1/* 2 * Copyright (c) 1999-2010 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28/* 29 * File: brk.c 30 * 31 * Unix compatibility for sbrk system call. 32 * 33 * HISTORY 34 * 09-Mar-90 Gregg Kellogg (gk) at NeXT. 35 * include <kern/mach_interface.h> instead of <kern/mach.h> 36 * 37 * 14-Feb-89 Avadis Tevanian (avie) at NeXT. 38 * Total rewrite using a fixed area of VM from break region. 39 */ 40 41#include <mach/mach.h> /* for vm_allocate, vm_offset_t */ 42#include <mach/vm_statistics.h> 43#include <errno.h> 44#include <unistd.h> 45 46static int sbrk_needs_init = TRUE; 47static vm_size_t sbrk_region_size = 4*1024*1024; /* Well, what should it be? */ 48static vm_address_t sbrk_curbrk; 49 50void *sbrk(int size) 51{ 52 kern_return_t ret; 53 54 if (sbrk_needs_init) { 55 sbrk_needs_init = FALSE; 56 /* 57 * Allocate a big region to simulate break region. 58 */ 59 ret = vm_allocate(mach_task_self(), &sbrk_curbrk, sbrk_region_size, 60 VM_MAKE_TAG(VM_MEMORY_SBRK)|TRUE); 61 if (ret != KERN_SUCCESS) { 62 errno = ENOMEM; 63 return((void *)-1); 64 } 65 } 66 67 if (size <= 0) 68 return((void *)sbrk_curbrk); 69 else if (size > sbrk_region_size) { 70 errno = ENOMEM; 71 return((void *)-1); 72 } 73 sbrk_curbrk += size; 74 sbrk_region_size -= size; 75 return((void *)(sbrk_curbrk - size)); 76} 77 78void *brk(const void *x) 79{ 80 errno = ENOMEM; 81 return((void *)-1); 82} 83