1 | /* $Id: shmem-win.cpp 106061 2024-09-16 14:03:52Z vboxsync $ */
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2 | /** @file
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3 | * IPRT - Named shared memory object, Windows Implementation.
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4 | */
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5 |
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6 | /*
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7 | * Copyright (C) 2018-2024 Oracle and/or its affiliates.
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8 | *
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9 | * This file is part of VirtualBox base platform packages, as
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10 | * available from https://www.virtualbox.org.
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11 | *
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12 | * This program is free software; you can redistribute it and/or
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13 | * modify it under the terms of the GNU General Public License
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14 | * as published by the Free Software Foundation, in version 3 of the
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15 | * License.
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16 | *
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17 | * This program is distributed in the hope that it will be useful, but
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18 | * WITHOUT ANY WARRANTY; without even the implied warranty of
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19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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20 | * General Public License for more details.
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21 | *
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22 | * You should have received a copy of the GNU General Public License
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23 | * along with this program; if not, see <https://www.gnu.org/licenses>.
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24 | *
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25 | * The contents of this file may alternatively be used under the terms
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26 | * of the Common Development and Distribution License Version 1.0
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27 | * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
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28 | * in the VirtualBox distribution, in which case the provisions of the
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29 | * CDDL are applicable instead of those of the GPL.
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30 | *
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31 | * You may elect to license modified versions of this file under the
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32 | * terms and conditions of either the GPL or the CDDL or both.
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33 | *
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34 | * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
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35 | */
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36 |
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37 |
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38 | /*********************************************************************************************************************************
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39 | * Header Files *
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40 | *********************************************************************************************************************************/
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41 | #include <iprt/nt/nt-and-windows.h>
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42 |
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43 | #include <iprt/shmem.h>
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44 | #include "internal/iprt.h"
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45 |
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46 | #include <iprt/asm.h>
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47 | #include <iprt/assert.h>
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48 | #include <iprt/cdefs.h>
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49 | #include <iprt/err.h>
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50 | #include <iprt/mem.h>
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51 | #include <iprt/string.h>
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52 | #include <iprt/utf16.h>
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53 | #include "internal/magics.h"
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54 | #include "internal/path.h"
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55 | #include "internal-r3-win.h" /* For g_enmWinVer + kRTWinOSType_XXX */
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56 |
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57 | /*
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58 | * Define values ourselves in case the compiling host is too old.
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59 | * See https://docs.microsoft.com/en-us/windows/desktop/api/winbase/nf-winbase-createfilemappinga
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60 | * for when these were introduced.
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61 | */
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62 | #ifndef PAGE_EXECUTE_READ
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63 | # define PAGE_EXECUTE_READ 0x20
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64 | #endif
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65 | #ifndef PAGE_EXECUTE_READWRITE
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66 | # define PAGE_EXECUTE_READWRITE 0x40
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67 | #endif
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68 | #ifndef PAGE_EXECUTE_WRITECOPY
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69 | # define PAGE_EXECUTE_WRITECOPY 0x80
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70 | #endif
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71 | #ifndef FILE_MAP_EXECUTE
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72 | # define FILE_MAP_EXECUTE 0x20
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73 | #endif
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74 |
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75 |
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76 | /*********************************************************************************************************************************
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77 | * Structures and Typedefs *
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78 | *********************************************************************************************************************************/
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79 |
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80 | /**
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81 | * Shared memory object mapping descriptor.
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82 | */
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83 | typedef struct RTSHMEMMAPPINGDESC
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84 | {
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85 | /** Number of references held to this mapping, 0 if the descriptor is free. */
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86 | volatile uint32_t cMappings;
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87 | /** Pointer to the region mapping. */
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88 | void *pvMapping;
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89 | /** Start offset */
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90 | size_t offRegion;
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91 | /** Size of the region. */
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92 | size_t cbRegion;
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93 | /** Access flags for this region .*/
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94 | uint32_t fFlags;
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95 | } RTSHMEMMAPPINGDESC;
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96 | /** Pointer to a shared memory object mapping descriptor. */
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97 | typedef RTSHMEMMAPPINGDESC *PRTSHMEMMAPPINGDESC;
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98 | /** Pointer to a constant shared memory object mapping descriptor. */
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99 | typedef const RTSHMEMMAPPINGDESC *PCRTSHMEMMAPPINGDESC;
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100 |
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101 |
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102 | /**
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103 | * Internal shared memory object state.
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104 | */
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105 | typedef struct RTSHMEMINT
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106 | {
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107 | /** Magic value (RTSHMEM_MAGIC). */
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108 | uint32_t u32Magic;
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109 | /** Flag whether this instance created the named shared memory object. */
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110 | bool fCreate;
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111 | /** Handle to the underlying mapping object. */
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112 | HANDLE hShmObj;
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113 | /** Size of the mapping object in bytes. */
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114 | size_t cbMax;
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115 | /** Overall number of mappings active for this shared memory object. */
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116 | volatile uint32_t cMappings;
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117 | /** Maximum number of mapping descriptors allocated. */
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118 | uint32_t cMappingDescsMax;
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119 | /** Number of mapping descriptors used. */
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120 | volatile uint32_t cMappingDescsUsed;
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121 | /** Array of mapping descriptors - variable in size. */
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122 | RTSHMEMMAPPINGDESC aMappingDescs[1];
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123 | } RTSHMEMINT;
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124 | /** Pointer to the internal shared memory object state. */
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125 | typedef RTSHMEMINT *PRTSHMEMINT;
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126 |
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127 |
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128 |
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129 |
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130 | /**
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131 | * Returns a mapping descriptor matching the given region properties or NULL if none was found.
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132 | *
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133 | * @returns Pointer to the matching mapping descriptor or NULL if not found.
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134 | * @param pThis Pointer to the shared memory object instance.
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135 | * @param offRegion Offset into the shared memory object to start mapping at.
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136 | * @param cbRegion Size of the region to map.
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137 | * @param fFlags Desired properties of the mapped region, combination of RTSHMEM_MAP_F_* defines.
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138 | */
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139 | DECLINLINE(PRTSHMEMMAPPINGDESC) rtShMemMappingDescFindByProp(PRTSHMEMINT pThis, size_t offRegion, size_t cbRegion, uint32_t fFlags)
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140 | {
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141 | for (uint32_t i = 0; i < pThis->cMappingDescsMax; i++)
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142 | {
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143 | if ( pThis->aMappingDescs[i].offRegion == offRegion
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144 | && pThis->aMappingDescs[i].cbRegion == cbRegion
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145 | && pThis->aMappingDescs[i].fFlags == fFlags)
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146 | return &pThis->aMappingDescs[i];
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147 | }
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148 |
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149 | return NULL;
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150 | }
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151 |
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152 |
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153 | RTDECL(int) RTShMemOpen(PRTSHMEM phShMem, const char *pszName, uint32_t fFlags, size_t cbMax, uint32_t cMappingsHint)
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154 | {
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155 | AssertPtrReturn(phShMem, VERR_INVALID_PARAMETER);
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156 | AssertPtrReturn(pszName, VERR_INVALID_PARAMETER);
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157 | AssertReturn(!(fFlags & ~RTSHMEM_O_F_VALID_MASK), VERR_INVALID_PARAMETER);
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158 | AssertReturn(cMappingsHint < 64, VERR_OUT_OF_RANGE);
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159 | AssertReturn(cbMax > 0 || !(fFlags & RTSHMEM_O_F_CREATE), VERR_NOT_SUPPORTED);
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160 |
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161 | if (fFlags & RTSHMEM_O_F_TRUNCATE)
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162 | return VERR_NOT_SUPPORTED;
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163 |
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164 | /*
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165 | * The executable access was introduced with Windows XP SP2 and Windows Server 2003 SP1,
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166 | * PAGE_EXECUTE_WRITECOPY was not available until Windows Vista SP1.
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167 | * Allow execute mappings only starting from Windows 7 to keep the checks simple here (lazy coder).
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168 | */
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169 | if ( (fFlags & RTSHMEM_O_F_MAYBE_EXEC)
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170 | && g_enmWinVer < kRTWinOSType_7)
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171 | return VERR_NOT_SUPPORTED;
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172 |
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173 | cMappingsHint = cMappingsHint == 0 ? 5 : cMappingsHint;
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174 | int rc = VINF_SUCCESS;
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175 | PRTSHMEMINT pThis = (PRTSHMEMINT)RTMemAllocZ(RT_UOFFSETOF_DYN(RTSHMEMINT, aMappingDescs[cMappingsHint]));
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176 | if (RT_LIKELY(pThis))
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177 | {
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178 | pThis->u32Magic = RTSHMEM_MAGIC;
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179 | /*pThis->fCreate = false; */
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180 | /*pThis->cMappings = 0; */
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181 | pThis->cMappingDescsMax = cMappingsHint;
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182 | /*pThis->cMappingDescsUsed = 0; */
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183 | /* Construct the filename, always use the local namespace, global requires special privileges. */
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184 | char szName[RTPATH_MAX];
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185 | ssize_t cch = RTStrPrintf2(&szName[0], sizeof(szName), "Local\\%s", pszName);
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186 | if (cch > 0)
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187 | {
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188 | PRTUTF16 pwszName = NULL;
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189 | rc = RTStrToUtf16Ex(&szName[0], RTSTR_MAX, &pwszName, 0, NULL);
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190 | if (RT_SUCCESS(rc))
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191 | {
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192 | if (fFlags & RTSHMEM_O_F_CREATE)
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193 | {
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194 | #if HC_ARCH_BITS == 64
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195 | DWORD dwSzMaxHigh = cbMax >> 32;
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196 | #elif HC_ARCH_BITS == 32
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197 | DWORD dwSzMaxHigh = 0;
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198 | #else
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199 | # error "Port me"
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200 | #endif
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201 | DWORD dwSzMaxLow = cbMax & UINT32_C(0xffffffff);
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202 | DWORD fProt = 0;
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203 |
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204 | if (fFlags & RTSHMEM_O_F_MAYBE_EXEC)
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205 | {
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206 | if ((fFlags & RTSHMEM_O_F_READWRITE) == RTSHMEM_O_F_READ)
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207 | fProt |= PAGE_EXECUTE_READ;
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208 | else
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209 | fProt |= PAGE_EXECUTE_READWRITE;
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210 | }
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211 | else
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212 | {
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213 | if ((fFlags & RTSHMEM_O_F_READWRITE) == RTSHMEM_O_F_READ)
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214 | fProt |= PAGE_READONLY;
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215 | else
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216 | fProt |= PAGE_READWRITE;
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217 | }
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218 | pThis->hShmObj = CreateFileMappingW(INVALID_HANDLE_VALUE, NULL, fProt,
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219 | dwSzMaxHigh, dwSzMaxLow, pwszName);
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220 | }
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221 | else
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222 | {
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223 | DWORD fProt = SECTION_QUERY;
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224 | if (fFlags & RTSHMEM_O_F_MAYBE_EXEC)
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225 | fProt |= FILE_MAP_EXECUTE;
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226 | if (fFlags & RTSHMEM_O_F_READ)
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227 | fProt |= FILE_MAP_READ;
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228 | if (fFlags & RTSHMEM_O_F_WRITE)
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229 | fProt |= FILE_MAP_WRITE;
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230 |
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231 | pThis->hShmObj = OpenFileMappingW(fProt, FALSE, pwszName);
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232 | }
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233 | RTUtf16Free(pwszName);
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234 | if (pThis->hShmObj != NULL)
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235 | {
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236 | *phShMem = pThis;
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237 | return VINF_SUCCESS;
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238 | }
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239 | else
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240 | rc = RTErrConvertFromWin32(GetLastError());
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241 | }
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242 | }
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243 | else
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244 | rc = VERR_BUFFER_OVERFLOW;
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245 |
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246 | RTMemFree(pThis);
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247 | }
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248 | else
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249 | rc = VERR_NO_MEMORY;
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250 |
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251 | return rc;
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252 | }
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253 |
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254 |
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255 | RTDECL(int) RTShMemClose(RTSHMEM hShMem)
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256 | {
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257 | PRTSHMEMINT pThis = hShMem;
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258 | AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
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259 | AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, VERR_INVALID_HANDLE);
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260 | AssertReturn(!pThis->cMappings, VERR_INVALID_STATE);
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261 |
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262 | int rc = VINF_SUCCESS;
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263 | if (CloseHandle(pThis->hShmObj))
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264 | {
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265 | pThis->u32Magic = RTSHMEM_MAGIC_DEAD;
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266 | RTMemFree(pThis);
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267 | }
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268 | else
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269 | rc = RTErrConvertFromWin32(GetLastError());
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270 |
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271 | return rc;
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272 | }
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273 |
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274 |
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275 | RTDECL(int) RTShMemDelete(const char *pszName)
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276 | {
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277 | AssertPtrReturn(pszName, VERR_INVALID_POINTER);
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278 | AssertReturn(*pszName != '\0', VERR_INVALID_PARAMETER);
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279 |
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280 | return VERR_NOT_SUPPORTED;
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281 | }
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282 |
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283 |
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284 | RTDECL(uint32_t) RTShMemRefCount(RTSHMEM hShMem)
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285 | {
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286 | PRTSHMEMINT pThis = hShMem;
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287 | AssertPtrReturn(pThis, 0);
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288 | AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, 0);
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289 |
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290 | return pThis->cMappings;
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291 | }
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292 |
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293 |
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294 | RTDECL(int) RTShMemSetSize(RTSHMEM hShMem, size_t cbMem)
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295 | {
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296 | PRTSHMEMINT pThis = hShMem;
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297 | AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
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298 | AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, VERR_INVALID_HANDLE);
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299 | AssertReturn(!pThis->cMappings, VERR_INVALID_STATE);
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300 | AssertReturn(cbMem, VERR_NOT_SUPPORTED);
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301 |
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302 | return VERR_NOT_SUPPORTED;
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303 | }
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304 |
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305 |
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306 | RTDECL(int) RTShMemQuerySize(RTSHMEM hShMem, size_t *pcbMem)
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307 | {
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308 | PRTSHMEMINT pThis = hShMem;
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309 | AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
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310 | AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, VERR_INVALID_HANDLE);
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311 | AssertPtrReturn(pcbMem, VERR_INVALID_PARAMETER);
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312 |
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313 | int rc = VINF_SUCCESS;
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314 | SECTION_BASIC_INFORMATION SecInf;
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315 | SIZE_T cbRet;
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316 | NTSTATUS rcNt = NtQuerySection(pThis->hShmObj, SectionBasicInformation, &SecInf, sizeof(SecInf), &cbRet);
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317 | if (NT_SUCCESS(rcNt))
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318 | {
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319 | AssertReturn(cbRet == sizeof(SecInf), VERR_INTERNAL_ERROR);
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320 | #if HC_ARCH_BITS == 32
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321 | AssertReturn(SecInf.MaximumSize.HighPart == 0, VERR_INTERNAL_ERROR_2);
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322 | *pcbMem = SecInf.MaximumSize.LowPart;
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323 | #elif HC_ARCH_BITS == 64
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324 | *pcbMem = SecInf.MaximumSize.QuadPart;
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325 | #else
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326 | # error "Port me"
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327 | #endif
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328 | }
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329 | else
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330 | rc = RTErrConvertFromNtStatus(rcNt);
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331 |
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332 | return rc;
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333 | }
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334 |
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335 |
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336 | RTDECL(int) RTShMemMapRegion(RTSHMEM hShMem, size_t offRegion, size_t cbRegion, uint32_t fFlags, void **ppv)
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337 | {
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338 | PRTSHMEMINT pThis = hShMem;
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339 | AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
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340 | AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, VERR_INVALID_HANDLE);
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341 | AssertPtrReturn(ppv, VERR_INVALID_PARAMETER);
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342 | AssertReturn(!(fFlags & ~RTSHMEM_MAP_F_VALID_MASK), VERR_INVALID_PARAMETER);
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343 |
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344 | /* See comment in RTShMemOpen(). */
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345 | if ( (fFlags & RTSHMEM_MAP_F_EXEC)
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346 | && g_enmWinVer < kRTWinOSType_7)
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347 | return VERR_NOT_SUPPORTED;
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348 |
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349 | /* Try to find a mapping with compatible parameters first. */
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350 | PRTSHMEMMAPPINGDESC pMappingDesc = NULL;
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351 | for (uint32_t iTry = 0; iTry < 10; iTry++)
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352 | {
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353 | pMappingDesc = rtShMemMappingDescFindByProp(pThis, offRegion, cbRegion, fFlags);
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354 | if (!pMappingDesc)
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355 | break;
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356 |
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357 | /* Increase the mapping count and check that the region is still accessible by us. */
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358 | if ( ASMAtomicIncU32(&pMappingDesc->cMappings) > 1
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359 | && pMappingDesc->offRegion == offRegion
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360 | && pMappingDesc->cbRegion == cbRegion
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361 | && pMappingDesc->fFlags == fFlags)
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362 | break;
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363 | /* Mapping was freed inbetween, next round. */
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364 | }
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365 |
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366 | int rc = VINF_SUCCESS;
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367 | if (!pMappingDesc)
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368 | {
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369 | /* Find an empty region descriptor and map the region. */
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370 | for (uint32_t i = 0; i < pThis->cMappingDescsMax && !pMappingDesc; i++)
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371 | {
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372 | if (!pThis->aMappingDescs[i].cMappings)
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373 | {
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374 | pMappingDesc = &pThis->aMappingDescs[i];
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375 |
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376 | /* Try to grab this one. */
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377 | if (ASMAtomicIncU32(&pMappingDesc->cMappings) == 1)
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378 | break;
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379 |
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380 | /* Somebody raced us, drop reference and continue. */
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381 | ASMAtomicDecU32(&pMappingDesc->cMappings);
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382 | pMappingDesc = NULL;
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383 | }
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384 | }
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385 |
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386 | if (RT_LIKELY(pMappingDesc))
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387 | {
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388 | /* Try to map it. */
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389 | DWORD fProt = 0;
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390 | DWORD offLow = offRegion & UINT32_C(0xffffffff);
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391 | #if HC_ARCH_BITS == 64
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392 | DWORD offHigh = offRegion >> 32;
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393 | #elif HC_ARCH_BITS == 32
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394 | DWORD offHigh = 0;
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395 | #else
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396 | # error "Port me"
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397 | #endif
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398 | if (fFlags & RTSHMEM_MAP_F_READ)
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399 | fProt |= FILE_MAP_READ;
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400 | if (fFlags & RTSHMEM_MAP_F_WRITE)
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401 | fProt |= FILE_MAP_WRITE;
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402 | if (fFlags & RTSHMEM_MAP_F_EXEC)
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403 | fProt |= FILE_MAP_EXECUTE;
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404 | if (fFlags & RTSHMEM_MAP_F_COW)
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405 | fProt |= FILE_MAP_COPY;
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406 |
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407 | void *pv = MapViewOfFile(pThis->hShmObj, fProt, offHigh, offLow, cbRegion);
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408 | if (pv != NULL)
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409 | {
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410 | pMappingDesc->pvMapping = pv;
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411 | pMappingDesc->offRegion = offRegion;
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412 | pMappingDesc->cbRegion = cbRegion;
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413 | pMappingDesc->fFlags = fFlags;
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414 | }
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415 | else
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416 | {
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417 | rc = RTErrConvertFromWin32(GetLastError());
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418 | ASMAtomicDecU32(&pMappingDesc->cMappings);
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419 | }
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420 | }
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421 | else
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422 | rc = VERR_SHMEM_MAXIMUM_MAPPINGS_REACHED;
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423 | }
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424 |
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425 | if (RT_SUCCESS(rc))
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426 | {
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427 | *ppv = pMappingDesc->pvMapping;
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428 | ASMAtomicIncU32(&pThis->cMappings);
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429 | }
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430 |
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431 | return rc;
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432 | }
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433 |
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434 |
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435 | RTDECL(int) RTShMemUnmapRegion(RTSHMEM hShMem, void *pv)
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436 | {
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437 | PRTSHMEMINT pThis = hShMem;
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438 | AssertPtrReturn(pThis, VERR_INVALID_PARAMETER);
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439 | AssertReturn(pThis->u32Magic == RTSHMEM_MAGIC, VERR_INVALID_HANDLE);
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440 | AssertPtrReturn(pv, VERR_INVALID_PARAMETER);
|
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441 |
|
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442 | /* Find the mapping descriptor by the given region address. */
|
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443 | PRTSHMEMMAPPINGDESC pMappingDesc = NULL;
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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];
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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);
|
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462 | ASMAtomicDecU32(&pThis->cMappings);
|
---|
463 | }
|
---|
464 | else
|
---|
465 | {
|
---|
466 | ASMAtomicIncU32(&pMappingDesc->cMappings);
|
---|
467 | rc = RTErrConvertFromWin32(GetLastError());
|
---|
468 | }
|
---|
469 | }
|
---|
470 |
|
---|
471 | return rc;
|
---|
472 | }
|
---|
473 |
|
---|