Skip to content

Possible interop memory leak when passing temporary strings from native to managed #43

Open
@MuffinTastic

Description

@MuffinTastic

In Host engine.h, a new C string is allocated like so:

GENERATE_BINDINGS inline const char* GetProjectPath()
{
	std::string str = EngineProperties::LoadedProject.GetValue();

	// Copy string so we can use it out-of-scope
	char* cstr = new char[str.length() + 1];
	strcpy_s( cstr, str.length() + 1, str.c_str() );
		
	return cstr;
};

In the generated interop code on the managed side it's then converted to a C# string by use of MemoryContext:

public static string GetProjectPath(  ) 
{
	using var ctx = new MemoryContext( "Engine.GetProjectPath" );
	return ctx.GetString( _GetProjectPath(  ) );
}

MemoryContext.GetString() is defined as such:

internal string GetString( IntPtr strPtr )
{
	return Marshal.PtrToStringUTF8( strPtr ) ?? "UNKNOWN";
}

Marshal.PtrToStringUTF8()'s description says:

Allocates a managed String and copies all characters up to the first null character from an unmanaged UTF-8 string into it.

I don't see where cstr gets deallocated in this chain.

Metadata

Metadata

Assignees

No one assigned

    Labels

    No labels
    No labels

    Type

    No type

    Projects

    No projects

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions