| 96 | |
| 97 | |
| 98 | bool LockedFile::lock(LockMode mode, bool block) |
| 99 | { |
| 100 | if (!isOpen()) { |
| 101 | qWarning("QtLockedFile::lock(): file is not opened"); |
| 102 | return false; |
| 103 | } |
| 104 | |
| 105 | if (mode == NoLock) |
| 106 | return unlock(); |
| 107 | |
| 108 | if (mode == m_lock_mode) |
| 109 | return true; |
| 110 | |
| 111 | if (m_lock_mode != NoLock) |
| 112 | unlock(); |
| 113 | |
| 114 | if (!wmutex && !(wmutex = getMutexHandle(-1, true))) |
| 115 | return false; |
| 116 | |
| 117 | if (!waitMutex(wmutex, block)) |
| 118 | return false; |
| 119 | |
| 120 | if (mode == ReadLock) { |
| 121 | int idx = 0; |
| 122 | for (; idx < MAX_READERS; idx++) { |
| 123 | rmutex = getMutexHandle(idx, false); |
| 124 | if (!rmutex || waitMutex(rmutex, false)) |
| 125 | break; |
| 126 | CloseHandle(rmutex); |
| 127 | } |
| 128 | bool ok = true; |
| 129 | if (idx >= MAX_READERS) { |
| 130 | qWarning("QtLockedFile::lock(): too many readers"); |
| 131 | rmutex = 0; |
| 132 | ok = false; |
| 133 | } |
| 134 | else if (!rmutex) { |
| 135 | rmutex = getMutexHandle(idx, true); |
| 136 | if (!rmutex || !waitMutex(rmutex, false)) |
| 137 | ok = false; |
| 138 | } |
| 139 | if (!ok && rmutex) { |
| 140 | CloseHandle(rmutex); |
| 141 | rmutex = 0; |
| 142 | } |
| 143 | ReleaseMutex(wmutex); |
| 144 | if (!ok) |
| 145 | return false; |
| 146 | } |
| 147 | else { |
| 148 | Q_ASSERT(rmutexes.isEmpty()); |
| 149 | for (int i = 0; i < MAX_READERS; i++) { |
| 150 | Qt::HANDLE mutex = getMutexHandle(i, false); |
| 151 | if (mutex) |
| 152 | rmutexes.append(mutex); |
| 153 | } |
| 154 | if (rmutexes.size()) { |
| 155 | DWORD res = WaitForMultipleObjects(rmutexes.size(), rmutexes.constData(), |