The QtLockedFile class extends QFile with advisory locking functions.

This class extends the QFile class with inter-process file locking capabilities. If an application requires that several processes should access the same file, QtLockedFile can be used to easily ensure that only one process at a time is writing to the file, and that no process is writing to it while others are reading it.

This Qt Solutions component is for Qt 4. For Qt 3 Solutions, please visit the Qt 3 Solutions Catalog.

Documentation:

Classes

• QtLockedFile

Tested on:

• Qt 4.2.1 / Windows XP / MSVC.NET 2003
• Qt 4.2.1 / Linux / gcc
• Qt 4.2.1 / SunOS 5.9 / SunC++
• Qt 4.2.1 / MacOS X 10.4 / gcc

Unsupported platforms:

Only the tested platforms are supported, however the classes should be platform independent and are likely to work on the platforms supported by Qt.

Download Commercial Edition:

• qtlockedfile-2.3-commercial.zip
• qtlockedfile-2.3-commercial.tar.gz

Changes:

• 2.3: Windows: Bugfix; non-blocking lock attempt could cause locking failures later.
• 2.2: Windows: Compilation fix for MinGW.
• 2.2: Windows: Allow file names with paths.
• 2.2: Windows: Possible deadlock removed.
• 2.1: Fix non-blocking lock() on Windows.
• 2.0: This is a port to Qt 4 of the latest Qt 3 version (1.1).