Multiple HTTP sessions

hi guys,

I have a REST method which returns me the device list of given user.
User id and the cookie (which is given after login request) are my inputs.
I am trying to perform a load test for this method and the test scenario includes multiple users calling the same method at the same time.

I need to set seperate cookies for each user but there is only one cookie field for the test suite.
Every thread tries to clear the cookie store then set its own cookie at the same time.
This results in a race condition.

Anyone there to help me please ?

I can provide more information about my current set up.