A nice music player
The QtLockedFile class extends QFile with advisory locking functions.
A file may be locked in read or write mode. Multiple instances of QtLockedFile, created in multiple processes running on the same machine, may have a file locked in read mode. Exactly one instance may have it locked in write mode. A read and a write lock cannot exist simultaneously on the same file.
The file locks are advisory. This means that nothing prevents another process from manipulating a locked file using QFile or file system functions offered by the OS. Serialization is only guaranteed if all processes that access the file use QLockedFile. Also, while holding a lock on a file, a process must not open the same file again (through any API), or locks can be unexpectedly lost.
The lock provided by an instance of QtLockedFile is released whenever the program terminates. This is true even when the program crashes and no destructors are called.