public async Task <bool> CheckIsStillLockedAsync(DistributedLockSettings settings)
{
Check.NotNull(settings, nameof(settings));
if (settings is NullLockSettings)
{
return(await NullLockManager.CheckIsStillLockedAsync(settings).ConfigureAwait(false));
}
try
{
using var scope = _serviceScopeFactory.CreateScope();
return(await CheckIsStillLockedAsync(
settings.ResourceName,
settings.UniqueId,
settings.HeartbeatTimeout,
scope.ServiceProvider)
.ConfigureAwait(false));
}
catch (Exception ex)
{
_logger.LogFailedToCheckLock(settings, ex);
return(false);
}
}
public async Task <DistributedLock> Acquire(DistributedLockSettings settings, CancellationToken cancellationToken = default)
{
if (settings == null)
{
throw new ArgumentNullException(nameof(settings));
}
_logger.LogInformation("Trying to acquire lock {lockName} ({lockUniqueId})...", settings.ResourceName, settings.UniqueId);
var stopwatch = Stopwatch.StartNew();
while (settings.AcquireTimeout == null || stopwatch.Elapsed < settings.AcquireTimeout)
{
if (await TryAcquireLock(settings))
{
_logger.LogInformation("Acquired lock {lockName} ({lockUniqueId}).", settings.ResourceName, settings.UniqueId);
return(new DistributedLock(settings, this));
}
await Task.Delay(settings.AcquireRetryInterval, cancellationToken);
if (cancellationToken.IsCancellationRequested)
{
break;
}
}
throw new TimeoutException($"Timeout waiting to get the required lock '{settings.ResourceName}'.");
}
public async Task ReleaseAsync(DistributedLockSettings settings)
{
Check.NotNull(settings, nameof(settings));
if (settings is NullLockSettings)
{
await NullLockManager.ReleaseAsync(settings).ConfigureAwait(false);
}
var tryCount = 1;
while (tryCount <= 3)
{
try
{
using var scope = _serviceScopeFactory.CreateScope();
await ReleaseAsync(settings.ResourceName, settings.UniqueId, scope.ServiceProvider)
.ConfigureAwait(false);
_logger.LogLockReleased(settings);
break;
}
catch (Exception ex)
{
_logger.LogFailedToReleaseLock(settings, ex);
tryCount++;
}
}
}
public async Task <bool> CheckIsStillLockedAsync(DistributedLockSettings settings)
{
Check.NotNull(settings, nameof(settings));
if (settings is NullLockSettings)
{
return(await NullLockManager.CheckIsStillLockedAsync(settings).ConfigureAwait(false));
}
try
{
using var scope = _serviceScopeFactory.CreateScope();
return(await CheckIsStillLockedAsync(
settings.ResourceName,
settings.UniqueId,
settings.HeartbeatTimeout,
scope.ServiceProvider)
.ConfigureAwait(false));
}
catch (Exception ex)
{
_logger.LogError(
CoreEventIds.FailedToCheckDistributedLock,
ex,
"Failed to check lock {lockName} ({lockUniqueId}). See inner exception for details.",
settings.ResourceName,
settings.UniqueId);
return(false);
}
}
public async Task <bool> SendHeartbeatAsync(DistributedLockSettings settings)
{
Check.NotNull(settings, nameof(settings));
if (settings is NullLockSettings)
{
return(await NullLockManager.SendHeartbeatAsync(settings).ConfigureAwait(false));
}
try
{
using var scope = _serviceScopeFactory.CreateScope();
return(await SendHeartbeatAsync(settings.ResourceName, settings.UniqueId, scope.ServiceProvider)
.ConfigureAwait(false));
}
catch (Exception ex)
{
_logger.LogDebug(
CoreEventIds.FailedToSendDistributedLockHeartbeat,
ex,
"Failed to send heartbeat for lock {lockName} ({lockUniqueId}). See inner exception for details.",
settings.ResourceName,
settings.UniqueId);
return(false);
}
}
public DistributedLock(DistributedLockSettings settings, IDistributedLockManager lockManager)
{
_settings = settings ?? throw new ArgumentNullException(nameof(settings));
_lockManager = lockManager ?? throw new ArgumentNullException(nameof(lockManager));
Status = DistributedLockStatus.Acquired;
Task.Run(SendHeartbeats);
}
protected DistributedBackgroundService(DistributedLockSettings distributedLockSettings, IDistributedLockManager distributedLockManager, ILogger <DistributedBackgroundService> logger)
{
_distributedLockSettings = distributedLockSettings ?? new DistributedLockSettings();
_distributedLockManager = distributedLockManager ?? throw new ArgumentNullException(nameof(distributedLockManager));
_logger = logger ?? throw new ArgumentNullException(nameof(logger));
if (string.IsNullOrEmpty(_distributedLockSettings.ResourceName))
{
_distributedLockSettings.ResourceName = GetType().FullName;
}
}
/// <summary>
/// Initializes a new instance of the <see cref="DistributedBackgroundService" /> class.
/// </summary>
/// <param name="distributedLockSettings">
/// Customizes the lock mechanism settings.
/// </param>
/// <param name="distributedLockManager">
/// The <see cref="IDistributedLockManager" />.
/// </param>
/// <param name="logger">
/// The <see cref="ISilverbackLogger" />.
/// </param>
protected DistributedBackgroundService(
DistributedLockSettings?distributedLockSettings,
IDistributedLockManager distributedLockManager,
ISilverbackLogger <DistributedBackgroundService> logger)
{
_distributedLockSettings = distributedLockSettings ?? new DistributedLockSettings();
_distributedLockSettings.EnsureResourceNameIsSet(GetType().FullName);
_distributedLockManager = Check.NotNull(distributedLockManager, nameof(distributedLockManager));
_logger = Check.NotNull(logger, nameof(logger));
}
/// <summary>
/// Initializes a new instance of the <see cref="DistributedLock" /> class.
/// </summary>
/// <param name="settings">
/// Specifies all settings of the lock to be acquired.
/// </param>
/// <param name="lockManager">
/// The <see cref="IDistributedLockManager" /> that generated the lock and can be used to keep it alive
/// and finally release it.
/// </param>
public DistributedLock(DistributedLockSettings settings, IDistributedLockManager lockManager)
{
_settings = Check.NotNull(settings, nameof(settings));
_lockManager = Check.NotNull(lockManager, nameof(lockManager));
Status = DistributedLockStatus.Acquired;
Task.Factory.StartNew(
SendHeartbeatsAsync,
CancellationToken.None,
TaskCreationOptions.LongRunning,
TaskScheduler.Default);
}
private async Task <bool> AcquireLock(DistributedLockSettings settings, IServiceProvider serviceProvider)
{
var heartbeatThreshold = GetHeartbeatThreshold(settings.HeartbeatTimeout);
var(dbSet, dbContext) = GetDbSet(serviceProvider);
if (await dbSet.AsQueryable().AnyAsync(l => l.Name == settings.ResourceName && l.Heartbeat >= heartbeatThreshold))
{
return(false);
}
return(await WriteLock(settings.ResourceName, settings.UniqueId, heartbeatThreshold, dbSet, dbContext));
}
private async Task <bool> TryAcquireLockAsync(DistributedLockSettings settings)
{
try
{
using var scope = _serviceScopeFactory.CreateScope();
return(await AcquireLockAsync(settings, scope.ServiceProvider).ConfigureAwait(false));
}
catch (Exception ex)
{
_logger.LogFailedToAcquireLock(settings, ex);
}
return(false);
}
private async Task <bool> TryAcquireLock(DistributedLockSettings settings)
{
try
{
using var scope = _serviceProvider.CreateScope();
return(await AcquireLock(settings, scope.ServiceProvider));
}
catch (Exception ex)
{
_logger.LogDebug(ex, "Failed to acquire lock {lockName} ({lockUniqueId}). See inner exception for details.",
settings.ResourceName, settings.UniqueId);
}
return(false);
}
public async Task Release(DistributedLockSettings settings)
{
try
{
using var scope = _serviceProvider.CreateScope();
await Release(settings.ResourceName, settings.UniqueId, scope.ServiceProvider);
_logger.LogInformation("Released lock {lockName} ({lockUniqueId}).", settings.ResourceName, settings.UniqueId);
}
catch (Exception ex)
{
_logger.LogWarning(
ex, "Failed to release lock '{lockName} ({lockUniqueId})'. See inner exception for details.",
settings.ResourceName, settings.UniqueId);
}
}
public async Task <bool> CheckIsStillLocked(DistributedLockSettings settings)
{
try
{
using var scope = _serviceProvider.CreateScope();
return(await CheckIsStillLocked(settings.ResourceName, settings.UniqueId, settings.HeartbeatTimeout, scope.ServiceProvider));
}
catch (Exception ex)
{
_logger.LogError(ex,
"Failed to check lock {lockName} ({lockUniqueId}). See inner exception for details.",
settings.ResourceName, settings.UniqueId);
}
return(false);
}
/// <inheritdoc cref="IDistributedLockManager.AcquireAsync" />
public async Task <DistributedLock?> AcquireAsync(
DistributedLockSettings settings,
CancellationToken cancellationToken = default)
{
Check.NotNull(settings, nameof(settings));
if (string.IsNullOrEmpty(settings.ResourceName))
{
throw new InvalidOperationException(
"ResourceName cannot be null. Please provide a valid resource name in the settings.");
}
if (settings is NullLockSettings)
{
return(await NullLockManager.AcquireAsync(settings, cancellationToken).ConfigureAwait(false));
}
_logger.LogInformation(
CoreEventIds.AcquiringDistributedLock,
"Trying to acquire lock {lockName} ({lockUniqueId})...",
settings.ResourceName,
settings.UniqueId);
var stopwatch = Stopwatch.StartNew();
while (settings.AcquireTimeout == null || stopwatch.Elapsed < settings.AcquireTimeout)
{
if (await TryAcquireLockAsync(settings).ConfigureAwait(false))
{
_logger.LogInformation(
CoreEventIds.DistributedLockAcquired,
"Acquired lock {lockName} ({lockUniqueId}).",
settings.ResourceName,
settings.UniqueId);
return(new DistributedLock(settings, this));
}
await Task.Delay(settings.AcquireRetryInterval, cancellationToken).ConfigureAwait(false);
if (cancellationToken.IsCancellationRequested)
{
break;
}
}
throw new TimeoutException($"Timeout waiting to get the required lock '{settings.ResourceName}'.");
}
public async Task <bool> SendHeartbeat(DistributedLockSettings settings)
{
try
{
using var scope = _serviceProvider.CreateScope();
return(await SendHeartbeat(settings.ResourceName, settings.UniqueId, scope.ServiceProvider));
}
catch (Exception ex)
{
_logger.LogDebug(ex,
"Failed to send heartbeat for lock {lockName} ({lockUniqueId}). See inner exception for details.",
settings.ResourceName, settings.UniqueId);
return(false);
}
}
public async Task ReleaseAsync(DistributedLockSettings settings)
{
Check.NotNull(settings, nameof(settings));
if (settings is NullLockSettings)
{
await NullLockManager.ReleaseAsync(settings).ConfigureAwait(false);
}
var tryCount = 1;
while (tryCount <= 3)
{
try
{
using var scope = _serviceScopeFactory.CreateScope();
await ReleaseAsync(settings.ResourceName, settings.UniqueId, scope.ServiceProvider)
.ConfigureAwait(false);
_logger.LogInformation(
CoreEventIds.DistributedLockReleased,
"Released lock {lockName} ({lockUniqueId}).",
settings.ResourceName,
settings.UniqueId);
break;
}
catch (Exception ex)
{
_logger.LogWarning(
CoreEventIds.FailedToReleaseDistributedLock,
ex,
"Failed to release lock '{lockName} ({lockUniqueId})'. See inner exception for details.",
settings.ResourceName,
settings.UniqueId);
tryCount++;
}
}
}
protected DistributedBackgroundService(DistributedLockSettings distributedLockSettings, IDistributedLockManager distributedLockManager, ILogger <DistributedBackgroundService> logger)
{
_distributedLockSettings = distributedLockSettings ?? throw new ArgumentNullException(nameof(distributedLockSettings));
_distributedLockManager = distributedLockManager ?? throw new ArgumentNullException(nameof(distributedLockManager));
_logger = logger;
}
protected RecurringDistributedBackgroundService(TimeSpan interval, DistributedLockSettings distributedLockSettings, IDistributedLockManager distributedLockManager, ILogger <RecurringDistributedBackgroundService> logger)
: base(distributedLockSettings, distributedLockManager, logger)
{
_interval = interval;
_logger = logger;
}
public Task <DistributedLock> Acquire(DistributedLockSettings settings, CancellationToken cancellationToken = default) => Task.FromResult <DistributedLock>(null);
public Task <bool> CheckIsStillLocked(DistributedLockSettings settings) => Task.FromResult(true);
public Task <bool> SendHeartbeat(DistributedLockSettings settings) => Task.FromResult(true);
public Task Release(DistributedLockSettings settings) => Task.CompletedTask;
public Task <DistributedLock> Acquire(DistributedLockSettings settings, CancellationToken cancellationToken = default) => Acquire(settings.ResourceName, settings.AcquireTimeout, settings.AcquireRetryInterval, settings.HeartbeatTimeout, cancellationToken);