mbk-lab
/
nextcloud
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Merge pull request #10116 from nextcloud/lock-negative 

prevent lock values from going negative with memcache backend
This commit is contained in:
Morris Jobke 2018-07-06 14:50:18 +02:00 committed by GitHub
parent 3c9b12139e 3d5acbb1d0
commit 422c805e26
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 20 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
lib/private/Lock/MemcacheLockingProvider.php
View File

@ -90,14 +90,20 @@ class MemcacheLockingProvider extends AbstractLockingProvider {
*/
public function releaseLock(string $path, int $type) {
if ($type === self::LOCK_SHARED) {
$newValue = 0;
if ($this->getOwnSharedLockCount($path) === 1) {
$removed = $this->memcache->cad($path, 1); // if we're the only one having a shared lock we can remove it in one go
if (!$removed) { //someone else also has a shared lock, decrease only
$this->memcache->dec($path);
$newValue = $this->memcache->dec($path);
}
} else {
// if we own more than one lock ourselves just decrease
$this->memcache->dec($path);
$newValue = $this->memcache->dec($path);
}
// if we somehow release more locks then exists, reset the lock
if ($newValue < 0) {
$this->memcache->cad($path, $newValue);
}
} else if ($type === self::LOCK_EXCLUSIVE) {
$this->memcache->cad($path, 'exclusive');

12
tests/lib/Lock/LockingProvider.php
View File

@ -243,4 +243,16 @@ abstract class LockingProvider extends TestCase {
$this->instance->acquireLock('foo', ILockingProvider::LOCK_SHARED);
$this->instance->changeLock('foo', ILockingProvider::LOCK_SHARED);
}
public function testReleaseNonExistingShared() {
$this->instance->acquireLock('foo', ILockingProvider::LOCK_SHARED);
$this->instance->releaseLock('foo', ILockingProvider::LOCK_SHARED);
// releasing a lock once to many should not result in a locked state
$this->instance->releaseLock('foo', ILockingProvider::LOCK_SHARED);
$this->instance->acquireLock('foo', ILockingProvider::LOCK_EXCLUSIVE);
$this->assertTrue($this->instance->isLocked('foo', ILockingProvider::LOCK_EXCLUSIVE));
$this->instance->releaseLock('foo', ILockingProvider::LOCK_EXCLUSIVE);
}
}