src/runtime/os-common.c

   1 /*
   2  * This software is part of the SBCL system. See the README file for
   3  * more information.
   4  *
   5  * This software is derived from the CMU CL system, which was
   6  * written at Carnegie Mellon University and released into the
   7  * public domain. The software is in the public domain and is
   8  * provided with absolutely no warranty. See the COPYING and CREDITS
   9  * files for more information.
  10  */
  11
  12 /*
  13  * $Header$
  14  */
  15
  16 #include <stdio.h>
  17 #include <errno.h>
  18
  19 #include "os.h"
  20
  21 /* Except for os_zero, these routines are only called by Lisp code.
  22  * These routines may also be replaced by os-dependent versions
  23  * instead. See hpux-os.c for some useful restrictions on actual
  24  * usage. */
  25
  26 void
  27 os_zero(os_vm_address_t addr, os_vm_size_t length)
  28 {
  29     os_vm_address_t block_start;
  30     os_vm_size_t block_size;
  31
  32 #ifdef DEBUG
  33     fprintf(stderr,";;; os_zero: addr: 0x%08x, len: 0x%08x\n",addr,length);
  34 #endif
  35
  36     block_start = os_round_up_to_page(addr);
  37
  38     length -= block_start-addr;
  39     block_size = os_trunc_size_to_page(length);
  40
  41     if (block_start > addr)
  42         bzero((char *)addr, block_start-addr);
  43     if (block_size < length)
  44         bzero((char *)block_start+block_size, length-block_size);
  45
  46     if (block_size != 0) {
  47         /* Now deallocate and allocate the block so that it faults in
  48          * zero-filled. */
  49
  50         os_invalidate(block_start, block_size);
  51         addr = os_validate(block_start, block_size);
  52
  53         if(addr == NULL || addr != block_start)
  54             lose("os_zero: block moved! 0x%08x ==> 0x%08x",
  55                  block_start,
  56                  addr);
  57     }
  58 }
  59
  60 os_vm_address_t
  61 os_allocate(os_vm_size_t len)
  62 {
  63     return os_validate((os_vm_address_t)NULL, len);
  64 }
  65
  66 os_vm_address_t
  67 os_allocate_at(os_vm_address_t addr, os_vm_size_t len)
  68 {
  69     return os_validate(addr, len);
  70 }
  71
  72 void
  73 os_deallocate(os_vm_address_t addr, os_vm_size_t len)
  74 {
  75     os_invalidate(addr,len);
  76 }
  77
  78 /* (This function once tried to grow the chunk by asking os_validate
  79  * whether the space was available, but that really only works under
  80  * Mach.) */
  81 os_vm_address_t
  82 os_reallocate(os_vm_address_t addr, os_vm_size_t old_len, os_vm_size_t len)
  83 {
  84     addr=os_trunc_to_page(addr);
  85     len=os_round_up_size_to_page(len);
  86     old_len=os_round_up_size_to_page(old_len);
  87
  88     if(addr==NULL)
  89         return os_allocate(len);
  90     else{
  91         long len_diff=len-old_len;
  92
  93         if(len_diff<0)
  94             os_invalidate(addr+len,-len_diff);
  95         else{
  96             if(len_diff!=0){
  97               os_vm_address_t new=os_allocate(len);
  98
  99               if(new!=NULL){
 100                 bcopy(addr,new,old_len);
 101                 os_invalidate(addr,old_len);
 102                 }
 103
 104               addr=new;
 105             }
 106         }
 107         return addr;
 108     }
 109 }
 110
 111 int
 112 os_get_errno(void)
 113 {
 114     return errno;
 115 }