Another small pitfall for the docs - GSlice memory error

[docb]

hi,
in my node-gdk app i got frequently
MEMORY-ERROR: node[112483]: GSlice: assertion failed: sinfo->n_allocated > 0
Aborted (core dumped)

Solution (due to some posts and it does so far not occur anymore):

G_SLICE=always-malloc node index.js

best, christian

[romgrk]

That's an interesting one. I'd rather try to understand and fix it first, if there is a technical reason for why it can't be fixed I'll include a mention in the pitfalls section. Would you be willing to help me by giving more info on how to reproduce the bug with a minimal test case? If for some reason your test case is big, would you be able to run your application with gdb -ex run --args node ./your-file.js, and get a backtrace (by typing backtrace) when there is a segfault?

[docb]

yes sure it is better to fix it. i was not sure if it is a glib/gtk problem.
These errors occur sporadically - i cannot narrow down to actions or node js code.
here is a backtrace
Thread 1 "node" received signal SIGSEGV, Segmentation fault.
0x00007fffdf8797f3 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
(gdb) backtrace
#0 0x00007fffdf8797f3 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#1 0x00007fffdf879e36 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007fffdf87b013 in g_slice_free1 () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3 0x00007fffd388c0d5 in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#4 0x00007fffdfb3cfa3 in g_object_unref () at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#5 0x00007fffd387b12d in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#6 0x00007fffdf84b022 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#7 0x00007fffdf84b98f in g_hash_table_unref () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#8 0x00007fffd387b13b in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#9 0x00007fffd3878f1c in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#10 0x00007fffd3879cc5 in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#11 0x00007fffd3879cdb in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#12 0x00007fffd3879cdb in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#13 0x00007fffd3879cdb in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#14 0x00007fffd3879cdb in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#15 0x00007fffd3879cdb in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#16 0x00007fffd3879cdb in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#17 0x00007fffd3879cdb in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#18 0x00007fffd38608c6 in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#19 0x00007fffdfb3810d in g_closure_invoke () at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#20 0x00007fffdfb4b05e in () at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#21 0x00007fffdfb53715 in g_signal_emit_valist () at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#22 0x00007fffdfb5412f in g_signal_emit () at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#23 0x00007fffda89aa22 in () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#24 0x00007fffda886080 in () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#25 0x00007fffdf85dd03 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#26 0x00007fffdf85d285 in g_main_context_dispatch () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#27 0x00007fffdf85d650 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#28 0x00007fffdf85d962 in g_main_loop_run () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#29 0x00007fffd3927a25 in gtk_main () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#30 0x00007fffded4edae in ffi_call_unix64 () at /usr/lib/x86_64-linux-gnu/libffi.so.6
#31 0x00007fffded4e71f in ffi_call () at /usr/lib/x86_64-linux-gnu/libffi.so.6
#32 0x00007fffdfda5382 in GNodeJS::FunctionCall(GNodeJS::FunctionInfo*, Nan::FunctionCallbackInfov8::Value const&, _GIArgument*, _GError**) (func=0x2ed8ee0, info=..., return_value=return_value@entry=0x0, error=error@entry=0x0) at ../src/function.cc:258
#33 0x00007fffdfda5824 in GNodeJS::FunctionInvoker(Nan::FunctionCallbackInfov8::Value const&) (info=...) at ../src/function.cc:638
#34 0x00007fffdfda3aef in Nan::imp::FunctionCallbackWrapper(v8::FunctionCallbackInfov8::Value const&) (info=...) at ../node_modules/nan/nan_callbacks_12_inl.h:176
#35 0x0000000000b917ef in v8::internal::MaybeHandlev8::internal::Object v8::internal::(anonymous namespace)::HandleApiCallHelper(v8::internal::Isolate*, v8::internal::Handlev8::internal::HeapObject, v8::internal::Handlev8::internal::HeapObject, v8::internal::Handlev8::internal::FunctionTemplateInfo, v8::internal::Handlev8::internal::Object, v8::internal::BuiltinArguments) ()
#36 0x0000000000b92359 in v8::internal::Builtin_HandleApiCall(int, v8::internal::Object**, v8::internal::Isolate*) ()
#37 0x00000c4a291dbe1d in ()
#38 0x00000c4a291dbd81 in ()
#39 0x00007fffffffb8d0 in ()
#40 0x0000000000000006 in ()
#41 0x00007fffffffb960 in ()
#42 0x00000c4a291918d5 in ()
#43 0x00001a1c920026f1 in ()

[docb]

here is one with the GSlice Error
MEMORY-ERROR: node[40442]: GSlice: assertion failed: sinfo->n_allocated > 0

Thread 1 "node" received signal SIGABRT, Aborted.
__GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
51 ../sysdeps/unix/sysv/linux/raise.c: No such file or directory.
(gdb) backtrace
#0 0x00007ffff6ab8f47 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
#1 0x00007ffff6aba8b1 in __GI_abort () at abort.c:79
#2 0x00007fffdf879724 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3 0x00007fffdf879794 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#4 0x00007fffdf879e36 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#5 0x00007fffdf87b013 in g_slice_free1 () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#6 0x00007fffd388c0d5 in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#7 0x00007fffdfb3cfa3 in g_object_unref () at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#8 0x00007fffd3862dbd in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#9 0x00007fffdfb3d012 in g_object_unref () at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#10 0x00007fffd388596c in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#11 0x00007fffd38943f2 in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#12 0x00007fffd3879c7b in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#13 0x00007fffd3879cdb in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#14 0x00007fffd3879cdb in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#15 0x00007fffd3879cdb in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#16 0x00007fffd3879cdb in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#17 0x00007fffd3879cdb in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#18 0x00007fffd38608c6 in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#19 0x00007fffdfb3810d in g_closure_invoke () at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#20 0x00007fffdfb4b05e in () at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#21 0x00007fffdfb53715 in g_signal_emit_valist () at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#22 0x00007fffdfb5412f in g_signal_emit () at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#23 0x00007fffda8e1a22 in () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#24 0x00007fffda8cd080 in () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#25 0x00007fffdf85dd03 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#26 0x00007fffdf85d285 in g_main_context_dispatch () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#27 0x00007fffdf85d650 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#28 0x00007fffdf85d962 in g_main_loop_run () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#29 0x00007fffd3927a25 in gtk_main () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#30 0x00007fffded4edae in ffi_call_unix64 () at /usr/lib/x86_64-linux-gnu/libffi.so.6
#31 0x00007fffded4e71f in ffi_call () at /usr/lib/x86_64-linux-gnu/libffi.so.6
#32 0x00007fffdfda5382 in GNodeJS::FunctionCall(GNodeJS::FunctionInfo*, Nan::FunctionCallbackInfov8::Value const&, _GIArgument*, _GError**) (func=0x2ed4680, info=..., return_value=return_value@entry=0x0, error=error@entry=0x0) at ../src/function.cc:258
#33 0x00007fffdfda5824 in GNodeJS::FunctionInvoker(Nan::FunctionCallbackInfov8::Value const&) (info=...) at ../src/function.cc:638
#34 0x00007fffdfda3aef in Nan::imp::FunctionCallbackWrapper(v8::FunctionCallbackInfov8::Value const&) (info=...) at ../node_modules/nan/nan_callbacks_12_inl.h:176
#35 0x0000000000b917ef in v8::internal::MaybeHandlev8::internal::Object v8::internal::(anonymous namespace)::HandleApiCallHelper(v8::internal::Isolate*, v8::internal::Handlev8::internal::HeapObject, v8::internal::Handlev8::internal::HeapObject, v8::internal::Handlev8::internal::FunctionTemplateInfo, v8::internal::Handlev8::internal::Object, v8::internal::BuiltinArguments) ()
#36 0x0000000000b92359 in v8::internal::Builtin_HandleApiCall(int, v8::internal::Object**, v8::internal::Isolate*) ()
#37 0x00002b78b99dbe1d in ()
#38 0x00002b78b99dbd81 in ()
#39 0x00007fffffffb8d0 in ()
#40 0x0000000000000006 in ()
#41 0x00007fffffffb960 in ()

[docb]

it happens when the mouse pointer leaves the window. may be not all cases but this i could observe multiple times.

[docb]

another observation: with G_SLICE=always-malloc set i have no sudden crashes anymore but suddenly the motion event frequency goes down to c.a 3 events per second which is either unusable. however so far i cannot see any leaks in the system monitor.

[romgrk]

Got it. Do you happen to have a reproducible example? If your code is in a public repo I'd be happy to test it.

[docb]

https://github.com/docb/gtkosc
i have pushed this one. call node index.js and play arround.

[romgrk]

Got it. I've been able to reproduce quite quickly, I'll investigate.