Test that control checkpoints survive recompute (fixes #5082)#5093
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sghelichkhani wants to merge 1 commit into
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Test that control checkpoints survive recompute (fixes #5082)#5093sghelichkhani wants to merge 1 commit into
sghelichkhani wants to merge 1 commit into
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The clear-down assertions in _check_forward, _check_recompute, and _check_reverse swept every block variable and required _checkpoint to be None after recompute. That codified the pre-fix behaviour where the checkpoint manager would silently clobber the control's checkpoint during forward replay. Now that the manager goes through the BlockVariable setter and respects the is_control guard, the control's block variable legitimately retains the user-supplied value across replays. The helpers now take an optional list of controls and skip those block variables. Also add a regression test for #5082: a 4-step model with J = sum(m**2) evaluated at m0 = 2 must have derivative 16 (the bug produced 8 because the adjoint replay saw the original m = 1).
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Companion to dolfin-adjoint/pyadjoint#257, which fixes the underlying bug in
CheckpointManagerwhere direct writes toBlockVariable._checkpointbypassed theis_controlguard and wiped the user-supplied control value during forward replay. With that pyadjoint fix in place the control's checkpoint now legitimately survives across replays, which makes two changes necessary here.The first is that
_check_forward,_check_recomputeand_check_reverseintests/firedrake/adjoint/test_burgers_newton.pywere asserting that every block-variable checkpoint must beNoneafter replay. That assertion codified the buggy behaviour — under the fix, the control's block variable correctly retains its checkpoint between calls torf(new_value)andrf.derivative(). The helpers now take an optional list of controls (accepting eitherControlobjects or the underlying overloaded variables) and skip those block variables in the clear-down sweeps. All existing call sites intest_burgers_newton.pyandtest_checkpointing_multistep.pyare updated to thread the controls through.The second is a regression test
test_control_value_survives_recomputeintest_checkpointing_multistep.pythat captures Steph's MFE from #5082 directly: four timesteps ofJ = sum_k m**2, evaluated atm0 = 2, must give a derivative of16. Before the pyadjoint fix this returned8because the adjoint replay saw the stale underlyingm = 1.Depends on dolfin-adjoint/pyadjoint#257 — without it the new regression test will fail.