2 * winmisc.c: miscellaneous Windows-specific things.
10 void platform_get_x11_auth(char *display, int *proto,
11 unsigned char *data, int *datalen)
13 /* We don't support this at all under Windows. */
16 Filename filename_from_str(const char *str)
19 strncpy(ret.path, str, sizeof(ret.path));
20 ret.path[sizeof(ret.path)-1] = '\0';
24 const char *filename_to_str(const Filename *fn)
29 int filename_equal(Filename f1, Filename f2)
31 return !strcmp(f1.path, f2.path);
34 int filename_is_null(Filename fn)
40 static FILE *debug_fp = NULL;
41 static HANDLE debug_hdl = INVALID_HANDLE_VALUE;
42 static int debug_got_console = 0;
48 if (!debug_got_console) {
50 debug_got_console = 1;
51 debug_hdl = GetStdHandle(STD_OUTPUT_HANDLE);
55 debug_fp = fopen("debug.log", "w");
58 if (debug_hdl != INVALID_HANDLE_VALUE) {
59 WriteFile(debug_hdl, buf, strlen(buf), &dw, NULL);
68 * Minefield - a Windows equivalent for Electric Fence
76 * We start by reserving as much virtual address space as Windows
77 * will sensibly (or not sensibly) let us have. We flag it all as
80 * Any allocation attempt is satisfied by committing one or more
81 * pages, with an uncommitted page on either side. The returned
82 * memory region is jammed up against the _end_ of the pages.
84 * Freeing anything causes instantaneous decommitment of the pages
85 * involved, so stale pointers are caught as soon as possible.
88 static int minefield_initialised = 0;
89 static void *minefield_region = NULL;
90 static long minefield_size = 0;
91 static long minefield_npages = 0;
92 static long minefield_curpos = 0;
93 static unsigned short *minefield_admin = NULL;
94 static void *minefield_pages = NULL;
96 static void minefield_admin_hide(int hide)
98 int access = hide ? PAGE_NOACCESS : PAGE_READWRITE;
99 VirtualProtect(minefield_admin, minefield_npages * 2, access, NULL);
102 static void minefield_init(void)
108 for (size = 0x40000000; size > 0; size = ((size >> 3) * 7) & ~0xFFF) {
109 minefield_region = VirtualAlloc(NULL, size,
110 MEM_RESERVE, PAGE_NOACCESS);
111 if (minefield_region)
114 minefield_size = size;
117 * Firstly, allocate a section of that to be the admin block.
118 * We'll need a two-byte field for each page.
120 minefield_admin = minefield_region;
121 minefield_npages = minefield_size / PAGESIZE;
122 admin_size = (minefield_npages * 2 + PAGESIZE - 1) & ~(PAGESIZE - 1);
123 minefield_npages = (minefield_size - admin_size) / PAGESIZE;
124 minefield_pages = (char *) minefield_region + admin_size;
127 * Commit the admin region.
129 VirtualAlloc(minefield_admin, minefield_npages * 2,
130 MEM_COMMIT, PAGE_READWRITE);
133 * Mark all pages as unused (0xFFFF).
135 for (i = 0; i < minefield_npages; i++)
136 minefield_admin[i] = 0xFFFF;
139 * Hide the admin region.
141 minefield_admin_hide(1);
143 minefield_initialised = 1;
146 static void minefield_bomb(void)
148 div(1, *(int *) minefield_pages);
151 static void *minefield_alloc(int size)
154 int pos, lim, region_end, region_start;
158 npages = (size + PAGESIZE - 1) / PAGESIZE;
160 minefield_admin_hide(0);
163 * Search from current position until we find a contiguous
164 * bunch of npages+2 unused pages.
166 pos = minefield_curpos;
167 lim = minefield_npages;
169 /* Skip over used pages. */
170 while (pos < lim && minefield_admin[pos] != 0xFFFF)
172 /* Count unused pages. */
174 while (pos < lim && pos - start < npages + 2 &&
175 minefield_admin[pos] == 0xFFFF)
177 if (pos - start == npages + 2)
179 /* If we've reached the limit, reset the limit or stop. */
181 if (lim == minefield_npages) {
182 /* go round and start again at zero */
183 lim = minefield_curpos;
186 minefield_admin_hide(1);
192 minefield_curpos = pos - 1;
195 * We have npages+2 unused pages starting at start. We leave
196 * the first and last of these alone and use the rest.
198 region_end = (start + npages + 1) * PAGESIZE;
199 region_start = region_end - size;
200 /* FIXME: could align here if we wanted */
203 * Update the admin region.
205 for (i = start + 2; i < start + npages + 1; i++)
206 minefield_admin[i] = 0xFFFE; /* used but no region starts here */
207 minefield_admin[start + 1] = region_start % PAGESIZE;
209 minefield_admin_hide(1);
211 VirtualAlloc((char *) minefield_pages + region_start, size,
212 MEM_COMMIT, PAGE_READWRITE);
213 return (char *) minefield_pages + region_start;
216 static void minefield_free(void *ptr)
218 int region_start, i, j;
220 minefield_admin_hide(0);
222 region_start = (char *) ptr - (char *) minefield_pages;
223 i = region_start / PAGESIZE;
224 if (i < 0 || i >= minefield_npages ||
225 minefield_admin[i] != region_start % PAGESIZE)
227 for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++) {
228 minefield_admin[j] = 0xFFFF;
231 VirtualFree(ptr, j * PAGESIZE - region_start, MEM_DECOMMIT);
233 minefield_admin_hide(1);
236 static int minefield_get_size(void *ptr)
238 int region_start, i, j;
240 minefield_admin_hide(0);
242 region_start = (char *) ptr - (char *) minefield_pages;
243 i = region_start / PAGESIZE;
244 if (i < 0 || i >= minefield_npages ||
245 minefield_admin[i] != region_start % PAGESIZE)
247 for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++);
249 minefield_admin_hide(1);
251 return j * PAGESIZE - region_start;
254 void *minefield_c_malloc(size_t size)
256 if (!minefield_initialised)
258 return minefield_alloc(size);
261 void minefield_c_free(void *p)
263 if (!minefield_initialised)
269 * realloc _always_ moves the chunk, for rapid detection of code
270 * that assumes it won't.
272 void *minefield_c_realloc(void *p, size_t size)
276 if (!minefield_initialised)
278 q = minefield_alloc(size);
279 oldsize = minefield_get_size(p);
280 memcpy(q, p, (oldsize < size ? oldsize : size));
285 #endif /* MINEFIELD */