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ocaml-multicore
data-race/rare crash with with IO
Still trying to track down exactly what is causing this, but it triggers now with a small testcase in 5.2.0 and 5.3.0+trunk on x86_64 with the following program:
let () =
Eio_main.run @@ fun env ->
Eio.Switch.run @@ fun sw ->
let pool = Eio.Executor_pool.create
~sw (Eio.Stdenv.domain_mgr env)
~domain_count:(Domain.recommended_domain_count () - 1)
in
let cwd = Eio.Stdenv.cwd env in
let temp_files = List.init 1000 (fun _ ->
let f = Filename.temp_file ~temp_dir:"." "stresstest" "" in
let p = Eio.Path.(cwd / (Filename.basename f)) in
Eio.Path.with_open_out ~create:`Never p (fun f ->
let _ = Eio.File.pwrite_all f ~file_offset:(Optint.Int63.of_int 2000) [Cstruct.create 4096] in
()
);
p
) in
let process m () =
for _ = 0 to 1000 do
let _ = String.make 10000 'a' in
ignore(Eio.Path.load m)
done
in
Eio.Fiber.List.iter ~max_fibers:100 (fun msg ->
Eio.Executor_pool.submit_exn pool ~weight:0.5 (process msg)
) temp_files;
List.iter Eio.Path.unlink temp_files
built with:
(executable
(public_name test)
(name test)
(flags (:standard -g -runtime-variant d))
(libraries eio_main))
It triggers the following data race reliably on Linux:
==================
WARNING: ThreadSanitizer: data race (pid=912737)
Write of size 8 at 0x7f8561e08d08 by thread T16 (mutexes: write M0):
#0 camlEio__core__Switch.dec_fibers_1051 lib_eio/core/switch.ml:71 (test.exe+0x1978e0) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#1 camlStdlib__Fun.finally_no_exn_330 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:30 (test.exe+0x247652) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#2 camlStdlib__Fun.protect_326 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:35 (test.exe+0x2475ae) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#3 caml_runstack <null> (test.exe+0x2f2d91) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#4 camlStdlib__Fun.protect_326 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:34 (test.exe+0x24753a) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#5 camlEio_posix__Sched.run_1355 lib_eio_posix/sched.ml:381 (test.exe+0x119644) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#6 camlEio_posix__Sched.with_sched_1218 lib_eio_posix/sched.ml:258 (test.exe+0x118959) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#7 camlStdlib__Fun.protect_326 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:34 (test.exe+0x24753a) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#8 camlStdlib__Domain.body_741 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/domain.ml:266 (test.exe+0x2258ef) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#9 caml_start_program <null> (test.exe+0x2f25b3) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#10 caml_callback_exn runtime/callback.c:205 (test.exe+0x2a1973) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#11 caml_callback_res runtime/callback.c:320 (test.exe+0x2a29b4) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#12 domain_thread_func runtime/domain.c:1245 (test.exe+0x2a79a5) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
Previous atomic read of size 8 at 0x7f8561e08d08 by thread T40587 (mutexes: write M1, write M2):
#0 mark_stack_push_block runtime/major_gc.c:871 (test.exe+0x2c815b) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#1 caml_darken runtime/major_gc.c:1208 (test.exe+0x2ca02e) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#2 caml_darken runtime/major_gc.c:1186 (test.exe+0x2ca02e)
#3 scan_stack_frames runtime/fiber.c:280 (test.exe+0x2b1756) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#4 caml_scan_stack runtime/fiber.c:301 (test.exe+0x2b1756)
#5 caml_darken_cont runtime/major_gc.c:1177 (test.exe+0x2c9d9f) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#6 do_some_marking runtime/major_gc.c:1009 (test.exe+0x2cafa7) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#7 mark runtime/major_gc.c:1124 (test.exe+0x2cb199) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#8 major_collection_slice runtime/major_gc.c:1704 (test.exe+0x2cbcb7) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#9 caml_major_collection_slice runtime/major_gc.c:1884 (test.exe+0x2ccec4) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#10 caml_poll_gc_work runtime/domain.c:1874 (test.exe+0x2a8990) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#11 stw_handler runtime/domain.c:1502 (test.exe+0x2a8d81) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#12 handle_incoming runtime/domain.c:351 (test.exe+0x2a8d81)
#13 caml_handle_incoming_interrupts runtime/domain.c:364 (test.exe+0x2a9648) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#14 caml_try_run_on_all_domains_with_spin_work runtime/domain.c:1606 (test.exe+0x2a9648)
#15 caml_try_run_on_all_domains runtime/domain.c:1717 (test.exe+0x2a97f3) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#16 major_collection_slice runtime/major_gc.c:1866 (test.exe+0x2cc892) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#17 caml_major_collection_slice runtime/major_gc.c:1884 (test.exe+0x2ccec4) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#18 caml_poll_gc_work runtime/domain.c:1874 (test.exe+0x2a8990) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#19 caml_handle_gc_interrupt runtime/domain.c:1901 (test.exe+0x2aa01f) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#20 caml_do_pending_actions_res runtime/signals.c:338 (test.exe+0x2e5410) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#21 caml_alloc_small_dispatch runtime/minor_gc.c:896 (test.exe+0x2da4b4) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#22 caml_garbage_collection runtime/signals_nat.c:86 (test.exe+0x2f7140) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#23 caml_call_gc <null> (test.exe+0x2f219f) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#24 camlLwt_dllist.add_r_311 src/lwt_dllist.ml:69 (test.exe+0x1c84c4) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#25 camlEio__core__Switch.on_release_full_1241 lib_eio/core/switch.ml:184 (test.exe+0x198c58) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#26 camlEio_unix__Fd.of_unix_650 lib_eio/core/switch.ml:199 (test.exe+0x14c731) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#27 camlEio_posix__Low_level.with_state_1607 lib_eio_posix/low_level.ml:284 (test.exe+0x11d49d) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#28 camlEio_unix__Thread_pool.fun_749 lib_eio/unix/thread_pool.ml:71 (test.exe+0x14a677) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#29 camlThread.fun_769 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/otherlibs/systhreads/thread.ml:48 (test.exe+0x153700) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#30 caml_start_program <null> (test.exe+0x2f25b3) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#31 caml_callback_exn runtime/callback.c:205 (test.exe+0x2a1973) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#32 caml_thread_start /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/otherlibs/systhreads/st_stubs.c:648 (test.exe+0x280703) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
Mutex M0 (0x72b4000008e0) created at:
#0 pthread_mutex_init ../../../../src/libsanitizer/tsan/tsan_interceptors_posix.cpp:1315 (libtsan.so.2+0x58bfd) (BuildId: 64c1e8de04b11a7d960abd7e45f94f3b277b7779)
#1 caml_plat_mutex_init runtime/platform.c:59 (test.exe+0x2dc362) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#2 caml_init_domains runtime/domain.c:974 (test.exe+0x2a7634) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#3 caml_init_gc runtime/gc_ctrl.c:348 (test.exe+0x2b6ab5) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#4 caml_startup_common runtime/startup_nat.c:106 (test.exe+0x2f1b37) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#5 caml_startup_common runtime/startup_nat.c:86 (test.exe+0x2f1b37)
#6 caml_startup_exn runtime/startup_nat.c:134 (test.exe+0x2f1d3b) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#7 caml_startup runtime/startup_nat.c:139 (test.exe+0x2f1d3b)
#8 caml_main runtime/startup_nat.c:146 (test.exe+0x2f1d3b)
#9 main runtime/main.c:37 (test.exe+0x111239) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
Mutex M1 (0x72b400000d00) created at:
#0 pthread_mutex_init ../../../../src/libsanitizer/tsan/tsan_interceptors_posix.cpp:1315 (libtsan.so.2+0x58bfd) (BuildId: 64c1e8de04b11a7d960abd7e45f94f3b277b7779)
#1 caml_plat_mutex_init runtime/platform.c:59 (test.exe+0x2dc362) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#2 caml_init_domains runtime/domain.c:974 (test.exe+0x2a7634) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#3 caml_init_gc runtime/gc_ctrl.c:348 (test.exe+0x2b6ab5) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#4 caml_startup_common runtime/startup_nat.c:106 (test.exe+0x2f1b37) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#5 caml_startup_common runtime/startup_nat.c:86 (test.exe+0x2f1b37)
#6 caml_startup_exn runtime/startup_nat.c:134 (test.exe+0x2f1d3b) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#7 caml_startup runtime/startup_nat.c:139 (test.exe+0x2f1d3b)
#8 caml_main runtime/startup_nat.c:146 (test.exe+0x2f1d3b)
#9 main runtime/main.c:37 (test.exe+0x111239) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
Mutex M2 (0x720c00039030) created at:
#0 pthread_mutex_init ../../../../src/libsanitizer/tsan/tsan_interceptors_posix.cpp:1315 (libtsan.so.2+0x58bfd) (BuildId: 64c1e8de04b11a7d960abd7e45f94f3b277b7779)
#1 sync_mutex_create runtime/sync_posix.h:44 (test.exe+0x2e84aa) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#2 caml_ml_mutex_new runtime/sync.c:77 (test.exe+0x2e84aa)
#3 caml_c_call <null> (test.exe+0x2f2439) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#4 camlEio__core__Switch.create_1177 lib_eio/core/switch.ml:127 (test.exe+0x198298) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#5 camlEio__core__Switch.fun_1376 lib_eio/core/switch.ml:152 (test.exe+0x19858b) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#6 camlEio__core__Cancel.with_cc_1067 lib_eio/core/cancel.ml:118 (test.exe+0x194b3b) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#7 camlDune__exe__Test.process_822 bin/test.ml:21 (test.exe+0x115090) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#8 camlEio__Executor_pool.fun_814 lib_eio/executor_pool.ml:31 (test.exe+0x189be6) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#9 camlEio__core__Fiber.fun_1441 lib_eio/core/fiber.ml:21 (test.exe+0x19f2e6) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#10 camlStdlib__Fun.protect_326 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:34 (test.exe+0x24753a) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#11 caml_runstack <null> (test.exe+0x2f2d91) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#12 camlStdlib__Fun.protect_326 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:34 (test.exe+0x24753a) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#13 camlEio_posix__Sched.run_1355 lib_eio_posix/sched.ml:381 (test.exe+0x119644) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#14 camlEio_posix__Sched.with_sched_1218 lib_eio_posix/sched.ml:258 (test.exe+0x118959) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#15 camlStdlib__Fun.protect_326 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:34 (test.exe+0x24753a) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#16 camlStdlib__Domain.body_741 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/domain.ml:266 (test.exe+0x2258ef) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#17 caml_start_program <null> (test.exe+0x2f25b3) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#18 caml_callback_exn runtime/callback.c:205 (test.exe+0x2a1973) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#19 caml_callback_res runtime/callback.c:320 (test.exe+0x2a29b4) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#20 domain_thread_func runtime/domain.c:1245 (test.exe+0x2a79a5) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
Thread T16 (tid=912754, running) created by main thread at:
#0 pthread_create ../../../../src/libsanitizer/tsan/tsan_interceptors_posix.cpp:1022 (libtsan.so.2+0x5a267) (BuildId: 64c1e8de04b11a7d960abd7e45f94f3b277b7779)
#1 caml_domain_spawn runtime/domain.c:1294 (test.exe+0x2a9cbe) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#2 caml_c_call <null> (test.exe+0x2f2439) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#3 camlStdlib__Domain.spawn_736 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/domain.ml:284 (test.exe+0x225806) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#4 camlEio_posix__Domain_mgr.fun_1449 lib_eio_posix/domain_mgr.ml:117 (test.exe+0x128f6e) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#5 camlEio_posix__Sched.fun_1761 lib_eio_posix/sched.ml:355 (test.exe+0x119f4c) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#6 camlStdlib__Fun.protect_326 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:34 (test.exe+0x24753a) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#7 camlEio_posix__Sched.run_1355 lib_eio_posix/sched.ml:381 (test.exe+0x119644) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#8 camlEio_posix__Sched.with_sched_1218 lib_eio_posix/sched.ml:258 (test.exe+0x118959) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#9 camlDune__exe__Test.entry bin/test.ml:2 (test.exe+0x115211) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#10 caml_program <null> (test.exe+0x111e6e) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#11 caml_start_program <null> (test.exe+0x2f25b3) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#12 caml_startup_common runtime/startup_nat.c:127 (test.exe+0x2f1c58) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#13 caml_startup_common runtime/startup_nat.c:86 (test.exe+0x2f1c58)
#14 caml_startup_exn runtime/startup_nat.c:134 (test.exe+0x2f1d3b) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#15 caml_startup runtime/startup_nat.c:139 (test.exe+0x2f1d3b)
#16 caml_main runtime/startup_nat.c:146 (test.exe+0x2f1d3b)
#17 main runtime/main.c:37 (test.exe+0x111239) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
Thread T40587 (tid=953475, finished) created by thread T24 at:
#0 pthread_create ../../../../src/libsanitizer/tsan/tsan_interceptors_posix.cpp:1022 (libtsan.so.2+0x5a267) (BuildId: 64c1e8de04b11a7d960abd7e45f94f3b277b7779)
#1 st_thread_create /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/otherlibs/systhreads/st_pthreads.h:50 (test.exe+0x280885) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#2 caml_thread_new /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/otherlibs/systhreads/st_stubs.c:707 (test.exe+0x280885)
#3 caml_c_call <null> (test.exe+0x2f2439) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#4 camlThread.create_288 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/otherlibs/systhreads/thread.ml:45 (test.exe+0x153679) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#5 camlEio_unix__Thread_pool.make_thread_481 lib_eio/unix/thread_pool.ml:64 (test.exe+0x14a542) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#6 camlEio_unix__Thread_pool.submit_579 lib_eio/unix/thread_pool.ml:119 (test.exe+0x14ac39) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#7 camlEio_posix__Sched.fun_1791 lib_eio_posix/sched.ml:372 (test.exe+0x11a217) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#8 camlStdlib__Fun.protect_326 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:34 (test.exe+0x24753a) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#9 camlEio_posix__Sched.run_1355 lib_eio_posix/sched.ml:381 (test.exe+0x119644) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#10 camlEio_posix__Sched.with_sched_1218 lib_eio_posix/sched.ml:258 (test.exe+0x118959) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#11 camlStdlib__Fun.protect_326 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:34 (test.exe+0x24753a) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#12 camlStdlib__Domain.body_741 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/domain.ml:266 (test.exe+0x2258ef) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#13 caml_start_program <null> (test.exe+0x2f25b3) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#14 caml_callback_exn runtime/callback.c:205 (test.exe+0x2a1973) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#15 caml_callback_res runtime/callback.c:320 (test.exe+0x2a29b4) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#16 domain_thread_func runtime/domain.c:1245 (test.exe+0x2a79a5) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
SUMMARY: ThreadSanitizer: data race lib_eio/core/switch.ml:71 in camlEio__core__Switch.dec_fibers_1051
==================
==================
WARNING: ThreadSanitizer: data race (pid=912737)
Atomic read of size 8 at 0x7f8560b79f48 by thread T12 (mutexes: write M0):
#0 mark_stack_push_block runtime/major_gc.c:871 (test.exe+0x2c815b) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#1 caml_darken runtime/major_gc.c:1208 (test.exe+0x2ca02e) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#2 caml_darken runtime/major_gc.c:1186 (test.exe+0x2ca02e)
#3 scan_stack_frames runtime/fiber.c:280 (test.exe+0x2b1756) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#4 caml_scan_stack runtime/fiber.c:301 (test.exe+0x2b1756)
#5 caml_darken_cont runtime/major_gc.c:1177 (test.exe+0x2c9d9f) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#6 do_some_marking runtime/major_gc.c:1009 (test.exe+0x2cafa7) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#7 mark runtime/major_gc.c:1124 (test.exe+0x2cb199) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#8 major_collection_slice runtime/major_gc.c:1704 (test.exe+0x2cbcb7) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#9 caml_major_collection_slice runtime/major_gc.c:1884 (test.exe+0x2ccec4) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#10 caml_poll_gc_work runtime/domain.c:1874 (test.exe+0x2a8990) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#11 caml_handle_gc_interrupt runtime/domain.c:1901 (test.exe+0x2aa01f) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#12 caml_check_urgent_gc runtime/minor_gc.c:950 (test.exe+0x2da709) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#13 caml_alloc_string runtime/alloc.c:186 (test.exe+0x295bf4) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#14 caml_create_bytes runtime/str.c:78 (test.exe+0x2e729b) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#15 caml_c_call <null> (test.exe+0x2f2439) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#16 camlCstruct.copy_to_string_1171 lib/cstruct.ml:207 (test.exe+0x1cd138) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#17 camlEio__Path.fun_2315 lib_eio/path.ml:143 (test.exe+0x17ffba) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#18 camlEio__core__Switch.run_internal_1180 lib_eio/core/switch.ml:133 (test.exe+0x198393) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#19 camlEio__core__Cancel.with_cc_1067 lib_eio/core/cancel.ml:118 (test.exe+0x194b3b) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#20 camlDune__exe__Test.process_822 bin/test.ml:21 (test.exe+0x115090) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#21 camlEio__Executor_pool.fun_814 lib_eio/executor_pool.ml:31 (test.exe+0x189be6) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#22 camlEio__core__Fiber.fun_1441 lib_eio/core/fiber.ml:21 (test.exe+0x19f2e6) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#23 camlStdlib__Fun.protect_326 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:34 (test.exe+0x24753a) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#24 caml_runstack <null> (test.exe+0x2f2d91) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#25 camlStdlib__Fun.protect_326 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:34 (test.exe+0x24753a) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#26 camlEio_posix__Sched.run_1355 lib_eio_posix/sched.ml:381 (test.exe+0x119644) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#27 camlEio_posix__Sched.with_sched_1218 lib_eio_posix/sched.ml:258 (test.exe+0x118959) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#28 camlStdlib__Fun.protect_326 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:34 (test.exe+0x24753a) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#29 camlStdlib__Domain.body_741 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/domain.ml:266 (test.exe+0x2258ef) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#30 caml_start_program <null> (test.exe+0x2f25b3) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#31 caml_callback_exn runtime/callback.c:205 (test.exe+0x2a1973) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#32 caml_callback_res runtime/callback.c:320 (test.exe+0x2a29b4) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#33 domain_thread_func runtime/domain.c:1245 (test.exe+0x2a79a5) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
Previous write of size 8 at 0x7f8560b79f48 by thread T28 (mutexes: write M1):
#0 camlEio__core__Switch.dec_fibers_1051 lib_eio/core/switch.ml:71 (test.exe+0x1978e0) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#1 camlStdlib__Fun.finally_no_exn_330 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:30 (test.exe+0x247652) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#2 camlStdlib__Fun.protect_326 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:35 (test.exe+0x2475ae) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#3 caml_runstack <null> (test.exe+0x2f2d91) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#4 camlStdlib__Fun.protect_326 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:34 (test.exe+0x24753a) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#5 camlEio_posix__Sched.run_1355 lib_eio_posix/sched.ml:381 (test.exe+0x119644) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#6 camlEio_posix__Sched.with_sched_1218 lib_eio_posix/sched.ml:258 (test.exe+0x118959) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#7 camlStdlib__Fun.protect_326 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:34 (test.exe+0x24753a) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#8 camlStdlib__Domain.body_741 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/domain.ml:266 (test.exe+0x2258ef) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#9 caml_start_program <null> (test.exe+0x2f25b3) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#10 caml_callback_exn runtime/callback.c:205 (test.exe+0x2a1973) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#11 caml_callback_res runtime/callback.c:320 (test.exe+0x2a29b4) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#12 domain_thread_func runtime/domain.c:1245 (test.exe+0x2a79a5) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
Mutex M0 (0x72b4000006d0) created at:
#0 pthread_mutex_init ../../../../src/libsanitizer/tsan/tsan_interceptors_posix.cpp:1315 (libtsan.so.2+0x58bfd) (BuildId: 64c1e8de04b11a7d960abd7e45f94f3b277b7779)
#1 caml_plat_mutex_init runtime/platform.c:59 (test.exe+0x2dc362) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#2 caml_init_domains runtime/domain.c:974 (test.exe+0x2a7634) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#3 caml_init_gc runtime/gc_ctrl.c:348 (test.exe+0x2b6ab5) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#4 caml_startup_common runtime/startup_nat.c:106 (test.exe+0x2f1b37) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#5 caml_startup_common runtime/startup_nat.c:86 (test.exe+0x2f1b37)
#6 caml_startup_exn runtime/startup_nat.c:134 (test.exe+0x2f1d3b) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#7 caml_startup runtime/startup_nat.c:139 (test.exe+0x2f1d3b)
#8 caml_main runtime/startup_nat.c:146 (test.exe+0x2f1d3b)
#9 main runtime/main.c:37 (test.exe+0x111239) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
Mutex M1 (0x72b400000f10) created at:
#0 pthread_mutex_init ../../../../src/libsanitizer/tsan/tsan_interceptors_posix.cpp:1315 (libtsan.so.2+0x58bfd) (BuildId: 64c1e8de04b11a7d960abd7e45f94f3b277b7779)
#1 caml_plat_mutex_init runtime/platform.c:59 (test.exe+0x2dc362) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#2 caml_init_domains runtime/domain.c:974 (test.exe+0x2a7634) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#3 caml_init_gc runtime/gc_ctrl.c:348 (test.exe+0x2b6ab5) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#4 caml_startup_common runtime/startup_nat.c:106 (test.exe+0x2f1b37) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#5 caml_startup_common runtime/startup_nat.c:86 (test.exe+0x2f1b37)
#6 caml_startup_exn runtime/startup_nat.c:134 (test.exe+0x2f1d3b) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#7 caml_startup runtime/startup_nat.c:139 (test.exe+0x2f1d3b)
#8 caml_main runtime/startup_nat.c:146 (test.exe+0x2f1d3b)
#9 main runtime/main.c:37 (test.exe+0x111239) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
Thread T12 (tid=912750, running) created by main thread at:
#0 pthread_create ../../../../src/libsanitizer/tsan/tsan_interceptors_posix.cpp:1022 (libtsan.so.2+0x5a267) (BuildId: 64c1e8de04b11a7d960abd7e45f94f3b277b7779)
#1 caml_domain_spawn runtime/domain.c:1294 (test.exe+0x2a9cbe) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#2 caml_c_call <null> (test.exe+0x2f2439) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#3 camlStdlib__Domain.spawn_736 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/domain.ml:284 (test.exe+0x225806) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#4 camlEio_posix__Domain_mgr.fun_1449 lib_eio_posix/domain_mgr.ml:117 (test.exe+0x128f6e) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#5 camlEio_posix__Sched.fun_1761 lib_eio_posix/sched.ml:355 (test.exe+0x119f4c) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#6 camlStdlib__Fun.protect_326 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:34 (test.exe+0x24753a) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#7 camlEio_posix__Sched.run_1355 lib_eio_posix/sched.ml:381 (test.exe+0x119644) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#8 camlEio_posix__Sched.with_sched_1218 lib_eio_posix/sched.ml:258 (test.exe+0x118959) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#9 camlDune__exe__Test.entry bin/test.ml:2 (test.exe+0x115211) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#10 caml_program <null> (test.exe+0x111e6e) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#11 caml_start_program <null> (test.exe+0x2f25b3) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#12 caml_startup_common runtime/startup_nat.c:127 (test.exe+0x2f1c58) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#13 caml_startup_common runtime/startup_nat.c:86 (test.exe+0x2f1c58)
#14 caml_startup_exn runtime/startup_nat.c:134 (test.exe+0x2f1d3b) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#15 caml_startup runtime/startup_nat.c:139 (test.exe+0x2f1d3b)
#16 caml_main runtime/startup_nat.c:146 (test.exe+0x2f1d3b)
#17 main runtime/main.c:37 (test.exe+0x111239) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
Thread T28 (tid=912766, running) created by main thread at:
#0 pthread_create ../../../../src/libsanitizer/tsan/tsan_interceptors_posix.cpp:1022 (libtsan.so.2+0x5a267) (BuildId: 64c1e8de04b11a7d960abd7e45f94f3b277b7779)
#1 caml_domain_spawn runtime/domain.c:1294 (test.exe+0x2a9cbe) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#2 caml_c_call <null> (test.exe+0x2f2439) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#3 camlStdlib__Domain.spawn_736 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/domain.ml:284 (test.exe+0x225806) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#4 camlEio_posix__Domain_mgr.fun_1449 lib_eio_posix/domain_mgr.ml:117 (test.exe+0x128f6e) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#5 camlEio_posix__Sched.fun_1761 lib_eio_posix/sched.ml:355 (test.exe+0x119f4c) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#6 camlStdlib__Fun.protect_326 /home/avsm/.opam/5.3.0+tsan/.opam-switch/build/ocaml-variants.5.3.0+trunk/stdlib/fun.ml:34 (test.exe+0x24753a) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#7 camlEio_posix__Sched.run_1355 lib_eio_posix/sched.ml:381 (test.exe+0x119644) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#8 camlEio_posix__Sched.with_sched_1218 lib_eio_posix/sched.ml:258 (test.exe+0x118959) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#9 camlDune__exe__Test.entry bin/test.ml:2 (test.exe+0x115211) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#10 caml_program <null> (test.exe+0x111e6e) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#11 caml_start_program <null> (test.exe+0x2f25b3) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#12 caml_startup_common runtime/startup_nat.c:127 (test.exe+0x2f1c58) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#13 caml_startup_common runtime/startup_nat.c:86 (test.exe+0x2f1c58)
#14 caml_startup_exn runtime/startup_nat.c:134 (test.exe+0x2f1d3b) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
#15 caml_startup runtime/startup_nat.c:139 (test.exe+0x2f1d3b)
#16 caml_main runtime/startup_nat.c:146 (test.exe+0x2f1d3b)
#17 main runtime/main.c:37 (test.exe+0x111239) (BuildId: 228a6c9ad794879ebbb16feade2d642f12a5cf5c)
SUMMARY: ThreadSanitizer: data race runtime/major_gc.c:871 in mark_stack_push_block
==================
It happens with both the uring and posix backend
The fact that it's racing with a read by the GC suggests these tsan reports are both false positives. I would expect it's perfectly reasonable for one domain to be examining the block's fields during marking in a major slice while another one is updating the count.
@OlivierNicole might know for sure.
Does it actually crash, or just give warnings from tsan? (on my machine, I only see the warnings)
I'm trying to reproduce the crash but have only gotten it once on the bigger program from which I extracted this testcase
ThreadSanitizer:DEADLYSIGNAL
==800191==ERROR: ThreadSanitizer: SEGV on unknown address 0x557e838d93a4 (pc 0x557e83a6f782 bp 0x722c0001ff80 sp 0x7f5624dff160 T800204)
==800191==The signal is caused by a WRITE memory access.
#0 oldify_one runtime/minor_gc.c:252 (main.exe+0x413782) (BuildId: 15be3c35d13b78db78a598b67ef2ce684d8ad79d)
#1 caml_empty_minor_heap_promote runtime/minor_gc.c:561 (main.exe+0x41495a) (BuildId: 15be3c35d13b78db78a598b67ef2ce684d8ad79d)
#2 caml_stw_empty_minor_heap_no_major_slice runtime/minor_gc.c:792 (main.exe+0x414fc0) (BuildId: 15be3c35d13b78db78a598b67ef2ce684d8ad79d)
#3 caml_stw_empty_minor_heap runtime/minor_gc.c:823 (main.exe+0x4152b6) (BuildId: 15be3c35d13b78db78a598b67ef2ce684d8ad79d)
#4 stw_handler runtime/domain.c:1486 (main.exe+0x3eb508) (BuildId: 15be3c35d13b78db78a598b67ef2ce684d8ad79d)
#5 handle_incoming runtime/domain.c:351 (main.exe+0x3eb508)
#6 caml_handle_incoming_interrupts runtime/domain.c:364 (main.exe+0x3ec18b) (BuildId: 15be3c35d13b78db78a598b67ef2ce684d8ad79d)
#7 caml_handle_gc_interrupt runtime/domain.c:1897 (main.exe+0x3ec18b)
#8 caml_do_pending_actions_res runtime/signals.c:338 (main.exe+0x41e06c) (BuildId: 15be3c35d13b78db78a598b67ef2ce684d8ad79d)
#9 caml_alloc_small_dispatch runtime/minor_gc.c:896 (main.exe+0x415514) (BuildId: 15be3c35d13b78db78a598b67ef2ce684d8ad79d)
#10 caml_garbage_collection runtime/signals_nat.c:86 (main.exe+0x42dd78) (BuildId: 15be3c35d13b78db78a598b67ef2ce684d8ad79d)
#11 caml_call_gc <null> (main.exe+0x42a165) (BuildId: 15be3c35d13b78db78a598b67ef2ce684d8ad79d)
#12 camlBase64_rfc2045.pp_base64_761 src/base64_rfc2045.ml:252 (main.exe+0x2ba8a6) (BuildId: 15be3c35d13b78db78a598b67ef2ce684d8ad79d)
#13 camlMrmime__B64.parser_898 src/base64_rfc2045.ml:278 (main.exe+0x27d255) (BuildId: 15be3c35d13b78db78a598b67ef2ce684d8ad79d)
#14 camlMrmime__B64.parser_898 lib/b64.ml:98 (main.exe+0x27d3a3) (BuildId: 15be3c35d13b78db78a598b67ef2ce684d8ad79d)
#15 camlMrmime__B64.parser_898 lib/b64.ml:98 (main.exe+0x27d3a3) (BuildId: 15be3c35d13b78db78a598b67ef2ce684d8ad79d)
#16 camlMrmime__B64.parser_898 lib/b64.ml:98 (main.exe+0x27d3a3) (BuildId: 15be3c35d13b78db78a598b67ef2ce684d8ad79d)
#17 camlMrmime__B64.parser_898 lib/b64.ml:98 (main.exe+0x27d3a3) (BuildId: 15be3c35d13b78db78a598b67ef2ce684d8ad79d)
Here's a simpler way to trigger the tsan error (no IO, works on Linux and Posix backends):
open Eio.Std
let run_worker () =
Switch.run ~name:"run_worker" @@ fun sw ->
while true do
Fiber.fork ~sw (fun () ->
for _ = 0 to 1000 do
ignore (String.make 10000 'a')
done
);
done
let () =
Eio_main.run @@ fun env ->
Eio.Switch.run @@ fun sw ->
let domain_mgr = Eio.Stdenv.domain_mgr env in
for _ = 1 to 7 do
Fiber.fork_daemon ~sw (fun () -> Eio.Domain_manager.run domain_mgr run_worker)
done;
for _ = 1 to 10000 do
Fiber.fork ~sw (fun () ->
for _ = 1 to 1000 do
ignore (Sys.opaque_identity ())
done
)
done