Source/cmFileLockWin32.cxx

   1 /* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
   2    file Copyright.txt or https://cmake.org/licensing for details.  */
   3 #include <windows.h> // CreateFileW
   4
   5 #include "cmFileLock.h"
   6 #include "cmSystemTools.h"
   7
   8 cmFileLock::cmFileLock()
   9 {
  10 }
  11
  12 cmFileLockResult cmFileLock::Release()
  13 {
  14   if (this->Filename.empty()) {
  15     return cmFileLockResult::MakeOk();
  16   }
  17   const unsigned long len = static_cast<unsigned long>(-1);
  18   static OVERLAPPED overlapped;
  19   const DWORD reserved = 0;
  20   const BOOL unlockResult =
  21     UnlockFileEx(File, reserved, len, len, &overlapped);
  22
  23   this->Filename = "";
  24
  25   CloseHandle(this->File);
  26   this->File = INVALID_HANDLE_VALUE;
  27
  28   if (unlockResult) {
  29     return cmFileLockResult::MakeOk();
  30   } else {
  31     return cmFileLockResult::MakeSystem();
  32   }
  33 }
  34
  35 cmFileLockResult cmFileLock::OpenFile()
  36 {
  37   const DWORD access = GENERIC_READ | GENERIC_WRITE;
  38   const DWORD shareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
  39   const PSECURITY_ATTRIBUTES security = nullptr;
  40   const DWORD attr = 0;
  41   const HANDLE templ = nullptr;
  42   this->File = CreateFileW(
  43     cmSystemTools::ConvertToWindowsExtendedPath(this->Filename).c_str(),
  44     access, shareMode, security, OPEN_EXISTING, attr, templ);
  45   if (this->File == INVALID_HANDLE_VALUE) {
  46     return cmFileLockResult::MakeSystem();
  47   } else {
  48     return cmFileLockResult::MakeOk();
  49   }
  50 }
  51
  52 cmFileLockResult cmFileLock::LockWithoutTimeout()
  53 {
  54   if (!this->LockFile(LOCKFILE_EXCLUSIVE_LOCK)) {
  55     return cmFileLockResult::MakeSystem();
  56   } else {
  57     return cmFileLockResult::MakeOk();
  58   }
  59 }
  60
  61 cmFileLockResult cmFileLock::LockWithTimeout(unsigned long seconds)
  62 {
  63   const DWORD flags = LOCKFILE_EXCLUSIVE_LOCK | LOCKFILE_FAIL_IMMEDIATELY;
  64   while (true) {
  65     const BOOL result = this->LockFile(flags);
  66     if (result) {
  67       return cmFileLockResult::MakeOk();
  68     }
  69     const DWORD error = GetLastError();
  70     if (error != ERROR_LOCK_VIOLATION) {
  71       return cmFileLockResult::MakeSystem();
  72     }
  73     if (seconds == 0) {
  74       return cmFileLockResult::MakeTimeout();
  75     }
  76     --seconds;
  77     cmSystemTools::Delay(1000);
  78   }
  79 }
  80
  81 int cmFileLock::LockFile(int flags)
  82 {
  83   const DWORD reserved = 0;
  84   const unsigned long len = static_cast<unsigned long>(-1);
  85   static OVERLAPPED overlapped;
  86   return LockFileEx(this->File, flags, reserved, len, len, &overlapped);
  87 }