• Rick Mann <rmann-d-lang latencyzero.com> Feb 19 2007
• Bill Baxter <dnewsgroup billbaxter.com> Feb 19 2007

Rick Mann <rmann-d-lang latencyzero.com> writes:

Kirk McDonald Wrote:

 However, there's a very important detail which you should not overlook: 
 You are passing a pointer to GC-controlled data to a C library. The D 
 garbage collector doesn't scan the C library for references, so you will 
 need to keep a reference to any structs you pass to Carbon in your D 
 code. Otherwise, the GC will feel free to collect them when you least 
 expect it. This can be done with an AA:


Yes, thank you, I was aware of that. As it turns out, there's other stuff I
need to do with my delegate that I can't do (namely, treat the .ptr portion of
it as a pointer to a class derived from some interface Foo), so I ended up
having to create a little class wrapper.

I add the class to the GC's root with std.gc.addRoot(). This should work, right
(rather than storing it in an AA)?

Bill Baxter <dnewsgroup billbaxter.com> writes:

Rick Mann wrote:
 Kirk McDonald Wrote:
 
 However, there's a very important detail which you should not overlook: 
 You are passing a pointer to GC-controlled data to a C library. The D 
 garbage collector doesn't scan the C library for references, so you will 
 need to keep a reference to any structs you pass to Carbon in your D 
 code. Otherwise, the GC will feel free to collect them when you least 
 expect it. This can be done with an AA:


 Yes, thank you, I was aware of that. As it turns out, there's other stuff I
need to do with my delegate that I can't do (namely, treat the .ptr portion of
it as a pointer to a class derived from some interface Foo), so I ended up
having to create a little class wrapper.
 
 I add the class to the GC's root with std.gc.addRoot(). This should work,
right (rather than storing it in an AA)?


That's going to tie you to a particular gc implementation, though.  So I 
think the practice should be avoided unless you have a compelling reason 
to do it that way.

--bb