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 #include <stdio.h>
  13 #include <errno.h>
  14
  15 #include "os.h"
  16
  17 /* Except for os_zero, these routines are only called by Lisp code.
  18  * These routines may also be replaced by os-dependent versions
  19  * instead. See hpux-os.c for some useful restrictions on actual
  20  * usage. */
  21
  22 void
  23 os_zero(os_vm_address_t addr, os_vm_size_t length)
  24 {
  25     os_vm_address_t block_start;
  26     os_vm_size_t block_size;
  27
  28 #ifdef DEBUG
  29     fprintf(stderr,";;; os_zero: addr: 0x%08x, len: 0x%08x\n",addr,length);
  30 #endif
  31
  32     block_start = os_round_up_to_page(addr);
  33
  34     length -= block_start-addr;
  35     block_size = os_trunc_size_to_page(length);
  36
  37     if (block_start > addr)
  38         bzero((char *)addr, block_start-addr);
  39     if (block_size < length)
  40         bzero((char *)block_start+block_size, length-block_size);
  41
  42     if (block_size != 0) {
  43         /* Now deallocate and allocate the block so that it faults in
  44          * zero-filled. */
  45
  46         os_invalidate(block_start, block_size);
  47         addr = os_validate(block_start, block_size);
  48
  49         if(addr == NULL || addr != block_start)
  50             lose("os_zero: block moved! 0x%08x ==> 0x%08x",
  51                  block_start,
  52                  addr);
  53     }
  54 }
  55
  56 os_vm_address_t
  57 os_allocate(os_vm_size_t len)
  58 {
  59     return os_validate((os_vm_address_t)NULL, len);
  60 }
  61
  62 os_vm_address_t
  63 os_allocate_at(os_vm_address_t addr, os_vm_size_t len)
  64 {
  65     return os_validate(addr, len);
  66 }
  67
  68 void
  69 os_deallocate(os_vm_address_t addr, os_vm_size_t len)
  70 {
  71     os_invalidate(addr,len);
  72 }
  73
  74 /* (This function once tried to grow the chunk by asking os_validate
  75  * whether the space was available, but that really only works under
  76  * Mach.) */
  77 os_vm_address_t
  78 os_reallocate(os_vm_address_t addr, os_vm_size_t old_len, os_vm_size_t len)
  79 {
  80     addr=os_trunc_to_page(addr);
  81     len=os_round_up_size_to_page(len);
  82     old_len=os_round_up_size_to_page(old_len);
  83
  84     if(addr==NULL)
  85         return os_allocate(len);
  86     else{
  87         long len_diff=len-old_len;
  88
  89         if(len_diff<0)
  90             os_invalidate(addr+len,-len_diff);
  91         else{
  92             if(len_diff!=0){
  93               os_vm_address_t new=os_allocate(len);
  94
  95               if(new!=NULL){
  96                 bcopy(addr,new,old_len);
  97                 os_invalidate(addr,old_len);
  98                 }
  99
 100               addr=new;
 101             }
 102         }
 103         return addr;
 104     }
 105 }
 106
 107 int
 108 os_get_errno(void)
 109 {
 110     return errno;
 111 }