1 /* -----------------------------------------------------------------------------
2 * $Id: MBlock.c,v 1.2 1998/12/02 13:28:28 simonm Exp $
4 * MegaBlock Allocator Interface. This file contains all the dirty
5 * architecture-dependent hackery required to get a chunk of aligned
6 * memory from the operating system.
8 * ---------------------------------------------------------------------------*/
10 #define NON_POSIX_SOURCE
16 #include "BlockAlloc.h"
22 #ifdef HAVE_SYS_TYPES_H
23 #include <sys/types.h>
26 #ifdef HAVE_SYS_MMAN_H
34 #if cygwin32_TARGET_OS
38 #if freebsd2_TARGET_OS || freebsd3_TARGET_OS
39 /* Executable is loaded from 0x0
40 * Shared libraries are loaded at 0x2000000
41 * Stack is at the top of the address space. The kernel probably owns
42 * 0x8000000 onwards, so we'll pick 0x5000000.
44 #define ASK_FOR_MEM_AT 0x50000000
49 #define ASK_FOR_MEM_AT 0x50000000
51 #elif cygwin32_TARGET_OS
54 #define ASK_FOR_MEM_AT 0x50000000
56 #elif solaris2_TARGET_OS
58 #define ASK_FOR_MEM_AT 0x50000000
61 #error Dont know where to get memory from on this architecture
62 /* ToDo: memory locations on other architectures */
74 static caddr_t next_request = (caddr_t)ASK_FOR_MEM_AT;
76 lnat size = MBLOCK_SIZE * n;
78 #ifdef solaris2_TARGET_OS
80 int fd = open("/dev/zero",O_RDONLY);
81 ret = mmap(next_request, size, PROT_READ | PROT_WRITE,
82 MAP_FIXED | MAP_PRIVATE, fd, 0);
88 /* avoid using cygwin32's mmap implementation, it's buggy and
89 it's just as easy to do what we want to do directly.
91 HANDLE hFile = (HANDLE)0xFFFFFFFF;
92 SECURITY_ATTRIBUTES sa;
95 sa.nLength = sizeof (SECURITY_ATTRIBUTES);
96 sa.bInheritHandle = TRUE;
97 sa.lpSecurityDescriptor = 0;
99 h = CreateFileMapping(hFile, &sa, PAGE_READWRITE, 0, size, NULL);
102 fprintf(stderr, "getMBlocks: CreateFileMapping failed with: %d\n", GetLastError());
106 ret = MapViewOfFileEx (h, FILE_MAP_WRITE, 0, 0, size, next_request);
107 if ( ret != next_request ) {
109 fprintf(stderr, "getMBlocks: MapViewOfFileEx failed with: %d\n", GetLastError());
116 ret = mmap(next_request, size, PROT_READ | PROT_WRITE,
117 MAP_ANON | MAP_PRIVATE, -1, 0);
121 if (ret == (void *)-1) {
122 if (errno == ENOMEM) {
123 barf("getMBlock: out of memory");
125 barf("GetMBlock: mmap failed");
129 if (((W_)ret & MBLOCK_MASK) != 0) {
130 barf("GetMBlock: misaligned block returned");
133 IF_DEBUG(gc,fprintf(stderr,"Allocated %d megablock(s) at %x\n",n,(nat)ret));
135 next_request += size;