/// <summary>
/// Asynchronously acquire a lock on the specified TLockableObject.
/// This will wait the specified amount of time before either throwing an exception (if throwOnFailure is true) or retuning false.
/// </summary>
/// <param name="obj">The object to take a lock on.</param>
/// <param name="timeout">The amount of time to spend attempting to acquire the lock.</param>
/// <param name="throwOnFailure">Throw an exception if the acquisition fails.</param>
/// <param name="cancellationToken">The cancellation token to use during lock acquisition.</param>
/// <returns>A <see cref="bool"/> indicating if the lock attempt was successful.</returns>
public async Task <TLockableObject> AcquireLockAsync(TLockableObject obj, TimeSpan timeout, bool throwOnFailure = false, CancellationToken cancellationToken = default(CancellationToken))
{
var timeoutDate = DateTime.UtcNow.Add(timeout);
_lockedObjectType = obj.GetType();
_lockedObjectId = obj.Id;
// TODO: Check if the supplied TLockableObject implements IEnumerable and that they supplied an IEnumerable<TLockableObject> selector.
TLockableObject lockedObj = null;
while (lockedObj == null && !cancellationToken.IsCancellationRequested && DateTime.UtcNow < timeoutDate)
{
lockedObj = await _store.AcquireLockAsync(obj.Id, obj, _staleLockMultiplier, cancellationToken);
if (lockedObj == null)
{
await Task.Delay(TimeSpan.FromSeconds(1), cancellationToken);
}
else
{
LockedObjectLockId = lockedObj.LockId;
LockedObjectId = lockedObj.Id;
}
}
_sharpLockLogger.Trace("Lock attempt complete on {0} with LockId: {1}. Lock Acquired? {2}", _lockedObjectType, _lockedObjectId, LockAcquired);
if (lockedObj == null && throwOnFailure)
{
throw new AcquireDistributedLockException("Failed to acquire lock.");
}
return(lockedObj);
}
