private void WriteTryCatchBlockBody(ILWriter writer, IImmutableQueue <Type> exceptionTypes)
{
var currentExecutionAttempt = writer.DeclareLocal <int>();
var shouldRetry = writer.DeclareLocal <bool>();
var retryLabel = writer.DefineLabel();
writer.MarkLabel(retryLabel);
writer.WriteIncrement(currentExecutionAttempt, 1);
writer.TryCatch(
endOfTryCatch =>
{
writer.LoadFalse();
writer.SetLocal(shouldRetry);
var method = KnownMetadata.Methods.IExceptionAwareAction_Do;
writer.LoadFirstParameter();
writer.InstanceMethodCall(method);
},
WriteUnrolledCatchBlocks(writer, exceptionTypes, shouldRetry, currentExecutionAttempt)
);
writer.LoadLocal(shouldRetry);
var shouldNotRetry = writer.IfTrueThen();
writer.GoTo(retryLabel);
writer.MarkLabel(shouldNotRetry);
writer.Return();
}
private IEnumerable <Action <Label> > WriteUnrolledCatchBlocks(ILWriter writer, IImmutableQueue <Type> exceptionTypes, LocalBuilder shouldRetry, LocalBuilder currentExecutionAttempt)
{
var handleException = KnownMetadata.Methods.IExceptionAwareAction_HandleException;
foreach (var exceptionType in exceptionTypes)
{
yield return(endOfTryCatch =>
{
var handleSpecificException = handleException.MakeGenericMethod(exceptionType);
Action catchBlockBody = () =>
{
var endOfCatch = writer.DefineLabel();
var localException = writer.DeclareLocal(exceptionType);
writer.SetLocal(localException);
writer.LoadFirstParameter(); //Exception-aware instance
writer.LoadLocal(localException);
writer.LoadLocal(currentExecutionAttempt);
writer.InstanceMethodCall(handleSpecificException);
//The handler refusing to handle it indicates that we should perform a retry.
var wasHandled = writer.IfFalseThen();
writer.LoadTrue();
writer.SetLocal(shouldRetry);
writer.GoTo(endOfCatch);
writer.MarkLabel(wasHandled);
writer.LoadFalse();
writer.SetLocal(shouldRetry);
writer.MarkLabel(endOfCatch);
};
writer.CatchBlock(exceptionType, endOfTryCatch, catchBlockBody);
});
}
}
