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 #include <strings.h>
  15
  16 #include "os.h"
  17 #include "interr.h"
  18
  19 /* Except for os_zero, these routines are only called by Lisp code.
  20  * These routines may also be replaced by os-dependent versions
  21  * instead. See hpux-os.c for some useful restrictions on actual
  22  * usage. */
  23
  24 void
  25 os_zero(os_vm_address_t addr, os_vm_size_t length)
  26 {
  27     os_vm_address_t block_start;
  28     os_vm_size_t block_size;
  29
  30 #ifdef DEBUG
  31     fprintf(stderr,";;; os_zero: addr: 0x%08x, len: 0x%08x\n",addr,length);
  32 #endif
  33
  34     block_start = os_round_up_to_page(addr);
  35
  36     length -= block_start-addr;
  37     block_size = os_trunc_size_to_page(length);
  38
  39     if (block_start > addr)
  40         bzero((char *)addr, block_start-addr);
  41     if (block_size < length)
  42         bzero((char *)block_start+block_size, length-block_size);
  43
  44     if (block_size != 0) {
  45         /* Now deallocate and allocate the block so that it faults in
  46          * zero-filled. */
  47
  48         os_invalidate(block_start, block_size);
  49         addr = os_validate(block_start, block_size);
  50
  51         if (addr == NULL || addr != block_start)
  52             lose("os_zero: block moved! 0x%08x ==> 0x%08x",
  53                  block_start,
  54                  addr);
  55     }
  56 }
  57
  58 os_vm_address_t
  59 os_allocate(os_vm_size_t len)
  60 {
  61     return os_validate((os_vm_address_t)NULL, len);
  62 }
  63
  64 os_vm_address_t
  65 os_allocate_at(os_vm_address_t addr, os_vm_size_t len)
  66 {
  67     return os_validate(addr, len);
  68 }
  69
  70 void
  71 os_deallocate(os_vm_address_t addr, os_vm_size_t len)
  72 {
  73     os_invalidate(addr,len);
  74 }
  75
  76 /* (This function once tried to grow the chunk by asking os_validate
  77  * whether the space was available, but that really only works under
  78  * Mach.) */
  79 os_vm_address_t
  80 os_reallocate(os_vm_address_t addr, os_vm_size_t old_len, os_vm_size_t len)
  81 {
  82     addr=os_trunc_to_page(addr);
  83     len=os_round_up_size_to_page(len);
  84     old_len=os_round_up_size_to_page(old_len);
  85
  86     if (addr==NULL)
  87         return os_allocate(len);
  88     else{
  89         long len_diff=len-old_len;
  90
  91         if (len_diff<0)
  92             os_invalidate(addr+len,-len_diff);
  93         else{
  94             if (len_diff!=0) {
  95               os_vm_address_t new=os_allocate(len);
  96
  97               if(new!=NULL){
  98                 bcopy(addr,new,old_len);
  99                 os_invalidate(addr,old_len);
 100                 }
 101
 102               addr=new;
 103             }
 104         }
 105         return addr;
 106     }
 107 }
 108
 109 int
 110 os_get_errno(void)
 111 {
 112     return errno;
 113 }