Struct file_lock::Lock
[−]
[src]
pub struct Lock {
// some fields omitted
}Represents a write lock on a file.
The lock(LockKind) method tries to obtain a write-lock on the file identified by a
file-descriptor. One can obtain different kinds of write-locks.
- LockKind::NonBlocking - immediately return with an
Errnoerror. - LockKind::Blocking - waits (i.e. blocks the running thread) for the current owner of the lock to relinquish the lock.
Example
Please note that the examples use tempfile merely to quickly create a file which is removed
automatically. In the common case, you would want to lock a file which is known to multiple
processes.
extern crate file_lock; extern crate tempfile; use file_lock::*; use std::os::unix::io::AsRawFd; fn main() { let f = tempfile::TempFile::new().unwrap(); match Lock::new(f.as_raw_fd()).lock(LockKind::NonBlocking, AccessMode::Write) { Ok(_) => { // we have a lock, which is discarded automatically. Otherwise you could call // `unlock()` to make it explicit println!("Got lock"); }, Err(Error::Errno(i)) => println!("Got filesystem error {}", i), } }
Methods
impl Lock
fn new(fd: RawFd) -> Lock
Create a new lock instance from the given file descriptor fd.
You will have to call lock(...) on it to acquire any lock.
fn lock(&self, kind: LockKind, mode: AccessMode) -> Result<(), Error>
Obtain a write-lock the file-descriptor
For an example, please see the documentation of the Lock structure.
fn unlock(&self) -> Result<(), Error>
Unlocks the file held by Lock.
In reality, you shouldn't need to call unlock(). As Lock implements the Drop trait,
once the Lock reference goes out of scope, unlock() will be called automatically.
For an example, please see the documentation of the Lock structure.