view release on metacpan or  search on metacpan

libjit/jit/jit-alloc.c  view on Meta::CPAN

/*
 * jit-alloc.c - Memory allocation routines.
 *
 * Copyright (C) 2004  Southern Storm Software, Pty Ltd.
 *
 * This file is part of the libjit library.
 *
 * The libjit library is free software: you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation, either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * The libjit library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the libjit library.  If not, see
 * <http://www.gnu.org/licenses/>.
 */

#include "jit-config.h"

#ifdef HAVE_STDLIB_H
	#include <stdlib.h>
#endif
#ifndef JIT_WIN32_PLATFORM
#ifdef HAVE_SYS_TYPES_H
	#include <sys/types.h>
#endif
#ifdef HAVE_UNISTD_H
	#include <unistd.h>
#endif
#ifdef HAVE_SYS_MMAN_H
	#include <sys/mman.h>
#endif
#ifdef HAVE_FCNTL_H
	#include <fcntl.h>
#endif
#else /* JIT_WIN32_PLATFORM */
	#include <windows.h>
	#include <io.h>
#endif
#if defined(HAVE_SYS_MMAN_H) && defined(HAVE_MMAP) && defined(HAVE_MUNMAP)
/*
 * Make sure that "MAP_ANONYMOUS" is correctly defined, because it
 * may not exist on some variants of Unix.
 */
#ifndef MAP_ANONYMOUS
    #ifdef MAP_ANON
        #define MAP_ANONYMOUS        MAP_ANON
    #endif
#endif
#ifdef MAP_ANONYMOUS
#define JIT_USE_MMAP
#endif
#endif

/*@
 * @deftypefun {void *} _jit_malloc_exec (unsigned int @var{size})
 * Allocate a block of memory that is read/write/executable.  Such blocks
 * are used to store JIT'ed code, function closures, and other trampolines.
 * The size should be a multiple of @code{jit_vmem_page_size()}.
 *
 * This will usually be identical to @code{jit_malloc}.  However,
 * some systems may need special handling to create executable code
 * segments, so this function must be used instead.
 *
 * You must never mix regular and executable segment allocation.  That is,
 * do not use @code{jit_free} to free the result of @code{_jit_malloc_exec}.
 * @end deftypefun
@*/
void *
_jit_malloc_exec(unsigned int size)
{
#if defined(JIT_WIN32_PLATFORM)
	return VirtualAlloc(NULL, size,
			    MEM_COMMIT | MEM_RESERVE,
			    PAGE_EXECUTE_READWRITE);
#elif defined(JIT_USE_MMAP)
	void *ptr = mmap(0, size,
			 PROT_READ | PROT_WRITE | PROT_EXEC,
			 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
	if(ptr == (void *)-1)
	{
		return (void *)0;
	}
	return ptr;
#else
	return malloc(size);
#endif
}

/*@
 * @deftypefun void _jit_free_exec (void *@var{ptr}, unsigned int @var{size})
 * Free a block of memory that was previously allocated by
 * @code{_jit_malloc_exec}.  The @var{size} must be identical to the
 * original allocated size, as some systems need to know this information
 * to be able to free the block.
 * @end deftypefun
@*/
void
_jit_free_exec(void *ptr, unsigned int size)
{
	if(ptr)
	{
#if defined(JIT_WIN32_PLATFORM)