Datei-Locking unter Linux
Ich musste wieder einmal zu oft nachlesen, welche Varianten von Datei-Locking es unter Linux gibt und was die Stolperfallen sind.
| Variante | POSIX Lock | BSD Lock | Linux Open File Description Locks |
|---|---|---|---|
| Range | Byte | File | Byte |
| Owner | Process | File | File |
| Issues | - not fork() save - not thread save - released on first close() |
- exclusive not fork() save - not NFS save - sometimes implemented through fcntl() |
Linux 3.15+ |
| C-API | fcntl(fd, F_{GETLK,SETLK,SETLKW}, struct flock *), lockf(fd, F_{LOCK,TLOCK,ULOCK,TEST}, len) |
flock(fd, LOCK_{SH,EX,UN} |
fcntl(fd, F_OFD_{GETLK,SETLK,SETLKW}, struct flock *) |
Literatur zum nach-/weiterlesen:
Written on November 27, 2017