diff options
Diffstat (limited to 'lib/common/NamedLock.cpp')
| -rw-r--r-- | lib/common/NamedLock.cpp | 39 |
1 files changed, 35 insertions, 4 deletions
diff --git a/lib/common/NamedLock.cpp b/lib/common/NamedLock.cpp index 3c2c99dd..fadf4df3 100644 --- a/lib/common/NamedLock.cpp +++ b/lib/common/NamedLock.cpp @@ -73,6 +73,8 @@ bool NamedLock::TryAndGetLock(const std::string& rFilename, int mode) THROW_EXCEPTION(CommonException, NamedLockAlreadyLockingSomething) } + mFileName = rFilename; + // See if the lock can be got #if HAVE_DECL_O_EXLOCK int fd = ::open(rFilename.c_str(), @@ -94,11 +96,28 @@ bool NamedLock::TryAndGetLock(const std::string& rFilename, int mode) return false; #else - int fd = ::open(rFilename.c_str(), O_WRONLY | O_CREAT | O_TRUNC, mode); + int flags = O_WRONLY | O_CREAT | O_TRUNC; + +# if !HAVE_DECL_F_SETLK && !defined HAVE_FLOCK + // We have no other way to get a lock, so all we can do is fail if + // the file already exists, and take the risk of stale locks. + flags |= O_EXCL; +# endif + + int fd = ::open(rFilename.c_str(), flags, mode); if(fd == -1) { - THROW_SYS_FILE_ERROR("Failed to open lockfile", rFilename, - CommonException, OSFileError); + if(errno == EEXIST && (flags & O_EXCL)) + { + // Lockfile already exists, and we tried to open it + // exclusively, which means we failed to lock it. + return false; + } + else + { + THROW_SYS_FILE_ERROR("Failed to open lockfile", + rFilename, CommonException, OSFileError); + } } #ifdef HAVE_FLOCK @@ -162,8 +181,20 @@ void NamedLock::ReleaseLock() // Close the file if(::close(mFileDescriptor) != 0) { - THROW_EXCEPTION(CommonException, OSFileError) + THROW_EMU_ERROR( + BOX_FILE_MESSAGE(mFileName, "Failed to close lockfile"), + CommonException, OSFileError); } + + // Delete the file + if(::unlink(mFileName.c_str()) != 0) + { + THROW_EMU_ERROR( + BOX_FILE_MESSAGE(mFileName, + "Failed to delete lockfile"), + CommonException, OSFileError); + } + // Mark as unlocked mFileDescriptor = -1; } |