GNU/Linux man pages
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Syntaxe et mise en oeuvre :
GNU/Linux |
CentOS 2.1AS(Slurm) |
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lockf(3) |
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lockf − apply, test or remove a POSIX lock on an open file
#include <sys/file.h>
int lockf(int fd, int cmd, off_t len);
Apply, test or remove a POSIX lock on an open file. The file is specified by fd. This call is just an interface for fcntl(2). Valid operations are given below:
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F_LOCK |
Set an exclusive lock to the file. Only one process may hold an exclusive lock for a given file at a given time. If the file is already locked it blocks until the previous lock is released. | ||
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F_TLOCK |
Same as F_LOCK but never blocks and return error instead if the file is already locked. | ||
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F_ULOCK |
Unlock the file. | ||
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F_TEST |
Test the lock: return 0 if fd is unlocked or locked by this process; return −1, set errno to EACCES, if another process holds the lock. |
On success, zero is returned. On error, −1 is returned, and errno is set appropriately.
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EAGAIN |
The file is locked and the LOCK_NB flag was selected, or operation is prohibited because the file has been memory-mapped by another process. | ||
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EBADF |
fd is not an open file descriptor. |
EDEADLK
Specified lock operation would cause a deadlock.
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EINVAL |
An invalid operation was specified in fd. |
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ENOLCK |
Too many segment locks open, lock table is full. |
SYSV
fcntl(2),
flock(2)
There are also locks.txt and mandatory.txt in
/usr/src/linux/Documentation.
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lockf(3) | |