1 /* -----------------------------------------------------------------------------
2 * $Id: MBlock.c,v 1.4 1999/01/14 18:31:17 sof 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 */
65 lnat mblocks_allocated = 0;
76 static caddr_t next_request = (caddr_t)ASK_FOR_MEM_AT;
78 lnat size = MBLOCK_SIZE * n;
80 #ifdef solaris2_TARGET_OS
82 int fd = open("/dev/zero",O_RDONLY);
83 ret = mmap(next_request, size, PROT_READ | PROT_WRITE,
84 MAP_FIXED | MAP_PRIVATE, fd, 0);
90 /* Note: on 95, the legal range for next_request is: [0x00400000, 0x7fffffff]
91 under NT it is: [0x00010000, 0x7fffffff]
93 We start allocating at 0x50000000, hopefully that's not conflicting with
94 others.. (ToDo: have the allocator try to gracefully rebase itself in
95 case our initial guess is conflicting with others.)
97 ret = VirtualAlloc(next_request, size, MEM_RESERVE | MEM_COMMIT , PAGE_READWRITE);
100 fprintf(stderr, "getMBlocks: VirtualAlloc failed with: %d\n", GetLastError());
108 ret = mmap(next_request, size, PROT_READ | PROT_WRITE,
109 MAP_ANON | MAP_PRIVATE, -1, 0);
113 if (ret == (void *)-1) {
114 if (errno == ENOMEM) {
115 barf("getMBlock: out of memory");
117 barf("GetMBlock: mmap failed");
121 if (((W_)ret & MBLOCK_MASK) != 0) {
122 barf("GetMBlock: misaligned block returned");
125 IF_DEBUG(gc,fprintf(stderr,"Allocated %d megablock(s) at %x\n",n,(nat)ret));
127 next_request += size;
129 mblocks_allocated += n;