diff options
Diffstat (limited to 'lib/dir_lock.cpp')
| -rw-r--r-- | lib/dir_lock.cpp | 124 |
1 files changed, 39 insertions, 85 deletions
diff --git a/lib/dir_lock.cpp b/lib/dir_lock.cpp index 88fb19b3..87864ce4 100644 --- a/lib/dir_lock.cpp +++ b/lib/dir_lock.cpp @@ -28,7 +28,6 @@ #elif defined FFS_LINUX #include <sys/stat.h> -#include <cerrno> #include <unistd.h> #endif @@ -76,24 +75,24 @@ public: const char buffer[1] = {' '}; #ifdef FFS_WIN - //ATTENTION: setting file pointer IS required! => use CreateFile/FILE_GENERIC_WRITE + SetFilePointerEx! + //ATTENTION: setting file pointer IS required! => use CreateFile/GENERIC_WRITE + SetFilePointerEx! //although CreateFile/FILE_APPEND_DATA without SetFilePointerEx works locally, it MAY NOT work on some network shares creating a 4 gig file!!! const HANDLE fileHandle = ::CreateFile(applyLongPathPrefix(lockfilename_).c_str(), GENERIC_READ | GENERIC_WRITE, //use both when writing over network, see comment in file_io.cpp FILE_SHARE_READ, - NULL, + nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, - NULL); + nullptr); if (fileHandle == INVALID_HANDLE_VALUE) return; - ZEN_ON_BLOCK_EXIT(::CloseHandle(fileHandle)); + ZEN_ON_SCOPE_EXIT(::CloseHandle(fileHandle)); const LARGE_INTEGER moveDist = {}; if (!::SetFilePointerEx(fileHandle, //__in HANDLE hFile, moveDist, //__in LARGE_INTEGER liDistanceToMove, - NULL, //__out_opt PLARGE_INTEGER lpNewFilePointer, + nullptr, //__out_opt PLARGE_INTEGER lpNewFilePointer, FILE_END)) //__in DWORD dwMoveMethod return; @@ -102,13 +101,13 @@ public: buffer, //__out LPVOID lpBuffer, 1, //__in DWORD nNumberOfBytesToRead, &bytesWritten, //__out_opt LPDWORD lpNumberOfBytesWritten, - NULL); //__inout_opt LPOVERLAPPED lpOverlapped + nullptr); //__inout_opt LPOVERLAPPED lpOverlapped #elif defined FFS_LINUX - const int fileHandle = ::open(lockfilename_.c_str(), O_WRONLY | O_APPEND); //O_EXCL contains a race condition on NFS file systems: http://linux.die.net/man/2/open + const int fileHandle = ::open(lockfilename_.c_str(), O_WRONLY | O_APPEND); if (fileHandle == -1) return; - ZEN_ON_BLOCK_EXIT(::close(fileHandle)); + ZEN_ON_SCOPE_EXIT(::close(fileHandle)); const ssize_t bytesWritten = ::write(fileHandle, buffer, 1); (void)bytesWritten; @@ -127,41 +126,25 @@ UInt64 getLockFileSize(const Zstring& filename) //throw FileError, ErrorNotExist #ifdef FFS_WIN WIN32_FIND_DATA fileInfo = {}; const HANDLE searchHandle = ::FindFirstFile(applyLongPathPrefix(filename).c_str(), &fileInfo); - if (searchHandle == INVALID_HANDLE_VALUE) + if (searchHandle != INVALID_HANDLE_VALUE) { - const DWORD lastError = ::GetLastError(); - - std::wstring errorMessage = _("Error reading file attributes:") + L"\n\"" + filename + L"\"" + L"\n\n" + getLastErrorFormatted(lastError); - - if (lastError == ERROR_FILE_NOT_FOUND || - lastError == ERROR_PATH_NOT_FOUND || - lastError == ERROR_BAD_NETPATH || - lastError == ERROR_NETNAME_DELETED) - throw ErrorNotExisting(errorMessage); - else - throw FileError(errorMessage); + ::FindClose(searchHandle); + return zen::UInt64(fileInfo.nFileSizeLow, fileInfo.nFileSizeHigh); } - ::FindClose(searchHandle); - - return zen::UInt64(fileInfo.nFileSizeLow, fileInfo.nFileSizeHigh); - #elif defined FFS_LINUX struct ::stat fileInfo = {}; - if (::stat(filename.c_str(), &fileInfo) != 0) //follow symbolic links - { - const int lastError = errno; - - std::wstring errorMessage = _("Error reading file attributes:") + L"\n\"" + filename + L"\"" + L"\n\n" + getLastErrorFormatted(lastError); + if (::stat(filename.c_str(), &fileInfo) == 0) //follow symbolic links + return zen::UInt64(fileInfo.st_size); +#endif - if (lastError == ENOENT) - throw ErrorNotExisting(errorMessage); - else - throw FileError(errorMessage); - } + const ErrorCode lastError = getLastError(); + const std::wstring errorMessage = _("Error reading file attributes:") + L"\n\"" + filename + L"\"" + L"\n\n" + getLastErrorFormatted(lastError); - return zen::UInt64(fileInfo.st_size); -#endif + if (errorCodeForNotExisting(lastError)) + throw ErrorNotExisting(errorMessage); + else + throw FileError(errorMessage); } @@ -177,29 +160,6 @@ Zstring deleteAbandonedLockName(const Zstring& lockfilename) //make sure to NOT namespace { -//read string from file stream -inline -std::string readString(wxInputStream& stream) //throw std::exception -{ - const auto strLength = readPOD<std::uint32_t>(stream); - std::string output; - if (strLength > 0) - { - output.resize(strLength); //throw std::bad_alloc - stream.Read(&output[0], strLength); - } - return output; -} - - -inline -void writeString(wxOutputStream& stream, const std::string& str) //write string to filestream -{ - writePOD(stream, static_cast<std::uint32_t>(str.length())); - stream.Write(str.c_str(), str.length()); -} - - std::string getComputerId() //returns empty string on error { const wxString fhn = ::wxGetFullHostName(); @@ -234,9 +194,9 @@ struct LockInformation //some format checking here? - lockId = readString(stream); + lockId = readString<std::string>(stream); procDescr.processId = static_cast<ProcessId>(readPOD<std::uint64_t>(stream)); //possible loss of precision (32/64 bit process) covered by buildId - procDescr.computerId = readString(stream); + procDescr.computerId = readString<std::string>(stream); } void toStream(wxOutputStream& stream) const //write @@ -282,7 +242,7 @@ ProcessStatus getProcessStatus(const LockInformation::ProcessDescription& procDe return PROC_STATUS_NO_IDEA; //lock owned by different computer #ifdef FFS_WIN - if (procDescr.processId == ::GetCurrentProcessId()) //may seem obscure, but it's possible: a lock file is "stolen" and put back while the program is running + if (procDescr.processId == ::GetCurrentProcessId()) //may seem obscure, but it's possible: deletion failed or a lock file is "stolen" and put back while the program is running return PROC_STATUS_ITS_US; //note: ::OpenProcess() is no option as it may successfully return for crashed processes! @@ -291,7 +251,7 @@ ProcessStatus getProcessStatus(const LockInformation::ProcessDescription& procDe 0); //__in DWORD th32ProcessID if (snapshot == INVALID_HANDLE_VALUE) return PROC_STATUS_NO_IDEA; - ZEN_ON_BLOCK_EXIT(::CloseHandle(snapshot)); + ZEN_ON_SCOPE_EXIT(::CloseHandle(snapshot)); PROCESSENTRY32 processEntry = {}; processEntry.dwSize = sizeof(processEntry); @@ -315,7 +275,7 @@ ProcessStatus getProcessStatus(const LockInformation::ProcessDescription& procDe if (procDescr.processId <= 0 || procDescr.processId >= 65536) return PROC_STATUS_NO_IDEA; //invalid process id - return zen::dirExists(Zstr("/proc/") + zen::toString<Zstring>(procDescr.processId)) ? PROC_STATUS_RUNNING : PROC_STATUS_NOT_RUNNING; + return zen::dirExists(Zstr("/proc/") + zen::numberTo<Zstring>(procDescr.processId)) ? PROC_STATUS_RUNNING : PROC_STATUS_NOT_RUNNING; #endif } @@ -374,9 +334,8 @@ void waitOnDirLock(const Zstring& lockfilename, DirLockCallback* callback) //thr const zen::UInt64 fileSizeNew = ::getLockFileSize(lockfilename); //throw FileError, ErrorNotExisting wxLongLong currentTime = wxGetLocalTimeMillis(); - if (fileSizeNew != fileSizeOld) + if (fileSizeNew != fileSizeOld) //received life sign from lock { - //received life sign from lock fileSizeOld = fileSizeNew; lockSilentStart = currentTime; } @@ -413,7 +372,7 @@ void waitOnDirLock(const Zstring& lockfilename, DirLockCallback* callback) //thr long remainingSeconds = ((DETECT_EXITUS_INTERVAL - (wxGetLocalTimeMillis() - lockSilentStart)) / 1000).ToLong(); remainingSeconds = std::max(0L, remainingSeconds); - const std::wstring remSecMsg = replaceCpy(_P("1 sec", "%x sec", remainingSeconds), L"%x", toString<std::wstring>(remainingSeconds)); + const std::wstring remSecMsg = replaceCpy(_P("1 sec", "%x sec", remainingSeconds), L"%x", numberTo<std::wstring>(remainingSeconds)); callback->reportInfo(infoMsg + L" " + remSecMsg); } @@ -446,10 +405,10 @@ bool tryLock(const Zstring& lockfilename) //throw FileError const HANDLE fileHandle = ::CreateFile(applyLongPathPrefix(lockfilename).c_str(), GENERIC_READ | GENERIC_WRITE, //use both when writing over network, see comment in file_io.cpp FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, - NULL, + nullptr, CREATE_NEW, FILE_ATTRIBUTE_NORMAL, - NULL); + nullptr); if (fileHandle == INVALID_HANDLE_VALUE) { if (::GetLastError() == ERROR_FILE_EXISTS) @@ -473,7 +432,7 @@ bool tryLock(const Zstring& lockfilename) //throw FileError ::close(fileHandle); #endif - ScopeGuard guardLockFile = zen::makeGuard([&] { zen::removeFile(lockfilename); }); + ScopeGuard guardLockFile = zen::makeGuard([&] { removeFile(lockfilename); }); //write UUID at the beginning of the file: this ID is a universal identifier for this lock (no matter what the path is, considering symlinks, etc.) writeLockInfo(lockfilename); //throw FileError @@ -487,7 +446,7 @@ bool tryLock(const Zstring& lockfilename) //throw FileError class DirLock::SharedDirLock { public: - SharedDirLock(const Zstring& lockfilename, DirLockCallback* callback = NULL) : //throw FileError + SharedDirLock(const Zstring& lockfilename, DirLockCallback* callback = nullptr) : //throw FileError lockfilename_(lockfilename) { while (!::tryLock(lockfilename)) //throw FileError @@ -530,17 +489,14 @@ public: FileToUuidMap::const_iterator iterUuid = fileToUuid.find(lockfilename); if (iterUuid != fileToUuid.end()) { - const std::shared_ptr<SharedDirLock>& activeLock = findActive(iterUuid->second); //returns null-lock if not found - if (activeLock) + if (const std::shared_ptr<SharedDirLock>& activeLock = findActive(iterUuid->second)) //returns null-lock if not found return activeLock; //SharedDirLock is still active -> enlarge circle of shared ownership } try //actual check based on lock UUID, deadlock prevention: "lockfilename" may be an alternative name for an already active lock { const std::string lockId = retrieveLockId(lockfilename); //throw FileError, ErrorNotExisting - - const std::shared_ptr<SharedDirLock>& activeLock = findActive(lockId); //returns null-lock if not found - if (activeLock) + if (const std::shared_ptr<SharedDirLock>& activeLock = findActive(lockId)) //returns null-lock if not found { fileToUuid[lockfilename] = lockId; //perf-optimization: update relation return activeLock; @@ -549,8 +505,8 @@ public: catch (FileError&) {} //catch everything, let SharedDirLock constructor deal with errors, e.g. 0-sized/corrupted lock file //not yet in buffer, so create a new directory lock - std::shared_ptr<SharedDirLock> newLock(new SharedDirLock(lockfilename, callback)); //throw FileError - const std::string newLockId = retrieveLockId(lockfilename); //throw FileError, ErrorNotExisting + auto newLock = std::make_shared<SharedDirLock>(lockfilename, callback); //throw FileError + const std::string& newLockId = retrieveLockId(lockfilename); //throw FileError, ErrorNotExisting //update registry fileToUuid[lockfilename] = newLockId; //throw() @@ -564,16 +520,14 @@ private: std::shared_ptr<SharedDirLock> findActive(const std::string& lockId) //returns null-lock if not found { - UuidToLockMap::const_iterator iterLock = uuidToLock.find(lockId); + auto iterLock = uuidToLock.find(lockId); return iterLock != uuidToLock.end() ? iterLock->second.lock() : nullptr; //try to get shared_ptr; throw() } - typedef std::weak_ptr<SharedDirLock> SharedLock; - typedef std::string UniqueId; - typedef std::map<Zstring, UniqueId, LessFilename> FileToUuidMap; //n:1 handle uppper/lower case correctly - typedef std::map<UniqueId, SharedLock> UuidToLockMap; //1:1 + typedef std::map<Zstring, UniqueId, LessFilename> FileToUuidMap; //n:1 handle uppper/lower case correctly + typedef std::map<UniqueId, std::weak_ptr<SharedDirLock>> UuidToLockMap; //1:1 FileToUuidMap fileToUuid; //lockname |-> UUID; locks can be referenced by a lockfilename or alternatively a UUID UuidToLockMap uuidToLock; //UUID |-> "shared lock ownership" @@ -583,7 +537,7 @@ private: DirLock::DirLock(const Zstring& lockfilename, DirLockCallback* callback) //throw FileError { #ifdef FFS_WIN - const DWORD bufferSize = std::max(lockfilename.size(), static_cast<size_t>(10000)); + const DWORD bufferSize = 10000; std::vector<wchar_t> volName(bufferSize); if (::GetVolumePathName(lockfilename.c_str(), //__in LPCTSTR lpszFileName, &volName[0], //__out LPTSTR lpszVolumePathName, |