xQueue dynamic RAM: Is all RAM allocated at create time? Or gradually until queue length is reached?

When using the xQueue API with dynamic RAM, does the whole memory a xQueue might possible need (queue length x sizeof(item) ) get allocated at xQueueCreate()? or is it gradually allocated as the queue grows in length (until it reaches its limit). An example:
xQueueCreate(): allocate memory for e.g. 2 positions.
If the used queue length grows (more items sent then received), allocate extra positions as needed, until the queue length limit is reached.
The xQueueCreate() documentation only mentions that the RAM is allocated automatically by the RTOS, does not mention this detail. The “Static Vs Dynamic Memory Allocation” help page mentions that “the RAM used by an RTOS object can be re-used if the object is deleted”, so it seems that the granularity is the object (in this case the complete queue), and therefore the whole memory is allocated at create time, but I would still like to clarify that.

Thanks in advance.

All is allocated at create time.

Remember this is open source code. You can find the answer to this question by looking at the implementation of the function, and stepping through the code in the debugger.