server/mapping.c

   1 /*
   2  * Server-side file mapping management
   3  *
   4  * Copyright (C) 1999 Alexandre Julliard
   5  */
   6
   7 #include <assert.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <unistd.h>
  11
  12 #include "config.h"
  13 #include "winerror.h"
  14 #include "winnt.h"
  15 #include "winbase.h"
  16
  17 #include "handle.h"
  18 #include "thread.h"
  19 #include "request.h"
  20
  21 struct mapping
  22 {
  23     struct object  obj;             /* object header */
  24     int            size_high;       /* mapping size */
  25     int            size_low;        /* mapping size */
  26     int            protect;         /* protection flags */
  27     struct file   *file;            /* file mapped */
  28 };
  29
  30 static void mapping_dump( struct object *obj, int verbose );
  31 static void mapping_destroy( struct object *obj );
  32
  33 static const struct object_ops mapping_ops =
  34 {
  35     sizeof(struct mapping),      /* size */
  36     mapping_dump,                /* dump */
  37     no_add_queue,                /* add_queue */
  38     NULL,                        /* remove_queue */
  39     NULL,                        /* signaled */
  40     NULL,                        /* satisfied */
  41     NULL,                        /* get_poll_events */
  42     NULL,                        /* poll_event */
  43     no_read_fd,                  /* get_read_fd */
  44     no_write_fd,                 /* get_write_fd */
  45     no_flush,                    /* flush */
  46     no_get_file_info,            /* get_file_info */
  47     mapping_destroy              /* destroy */
  48 };
  49
  50 #ifdef __i386__
  51
  52 /* These are always the same on an i386, and it will be faster this way */
  53 # define page_mask  0xfff
  54 # define page_shift 12
  55 # define init_page_size() /* nothing */
  56
  57 #else  /* __i386__ */
  58
  59 static int page_shift, page_mask;
  60
  61 static void init_page_size(void)
  62 {
  63     int page_size;
  64 # ifdef HAVE_GETPAGESIZE
  65     page_size = getpagesize();
  66 # else
  67 #  ifdef __svr4__
  68     page_size = sysconf(_SC_PAGESIZE);
  69 #  else
  70 #   error Cannot get the page size on this platform
  71 #  endif
  72 # endif
  73     page_mask = page_size - 1;
  74     /* Make sure we have a power of 2 */
  75     assert( !(page_size & page_mask) );
  76     page_shift = 0;
  77     while ((1 << page_shift) != page_size) page_shift++;
  78 }
  79 #endif  /* __i386__ */
  80
  81 #define ROUND_ADDR(addr) \
  82    ((int)(addr) & ~page_mask)
  83
  84 #define ROUND_SIZE(addr,size) \
  85    (((int)(size) + ((int)(addr) & page_mask) + page_mask) & ~page_mask)
  86
  87
  88 static struct object *create_mapping( int size_high, int size_low, int protect,
  89                                       int handle, const WCHAR *name, size_t len )
  90 {
  91     struct mapping *mapping;
  92     int access = 0;
  93
  94     if (!page_mask) init_page_size();
  95
  96     if (!(mapping = create_named_object( &mapping_ops, name, len )))
  97         return NULL;
  98     if (get_error() == ERROR_ALREADY_EXISTS)
  99         return &mapping->obj;  /* Nothing else to do */
 100
 101     if (protect & VPROT_READ) access |= GENERIC_READ;
 102     if (protect & VPROT_WRITE) access |= GENERIC_WRITE;
 103
 104     if (handle != -1)
 105     {
 106         if (!(mapping->file = get_file_obj( current->process, handle, access ))) goto error;
 107         if (!size_high && !size_low)
 108         {
 109             struct get_file_info_request req;
 110             struct object *obj = (struct object *)mapping->file;
 111             obj->ops->get_file_info( obj, &req );
 112             size_high = req.size_high;
 113             size_low  = ROUND_SIZE( 0, req.size_low );
 114         }
 115         else if (!grow_file( mapping->file, size_high, size_low )) goto error;
 116     }
 117     else  /* Anonymous mapping (no associated file) */
 118     {
 119         if (!size_high && !size_low)
 120         {
 121             set_error( ERROR_INVALID_PARAMETER );
 122             mapping->file = NULL;
 123             goto error;
 124         }
 125         if (!(mapping->file = create_temp_file( access ))) goto error;
 126         if (!grow_file( mapping->file, size_high, size_low )) goto error;
 127     }
 128     mapping->size_high = size_high;
 129     mapping->size_low  = ROUND_SIZE( 0, size_low );
 130     mapping->protect   = protect;
 131     return &mapping->obj;
 132
 133  error:
 134     release_object( mapping );
 135     return NULL;
 136 }
 137
 138 static void mapping_dump( struct object *obj, int verbose )
 139 {
 140     struct mapping *mapping = (struct mapping *)obj;
 141     assert( obj->ops == &mapping_ops );
 142     fprintf( stderr, "Mapping size=%08x%08x prot=%08x file=%p ",
 143              mapping->size_high, mapping->size_low, mapping->protect, mapping->file );
 144     dump_object_name( &mapping->obj );
 145     fputc( '\n', stderr );
 146 }
 147
 148 static void mapping_destroy( struct object *obj )
 149 {
 150     struct mapping *mapping = (struct mapping *)obj;
 151     assert( obj->ops == &mapping_ops );
 152     if (mapping->file) release_object( mapping->file );
 153 }
 154
 155 int get_page_size(void)
 156 {
 157     if (!page_mask) init_page_size();
 158     return page_mask + 1;
 159 }
 160
 161 /* create a file mapping */
 162 DECL_HANDLER(create_mapping)
 163 {
 164     size_t len = get_req_strlenW( req->name );
 165     struct object *obj;
 166
 167     req->handle = -1;
 168     if ((obj = create_mapping( req->size_high, req->size_low,
 169                                req->protect, req->file_handle, req->name, len )))
 170     {
 171         int access = FILE_MAP_ALL_ACCESS;
 172         if (!(req->protect & VPROT_WRITE)) access &= ~FILE_MAP_WRITE;
 173         req->handle = alloc_handle( current->process, obj, access, req->inherit );
 174         release_object( obj );
 175     }
 176 }
 177
 178 /* open a handle to a mapping */
 179 DECL_HANDLER(open_mapping)
 180 {
 181     size_t len = get_req_strlenW( req->name );
 182     req->handle = open_object( req->name, len, &mapping_ops, req->access, req->inherit );
 183 }
 184
 185 /* get a mapping information */
 186 DECL_HANDLER(get_mapping_info)
 187 {
 188     struct mapping *mapping;
 189
 190     if ((mapping = (struct mapping *)get_handle_obj( current->process, req->handle,
 191                                                      0, &mapping_ops )))
 192     {
 193         req->size_high = mapping->size_high;
 194         req->size_low  = mapping->size_low;
 195         req->protect   = mapping->protect;
 196         if (mapping->file) set_reply_fd( current, file_get_mmap_fd( mapping->file ) );
 197         release_object( mapping );
 198     }
 199 }
 200