When creating workers, passing lists of object FIFOs causes error: 'NoneType' object has no attribute 'tile'. Is this intentional?

[RonZ13]

Hello there,

I noticed that when I pass in a list of object FIFO when creating workers, like the code below, it cauese error: 'NoneType' object has no attribute 'tile'.

def core_func(in_fifos, in_fifos):
    in_item = in_fifos[0].acquire(1)
    out_item = out_fifos[0].acquire(1)
    ...
    in_fifos[0].release(1)
    out_fifos[0].release(1)


in_fifos = []
out_fifos = []
in_fifos.append(of_in_L2L1.cons())
out_fifos.append(of_out_L1L2.prod())
Worker(
    core_func,
    [in_fifos, out_fifos],
)

To avoid this error, I have to explicitly write out the input, like the code below.

def core_func(in_fifo, in_fifo):
    in_item = in_fifo.acquire(1)
    out_item = out_fifo.acquire(1)
    ...
    in_fifo.release(1)
    out_fifo.release(1)


Worker(
    core_func,
    [of_in_L2L1.cons(), of_out_L1L2.prod()],
)

OR

def core_func(*fifos):
    in_item = fifos[0].acquire(1)
    out_item = fifos[1].acquire(1)
    ...
    fifos[0].release(1)
    fifos[1].release(1)


in_fifos = []
out_fifos = []
in_fifos.append(of_in_L2L1.cons())
out_fifos.append(of_out_L1L2.prod())
Worker(
    core_func,
    [*in_fifos, *out_fifos],
)

Is this intentional?

Regards,
Ron

[AndraBisca]

Hello! Thank you for signaling this issue.

I was able to reproduce the same error (please let me know if it is different than yours):

File "/iron/program.py", line 75, in device_body
    placer.make_placement(
File "/iron/placers.py", line 134, in make_placement
    ofe.tile for ofe in of_endpoints if ofe.tile in computes
                                        ^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'tile'

The error is triggered during placement of ObjectFifoEndpoints. Before placement, these endpoints are collected in program.py by calling the fifos() function of the Worker class. This function goes through the arguments of the callable function assigned to each Worker, and if it finds an ObjectFifoEndpoint, it registers it. This is seen here.

At the moment, the implementation does not cover all possibilities for Python arguments, which is why in the first version of your code the ObjectFifoEndpoints are not found. This is an area which would benefit from further development so please don't hesitate if you have already spent time on this and would like to contribute!