what happens when a Stored procedure shared by two jobs and get called at same time ?

Hi All, 

Not sure its the right way to do it , I wrote a MASTER SP which calls three different SP using variables passed to MASTER SP.

MASTER SP calls the three SP using EXECUTE IMMEDIATE COMMAND, My question imagine two jobs (Job1) and (Job2) running same time and calling MASTER SP but passing different varaibles what happens here does Job2 wait for Job1 to complete or does SQL Server or any database engine clever enough to create two copies of MASTER SP to exeucte the varaibles passed by Job1 and Job2 so it can run in parallel.

Thanks

sri 

Sri.Tummala