with parallel: time error with loop

[SadFdW]

Question

with parallel: time error with loop

Category: FILL_IN

Description

I have a question about the with parallel. If I use some loop function, the output time sequence is incorrect, while it is corrent for the "regular experssion". How to solve this problem when using a loop function?
Please see the code below

from artiq.experiment import *

chnlist = ['ttl0', 'ttl1', 'ttl2']

class test(EnvExperiment):
    def build(self):
        self.setattr_device('core')
        for ele in chnlist:
            self.setattr_device(ele)
        self.ttls = [self.get_device(f'{ele}') for ele in chnlist]

    @kernel
    def run(self):
        self.core.reset()
        for ele in self.ttls:
            ele.output()

        delay(1000 * us)
        with parallel:
            for ele in self.ttls:
                ele.pulse(100 * us)
            # self.ttl0.pulse(100 * us)
            # self.ttl1.pulse(100 * us)
            # self.ttl2.pulse(100 * us)

the loop expression is

        with parallel:
            for ele in self.ttls:
                ele.pulse(100 * us)

the result of which is

the regular express is

        with parallel:
            self.ttl0.pulse(100 * us)
            self.ttl1.pulse(100 * us)
            self.ttl2.pulse(100 * us)

[sbourdeauducq]

Please use the forum for this type of question https://forum.m-labs.hk/

[sbourdeauducq]

In a parallel block, each statement is inside an implicit sequential block (this should be in the manual). This includes the for loop statement.
This behavior will be changed in NAC3 ARTIQ (most likely ARTIQ-8) where only function calls in a parallel block have an implicit sequential, and it will do what you want.

[SadFdW]

In a parallel block, each statement is inside an implicit sequential block (this should be in the manual). This includes the for loop statement. This behavior will be changed in NAC3 ARTIQ (most likely ARTIQ-8) where only function calls in a parallel block have an implicit sequential, and it will do what you want.

Thx a lot!

[dhslichter]

This behavior will be changed in NAC3 ARTIQ (most likely ARTIQ-8) where only function calls in a parallel block have an implicit sequential, and it will do what you want.

@sbourdeauducq this appears to be a breaking change to the parallel context as discussed in #1555, where I strongly advocated against such breaking changes because of the impact on legacy code. Why is this occurring? The compromise discussed in #1555 was to make a separate context (e.g. deep_parallel or something). Can we discuss? I propose discussion be carried out in #1555 and not here.