@@ -821,3 +821,192 @@ def test_metric_no_path(log_metric):
821821
822822 result = pytester .runpytest ()
823823 result .assert_outcomes (passed = 1 )
824+
825+
826+ # ---------------------------------------------------------------------------
827+ # Tests for the stdout-lock feature (_stdout_lock / set_stdout_lock / _listen)
828+ # ---------------------------------------------------------------------------
829+
830+
831+ def test_set_stdout_lock ():
832+ """set_stdout_lock updates the module-level _STDOUT_LOCK variable."""
833+ import pytest_embedded .dut_factory as m
834+ from pytest_embedded .dut_factory import set_stdout_lock
835+
836+ original = m ._STDOUT_LOCK
837+ try :
838+ sentinel = object ()
839+ set_stdout_lock (sentinel )
840+ assert m ._STDOUT_LOCK is sentinel
841+
842+ set_stdout_lock (None )
843+ assert m ._STDOUT_LOCK is None
844+ finally :
845+ set_stdout_lock (original )
846+
847+
848+ def test_listen_no_data_loss_without_lock (tmp_path ):
849+ """_listen writes every queued message to the logfile when no lock is used."""
850+ import time
851+
852+ from pytest_embedded .dut_factory import _ctx , _listen
853+ from pytest_embedded .log import MessageQueue
854+
855+ logfile = str (tmp_path / 'test.log' )
856+ q = MessageQueue ()
857+ messages = [f'line_{ i } \n ' .encode () for i in range (20 )]
858+
859+ p = _ctx .Process (target = _listen , args = (q , logfile ), kwargs = {'with_timestamp' : False })
860+ p .start ()
861+ try :
862+ for msg in messages :
863+ q .put (msg )
864+
865+ deadline = time .monotonic () + 10
866+ while time .monotonic () < deadline :
867+ try :
868+ content = open (logfile , 'rb' ).read ()
869+ if all (msg in content for msg in messages ):
870+ break
871+ except OSError :
872+ pass
873+ time .sleep (0.05 )
874+ finally :
875+ p .terminate ()
876+ p .join (timeout = 5 )
877+ assert p .exitcode is not None , 'listener process did not terminate'
878+
879+ content = open (logfile , 'rb' ).read ()
880+ for msg in messages :
881+ assert msg in content , f'{ msg !r}
882+
883+
884+ def test_listen_no_data_loss_with_lock (tmp_path ):
885+ """_listen writes every queued message to the logfile when a Manager lock is used."""
886+ import multiprocessing
887+ import time
888+
889+ from pytest_embedded .dut_factory import _ctx , _listen
890+ from pytest_embedded .log import MessageQueue
891+
892+ logfile = str (tmp_path / 'test.log' )
893+ q = MessageQueue ()
894+ messages = [f'line_{ i } \n ' .encode () for i in range (20 )]
895+
896+ manager = multiprocessing .Manager ()
897+ try :
898+ lock = manager .Lock ()
899+ p = _ctx .Process (
900+ target = _listen ,
901+ args = (q , logfile ),
902+ kwargs = {'with_timestamp' : False , '_stdout_lock' : lock },
903+ )
904+ p .start ()
905+ try :
906+ for msg in messages :
907+ q .put (msg )
908+
909+ deadline = time .monotonic () + 10
910+ while time .monotonic () < deadline :
911+ try :
912+ content = open (logfile , 'rb' ).read ()
913+ if all (msg in content for msg in messages ):
914+ break
915+ except OSError :
916+ pass
917+ time .sleep (0.05 )
918+ finally :
919+ p .terminate ()
920+ p .join (timeout = 5 )
921+ assert p .exitcode is not None , 'listener process did not terminate'
922+ finally :
923+ manager .shutdown ()
924+
925+ content = open (logfile , 'rb' ).read ()
926+ for msg in messages :
927+ assert msg in content , f'{ msg !r}
928+
929+
930+ def test_stdout_lock_concurrent_no_data_loss (tmp_path ):
931+ """Two concurrent _listen processes sharing a Manager lock both preserve all data."""
932+ import multiprocessing
933+ import time
934+
935+ from pytest_embedded .dut_factory import _ctx , _listen
936+ from pytest_embedded .log import MessageQueue
937+
938+ logfile0 = str (tmp_path / 'dut0.log' )
939+ logfile1 = str (tmp_path / 'dut1.log' )
940+ q0 = MessageQueue ()
941+ q1 = MessageQueue ()
942+ messages0 = [f'dut0_line_{ i } \n ' .encode () for i in range (20 )]
943+ messages1 = [f'dut1_line_{ i } \n ' .encode () for i in range (20 )]
944+
945+ manager = multiprocessing .Manager ()
946+ try :
947+ lock = manager .Lock ()
948+ p0 = _ctx .Process (
949+ target = _listen ,
950+ args = (q0 , logfile0 ),
951+ kwargs = {'with_timestamp' : False , 'count' : 1 , 'total' : 2 , '_stdout_lock' : lock },
952+ )
953+ p1 = _ctx .Process (
954+ target = _listen ,
955+ args = (q1 , logfile1 ),
956+ kwargs = {'with_timestamp' : False , 'count' : 2 , 'total' : 2 , '_stdout_lock' : lock },
957+ )
958+ p0 .start ()
959+ p1 .start ()
960+ try :
961+ # interleave writes from both DUTs to maximize lock contention
962+ for msg0 , msg1 in zip (messages0 , messages1 ):
963+ q0 .put (msg0 )
964+ q1 .put (msg1 )
965+
966+ deadline = time .monotonic () + 15
967+ while time .monotonic () < deadline :
968+ try :
969+ c0 = open (logfile0 , 'rb' ).read ()
970+ c1 = open (logfile1 , 'rb' ).read ()
971+ if all (m in c0 for m in messages0 ) and all (m in c1 for m in messages1 ):
972+ break
973+ except OSError :
974+ pass
975+ time .sleep (0.05 )
976+ finally :
977+ p0 .terminate ()
978+ p1 .terminate ()
979+ p0 .join (timeout = 5 )
980+ p1 .join (timeout = 5 )
981+ assert p0 .exitcode is not None , 'dut0 listener process did not terminate'
982+ assert p1 .exitcode is not None , 'dut1 listener process did not terminate'
983+ finally :
984+ manager .shutdown ()
985+
986+ c0 = open (logfile0 , 'rb' ).read ()
987+ c1 = open (logfile1 , 'rb' ).read ()
988+ for msg in messages0 :
989+ assert msg in c0 , f'{ msg !r}
990+ for msg in messages1 :
991+ assert msg in c1 , f'{ msg !r}
992+
993+
994+ def test_multi_dut_no_data_loss (testdir ):
995+ """In a 2-DUT test, all messages written by each DUT can be expected - nothing is dropped."""
996+ testdir .makepyfile (r"""
997+ import pytest
998+
999+ @pytest.mark.parametrize('count', [2], indirect=True)
1000+ def test_concurrent_dut_writes(dut):
1001+ n = 15
1002+ for i in range(n):
1003+ dut[0].write(f'dut0_msg_{i}')
1004+ dut[1].write(f'dut1_msg_{i}')
1005+
1006+ for i in range(n):
1007+ dut[0].expect_exact(f'dut0_msg_{i}')
1008+ dut[1].expect_exact(f'dut1_msg_{i}')
1009+ """ )
1010+
1011+ result = testdir .runpytest ()
1012+ result .assert_outcomes (passed = 1 )
0 commit comments