",
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STATIC_HEAP_SIZE,
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bss_sbrk_ptr - bss_sbrk_buffer, (int) request_size);
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exit (-1);
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return 0;
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}
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else if ((int) request_size < 0)
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{
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bss_sbrk_ptr += (int) request_size;
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if (debug_sheap)
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printf ("freed size %d\n", request_size);
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return bss_sbrk_ptr;
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}
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else
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{
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char *ret = bss_sbrk_ptr;
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if (debug_sheap)
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printf ("allocated 0x%08x size %d\n", ret, request_size);
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bss_sbrk_ptr += (int) request_size;
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return ret;
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}
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}
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void
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report_sheap_usage (int die_if_pure_storage_exceeded)
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{
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char buf[200];
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sprintf (buf, "Static heap usage: %d of %d bytes",
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bss_sbrk_ptr - bss_sbrk_buffer, STATIC_HEAP_SIZE);
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message ("%s", buf);
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}
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/* arch-tag: 1bc386e8-71c2-4da4-b8b5-c1674a9cf926
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(do not change this comment) */
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