Data race in EditorExportPlatformWeb::~EditorExportPlatformWeb() detected by ThreadSanitizer

[Rubonnek]

Tested versions

63d6bda - reproducible

System information

Godot v4.3.dev (63d6bda) - Arch Linux #1 SMP PREEMPT_DYNAMIC Fri, 02 Feb 2024 17:03:55 +0000 - Tty - Vulkan (Forward+) - dedicated AMD Radeon RX 6900 XT (RADV NAVI21) () - AMD Ryzen 9 5950X 16-Core Processor (32 Threads)

Issue description

Closing the Editor with ThreadSanitizer enabled against an empty project will generate a data race warning by ThreadSanitizer.

Steps to reproduce

1. Compile Godot with ThreadSanitizer enabled -- the following is the command I used:

scons -Q -s platform=linuxbsd dev_mode=yes dev_build=yes udev=yes target=editor debug_symbols=yes precision=single bits=64 optimize=debug compiledb=yes use_llvm=yes linker=lld tests=yes use_asan=no use_tsan=yes werror=no -j$(nproc)

If you are on Arch Linux, it seems that linking to libatomic.a is unnecessary -- you may need to apply the following patch and try to compile again if it previously failed:

diff --git a/platform/linuxbsd/detect.py b/platform/linuxbsd/detect.py
index 7946ef6228..14471c2393 100644
--- a/platform/linuxbsd/detect.py
+++ b/platform/linuxbsd/detect.py
@@ -520,8 +520,6 @@ def configure(env: "Environment"):
     # Link those statically for portability
     if env["use_static_cpp"]:
         env.Append(LINKFLAGS=["-static-libgcc", "-static-libstdc++"])
-        if env["use_llvm"] and platform.system() != "FreeBSD":
-            env["LINKCOM"] = env["LINKCOM"] + " -l:libatomic.a"
     else:
         if env["use_llvm"] and platform.system() != "FreeBSD":
             env.Append(LIBS=["atomic"])

2. Decompress the MRP below and open a terminal at the MRP project path and run:

TSAN_OPTIONS=second_deadlock_stack=1 /opt/godot/bin/godot.linuxbsd.editor.dev.x86_64.llvm.san -e

If the FATAL: ThreadSanitizer: unexpected memory mapping error appears, you may need to temporarily lower the ASLR entropy:

sudo sysctl vm.mmap_rnd_bits=28
# reverse it with: sudo sysctl vm.mmap_rnd_bits=32

OR disable ASLR entirely temporarily :

sudo sysctl kernel.randomize_va_space=0
# reverse it with: sudo sysctl kernel.randomize_va_space=2

3. The following ThreadSanitizer warning should appear somewhere in the log:

==================
WARNING: ThreadSanitizer: data race (pid=41490)
  Write of size 1 at 0x7b500000cbc0 by main thread:
    #0 EditorExportPlatformWeb::~EditorExportPlatformWeb() /opt/godot/platform/web/export/export_plugin.cpp:717:14 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x61abdfd) (BuildId: 77398a27c54674f8)
    #1 void memdelete<EditorExportPlatform>(EditorExportPlatform*) /opt/godot/./core/os/memory.h:109:13 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x628f507) (BuildId: 77398a27c54674f8)
    #2 Ref<EditorExportPlatform>::unref() /opt/godot/./core/object/ref_counted.h:210:4 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x628f507)
    #3 Ref<EditorExportPlatform>::~Ref() /opt/godot/./core/object/ref_counted.h:222:3 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x628f507)
    #4 CowData<Ref<EditorExportPlatform>>::_unref(void*) /opt/godot/./core/templates/cowdata.h:242:13 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x628f507)
    #5 CowData<Ref<EditorExportPlatform>>::~CowData() /opt/godot/./core/templates/cowdata.h:445:2 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x628dc11) (BuildId: 77398a27c54674f8)
    #6 Vector<Ref<EditorExportPlatform>>::~Vector() /opt/godot/./core/templates/vector.h:291:28 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x628dc11)
    #7 EditorExport::~EditorExport() /opt/godot/editor/export/editor_export.cpp:397:1 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x628dc11)
    #8 void memdelete<Node>(Node*) /opt/godot/./core/os/memory.h:109:13 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x708d0b9) (BuildId: 77398a27c54674f8)
    #9 Node::_notification(int) /opt/godot/scene/main/node.cpp:217:5 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x708d0b9)
    #10 Node::_notificationv(int, bool) /opt/godot/./scene/main/node.h:49:2 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x5a74b8c) (BuildId: 77398a27c54674f8)
    #11 EditorNode::_notificationv(int, bool) /opt/godot/editor/editor_node.h:123:2 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x5a74b8c)
    #12 Object::notification(int, bool) /opt/godot/core/object/object.cpp:851:3 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0xa16b995) (BuildId: 77398a27c54674f8)
    #13 Object::_predelete() /opt/godot/core/object/object.cpp:198:2 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0xa16b995)
    #14 predelete_handler(Object*) /opt/godot/core/object/object.cpp:2048:19 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0xa183df5) (BuildId: 77398a27c54674f8)
    #15 void memdelete<Node>(Node*) /opt/godot/./core/os/memory.h:105:7 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x708d0a1) (BuildId: 77398a27c54674f8)
    #16 Node::_notification(int) /opt/godot/scene/main/node.cpp:217:5 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x708d0a1)
    #17 Node::_notificationv(int, bool) /opt/godot/./scene/main/node.h:49:2 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x71dfd46) (BuildId: 77398a27c54674f8)
    #18 Viewport::_notificationv(int, bool) /opt/godot/./scene/main/viewport.h:95:2 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x71dfd46)
    #19 Window::_notificationv(int, bool) /opt/godot/scene/main/window.h:45:2 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x71dfd46)
    #20 Object::notification(int, bool) /opt/godot/core/object/object.cpp:851:3 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0xa16b995) (BuildId: 77398a27c54674f8)
    #21 Object::_predelete() /opt/godot/core/object/object.cpp:198:2 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0xa16b995)
    #22 predelete_handler(Object*) /opt/godot/core/object/object.cpp:2048:19 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0xa183df5) (BuildId: 77398a27c54674f8)
    #23 void memdelete<Window>(Window*) /opt/godot/./core/os/memory.h:105:7 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x70f3acd) (BuildId: 77398a27c54674f8)
    #24 SceneTree::finalize() /opt/godot/scene/main/scene_tree.cpp:628:3 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x70f3acd)
    #25 OS_LinuxBSD::run() /opt/godot/platform/linuxbsd/os_linuxbsd.cpp:950:13 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x3ba24c7) (BuildId: 77398a27c54674f8)
    #26 main /opt/godot/platform/linuxbsd/godot_linuxbsd.cpp:74:6 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x3b91e34) (BuildId: 77398a27c54674f8)

  Previous read of size 1 at 0x7b500000cbc0 by thread T48:
    #0 EditorExportPlatformWeb::_server_thread_poll(void*) /opt/godot/platform/web/export/export_plugin.cpp:679:14 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x61ab2ed) (BuildId: 77398a27c54674f8)
    #1 Thread::callback(unsigned long, Thread::Settings const&, void (*)(void*), void*) /opt/godot/core/os/thread.cpp:64:3 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x98e20a8) (BuildId: 77398a27c54674f8)
    #2 void std::__invoke_impl<void, void (*)(unsigned long, Thread::Settings const&, void (*)(void*), void*), unsigned long, Thread::Settings, void (*)(void*), void*>(std::__invoke_other, void (*&&)(unsigned long, Thread::Settings const&, void (*)(void*), void*), unsigned long&&, Thread::Settings&&, void (*&&)(void*
), void*&&) /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/13.2.1/../../../../include/c++/13.2.1/bits/invoke.h:61:14 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x98e25b3) (BuildId: 77398a27c54674f8)
    #3 std::__invoke_result<void (*)(unsigned long, Thread::Settings const&, void (*)(void*), void*), unsigned long, Thread::Settings, void (*)(void*), void*>::type std::__invoke<void (*)(unsigned long, Thread::Settings const&, void (*)(void*), void*), unsigned long, Thread::Settings, void (*)(void*), void*>(void (*&
&)(unsigned long, Thread::Settings const&, void (*)(void*), void*), unsigned long&&, Thread::Settings&&, void (*&&)(void*), void*&&) /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/13.2.1/../../../../include/c++/13.2.1/bits/invoke.h:96:14 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x98e25b3)
    #4 void std::thread::_Invoker<std::tuple<void (*)(unsigned long, Thread::Settings const&, void (*)(void*), void*), unsigned long, Thread::Settings, void (*)(void*), void*>>::_M_invoke<0ul, 1ul, 2ul, 3ul, 4ul>(std::_Index_tuple<0ul, 1ul, 2ul, 3ul, 4ul>) /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/13.2.1/../../../../
include/c++/13.2.1/bits/std_thread.h:292:13 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x98e25b3)
    #5 std::thread::_Invoker<std::tuple<void (*)(unsigned long, Thread::Settings const&, void (*)(void*), void*), unsigned long, Thread::Settings, void (*)(void*), void*>>::operator()() /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/13.2.1/../../../../include/c++/13.2.1/bits/std_thread.h:299:11 (godot.linuxbsd.editor.dev.
x86_64.llvm.san+0x98e25b3)
    #6 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (*)(unsigned long, Thread::Settings const&, void (*)(void*), void*), unsigned long, Thread::Settings, void (*)(void*), void*>>>::_M_run() /usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/13.2.1/../../../../include/c++/13.2.1/bits/std_thread.h:244:13 (godo
t.linuxbsd.editor.dev.x86_64.llvm.san+0x98e25b3)
    #7 execute_native_thread_routine msdf-error-correction.cpp (godot.linuxbsd.editor.dev.x86_64.llvm.san+0xa693862) (BuildId: 77398a27c54674f8)

  Location is heap block of size 512 at 0x7b500000ca00 allocated by main thread:
    #0 malloc <null> (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x3b22ba3) (BuildId: 77398a27c54674f8)
    #1 Memory::alloc_static(unsigned long, bool) /opt/godot/core/os/memory.cpp:75:14 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x98d942d) (BuildId: 77398a27c54674f8)
    #2 operator new(unsigned long, char const*) /opt/godot/core/os/memory.cpp:40:9 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x98d942d)
    #3 Ref<EditorExportPlatformWeb>::instantiate() /opt/godot/./core/object/ref_counted.h:216:7 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x6196962) (BuildId: 77398a27c54674f8)
    #4 register_web_exporter() /opt/godot/platform/web/export/export.cpp:55:11 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x61964cd) (BuildId: 77398a27c54674f8)
    #5 register_exporters() /opt/godot/editor/register_exporters.gen.cpp:14:2 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x606f903) (BuildId: 77398a27c54674f8)
    #6 EditorNode::EditorNode() /opt/godot/editor/editor_node.cpp:6465:2 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x5a49d25) (BuildId: 77398a27c54674f8)
    #7 Main::start() /opt/godot/main/main.cpp:3578:18 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x3ccea06) (BuildId: 77398a27c54674f8)
    #8 main /opt/godot/platform/linuxbsd/godot_linuxbsd.cpp:72:6 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x3b91e19) (BuildId: 77398a27c54674f8)

  Thread T48 (tid=41542, running) created by main thread at:
    #0 pthread_create <null> (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x3b0da76) (BuildId: 77398a27c54674f8)
    #1 std::thread::_M_start_thread(std::unique_ptr<std::thread::_State, std::default_delete<std::thread::_State>>, void (*)()) <null> (godot.linuxbsd.editor.dev.x86_64.llvm.san+0xa693949) (BuildId: 77398a27c54674f8)
    #2 EditorExportPlatformWeb::EditorExportPlatformWeb() /opt/godot/platform/web/export/export_plugin.cpp:691:17 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x61ab421) (BuildId: 77398a27c54674f8)
    #3 Ref<EditorExportPlatformWeb>::instantiate() /opt/godot/./core/object/ref_counted.h:216:7 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x619696d) (BuildId: 77398a27c54674f8)
    #4 register_web_exporter() /opt/godot/platform/web/export/export.cpp:55:11 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x61964cd) (BuildId: 77398a27c54674f8)
    #5 register_exporters() /opt/godot/editor/register_exporters.gen.cpp:14:2 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x606f903) (BuildId: 77398a27c54674f8)
    #6 EditorNode::EditorNode() /opt/godot/editor/editor_node.cpp:6465:2 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x5a49d25) (BuildId: 77398a27c54674f8)
    #7 Main::start() /opt/godot/main/main.cpp:3578:18 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x3ccea06) (BuildId: 77398a27c54674f8)
    #8 main /opt/godot/platform/linuxbsd/godot_linuxbsd.cpp:72:6 (godot.linuxbsd.editor.dev.x86_64.llvm.san+0x3b91e19) (BuildId: 77398a27c54674f8)

SUMMARY: ThreadSanitizer: data race /opt/godot/platform/web/export/export_plugin.cpp:717:14 in EditorExportPlatformWeb::~EditorExportPlatformWeb()
==================

Minimal reproduction project (MRP)

EmptyProject.zip