56 lines
1.9 KiB
C
56 lines
1.9 KiB
C
/* Copyright (C) 1991, 1995, 1996, 1997, 2000 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library 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 GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <unistd.h>
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#include <errno.h>
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/* Defined in brk.c. */
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extern void *__curbrk;
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extern int __brk (void *addr);
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extern int __libc_multiple_libcs; /* Defined in init-first.c. */
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/* Extend the process's data space by INCREMENT.
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If INCREMENT is negative, shrink data space by - INCREMENT.
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Return start of new space allocated, or -1 for errors. */
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void *
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__sbrk (intptr_t increment)
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{
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void *oldbrk;
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/* If this is not part of the dynamic library or the library is used
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via dynamic loading in a statically linked program update
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__curbrk from the kernel's brk value. That way two separate
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instances of __brk and __sbrk can share the heap, returning
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interleaved pieces of it. */
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if (__curbrk == NULL || __libc_multiple_libcs)
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if (__brk (0) < 0) /* Initialize the break. */
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return (void *) -1;
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if (increment == 0)
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return __curbrk;
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oldbrk = __curbrk;
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if (__brk (oldbrk + increment) < 0)
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return (void *) -1;
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return oldbrk;
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}
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weak_alias (__sbrk, sbrk)
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