public async Task <ShellScope> GetScopeAsync(ShellSettings settings)
{
ShellScope scope = null;
ShellContext shellContext = null;
while (scope == null)
{
if (!_shellContexts.TryGetValue(settings.Name, out shellContext))
{
shellContext = await GetOrCreateShellContextAsync(settings);
}
// We create a scope before checking if the shell has been released.
scope = shellContext.CreateScope();
// If CreateScope() returned null, the shell is released. We then remove it and
// retry with the hope to get one that won't be released before we create a scope.
if (scope == null)
{
// If the context is released, it is removed from the dictionary so that
// a new call on 'GetScope' will recreate a new shell context.
_shellContexts.TryRemove(settings.Name, out var value);
}
}
return(scope);
}
/// <summary>
/// Activate the shell, if not yet done, by calling the related tenant event handlers.
/// </summary>
public async Task ActivateShellAsync()
{
if (ShellContext.IsActivated)
{
return;
}
SemaphoreSlim semaphore;
lock (_semaphores)
{
if (!_semaphores.TryGetValue(ShellContext.Settings.Name, out semaphore))
{
_semaphores[ShellContext.Settings.Name] = semaphore = new SemaphoreSlim(1);
}
}
await semaphore.WaitAsync();
try
{
// The tenant gets activated here.
if (!ShellContext.IsActivated)
{
using (var scope = ShellContext.CreateScope())
{
if (scope == null)
{
return;
}
scope.StartAsyncFlow();
var tenantEvents = scope.ServiceProvider.GetServices <IModularTenantEvents>();
foreach (var tenantEvent in tenantEvents)
{
await tenantEvent.ActivatingAsync();
}
foreach (var tenantEvent in tenantEvents.Reverse())
{
await tenantEvent.ActivatedAsync();
}
await scope.BeforeDisposeAsync();
await scope.DisposeAsync();
}
ShellContext.IsActivated = true;
}
}
finally
{
semaphore.Release();
}
}
