1 | /* $Id: shmem-win.cpp 96407 2022-08-22 17:43:14Z vboxsync $ */
|
---|
2 | /** @file
|
---|
3 | * IPRT - Named shared memory object, Windows Implementation.
|
---|
4 | */
|
---|
5 |
|
---|
6 | /*
|
---|
7 | * Copyright (C) 2018-2022 Oracle and/or its affiliates.
|
---|
8 | *
|
---|
9 | * This file is part of VirtualBox base platform packages, as
|
---|
10 | * available from https://www.virtualbox.org.
|
---|
11 | *
|
---|
12 | * This program is free software; you can redistribute it and/or
|
---|
13 | * modify it under the terms of the GNU General Public License
|
---|
14 | * as published by the Free Software Foundation, in version 3 of the
|
---|
15 | * License.
|
---|
16 | *
|
---|
17 | * This program is distributed in the hope that it will be useful, but
|
---|
18 | * WITHOUT ANY WARRANTY; without even the implied warranty of
|
---|
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
---|
20 | * General Public License for more details.
|
---|
21 | *
|
---|
22 | * You should have received a copy of the GNU General Public License
|
---|
23 | * along with this program; if not, see <https://www.gnu.org/licenses>.
|
---|
24 | *
|
---|
25 | * The contents of this file may alternatively be used under the terms
|
---|
26 | * of the Common Development and Distribution License Version 1.0
|
---|
27 | * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
|
---|
28 | * in the VirtualBox distribution, in which case the provisions of the
|
---|
29 | * CDDL are applicable instead of those of the GPL.
|
---|
30 | *
|
---|
31 | * You may elect to license modified versions of this file under the
|
---|
32 | * terms and conditions of either the GPL or the CDDL or both.
|
---|
33 | *
|
---|
34 | * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
|
---|
35 | */
|
---|
36 |
|
---|
37 |
|
---|
38 | /*********************************************************************************************************************************
|
---|
39 | * Header Files *
|
---|
40 | *********************************************************************************************************************************/
|
---|
41 | #include <iprt/nt/nt-and-windows.h>
|
---|
42 |
|
---|
43 | #include <iprt/shmem.h>
|
---|
44 | #include "internal/iprt.h"
|
---|
45 |
|
---|
46 | #include <iprt/asm.h>
|
---|
47 | #include <iprt/assert.h>
|
---|
48 | #include <iprt/cdefs.h>
|
---|
49 | #include <iprt/err.h>
|
---|
50 | #include <iprt/mem.h>
|
---|
51 | #include <iprt/string.h>
|
---|
52 | #include <iprt/utf16.h>
|
---|
53 | #include "internal/magics.h"
|
---|
54 | #include "internal/path.h"
|
---|
55 | #include "internal-r3-win.h" /* For g_enmWinVer + kRTWinOSType_XXX */
|
---|
56 |
|
---|
57 | /*
|
---|
58 | * Define values ourselves in case the compiling host is too old.
|
---|
59 | * See https://docs.microsoft.com/en-us/windows/desktop/api/winbase/nf-winbase-createfilemappinga
|
---|
60 | * for when these were introduced.
|
---|
61 | */
|
---|
62 | #ifndef PAGE_EXECUTE_READ
|
---|
63 | # define PAGE_EXECUTE_READ 0x20
|
---|
64 | #endif
|
---|
65 | #ifndef PAGE_EXECUTE_READWRITE
|
---|
66 | # define PAGE_EXECUTE_READWRITE 0x40
|
---|
67 | #endif
|
---|
68 | #ifndef PAGE_EXECUTE_WRITECOPY
|
---|
69 | # define PAGE_EXECUTE_WRITECOPY 0x80
|
---|
70 | #endif
|
---|
71 | #ifndef FILE_MAP_EXECUTE
|
---|
72 | # define FILE_MAP_EXECUTE 0x20
|
---|
73 | #endif
|
---|
74 |
|
---|
75 |
|
---|
76 | /*********************************************************************************************************************************
|
---|
77 | * Structures and Typedefs *
|
---|
78 | *********************************************************************************************************************************/
|
---|
79 |
|
---|
80 | /**
|
---|
81 | * Shared memory object mapping descriptor.
|
---|
82 | */
|
---|
83 | typedef struct RTSHMEMMAPPINGDESC
|
---|
84 | {
|
---|
85 | /** Number of references held to this mapping, 0 if the descriptor is free. */
|
---|
86 | volatile uint32_t cMappings;
|
---|
87 | /** Pointer to the region mapping. */
|
---|
88 | void *pvMapping;
|
---|
89 | /** Start offset */
|
---|
90 | size_t offRegion;
|
---|
91 | /** Size of the region. */
|
---|
92 | size_t cbRegion;
|
---|
93 | /** Access flags for this region .*/
|
---|
94 | uint32_t fFlags;
|
---|
95 | } RTSHMEMMAPPINGDESC;
|
---|
96 | /** Pointer to a shared memory object mapping descriptor. */
|
---|
97 | typedef RTSHMEMMAPPINGDESC *PRTSHMEMMAPPINGDESC;
|
---|
98 | /** Pointer to a constant shared memory object mapping descriptor. */
|
---|
99 | typedef const RTSHMEMMAPPINGDESC *PCRTSHMEMMAPPINGDESC;
|
---|
100 |
|
---|
101 |
|
---|
102 | /**
|
---|
103 | * Internal shared memory object state.
|
---|
104 | */
|
---|
105 | typedef struct RTSHMEMINT
|
---|
106 | {
|
---|
107 | /** Magic value (RTSHMEM_MAGIC). */
|
---|
108 | uint32_t u32Magic;
|
---|
109 | /** Flag whether this instance created the named shared memory object. */
|
---|
110 | bool fCreate;
|
---|
111 | /** Handle to the underlying mapping object. */
|
---|
112 | HANDLE hShmObj;
|
---|
113 | /** Size of the mapping object in bytes. */
|
---|
114 | size_t cbMax;
|
---|
115 | /** Overall number of mappings active for this shared memory object. */
|
---|
116 | volatile uint32_t cMappings;
|
---|
117 | /** Maximum number of mapping descriptors allocated. */
|
---|
118 | uint32_t cMappingDescsMax;
|
---|
119 | /** Number of mapping descriptors used. */
|
---|
120 | volatile uint32_t cMappingDescsUsed;
|
---|
121 | /** Array of mapping descriptors - variable in size. */
|
---|
122 | RTSHMEMMAPPINGDESC aMappingDescs[1];
|
---|
123 | } RTSHMEMINT;
|
---|
124 | /** Pointer to the internal shared memory object state. */
|
---|
125 | typedef RTSHMEMINT *PRTSHMEMINT;
|
---|
126 |
|
---|
127 |
|
---|
128 |
|
---|
129 |
|
---|
130 | /**
|
---|
131 | * Returns a mapping descriptor matching the given region properties or NULL if none was found.
|
---|
132 | *
|
---|
133 | * @returns Pointer to the matching mapping descriptor or NULL if not found.
|
---|
134 | * @param pThis Pointer to the shared memory object instance.
|
---|
135 | * @param offRegion Offset into the shared memory object to start mapping at.
|
---|
136 | * @param cbRegion Size of the region to map.
|
---|
137 | * @param fFlags Desired properties of the mapped region, combination of RTSHMEM_MAP_F_* defines.
|
---|
138 | */
|
---|
139 | DECLINLINE(PRTSHMEMMAPPINGDESC) rtShMemMappingDescFindByProp(PRTSHMEMINT pThis, size_t offRegion, size_t cbRegion, uint32_t fFlags)
|
---|
140 | {
|
---|
141 | for (uint32_t i = 0; i < pThis->cMappingDescsMax; i++)
|
---|
142 | {
|
---|
143 | if ( pThis->aMappingDescs[i].offRegion == offRegion
|
---|
144 | && pThis->aMappingDescs[i].cbRegion == cbRegion
|
---|
145 | && pThis->aMappingDescs[i].fFlags == fFlags)
|
---|
146 | return &pThis->aMappingDescs[i];
|
---|
147 | }
|
---|
148 |
|
---|
149 | return NULL;
|
---|
150 | }
|
---|
151 |
|
---|
152 |
|
---|
153 | RTDECL(int) RTShMemOpen(PRTSHMEM phShMem, const char *pszName, uint32_t fFlags, size_t cbMax, uint32_t cMappingsHint)
|
---|
154 | {
|
---|
155 | AssertPtrReturn(phShMem, VERR_INVALID_PARAMETER);
|
---|
156 | AssertPtrReturn(pszName, VERR_INVALID_PARAMETER);
|
---|
157 | AssertReturn(!(fFlags & ~RTSHMEM_O_F_VALID_MASK), VERR_INVALID_PARAMETER);
|
---|
158 | AssertReturn(cMappingsHint < 64, VERR_OUT_OF_RANGE);
|
---|
159 | AssertReturn(cbMax > 0 || !(fFlags & RTSHMEM_O_F_CREATE), VERR_NOT_SUPPORTED);
|
---|
160 |
|
---|
161 | if (fFlags & RTSHMEM_O_F_TRUNCATE)
|
---|
162 | return VERR_NOT_SUPPORTED;
|
---|
163 |
|
---|
164 | /*
|
---|
165 | * The executable access was introduced with Windows XP SP2 and Windows Server 2003 SP1,
|
---|
166 | * PAGE_EXECUTE_WRITECOPY was not available until Windows Vista SP1.
|
---|
167 | * Allow execute mappings only starting from Windows 7 to keep the checks simple here (lazy coder).
|
---|
168 | */
|
---|
169 | if ( (fFlags & RTSHMEM_O_F_MAYBE_EXEC)
|
---|
170 | && g_enmWinVer < kRTWinOSType_7)
|
---|
171 | return VERR_NOT_SUPPORTED;
|
---|
172 |
|
---|
173 | cMappingsHint = cMappingsHint == 0 ? 5 : cMappingsHint;
|
---|
174 | int rc = VINF_SUCCESS;
|
---|
175 | PRTSHMEMINT pThis = (PRTSHMEMINT)RTMemAllocZ(RT_UOFFSETOF_DYN(RTSHMEMINT, aMappingDescs[cMappingsHint]));
|
---|
176 | if (RT_LIKELY(pThis))
|
---|
177 | {
|
---|
178 | pThis->u32Magic = RTSHMEM_MAGIC;
|
---|
179 | /*pThis->fCreate = false; */
|
---|
180 | /*pThis->cMappings = 0; */
|
---|
181 | pThis->cMappingDescsMax = cMappingsHint;
|
---|
182 | /*pThis->cMappingDescsUsed = 0; */
|
---|
183 | /* Construct the filename, always use the local namespace, global requires special privileges. */
|
---|
184 | char szName[RTPATH_MAX];
|
---|
185 | ssize_t cch = RTStrPrintf2(&szName[0], sizeof(szName), "Local\\%s", pszName);
|
---|
186 | if (cch > 0)
|
---|
187 | {
|
---|
188 | PRTUTF16 pwszName = NULL;
|
---|
189 | rc = RTStrToUtf16Ex(&szName[0], RTSTR_MAX, &pwszName, 0, NULL);
|
---|
190 | if (RT_SUCCESS(rc))
|
---|
191 | {
|
---|
192 | if (fFlags & RTSHMEM_O_F_CREATE)
|
---|
193 | {
|
---|
194 | #if HC_ARCH_BITS == 64
|
---|
195 | DWORD dwSzMaxHigh = cbMax >> 32;
|
---|
196 | #elif HC_ARCH_BITS == 32
|
---|
197 | DWORD dwSzMaxHigh = 0;
|
---|
198 | #else
|
---|
199 | # error "Port me"
|
---|
200 | #endif
|
---|
201 | DWORD dwSzMaxLow = cbMax & UINT32_C(0xffffffff);
|
---|
202 | DWORD fProt = 0;
|
---|
203 |
|
---|
204 | if (fFlags & RTSHMEM_O_F_MAYBE_EXEC)
|
---|
205 | {
|
---|
206 | if ((fFlags & RTSHMEM_O_F_READWRITE) == RTSHMEM_O_F_READ)
|
---|
207 | fProt |= PAGE_EXECUTE_READ;
|
---|
208 | else
|
---|
209 | fProt |= PAGE_EXECUTE_READWRITE;
|
---|
210 | }
|
---|
211 | else
|
---|
212 | {
|
---|
213 | if ((fFlags & RTSHMEM_O_F_READWRITE) == RTSHMEM_O_F_READ)
|
---|
214 | fProt |= PAGE_READONLY;
|
---|
215 | else
|
---|
216 | fProt |= PAGE_READWRITE;
|
---|
217 | }
|
---|
218 | pThis->hShmObj = CreateFileMappingW(INVALID_HANDLE_VALUE, NULL, fProt,
|
---|
219 | dwSzMaxHigh, dwSzMaxLow, pwszName);
|
---|
220 | }
|
---|
221 | else
|
---|
222 | {
|
---|
223 | DWORD fProt = SECTION_QUERY;
|
---|
224 | if (fFlags & RTSHMEM_O_F_MAYBE_EXEC)
|
---|
225 | fProt |= FILE_MAP_EXECUTE;
|
---|
226 | if (fFlags & RTSHMEM_O_F_READ)
|
---|
227 | fProt |= FILE_MAP_READ;
|
---|
228 | if (fFlags & RTSHMEM_O_F_WRITE)
|
---|
229 | fProt |= FILE_MAP_WRITE;
|
---|
230 |
|
---|
231 | pThis->hShmObj = OpenFileMappingW(fProt, FALSE, pwszName);
|
---|
232 | }
|
---|
233 | RTUtf16Free(pwszName);
|
---|
234 | if (pThis->hShmObj != NULL)
|
---|
235 | {
|
---|
236 | *phShMem = pThis;
|
---|
237 | return VINF_SUCCESS;
|
---|
238 | }
|
---|
239 | else
|
---|
240 | rc = RTErrConvertFromWin32(GetLastError());
|
---|
241 | }
|
---|
242 | }
|
---|
243 | else
|
---|
244 | rc = VERR_BUFFER_OVERFLOW;
|
---|
245 |
|
---|
246 | RTMemFree(pThis);
|
---|
247 | }
|
---|
248 | else
|
---|
249 | rc = VERR_NO_MEMORY;
|
---|
250 |
|
---|
251 | return rc;
|
---|
252 | }
|
---|
253 |
|
---|
254 |
|
---|
255 | RTDECL(int) RTShMemClose(RTSHMEM hShMem)
|
---|
256 | {
|
---|
257 | PRTSHMEMINT pThis = hShMem;
|
---|
258 | AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
|
---|
259 | AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, VERR_INVALID_HANDLE);
|
---|
260 | AssertReturn(!pThis->cMappings, VERR_INVALID_STATE);
|
---|
261 |
|
---|
262 | int rc = VINF_SUCCESS;
|
---|
263 | if (CloseHandle(pThis->hShmObj))
|
---|
264 | {
|
---|
265 | pThis->u32Magic = RTSHMEM_MAGIC_DEAD;
|
---|
266 | RTMemFree(pThis);
|
---|
267 | }
|
---|
268 | else
|
---|
269 | rc = RTErrConvertFromWin32(GetLastError());
|
---|
270 |
|
---|
271 | return rc;
|
---|
272 | }
|
---|
273 |
|
---|
274 |
|
---|
275 | RTDECL(int) RTShMemDelete(const char *pszName)
|
---|
276 | {
|
---|
277 | AssertPtrReturn(pszName, VERR_INVALID_POINTER);
|
---|
278 | AssertReturn(*pszName != '\0', VERR_INVALID_PARAMETER);
|
---|
279 |
|
---|
280 | return VERR_NOT_SUPPORTED;
|
---|
281 | }
|
---|
282 |
|
---|
283 |
|
---|
284 | RTDECL(uint32_t) RTShMemRefCount(RTSHMEM hShMem)
|
---|
285 | {
|
---|
286 | PRTSHMEMINT pThis = hShMem;
|
---|
287 | AssertPtrReturn(pThis, 0);
|
---|
288 | AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, 0);
|
---|
289 |
|
---|
290 | return pThis->cMappings;
|
---|
291 | }
|
---|
292 |
|
---|
293 |
|
---|
294 | RTDECL(int) RTShMemSetSize(RTSHMEM hShMem, size_t cbMem)
|
---|
295 | {
|
---|
296 | PRTSHMEMINT pThis = hShMem;
|
---|
297 | AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
|
---|
298 | AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, VERR_INVALID_HANDLE);
|
---|
299 | AssertReturn(!pThis->cMappings, VERR_INVALID_STATE);
|
---|
300 | AssertReturn(cbMem, VERR_NOT_SUPPORTED);
|
---|
301 |
|
---|
302 | return VERR_NOT_SUPPORTED;
|
---|
303 | }
|
---|
304 |
|
---|
305 |
|
---|
306 | RTDECL(int) RTShMemQuerySize(RTSHMEM hShMem, size_t *pcbMem)
|
---|
307 | {
|
---|
308 | PRTSHMEMINT pThis = hShMem;
|
---|
309 | AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
|
---|
310 | AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, VERR_INVALID_HANDLE);
|
---|
311 | AssertPtrReturn(pcbMem, VERR_INVALID_PARAMETER);
|
---|
312 |
|
---|
313 | int rc = VINF_SUCCESS;
|
---|
314 | SECTION_BASIC_INFORMATION SecInf;
|
---|
315 | SIZE_T cbRet;
|
---|
316 | NTSTATUS rcNt = NtQuerySection(pThis->hShmObj, SectionBasicInformation, &SecInf, sizeof(SecInf), &cbRet);
|
---|
317 | if (NT_SUCCESS(rcNt))
|
---|
318 | {
|
---|
319 | AssertReturn(cbRet == sizeof(SecInf), VERR_INTERNAL_ERROR);
|
---|
320 | #if HC_ARCH_BITS == 32
|
---|
321 | AssertReturn(SecInf.MaximumSize.HighPart == 0, VERR_INTERNAL_ERROR_2);
|
---|
322 | *pcbMem = SecInf.MaximumSize.LowPart;
|
---|
323 | #elif HC_ARCH_BITS == 64
|
---|
324 | *pcbMem = SecInf.MaximumSize.QuadPart;
|
---|
325 | #else
|
---|
326 | # error "Port me"
|
---|
327 | #endif
|
---|
328 | }
|
---|
329 | else
|
---|
330 | rc = RTErrConvertFromNtStatus(rcNt);
|
---|
331 |
|
---|
332 | return rc;
|
---|
333 | }
|
---|
334 |
|
---|
335 |
|
---|
336 | RTDECL(int) RTShMemMapRegion(RTSHMEM hShMem, size_t offRegion, size_t cbRegion, uint32_t fFlags, void **ppv)
|
---|
337 | {
|
---|
338 | PRTSHMEMINT pThis = hShMem;
|
---|
339 | AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
|
---|
340 | AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, VERR_INVALID_HANDLE);
|
---|
341 | AssertPtrReturn(ppv, VERR_INVALID_PARAMETER);
|
---|
342 | AssertReturn(!(fFlags & ~RTSHMEM_MAP_F_VALID_MASK), VERR_INVALID_PARAMETER);
|
---|
343 |
|
---|
344 | /* See comment in RTShMemOpen(). */
|
---|
345 | if ( (fFlags & RTSHMEM_MAP_F_EXEC)
|
---|
346 | && g_enmWinVer < kRTWinOSType_7)
|
---|
347 | return VERR_NOT_SUPPORTED;
|
---|
348 |
|
---|
349 | /* Try to find a mapping with compatible parameters first. */
|
---|
350 | PRTSHMEMMAPPINGDESC pMappingDesc = NULL;
|
---|
351 | for (uint32_t iTry = 0; iTry < 10; iTry++)
|
---|
352 | {
|
---|
353 | pMappingDesc = rtShMemMappingDescFindByProp(pThis, offRegion, cbRegion, fFlags);
|
---|
354 | if (!pMappingDesc)
|
---|
355 | break;
|
---|
356 |
|
---|
357 | /* Increase the mapping count and check that the region is still accessible by us. */
|
---|
358 | if ( ASMAtomicIncU32(&pMappingDesc->cMappings) > 1
|
---|
359 | && pMappingDesc->offRegion == offRegion
|
---|
360 | && pMappingDesc->cbRegion == cbRegion
|
---|
361 | && pMappingDesc->fFlags == fFlags)
|
---|
362 | break;
|
---|
363 | /* Mapping was freed inbetween, next round. */
|
---|
364 | }
|
---|
365 |
|
---|
366 | int rc = VINF_SUCCESS;
|
---|
367 | if (!pMappingDesc)
|
---|
368 | {
|
---|
369 | /* Find an empty region descriptor and map the region. */
|
---|
370 | for (uint32_t i = 0; i < pThis->cMappingDescsMax && !pMappingDesc; i++)
|
---|
371 | {
|
---|
372 | if (!pThis->aMappingDescs[i].cMappings)
|
---|
373 | {
|
---|
374 | pMappingDesc = &pThis->aMappingDescs[i];
|
---|
375 |
|
---|
376 | /* Try to grab this one. */
|
---|
377 | if (ASMAtomicIncU32(&pMappingDesc->cMappings) == 1)
|
---|
378 | break;
|
---|
379 |
|
---|
380 | /* Somebody raced us, drop reference and continue. */
|
---|
381 | ASMAtomicDecU32(&pMappingDesc->cMappings);
|
---|
382 | pMappingDesc = NULL;
|
---|
383 | }
|
---|
384 | }
|
---|
385 |
|
---|
386 | if (RT_LIKELY(pMappingDesc))
|
---|
387 | {
|
---|
388 | /* Try to map it. */
|
---|
389 | DWORD fProt = 0;
|
---|
390 | DWORD offLow = offRegion & UINT32_C(0xffffffff);
|
---|
391 | #if HC_ARCH_BITS == 64
|
---|
392 | DWORD offHigh = offRegion >> 32;
|
---|
393 | #elif HC_ARCH_BITS == 32
|
---|
394 | DWORD offHigh = 0;
|
---|
395 | #else
|
---|
396 | # error "Port me"
|
---|
397 | #endif
|
---|
398 | if (fFlags & RTSHMEM_MAP_F_READ)
|
---|
399 | fProt |= FILE_MAP_READ;
|
---|
400 | if (fFlags & RTSHMEM_MAP_F_WRITE)
|
---|
401 | fProt |= FILE_MAP_WRITE;
|
---|
402 | if (fFlags & RTSHMEM_MAP_F_EXEC)
|
---|
403 | fProt |= FILE_MAP_EXECUTE;
|
---|
404 | if (fFlags & RTSHMEM_MAP_F_COW)
|
---|
405 | fProt |= FILE_MAP_COPY;
|
---|
406 |
|
---|
407 | void *pv = MapViewOfFile(pThis->hShmObj, fProt, offHigh, offLow, cbRegion);
|
---|
408 | if (pv != NULL)
|
---|
409 | {
|
---|
410 | pMappingDesc->pvMapping = pv;
|
---|
411 | pMappingDesc->offRegion = offRegion;
|
---|
412 | pMappingDesc->cbRegion = cbRegion;
|
---|
413 | pMappingDesc->fFlags = fFlags;
|
---|
414 | }
|
---|
415 | else
|
---|
416 | {
|
---|
417 | rc = RTErrConvertFromWin32(GetLastError());
|
---|
418 | ASMAtomicDecU32(&pMappingDesc->cMappings);
|
---|
419 | }
|
---|
420 | }
|
---|
421 | else
|
---|
422 | rc = VERR_SHMEM_MAXIMUM_MAPPINGS_REACHED;
|
---|
423 | }
|
---|
424 |
|
---|
425 | if (RT_SUCCESS(rc))
|
---|
426 | {
|
---|
427 | *ppv = pMappingDesc->pvMapping;
|
---|
428 | ASMAtomicIncU32(&pThis->cMappings);
|
---|
429 | }
|
---|
430 |
|
---|
431 | return rc;
|
---|
432 | }
|
---|
433 |
|
---|
434 |
|
---|
435 | RTDECL(int) RTShMemUnmapRegion(RTSHMEM hShMem, void *pv)
|
---|
436 | {
|
---|
437 | PRTSHMEMINT pThis = hShMem;
|
---|
438 | AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
|
---|
439 | AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, VERR_INVALID_HANDLE);
|
---|
440 | AssertPtrReturn(pv, VERR_INVALID_PARAMETER);
|
---|
441 |
|
---|
442 | /* Find the mapping descriptor by the given region address. */
|
---|
443 | PRTSHMEMMAPPINGDESC pMappingDesc = NULL;
|
---|
444 | for (uint32_t i = 0; i < pThis->cMappingDescsMax && !pMappingDesc; i++)
|
---|
445 | {
|
---|
446 | if (pThis->aMappingDescs[i].pvMapping == pv)
|
---|
447 | {
|
---|
448 | pMappingDesc = &pThis->aMappingDescs[i];
|
---|
449 | break;
|
---|
450 | }
|
---|
451 | }
|
---|
452 |
|
---|
453 | AssertPtrReturn(pMappingDesc, VERR_INVALID_PARAMETER);
|
---|
454 |
|
---|
455 | int rc = VINF_SUCCESS;
|
---|
456 | if (!ASMAtomicDecU32(&pMappingDesc->cMappings))
|
---|
457 | {
|
---|
458 | /* Last mapping of this region was unmapped, so do the real unmapping now. */
|
---|
459 | if (UnmapViewOfFile(pv))
|
---|
460 | {
|
---|
461 | ASMAtomicDecU32(&pThis->cMappingDescsUsed);
|
---|
462 | ASMAtomicDecU32(&pThis->cMappings);
|
---|
463 | }
|
---|
464 | else
|
---|
465 | {
|
---|
466 | ASMAtomicIncU32(&pMappingDesc->cMappings);
|
---|
467 | rc = RTErrConvertFromWin32(GetLastError());
|
---|
468 | }
|
---|
469 | }
|
---|
470 |
|
---|
471 | return rc;
|
---|
472 | }
|
---|
473 |
|
---|