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 <string.h>
  15
  16 #include "sbcl.h"
  17 #include "os.h"
  18 #include "interr.h"
  19
  20 /* Except for os_zero, these routines are only called by Lisp code.
  21  * These routines may also be replaced by os-dependent versions
  22  * instead. See hpux-os.c for some useful restrictions on actual
  23  * usage. */
  24
  25 void
  26 os_zero(os_vm_address_t addr, os_vm_size_t length)
  27 {
  28     os_vm_address_t block_start;
  29     os_vm_size_t block_size;
  30
  31 #ifdef DEBUG
  32     fprintf(stderr,";;; os_zero: addr: 0x%08x, len: 0x%08x\n",addr,length);
  33 #endif
  34
  35     block_start = os_round_up_to_page(addr);
  36
  37     length -= block_start-addr;
  38     block_size = os_trunc_size_to_page(length);
  39
  40     if (block_start > addr)
  41         bzero((char *)addr, block_start-addr);
  42     if (block_size < length)
  43         bzero((char *)block_start+block_size, length-block_size);
  44
  45     if (block_size != 0) {
  46         /* Now deallocate and allocate the block so that it faults in
  47          * zero-filled. */
  48
  49         os_invalidate(block_start, block_size);
  50         addr = os_validate(block_start, block_size);
  51
  52         if (addr == NULL || addr != block_start)
  53             lose("os_zero: block moved! 0x%08x ==> 0x%08x\n",
  54                  block_start,
  55                  addr);
  56     }
  57 }
  58
  59 os_vm_address_t
  60 os_allocate(os_vm_size_t len)
  61 {
  62     return os_validate((os_vm_address_t)NULL, len);
  63 }
  64
  65 os_vm_address_t
  66 os_allocate_at(os_vm_address_t addr, os_vm_size_t len)
  67 {
  68     return os_validate(addr, len);
  69 }
  70
  71 void
  72 os_deallocate(os_vm_address_t addr, os_vm_size_t len)
  73 {
  74     os_invalidate(addr,len);
  75 }
  76
  77 /* (This function once tried to grow the chunk by asking os_validate
  78  * whether the space was available, but that really only works under
  79  * Mach.) */
  80 os_vm_address_t
  81 os_reallocate(os_vm_address_t addr, os_vm_size_t old_len, os_vm_size_t len)
  82 {
  83     addr=os_trunc_to_page(addr);
  84     len=os_round_up_size_to_page(len);
  85     old_len=os_round_up_size_to_page(old_len);
  86
  87     if (addr==NULL)
  88         return os_allocate(len);
  89     else{
  90         long len_diff=len-old_len;
  91
  92         if (len_diff<0)
  93             os_invalidate(addr+len,-len_diff);
  94         else{
  95             if (len_diff!=0) {
  96               os_vm_address_t new=os_allocate(len);
  97
  98               if(new!=NULL){
  99                 bcopy(addr,new,old_len);
 100                 os_invalidate(addr,old_len);
 101                 }
 102
 103               addr=new;
 104             }
 105         }
 106         return addr;
 107     }
 108 }
 109
 110 int
 111 os_get_errno(void)
 112 {
 113     return errno;
 114 }