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lock: use exponential backoff

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This commit is contained in:
Martin von Zweigbergk 2020-12-25 15:08:49 -08:00
parent 9138de6ff2
commit 4ce2aed17f
1 changed files with 20 additions and 12 deletions
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32
lib/src/lock.rs
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@ -12,6 +12,7 @@
// See the License for the specific language governing permissions and
// limitations under the License.
use backoff::{ExponentialBackoff, Operation};
use std::fs::{File, OpenOptions};
use std::path::PathBuf;
use std::time::Duration;
@ -26,19 +27,26 @@ impl FileLock {
let mut options = OpenOptions::new();
options.create_new(true);
options.write(true);
let retry_delay = Duration::from_millis(10);
loop {
match options.open(&path) {
Ok(file) => return FileLock { path, _file: file },
Err(err) if err.kind() == std::io::ErrorKind::AlreadyExists => {
std::thread::sleep(retry_delay);
}
Err(err) => panic!(
"failed to create lock file {}: {}",
path.to_string_lossy(),
err
),
let mut try_write_lock_file = || match options.open(&path) {
Ok(file) => Ok(FileLock {
path: path.clone(),
_file: file,
}),
Err(err) if err.kind() == std::io::ErrorKind::AlreadyExists => {
Err(backoff::Error::Transient(err))
}
Err(err) => Err(backoff::Error::Permanent(err)),
};
let mut backoff = ExponentialBackoff::default();
backoff.initial_interval = Duration::from_millis(1);
backoff.max_elapsed_time = Some(Duration::from_secs(10));
match try_write_lock_file.retry(&mut backoff) {
Err(err) => panic!(
"failed to create lock file {}: {}",
path.to_string_lossy(),
err
),
Ok(file_lock) => file_lock,
}
}
}