public EfDistributedLock(Func <AggregateDbContext> contextFactory, EfDistributedLockRecord record, TimeSpan expiration, Action expirationAction = null)
{
Guard.ArgumentNotNull(contextFactory, nameof(contextFactory));
Guard.ArgumentNotNull(record, nameof(record));
Guard.ArgumentNotNull(expiration, nameof(expiration));
_action = expirationAction;
_contextFactory = contextFactory;
Expiry = expiration;
ExpirationTime = record.LockDateTime;
IsAcquired = record.IsAcquired();
LockName = record.Name;
LockId = record.LockId;
var extendTime = (expiration.TotalMilliseconds * 0.9).Do(Convert.ToInt32);
_timer = new PeriodicAction(ct => ExtendLockAsync(ct), extendTime, null, true);
_timer.Start();
}
private async Task <EfDistributedLock> TryAquireLock(string name, TimeSpan expiry, Action expirationAction = null)
{
_logger.StartAcquireLock(name, expiry);
try
{
using (var context = _dbContextFactory())
{
var dlock = await context.DistributedLocks.SingleOrDefaultAsync(l => l.Name == name);
if (dlock == null)
{
dlock = new EfDistributedLockRecord(name, expiry, Guid.NewGuid());
context.DistributedLocks.Add(dlock);
dlock.Acquire(expiry);
var updated = await context.SaveChangesAsync();
if (updated > 0)
{
_logger.LockIsAcquired(name, expiry);
return(new EfDistributedLock(_dbContextFactory, dlock, expiry, expirationAction));
}
}
if (!dlock.IsAcquired())
{
dlock.Acquire(expiry);
var updated = await context.SaveChangesAsync();
if (updated > 0)
{
_logger.LockIsAcquired(name, expiry);
return(new EfDistributedLock(_dbContextFactory, dlock, expiry, expirationAction));
}
}
}
}
catch (DbUpdateConcurrencyException ex)
{
_logger.TraceVerboseEvent($"Distributed Lock {name} was not captured due to concurency exception. Exception Message was : {ex.Message}");
}
_logger.LockIsNotAcquired(name, expiry);
return(null);
}
