private async Task DisposeStatementAsync(ReservedForStatement reservationObject)
{
try
{
await this.UseStreamWithinStatementAsync(reservationObject, async() => await this.PerformDisposeStatementAsync(reservationObject));
}
finally
{
Interlocked.Exchange(ref this._currentlyExecutingStatement, NotInUse.Instance);
}
}
private async Task UseStreamOutsideStatementAsync(Func <Task> action, ReservedForStatement reservedState, Boolean oneTimeOnly)
{
if (ReferenceEquals(Interlocked.CompareExchange(ref this._currentlyExecutingStatement, reservedState, NotInUse.Instance), NotInUse.Instance))
{
try
{
await this.UseStreamWithinStatementAsync(reservedState, action);
}
finally
{
if (oneTimeOnly)
{
Interlocked.Exchange(ref this._currentlyExecutingStatement, NotInUse.Instance);
}
}
}
else
{
throw new InvalidOperationException("The connection is currently being used by another statement.");
}
}
public async Task <T> UseStreamWithinStatementAsync <T>(ReservedForStatement reservedState, Func <Task <T> > action)
{
ArgumentValidator.ValidateNotNull(nameof(reservedState), reservedState);
ConnectionStreamUsageState prevState;
if (ReferenceEquals((prevState = Interlocked.CompareExchange(ref this._currentlyExecutingStatement, reservedState.UsageState, reservedState)), reservedState) || // Transition
ReferenceEquals(prevState, reservedState.UsageState) // Re-entrance
)
{
try
{
return(await action());
}
finally
{
Interlocked.Exchange(ref this._currentlyExecutingStatement, prevState);
}
}
else
{
throw new InvalidOperationException("The stream is not reserved for this statement.");
}
}
protected abstract Task <(TEnumerableItem, MoveNextAsyncDelegate <TEnumerableItem>)> ExecuteStatement(TStatement stmt, ReservedForStatement reservationObject);
protected abstract Task PerformDisposeStatementAsync(ReservedForStatement reservationObject);