Lin.Internal Thread int CList test finds unexpected counterexample under bytecode

[jmid]

The test src/neg_tests/lin_tests_thread_conclist.ml using the Lin Thread mode to exercise int CList is expected not to trigger any issues.

However under bytecode I have now observed more than once that it does find a counterexample.

Here's a run on Win bytecode trunk from 2 days ago:
https://github.com/ocaml-multicore/multicoretests/actions/runs/5173787112/jobs/9319394100

random seed: 124760788
generated error fail pass / total     time test name

[ ]    0    0    0    0 / 1000     0.0s Lin CList int test with Thread
[ ]    0    0    0    0 / 1000     0.0s Lin CList int test with Thread (generating)
[ ]  269    0    0  269 / 1000    60.3s Lin CList int test with Thread (shrinking:    0.0073)
[✗]  270    0    1  269 / 1000   117.1s Lin CList int test with Thread

--- Failure --------------------------------------------------------------------

[...]

Messages for test Lin CList int test with Thread:

  Results incompatible with sequential execution

                                       |                   
                         Add_node (97) : RAdd_node true    
                           Member (2) : RMember false      
                          Member (79) : RMember false      
                         Add_node (88) : RAdd_node true    
                        Add_node (578) : RAdd_node true    
                          Member (665) : RMember false     
                         Add_node (54) : RAdd_node true    
                          Member (61) : RMember false      
                           Member (3) : RMember false      
                         Add_node (47) : RAdd_node true    
                           Member (97) : RMember true      
                         Add_node (21) : RAdd_node true    
                         Add_node (8) : RAdd_node true     
                          Member (429) : RMember false     
                         Add_node (5) : RAdd_node true     
                         Add_node (47) : RAdd_node true    
                         Add_node (8) : RAdd_node true     
                                       |                   
                    .------------------------------------.
                    |                                    |                   
        Member (6) : RMember false           Member (4) : RMember false      
        Member (6) : RMember false         Add_node (0) : RAdd_node true     
     Add_node (637) : RAdd_node true       Add_node (58) : RAdd_node true    
     Add_node (1312) : RAdd_node true       Member (560) : RMember false     
      Add_node (0) : RAdd_node true        Add_node (3) : RAdd_node true     
      Add_node (89) : RAdd_node true       Add_node (1) : RAdd_node true     
       Member (281) : RMember false          Member (6) : RMember false      
       Member (227) : RMember false          Member (6) : RMember false      
      Add_node (88) : RAdd_node true       Add_node (9) : RAdd_node true     
      Add_node (8) : RAdd_node true          Member (1) : RMember false      
      Add_node (1) : RAdd_node true          Member (6) : RMember false      

================================================================================
failure (1 tests failed, 0 tests errored, ran 1 tests)

Here's another from last week on Linux bytecode trunk:
https://github.com/ocaml-multicore/multicoretests/actions/runs/5131082066/jobs/9230704532

random seed: 124224253
generated error fail pass / total     time test name

[ ]    0    0    0    0 / 1000     0.0s Lin CList int test with Thread
[ ]    0    0    0    0 / 1000     0.0s Lin CList int test with Thread (generating)
[ ]  224    0    0  224 / 1000    60.0s Lin CList int test with Thread (shrinking:    0.0032)
[ ]  224    0    0  224 / 1000   120.1s Lin CList int test with Thread (shrinking:    0.0112)
[✗]  225    0    1  224 / 1000   170.2s Lin CList int test with Thread

--- Failure --------------------------------------------------------------------

[...]

Messages for test Lin CList int test with Thread:

  Results incompatible with sequential execution

                                       |                   
                          Member (96) : RMember false      
                        Add_node (722) : RAdd_node true    
                         Add_node (0) : RAdd_node true     
                        Add_node (4820) : RAdd_node true   
                         Add_node (55) : RAdd_node true    
                         Add_node (98) : RAdd_node true    
                           Member (8) : RMember false      
                          Member (89) : RMember false      
                                       |                   
                    .------------------------------------.
                    |                                    |                   
     Add_node (627) : RAdd_node true         Member (8) : RMember false      
        Member (0) : RMember true          Add_node (2) : RAdd_node true     
     Add_node (143) : RAdd_node true        Member (910) : RMember false     
      Add_node (82) : RAdd_node true       Add_node (76) : RAdd_node true    
        Member (8) : RMember false         Add_node (24) : RAdd_node true    
      Add_node (84) : RAdd_node true       Add_node (6) : RAdd_node true     
      Add_node (11) : RAdd_node true        Member (93) : RMember false      
       Member (633) : RMember false        Add_node (1) : RAdd_node true     
       Member (83) : RMember false           Member (9) : RMember false      
      Add_node (10) : RAdd_node true       Add_node (94) : RAdd_node true    
        Member (4) : RMember false           Member (2) : RMember false      
      Add_node (94) : RAdd_node true      Add_node (924) : RAdd_node true    

================================================================================
failure (1 tests failed, 0 tests errored, ran 1 tests)

[jmid]

The test unexpectedly failed under 32-bit Linux trunk 5.2:
https://github.com/ocaml-multicore/multicoretests/actions/runs/5283892318/jobs/9560725349

random seed: 13303944
generated error fail pass / total     time test name

[ ]    0    0    0    0 / 1000     0.0s Lin CList int test with Thread
[ ]    0    0    0    0 / 1000     0.0s Lin CList int test with Thread (generating)
[ ]  496    0    0  496 / 1000    63.6s Lin CList int test with Thread
[ ]  686    0    0  686 / 1000   123.6s Lin CList int test with Thread (shrinking:    0.0081)
[✗]  687    0    1  686 / 1000   168.3s Lin CList int test with Thread

--- Failure --------------------------------------------------------------------
File "src/neg_tests/dune", line 105, characters 29-54:
105 |  (names lin_tests_thread_ref lin_tests_thread_conclist)
                                   ^^^^^^^^^^^^^^^^^^^^^^^^^
(cd _build/default/src/neg_tests && ./lin_tests_thread_conclist.exe --verbose)
Command exited with code 1.
File "src/neg_tests/dune", line 105, characters 29-54:
105 |  (names lin_tests_thread_ref lin_tests_thread_conclist)
                                   ^^^^^^^^^^^^^^^^^^^^^^^^^
(cd _build/default/src/neg_tests && ./lin_tests_thread_conclist.exe --verbose)
Command exited with code 1.

Test Lin CList int test with Thread failed (0 shrink steps):

                           |             
                      Add_node (5)       
                      Add_node (6)       
                     Add_node (838)      
                     Add_node (21)       
                      Member (89)        
                      Member (98)        
                      Member (747)       
                      Add_node (8)       
                      Add_node (2)       
                      Member (81)        
                       Member (5)        
                      Member (609)       
                      Add_node (4)       
                      Member (11)        
                      Member (605)       
                           |             
                .---------------------.
                |                     |             
            Member (3)           Add_node (6)       
          Add_node (904)         Member (327)       
          Member (6581)           Member (4)        
            Member (5)          Add_node (845)      
           Add_node (9)           Member (1)        
          Add_node (331)        Member (3257)       
            Member (9)          Add_node (77)       
           Member (85)           Add_node (2)       
          Add_node (95)           Member (6)        
            Member (6)          Add_node (48)       
           Add_node (8)          Member (48)        
           Member (190)           Member (1)        


+++ Messages ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Messages for test Lin CList int test with Thread:

  Results incompatible with sequential execution

                                       |                   
                         Add_node (5) : RAdd_node true     
                         Add_node (6) : RAdd_node true     
                        Add_node (838) : RAdd_node true    
                        Add_node (21) : RAdd_node true     
                          Member (89) : RMember false      
                          Member (98) : RMember false      
                         Member (747) : RMember false      
                         Add_node (8) : RAdd_node true     
                         Add_node (2) : RAdd_node true     
                          Member (81) : RMember false      
                           Member (5) : RMember true       
                         Member (609) : RMember false      
                         Add_node (4) : RAdd_node true     
                          Member (11) : RMember false      
                         Member (605) : RMember false      
                                       |                   
                    .------------------------------------.
                    |                                    |                   
       Member (3) : RMember false          Add_node (6) : RAdd_node true     
     Add_node (904) : RAdd_node true       Member (327) : RMember false      
      Member (6581) : RMember false          Member (4) : RMember true       
        Member (5) : RMember true         Add_node (845) : RAdd_node true    
      Add_node (9) : RAdd_node true         Member (1) : RMember false       
     Add_node (331) : RAdd_node true       Member (3257) : RMember false     
        Member (9) : RMember true         Add_node (77) : RAdd_node true     
       Member (85) : RMember false         Add_node (2) : RAdd_node true     
     Add_node (95) : RAdd_node true          Member (6) : RMember true       
        Member (6) : RMember true         Add_node (48) : RAdd_node true     
      Add_node (8) : RAdd_node true         Member (48) : RMember false      
      Member (190) : RMember false          Member (1) : RMember false       

================================================================================
failure (1 tests failed, 0 tests errored, ran 1 tests)
Error: Process completed with exit code 1.

[jmid]

Also triggered a counterexample under Windows bytecode trunk 5.2:
https://github.com/ocaml-multicore/multicoretests/actions/runs/5283892319/jobs/9560725030

random seed: 495053076
generated error fail pass / total     time test name

[ ]    0    0    0    0 / 1000     0.0s Lin CList int test with Thread
[ ]    0    0    0    0 / 1000     0.0s Lin CList int test with Thread (generating)
[ ]  744    0    0  744 / 1000    60.4s Lin CList int test with Thread (shrinking:    0.0012)
[ ]  744    0    0  744 / 1000   120.6s Lin CList int test with Thread (shrinking:    0.0150)
[✗]  745    0    1  744 / 1000   125.0s Lin CList int test with Thread

--- Failure --------------------------------------------------------------------

Test Lin CList int test with Thread failed (0 shrink steps):

                            |            
                       Member (0)        
                      Add_node (4)       
                       Member (4)        
                      Add_node (85)      
                      Add_node (85)      
                      Add_node (8)       
                      Add_node (8)       
                      Add_node (5)       
                      Add_node (30)      
                       Member (3)        
                       Member (99)       
                      Add_node (8)       
                       Member (9)        
                       Member (6)        
                            |            
                 .---------------------.
                 |                     |            
           Member (5704)         Add_node (82)      
           Add_node (9)           Member (21)       
           Add_node (1)         Add_node (448)      
            Member (1)           Add_node (6)       
           Add_node (15)          Member (85)       
          Add_node (7460)         Member (7)        
          Add_node (600)         Add_node (58)      
            Member (7)           Add_node (56)      
           Add_node (8)           Member (6)        
           Add_node (2)         Add_node (968)      


+++ Messages ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Messages for test Lin CList int test with Thread:

  Results incompatible with sequential execution

                                       |                   
                           Member (0) : RMember true       
                         Add_node (4) : RAdd_node true     
                           Member (4) : RMember true       
                         Add_node (85) : RAdd_node true    
                         Add_node (85) : RAdd_node true    
                         Add_node (8) : RAdd_node true     
                         Add_node (8) : RAdd_node true     
                         Add_node (5) : RAdd_node true     
                         Add_node (30) : RAdd_node true    
                           Member (3) : RMember false      
                          Member (99) : RMember false      
                         Add_node (8) : RAdd_node true     
                           Member (9) : RMember false      
                           Member (6) : RMember false      
                                       |                   
                    .------------------------------------.
                    |                                    |                   
      Member (5704) : RMember false        Add_node (82) : RAdd_node true    
      Add_node (9) : RAdd_node true         Member (21) : RMember false      
      Add_node (1) : RAdd_node true       Add_node (448) : RAdd_node true    
        Member (1) : RMember false         Add_node (6) : RAdd_node true     
      Add_node (15) : RAdd_node true         Member (85) : RMember true      
     Add_node (7460) : RAdd_node true        Member (7) : RMember false      
     Add_node (600) : RAdd_node true       Add_node (58) : RAdd_node true    
        Member (7) : RMember false         Add_node (56) : RAdd_node true    
      Add_node (8) : RAdd_node true          Member (6) : RMember true       
      Add_node (2) : RAdd_node true       Add_node (968) : RAdd_node true    

================================================================================
failure (1 tests failed, 0 tests errored, ran 1 tests)
File "src/neg_tests/dune", line 105, characters 29-54:
105 |  (names lin_tests_thread_ref lin_tests_thread_conclist)
                                   ^^^^^^^^^^^^^^^^^^^^^^^^^
(cd _build/default/src/neg_tests && ./lin_tests_thread_conclist.exe --verbose)
Command exited with code 1.

[jmid]

Observed again on Windows bytecode 5.0.0
https://github.com/ocaml-multicore/multicoretests/actions/runs/5703723247/job/15456641444

random seed: 133807954
generated error fail pass / total     time test name

[ ]    0    0    0    0 / 1000     0.0s Lin CList int test with Thread
[ ]    0    0    0    0 / 1000     0.0s Lin CList int test with Thread (generating)
[ ]  826    0    0  826 / 1000    60.0s Lin CList int test with Thread
[✗]  863    0    1  862 / 1000    87.2s Lin CList int test with Thread

[jmid]

I updated the issue title to reflect #396 and #408 renaming