summaryrefslogtreecommitdiffstats
path: root/Source/cmFileLockWin32.cxx
blob: 7bee5f22bd7e2eba67fb19ef13dee68db11f5275 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
   file Copyright.txt or https://cmake.org/licensing for details.  */
#include <windows.h> // CreateFileW

#include "cmFileLock.h"
#include "cmSystemTools.h"

cmFileLock::cmFileLock()
{
}

cmFileLockResult cmFileLock::Release()
{
  if (this->Filename.empty()) {
    return cmFileLockResult::MakeOk();
  }
  const unsigned long len = static_cast<unsigned long>(-1);
  static OVERLAPPED overlapped;
  const DWORD reserved = 0;
  const BOOL unlockResult =
    UnlockFileEx(File, reserved, len, len, &overlapped);

  this->Filename = "";

  CloseHandle(this->File);
  this->File = INVALID_HANDLE_VALUE;

  if (unlockResult) {
    return cmFileLockResult::MakeOk();
  } else {
    return cmFileLockResult::MakeSystem();
  }
}

cmFileLockResult cmFileLock::OpenFile()
{
  const DWORD access = GENERIC_READ | GENERIC_WRITE;
  const DWORD shareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
  const PSECURITY_ATTRIBUTES security = nullptr;
  const DWORD attr = 0;
  const HANDLE templ = nullptr;
  this->File = CreateFileW(
    cmSystemTools::ConvertToWindowsExtendedPath(this->Filename).c_str(),
    access, shareMode, security, OPEN_EXISTING, attr, templ);
  if (this->File == INVALID_HANDLE_VALUE) {
    return cmFileLockResult::MakeSystem();
  } else {
    return cmFileLockResult::MakeOk();
  }
}

cmFileLockResult cmFileLock::LockWithoutTimeout()
{
  if (!this->LockFile(LOCKFILE_EXCLUSIVE_LOCK)) {
    return cmFileLockResult::MakeSystem();
  } else {
    return cmFileLockResult::MakeOk();
  }
}

cmFileLockResult cmFileLock::LockWithTimeout(unsigned long seconds)
{
  const DWORD flags = LOCKFILE_EXCLUSIVE_LOCK | LOCKFILE_FAIL_IMMEDIATELY;
  while (true) {
    const BOOL result = this->LockFile(flags);
    if (result) {
      return cmFileLockResult::MakeOk();
    }
    const DWORD error = GetLastError();
    if (error != ERROR_LOCK_VIOLATION) {
      return cmFileLockResult::MakeSystem();
    }
    if (seconds == 0) {
      return cmFileLockResult::MakeTimeout();
    }
    --seconds;
    cmSystemTools::Delay(1000);
  }
}

BOOL cmFileLock::LockFile(DWORD flags)
{
  const DWORD reserved = 0;
  const unsigned long len = static_cast<unsigned long>(-1);
  static OVERLAPPED overlapped;
  return LockFileEx(this->File, flags, reserved, len, len, &overlapped);
}