Deadlock during initializeData in multi-coupling scheme #1512
Description
Describe your setup
Operating system (e.g. Linux distribution and version): Ubuntu 20.04
preCICE version: 2.5.0
pyprecice version: 2.5.0.1
internal ATHLET adapter (commit cb161a9, based on 686656)
Describe the problem
I am running a case that involves three ATHLET participants: three pipes connected to each other in series. These are called SolverOne <-> SolverMid <-> SolverTwo.
They are coupled using a coupling-scheme:multi, with SolverMid as controller, everything in serial. Some data needs to be initialized, but all solvers deadlock into receiving state.
Step To Reproduce
The case is not publicly available.
Two tutorials we could use to reproduce this is the multiple perpendicular flaps and the heat exchanger simplified.
Expected behaviour
Data should initialize and the simulation should continue.
Additional context
Data initialization seems to work when composing two serial-implicit schemes (which should normally not work).
It also seems to work when initializing all or no data. The problem only appears when initializing some.