Is a stored procedure call inside a SQL Server trigger implictly thread safe and atomic?

Question

I have a SQL Server trigger. To be honest, I'm not quite sure if triggers implicitly follow ACID ( Atomicity, Consistency, Isolation, Durability ), but my trigger, at the moment, doesn't do anything particularly complex.

Now, I want to call a stored procedure from within the trigger. I have TRANSACTION surrounding the stored procedure call and an INSERT statement.

My question is: if a trigger, sans stored procedure call, is thread safe and atomic -- at least in part due to the TRANSACTION -- will the stored procedure call be implicitly thread safe and atomic?

Here's what the trigger looks like:

CREATE TRIGGER [triggerInsert_Foobar] 
ON [Foobar]
INSTEAD OF INSERT
AS 
BEGIN
    SET NOCOUNT ON;

    -- Turns on rollack if T-SQL statement raises a run-time error
    SET XACT_ABORT ON

    -- Start new transaction
    BEGIN TRANSACTION
        -- Insert statement for trigger
        INSERT INTO Foo ( Col1, Col2 )
            SELECT 
                RTRIM ( LTRIM ( Col1 ) ), 
                Col2
            FROM 
                INSERTED

    -- Call stored procedure (takes no parameters)
    EXECUTE sp_executesql N'FoobarApp_DoSomething'

    -- Complete transaction
    COMMIT TRANSACTION
END;

Thank you, kindly, for your help.

Additional question

This question is being poised after a few responses already (thank you). I apologize in advance.

Does my trigger and the subsequent calling of the stored procedure follow the ACID principle and avoid race conditions and deadlocks? Or, is there something I need to add to my trigger and/or the stored procedure to safeguard against race conditions and deadlocks?

Answer 1

The underlying operation and the trigger operation treated as atomic. They both commit in one transaction. From the documentation :

The trigger and the statement that fires it are treated as a single transaction...

Note that the trigger (and the SP is will call) wont' see the table change that fired the trigger. It hasn't committed yet.