diff options
Diffstat (limited to 'lib/dir_lock.cpp')
| -rw-r--r-- | lib/dir_lock.cpp | 201 |
1 files changed, 117 insertions, 84 deletions
diff --git a/lib/dir_lock.cpp b/lib/dir_lock.cpp index 5041b37e..f263d4ac 100644 --- a/lib/dir_lock.cpp +++ b/lib/dir_lock.cpp @@ -16,6 +16,7 @@ #include <zen/int64.h> #include <zen/file_handling.h> #include <zen/serialize.h> +#include <zen/optional.h> #ifdef FFS_WIN #include <tlhelp32.h> @@ -24,10 +25,12 @@ #include <Sddl.h> //login sid #include <Lmcons.h> //UNLEN -#elif defined FFS_LINUX -#include <fcntl.h> //::open() +#elif defined FFS_LINUX || defined FFS_MAC +#include <fcntl.h> //open() #include <sys/stat.h> // -#include <unistd.h> +#include <unistd.h> //getsid() +#include <signal.h> //kill() +#include <pwd.h> //getpwuid_r() #endif using namespace zen; @@ -103,7 +106,7 @@ public: &bytesWritten, //__out_opt LPDWORD lpNumberOfBytesWritten, nullptr); //__inout_opt LPOVERLAPPED lpOverlapped -#elif defined FFS_LINUX +#elif defined FFS_LINUX || defined FFS_MAC const int fileHandle = ::open(lockfilename_.c_str(), O_WRONLY | O_APPEND); if (fileHandle < 0) return; @@ -132,7 +135,7 @@ UInt64 getLockFileSize(const Zstring& filename) //throw FileError, ErrorNotExist return UInt64(fileInfo.nFileSizeLow, fileInfo.nFileSizeHigh); } -#elif defined FFS_LINUX +#elif defined FFS_LINUX || defined FFS_MAC struct ::stat fileInfo = {}; if (::stat(filename.c_str(), &fileInfo) == 0) //follow symbolic links return UInt64(fileInfo.st_size); @@ -159,13 +162,13 @@ Zstring deleteAbandonedLockName(const Zstring& lockfilename) //make sure to NOT #ifdef FFS_WIN -std::wstring getLoginSid() //throw FileError +Zstring getLoginSid() //throw FileError { HANDLE hToken = 0; if (!::OpenProcessToken(::GetCurrentProcess(), //__in HANDLE ProcessHandle, TOKEN_ALL_ACCESS, //__in DWORD DesiredAccess, &hToken)) //__out PHANDLE TokenHandle - throw FileError(_("Cannot get process information.") + L"\n\n" + getLastErrorFormatted()); + throw FileError(_("Cannot get process information.") + L" (OpenProcessToken)" + L"\n\n" + getLastErrorFormatted()); ZEN_ON_SCOPE_EXIT(::CloseHandle(hToken)); DWORD bufferSize = 0; @@ -177,7 +180,7 @@ std::wstring getLoginSid() //throw FileError &buffer[0], //__out_opt LPVOID TokenInformation, bufferSize, //__in DWORD TokenInformationLength, &bufferSize)) //__out PDWORD ReturnLength - throw FileError(_("Cannot get process information.") + L"\n\n" + getLastErrorFormatted()); + throw FileError(_("Cannot get process information.") + L" (GetTokenInformation)" + L"\n\n" + getLastErrorFormatted()); auto groups = reinterpret_cast<const TOKEN_GROUPS*>(&buffer[0]); @@ -187,67 +190,126 @@ std::wstring getLoginSid() //throw FileError LPTSTR sidStr = nullptr; if (!::ConvertSidToStringSid(groups->Groups[i].Sid, //__in PSID Sid, &sidStr)) //__out LPTSTR *StringSid - throw FileError(_("Cannot get process information.") + L"\n\n" + getLastErrorFormatted()); + throw FileError(_("Cannot get process information.") + L" (ConvertSidToStringSid)" + L"\n\n" + getLastErrorFormatted()); ZEN_ON_SCOPE_EXIT(::LocalFree(sidStr)); return sidStr; } - throw FileError(_("Cannot get process information.") + L"\n\n" + getLastErrorFormatted() + L"(no login found)"); //shouldn't happen + throw FileError(_("Cannot get process information.") + L" (no login found)" + L"\n\n" + getLastErrorFormatted()); //shouldn't happen } #endif +#ifdef FFS_WIN +typedef DWORD ProcessId; +typedef DWORD SessionId; +#elif defined FFS_LINUX || defined FFS_MAC +typedef pid_t ProcessId; +typedef pid_t SessionId; +#endif + +//return ppid on Windows, sid on Linux/Mac, "no value" if process corresponding to "processId" is not existing +Opt<SessionId> getSessionId(ProcessId processId) //throw FileError +{ +#ifdef FFS_WIN + //note: ::OpenProcess() is no alternative as it may successfully return for crashed processes! -> remark: "WaitForSingleObject" may identify this case! + HANDLE snapshot = ::CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, //__in DWORD dwFlags, + 0); //__in DWORD th32ProcessID + if (snapshot == INVALID_HANDLE_VALUE) + throw FileError(_("Cannot get process information.") + L" (CreateToolhelp32Snapshot)" + L"\n\n" + getLastErrorFormatted()); + ZEN_ON_SCOPE_EXIT(::CloseHandle(snapshot)); + + PROCESSENTRY32 processEntry = {}; + processEntry.dwSize = sizeof(processEntry); + + if (!::Process32First(snapshot, //__in HANDLE hSnapshot, + &processEntry)) //__inout LPPROCESSENTRY32 lppe + throw FileError(_("Cannot get process information.") + L" (Process32First)" + L"\n\n" + getLastErrorFormatted()); //ERROR_NO_MORE_FILES not possible + do + { + if (processEntry.th32ProcessID == processId) //yes, MSDN says this is the way: http://msdn.microsoft.com/en-us/library/windows/desktop/ms684868(v=vs.85).aspx + return processEntry.th32ParentProcessID; //parent id is stable, even if parent process has already terminated! + } + while (::Process32Next(snapshot, &processEntry)); + if (::GetLastError() != ERROR_NO_MORE_FILES) //yes, they call it "files" + throw FileError(_("Cannot get process information.") + L" (Process32Next)" + L"\n\n" + getLastErrorFormatted()); + + return NoValue(); + +#elif defined FFS_LINUX || defined FFS_MAC + if (::kill(processId, 0) != 0) //sig == 0: no signal sent, just existence check + return NoValue(); + + pid_t procSid = ::getsid(processId); //NOT to be confused with "login session", e.g. not stable on OS X!!! + if (procSid == -1) + throw FileError(_("Cannot get process information.") + L" (getsid)" + L"\n\n" + getLastErrorFormatted()); + + return procSid; +#endif +} + + class FromCurrentProcess {}; //tag struct LockInformation //throw FileError { explicit LockInformation(FromCurrentProcess) : lockId(zen::generateGUID()), + sessionId(), //dummy value #ifdef FFS_WIN - sessionId(utfCvrtTo<std::string>(getLoginSid())), //throw FileError processId(::GetCurrentProcessId()) //never fails { DWORD bufferSize = 0; ::GetComputerNameEx(ComputerNameDnsFullyQualified, nullptr, &bufferSize); //get required buffer size std::vector<wchar_t> buffer(bufferSize); - if (!GetComputerNameEx(ComputerNameDnsFullyQualified, //__in COMPUTER_NAME_FORMAT NameType, - &buffer[0], //__out LPTSTR lpBuffer, - &bufferSize)) //__inout LPDWORD lpnSize - throw FileError(_("Cannot get process information.") + L"\n\n" + getLastErrorFormatted()); + if (!::GetComputerNameEx(ComputerNameDnsFullyQualified, //__in COMPUTER_NAME_FORMAT NameType, + &buffer[0], //__out LPTSTR lpBuffer, + &bufferSize)) //__inout LPDWORD lpnSize + throw FileError(_("Cannot get process information.") + L" (GetComputerNameEx)" + L"\n\n" + getLastErrorFormatted()); computerName = "Windows." + utfCvrtTo<std::string>(&buffer[0]); bufferSize = UNLEN + 1; buffer.resize(bufferSize); if (!::GetUserName(&buffer[0], //__out LPTSTR lpBuffer, &bufferSize)) //__inout LPDWORD lpnSize - throw FileError(_("Cannot get process information.") + L"\n\n" + getLastErrorFormatted()); + throw FileError(_("Cannot get process information.") + L" (GetUserName)" + L"\n\n" + getLastErrorFormatted()); userId = utfCvrtTo<std::string>(&buffer[0]); - } -#elif defined FFS_LINUX + +#elif defined FFS_LINUX || defined FFS_MAC processId(::getpid()) //never fails { std::vector<char> buffer(10000); - if (::gethostname(&buffer[0], buffer.size()) != 0) - throw FileError(_("Cannot get process information.") + L"\n\n" + getLastErrorFormatted()); + if (::gethostname(&buffer[0], buffer.size()) != 0) + throw FileError(_("Cannot get process information.") + L" (gethostname)" + L"\n\n" + getLastErrorFormatted()); computerName += "Linux."; //distinguish linux/windows lock files computerName += &buffer[0]; if (::getdomainname(&buffer[0], buffer.size()) != 0) - throw FileError(_("Cannot get process information.") + L"\n\n" + getLastErrorFormatted()); + throw FileError(_("Cannot get process information.") + L" (getdomainname)" + L"\n\n" + getLastErrorFormatted()); computerName += "."; computerName += &buffer[0]; - uid_t userIdTmp = ::getuid(); //never fails - userId.assign(reinterpret_cast<const char*>(&userIdTmp), sizeof(userIdTmp)); + const uid_t userIdNo = ::getuid(); //never fails + userId.assign(reinterpret_cast<const char*>(&userIdNo), sizeof(userIdNo)); + + //the id alone is not very distinctive, e.g. often 1000 on Ubuntu => add name + buffer.resize(std::max<long>(buffer.size(), ::sysconf(_SC_GETPW_R_SIZE_MAX))); //::sysconf may return long(-1) + struct passwd buffer2 = {}; + struct passwd* pwsEntry = nullptr; + if (::getpwuid_r(userIdNo, &buffer2, &buffer[0], buffer.size(), &pwsEntry) != 0) //getlogin() is deprecated and not working on Ubuntu at all!!! + throw FileError(_("Cannot get process information.") + L" (getpwuid_r)" + L"\n\n" + getLastErrorFormatted()); + if (!pwsEntry) + throw FileError(_("Cannot get process information.") + L" (no login found)" + L"\n\n" + getLastErrorFormatted()); + userId += pwsEntry->pw_name; +#endif - pid_t sessionIdTmp = ::getsid(0); //new after each restart! - if (sessionIdTmp == -1) - throw FileError(_("Cannot get process information.") + L"\n\n" + getLastErrorFormatted()); - sessionId.assign(reinterpret_cast<const char*>(&sessionIdTmp), sizeof(sessionIdTmp)); + Opt<SessionId> sessionIdTmp = getSessionId(processId); //throw FileError + if (!sessionIdTmp) + throw FileError(_("Cannot get process information.") + L" (getSessionId)" + L"\n\n" + getLastErrorFormatted()); + sessionId = *sessionIdTmp; } -#endif explicit LockInformation(BinStreamIn& stream) //throw UnexpectedEndOfStreamError { @@ -262,8 +324,8 @@ struct LockInformation //throw FileError lockId = readContainer<std::string>(stream); // computerName = readContainer<std::string>(stream); //UnexpectedEndOfStreamError userId = readContainer<std::string>(stream); // - sessionId = readContainer<std::string>(stream); // - processId = static_cast<decltype(processId)>(readNumber<std::uint64_t>(stream)); //[!] conversion + sessionId = static_cast<SessionId>(readNumber<std::uint64_t>(stream)); //[!] conversion + processId = static_cast<ProcessId>(readNumber<std::uint64_t>(stream)); //[!] conversion } void toStream(BinStreamOut& stream) const //throw () @@ -271,25 +333,25 @@ struct LockInformation //throw FileError writeArray(stream, LOCK_FORMAT_DESCR, sizeof(LOCK_FORMAT_DESCR)); writeNumber<boost::int32_t>(stream, LOCK_FORMAT_VER); - assert_static(sizeof(processId) <= sizeof(std::uint64_t)); //ensure portability + assert_static(sizeof(processId) <= sizeof(std::uint64_t)); //ensure cross-platform compatibility! + assert_static(sizeof(sessionId) <= sizeof(std::uint64_t)); // writeContainer(stream, lockId); writeContainer(stream, computerName); writeContainer(stream, userId); - writeContainer(stream, sessionId); + writeNumber<std::uint64_t>(stream, sessionId); writeNumber<std::uint64_t>(stream, processId); } std::string lockId; //16 byte GUID - a universal identifier for this lock (no matter what the path is, considering symlinks, distributed network, etc.) + //identify local computer std::string computerName; //format: HostName.DomainName - std::string userId; //non-readable! - std::string sessionId; // -#ifdef FFS_WIN - DWORD processId; -#elif defined FFS_LINUX - pid_t processId; -#endif + std::string userId; + + //identify running process + SessionId sessionId; //Windows: parent process id; Linux/OS X: session of the process, NOT the user + ProcessId processId; }; @@ -325,71 +387,40 @@ std::string retrieveLockId(const Zstring& lockfilename) //throw FileError, Error } -//true: process not available, false: cannot say anything enum ProcessStatus { PROC_STATUS_NOT_RUNNING, PROC_STATUS_RUNNING, PROC_STATUS_ITS_US, - PROC_STATUS_NO_IDEA + PROC_STATUS_CANT_TELL }; + ProcessStatus getProcessStatus(const LockInformation& lockInfo) //throw FileError { const LockInformation localInfo((FromCurrentProcess())); //throw FileError if (lockInfo.computerName != localInfo.computerName || lockInfo.userId != localInfo.userId) //another user may run a session right now! - return PROC_STATUS_NO_IDEA; //lock owned by different computer in this network + return PROC_STATUS_CANT_TELL; //lock owned by different computer in this network - if (lockInfo.sessionId != localInfo.sessionId) - return PROC_STATUS_NOT_RUNNING; //different session but same user? there can be only one - - if (lockInfo.processId == localInfo.processId) //obscure, but possible: deletion failed or a lock file is "stolen" and put back while the program is running + if (lockInfo.sessionId == localInfo.sessionId && + lockInfo.processId == localInfo.processId) //obscure, but possible: deletion failed or a lock file is "stolen" and put back while the program is running return PROC_STATUS_ITS_US; -#ifdef FFS_WIN - //note: ::OpenProcess() is no alternative as it may successfully return for crashed processes! -> remark: "WaitForSingleObject" may identify this case! - HANDLE snapshot = ::CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, //__in DWORD dwFlags, - 0); //__in DWORD th32ProcessID - if (snapshot == INVALID_HANDLE_VALUE) - return PROC_STATUS_NO_IDEA; - ZEN_ON_SCOPE_EXIT(::CloseHandle(snapshot)); - - PROCESSENTRY32 processEntry = {}; - processEntry.dwSize = sizeof(processEntry); - - if (!::Process32First(snapshot, //__in HANDLE hSnapshot, - &processEntry)) //__inout LPPROCESSENTRY32 lppe - return PROC_STATUS_NO_IDEA; //ERROR_NO_MORE_FILES not possible - do - { - if (processEntry.th32ProcessID == lockInfo.processId) - return PROC_STATUS_RUNNING; //process still running - } - while (::Process32Next(snapshot, &processEntry)); - if (::GetLastError() != ERROR_NO_MORE_FILES) //yes, they call it "files" - return PROC_STATUS_NO_IDEA; - + if (Opt<SessionId> sessionId = getSessionId(lockInfo.processId)) //throw FileError + return *sessionId == lockInfo.sessionId ? PROC_STATUS_RUNNING : PROC_STATUS_NOT_RUNNING; return PROC_STATUS_NOT_RUNNING; - -#elif defined FFS_LINUX - if (lockInfo.processId <= 0 || lockInfo.processId >= 65536) - return PROC_STATUS_NO_IDEA; //invalid process id - - return zen::dirExists("/proc/" + zen::numberTo<Zstring>(lockInfo.processId)) ? PROC_STATUS_RUNNING : PROC_STATUS_NOT_RUNNING; -#endif } const std::int64_t TICKS_PER_SEC = ticksPerSec(); //= 0 on error - void waitOnDirLock(const Zstring& lockfilename, DirLockCallback* callback) //throw FileError { const std::wstring infoMsg = replaceCpy(_("Waiting while directory is locked (%x)..."), L"%x", fmtFileName(lockfilename)); if (callback) - callback->reportInfo(infoMsg); + callback->reportStatus(infoMsg); //--------------------------------------------------------------- try { @@ -407,7 +438,7 @@ void waitOnDirLock(const Zstring& lockfilename, DirLockCallback* callback) //thr lockOwnderDead = true; break; case PROC_STATUS_RUNNING: - case PROC_STATUS_NO_IDEA: + case PROC_STATUS_CANT_TELL: break; } } @@ -462,10 +493,10 @@ void waitOnDirLock(const Zstring& lockfilename, DirLockCallback* callback) //thr { const int remainingSeconds = std::max<int>(0, DETECT_ABANDONED_INTERVAL - dist(lastLifeSign, getTicks()) / TICKS_PER_SEC); const std::wstring remSecMsg = replaceCpy(_P("1 sec", "%x sec", remainingSeconds), L"%x", numberTo<std::wstring>(remainingSeconds)); - callback->reportInfo(infoMsg + L" " + remSecMsg); + callback->reportStatus(infoMsg + L" " + remSecMsg); } else - callback->reportInfo(infoMsg); //emit a message in any case (might clear other one) + callback->reportStatus(infoMsg); //emit a message in any case (might clear other one) } } } @@ -510,7 +541,7 @@ bool tryLock(const Zstring& lockfilename) //throw FileError ::SetFileAttributes(applyLongPathPrefix(lockfilename).c_str(), FILE_ATTRIBUTE_HIDDEN); //(try to) hide it -#elif defined FFS_LINUX +#elif defined FFS_LINUX || defined FFS_MAC //O_EXCL contains a race condition on NFS file systems: http://linux.die.net/man/2/open ::umask(0); //important! -> why? const int fileHandle = ::open(lockfilename.c_str(), O_CREAT | O_WRONLY | O_EXCL, S_IRWXU | S_IRWXG | S_IRWXO); @@ -538,7 +569,7 @@ bool tryLock(const Zstring& lockfilename) //throw FileError class DirLock::SharedDirLock { public: - SharedDirLock(const Zstring& lockfilename, DirLockCallback* callback = nullptr) : //throw FileError + SharedDirLock(const Zstring& lockfilename, DirLockCallback* callback) : //throw FileError lockfilename_(lockfilename) { while (!::tryLock(lockfilename)) //throw FileError @@ -560,7 +591,6 @@ private: SharedDirLock& operator=(const DirLock&); const Zstring lockfilename_; - boost::thread threadObj; }; @@ -633,6 +663,9 @@ private: DirLock::DirLock(const Zstring& lockfilename, DirLockCallback* callback) //throw FileError { + if (callback) + callback->reportStatus(replaceCpy(_("Creating file %x"), L"%x", fmtFileName(lockfilename))); + #ifdef FFS_WIN const DWORD bufferSize = 10000; std::vector<wchar_t> volName(bufferSize); |