Thread overview
Can't send messages to tid spawned in a Windows DLL. Bug?
Feb 16
kinke
February 16
This fails for me in a DLL:

auto tid = spawn(&func);
assert(tid != Tid.init);

If I print out the tid, I find that its message box is null. This is odd, since according the code in std.concurrency there's nothing weird about how it gets a message box, it's just `auto spawnTid = Tid(new MessageBox);`. So... `new` is returning null???

The really weird thing is that a thread is spawned and func starts executing. I just can't send it any messages without crashing.

Atila
February 16
On Thursday, 16 February 2017 at 12:07:40 UTC, Atila Neves wrote:
> This fails for me in a DLL:
>
> auto tid = spawn(&func);
> assert(tid != Tid.init);
>
> If I print out the tid, I find that its message box is null. This is odd, since according the code in std.concurrency there's nothing weird about how it gets a message box, it's just `auto spawnTid = Tid(new MessageBox);`. So... `new` is returning null???
>
> The really weird thing is that a thread is spawned and func starts executing. I just can't send it any messages without crashing.
>
> Atila

If you suspect `new` of returning null, a GC issue seems likely. Is your DLL linked statically against druntime, thus having its own GC? Or are you using a shared druntime (and thus GC) across multiple binaries?
February 16
On Thursday, 16 February 2017 at 15:14:25 UTC, kinke wrote:
> On Thursday, 16 February 2017 at 12:07:40 UTC, Atila Neves wrote:
>> This fails for me in a DLL:
>>
>> auto tid = spawn(&func);
>> assert(tid != Tid.init);
>>
>> If I print out the tid, I find that its message box is null. This is odd, since according the code in std.concurrency there's nothing weird about how it gets a message box, it's just `auto spawnTid = Tid(new MessageBox);`. So... `new` is returning null???
>>
>> The really weird thing is that a thread is spawned and func starts executing. I just can't send it any messages without crashing.
>>
>> Atila
>
> If you suspect `new` of returning null, a GC issue seems likely. Is your DLL linked statically against druntime, thus having its own GC? Or are you using a shared druntime (and thus GC) across multiple binaries?

Whatever's default on Windows 32-bit. The thing is, all other uses of GC allocations in the same DLL work as expected.

Atila