Connection use after free

[dahankzter]

I realize that the bigger issue may be a bit away but is there something to do to work around this at the moment?

I get this in all the time when i spawn to read some data asynchronously.

[sfackler]

You should be able to make changes like this: #34 (comment)

[sfackler]

Did that help?

[dahankzter]

I do not know I am sorry I did not have time to test it before and now there seems to have been changes in virtually all my libs. :(

Fixed it all except:

error: mismatched types: expected `&[&postgres::types::ToSql]`, found `[_, ..0]` (expected &-ptr, found array of 0 elements)
src/hello_world.rs:91         for row in stmt.query([]).unwrap() {

Does the example in the readme still work?

[zr40]

That [] should be changed to &[]. Apparently this was missed by #80.

[dahankzter]

Thanks!

And the trick in the referenced issue seems to work. I had much more complex logic so I used a for loop something like this:

 let mut rows = stmt.query(&[]).unwrap();

        for row in rows {
            let object = TestStruct {
                data_int: row.get(0u),
                data_str: row.get(1u),
                data_vector: row.get(2u),
            };

            let encoded = json::encode(&object);
            tx.send(encoded);
        }
        rows;

Is that correct?

[sfackler]

Yep! I believe that the important part is that the statement and rows objects are "rooted". If they're only part of the expression that generates the return value of the block, then things get destructed in the wrong order.

[sfackler]

I fixed the brokenness in the README examples too: 3fb5043

[dahankzter]

Nice, thanks! How will the underlying thing be resolved? The idea is that the workaround should not be needed right?

[sfackler]

The compiler will make sure that things are structured so that destructors will run in the right order, I believe by preventing the broken version from compiling.

[dahankzter]

But how much mental bookkeeping should be needed? Maybe this will get natural when I get more into Rust but now it feels like "I want to execute something in a task, lets code it but make sure we root things properly" seems a little bit cumbersome.