dlls/shlwapi/thread.c

   1 /*
   2  * SHLWAPI thread and MT synchronisation functions
   3  *
   4  * Copyright 2002 Juergen Schmied
   5  * Copyright 2002 Jon Griffiths
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  20  */
  21 #include <stdarg.h>
  22 #include <string.h>
  23
  24 #define COBJMACROS
  25
  26 #include "windef.h"
  27 #include "winbase.h"
  28 #include "winnls.h"
  29 #include "winuser.h"
  30 #define NO_SHLWAPI_REG
  31 #define NO_SHLWAPI_PATH
  32 #define NO_SHLWAPI_GDI
  33 #define NO_SHLWAPI_STREAM
  34 #define NO_SHLWAPI_USER
  35 #include "shlwapi.h"
  36 #include "shlobj.h"
  37 #include "wine/debug.h"
  38
  39 WINE_DEFAULT_DEBUG_CHANNEL(shell);
  40
  41 extern DWORD SHLWAPI_ThreadRef_index;  /* Initialised in shlwapi_main.c */
  42
  43 INT WINAPI SHStringFromGUIDA(REFGUID,LPSTR,INT);
  44
  45 /**************************************************************************
  46  *      CreateAllAccessSecurityAttributes       [SHLWAPI.356]
  47  *
  48  * Initialise security attributes from a security descriptor.
  49  *
  50  * PARAMS
  51  *  lpAttr [O] Security attributes
  52  *  lpSec  [I] Security descriptor
  53  *
  54  * RETURNS
  55  *  Success: lpAttr, initialised using lpSec.
  56  *  Failure: NULL, if any parameters are invalid.
  57  *
  58  * NOTES
  59  *  This function always returns NULL if the underlying OS version
  60  *  Wine is impersonating does not use security descriptors (i.e. anything
  61  *  before Windows NT).
  62  */
  63 LPSECURITY_ATTRIBUTES WINAPI CreateAllAccessSecurityAttributes(
  64         LPSECURITY_ATTRIBUTES lpAttr,
  65         PSECURITY_DESCRIPTOR lpSec,
  66         DWORD p3)
  67 {
  68   /* This function is used within SHLWAPI only to create security attributes
  69    * for shell semaphores. */
  70
  71   TRACE("(%p,%p,%08x)\n", lpAttr, lpSec, p3);
  72
  73   if (!(GetVersion() & 0x80000000))  /* NT */
  74   {
  75     if (!lpSec || !lpAttr)
  76       return NULL;
  77
  78     if (InitializeSecurityDescriptor(lpSec, 1))
  79     {
  80       if (SetSecurityDescriptorDacl(lpSec, TRUE, NULL, FALSE))
  81       {
  82          lpAttr->nLength = sizeof(SECURITY_ATTRIBUTES);
  83          lpAttr->lpSecurityDescriptor = lpSec;
  84          lpAttr->bInheritHandle = FALSE;
  85          return lpAttr;
  86       }
  87     }
  88   }
  89   return NULL;
  90 }
  91
  92 /*************************************************************************
  93  *      _SHGetInstanceExplorer  [SHLWAPI.@]
  94  *
  95  * Get an interface to the shell explorer.
  96  *
  97  * PARAMS
  98  *  lppUnknown [O] Destination for explorers IUnknown interface.
  99  *
 100  * RETURNS
 101  *  Success: S_OK. lppUnknown contains the explorer interface.
 102  *  Failure: An HRESULT error code.
 103  */
 104 HRESULT WINAPI _SHGetInstanceExplorer(IUnknown **lppUnknown)
 105 {
 106   /* This function is used within SHLWAPI only to hold the IE reference
 107    * for threads created with the CTF_PROCESS_REF flag set. */
 108     return SHGetInstanceExplorer(lppUnknown);
 109 }
 110
 111 /*************************************************************************
 112  *      SHGlobalCounterGetValue [SHLWAPI.223]
 113  *
 114  * Get the current count of a semaphore.
 115  *
 116  * PARAMS
 117  *  hSem [I] Semaphore handle
 118  *
 119  * RETURNS
 120  *  The current count of the semaphore.
 121  */
 122 LONG WINAPI SHGlobalCounterGetValue(HANDLE hSem)
 123 {
 124   LONG dwOldCount = 0;
 125
 126   TRACE("(%p)\n", hSem);
 127   ReleaseSemaphore(hSem, 1, &dwOldCount); /* +1 */
 128   WaitForSingleObject(hSem, 0);           /* -1 */
 129   return dwOldCount;
 130 }
 131
 132 /*************************************************************************
 133  *      SHGlobalCounterIncrement        [SHLWAPI.224]
 134  *
 135  * Claim a semaphore.
 136  *
 137  * PARAMS
 138  *  hSem [I] Semaphore handle
 139  *
 140  * RETURNS
 141  *  The new count of the semaphore.
 142  */
 143 LONG WINAPI SHGlobalCounterIncrement(HANDLE hSem)
 144 {
 145   LONG dwOldCount = 0;
 146
 147   TRACE("(%p)\n", hSem);
 148   ReleaseSemaphore(hSem, 1, &dwOldCount);
 149   return dwOldCount + 1;
 150 }
 151
 152 /*************************************************************************
 153  *      SHGlobalCounterDecrement        [SHLWAPI.424]
 154  *
 155  * Release a semaphore.
 156  *
 157  * PARAMS
 158  *  hSem [I] Semaphore handle
 159  *
 160  * RETURNS
 161  *  The new count of the semaphore.
 162  */
 163 DWORD WINAPI SHGlobalCounterDecrement(HANDLE hSem)
 164 {
 165   DWORD dwOldCount = 0;
 166
 167   TRACE("(%p)\n", hSem);
 168
 169   dwOldCount = SHGlobalCounterGetValue(hSem);
 170   WaitForSingleObject(hSem, 0);
 171   return dwOldCount - 1;
 172 }
 173
 174 /*************************************************************************
 175  *      SHGlobalCounterCreateNamedW     [SHLWAPI.423]
 176  *
 177  * Unicode version of SHGlobalCounterCreateNamedA.
 178  */
 179 HANDLE WINAPI SHGlobalCounterCreateNamedW(LPCWSTR lpszName, DWORD iInitial)
 180 {
 181   static const WCHAR szPrefix[] = { 's', 'h', 'e', 'l', 'l', '.', '\0' };
 182   const int iPrefixLen = 6;
 183   WCHAR szBuff[MAX_PATH];
 184   SECURITY_DESCRIPTOR sd;
 185   SECURITY_ATTRIBUTES sAttr, *pSecAttr;
 186   HANDLE hRet;
 187
 188   TRACE("(%s,%d)\n", debugstr_w(lpszName), iInitial);
 189
 190   /* Create Semaphore name */
 191   memcpy(szBuff, szPrefix, (iPrefixLen + 1) * sizeof(WCHAR));
 192   if (lpszName)
 193     StrCpyNW(szBuff + iPrefixLen, lpszName, ARRAY_SIZE(szBuff) - iPrefixLen);
 194
 195   /* Initialise security attributes */
 196   pSecAttr = CreateAllAccessSecurityAttributes(&sAttr, &sd, 0);
 197
 198   if (!(hRet = CreateSemaphoreW(pSecAttr , iInitial, MAXLONG, szBuff)))
 199     hRet = OpenSemaphoreW(SYNCHRONIZE|SEMAPHORE_MODIFY_STATE, 0, szBuff);
 200   return hRet;
 201 }
 202
 203 /*************************************************************************
 204  *      SHGlobalCounterCreateNamedA     [SHLWAPI.422]
 205  *
 206  * Create a semaphore.
 207  *
 208  * PARAMS
 209  *  lpszName [I] Name of semaphore
 210  *  iInitial [I] Initial count for semaphore
 211  *
 212  * RETURNS
 213  *  A new semaphore handle.
 214  */
 215 HANDLE WINAPI SHGlobalCounterCreateNamedA(LPCSTR lpszName, DWORD iInitial)
 216 {
 217   WCHAR szBuff[MAX_PATH];
 218
 219   TRACE("(%s,%d)\n", debugstr_a(lpszName), iInitial);
 220
 221   if (lpszName)
 222     MultiByteToWideChar(CP_ACP, 0, lpszName, -1, szBuff, MAX_PATH);
 223   return SHGlobalCounterCreateNamedW(lpszName ? szBuff : NULL, iInitial);
 224 }
 225
 226 /*************************************************************************
 227  *      SHGlobalCounterCreate   [SHLWAPI.222]
 228  *
 229  * Create a semaphore using the name of a GUID.
 230  *
 231  * PARAMS
 232  *  guid [I] GUID to use as semaphore name
 233  *
 234  * RETURNS
 235  *  A handle to the semaphore.
 236  *
 237  * NOTES
 238  *  The initial count of the semaphore is set to 0.
 239  */
 240 HANDLE WINAPI SHGlobalCounterCreate (REFGUID guid)
 241 {
 242   char szName[40];
 243
 244   TRACE("(%s)\n", debugstr_guid(guid));
 245
 246   /* Create a named semaphore using the GUID string */
 247   SHStringFromGUIDA(guid, szName, sizeof(szName) - 1);
 248   return SHGlobalCounterCreateNamedA(szName, 0);
 249 }