On 19-05-2020 21:00, Rasmus Thomsen wrote:


I'm using glibd in a GDBus server of mine and overall I really enjoy using it. However, I started profiling the thing with Valgrind and noticed some memory leaks, especially around using VariantBuilder. So I thought it might be a good idea to use the stack allocated VariantBuilders and explicitly call .clear on those to avoid leaking memory, but the following piece of code SIGSEGVs for me:

import glib.VariantBuilder;
import glib.VariantType;

void main() {
	VariantBuilder builder;
	builder.init(new VariantType("a(s)"));

I'm not exactly sure what I'm doing wrong, since this (seemingly) equivalent piece of code written with the C API seems to work:

import glib.c.types;
import glib.c.functions;
import glib.VariantType;

void main() {
	GVariantBuilder builder;
	g_variant_builder_init(&builder, new VariantType("a(s)").getVariantTypeStruct(true));

FWIW in my actual code I did something like this:

Variant getAll()
     auto builder = new VariantBuilder(new VariantType("a{sv}"));

     builder.open(new VariantType("{sv}"));
     builder.addValue(new Variant("allowUntrustedRepos"));
     builder.addValue(new Variant(new Variant(this.allowUntrustedRepositories)));

     builder.open(new VariantType("{sv}"));
     builder.addValue(new Variant("root"));
     builder.addValue(new Variant(new Variant(this.root)));

     return builder.end();

And apparently that leaks memory - or was that just Valgrind not liking what the GC did?

Since VariantBuilder is a class it's not allocated on the stack, so
currently you are calling init on a null pointer.

GVariantBuilder is a struct so it's on the stack and the C code works
like expected.

As far as i know Valgrind does indeed have issues with the GC.