i hate asking for help, but... now i'm pushed in the corner. so here is my problem:
i have struct with handle, and i need to send this struct or handle to second thread, all fine but feeding this struct or handle to send results in multiple errors(mostly complains about thread local data). and unfortunatelly shared and __gshared doesn't helps(complains about unknown size of handle).

well, i wish i could describe in details without code but... here is simplified example
--------

void main() {
  MyData data;
  // load data
  ...

  MyWindow wnd(data);
  wnd.show();
  auto tid = spawn(&newViewThread);
  send(tid, wnd);
}

// struct because i want benefit from RAII, but if necessary could switch to class
struct MyWindow {
  this ( MyData data ) { ... }
  // WINDOW defined as struct but has no size
  WINDOW* handle;
}

// 3rd party func to get window
WINDOW* createWindow(...);

----------
shortly speaking, WINDOW is pointer to window in C library so it's "shared", and i need it in another thread to make opengl context current in that thread, but compiler simply doesn't allow me to do anything with that, and i can't change definition since it's 3rd party bindings. any suggestions?

On 07/18/2013 08:29 AM, evilrat wrote:

> i hate asking for help

Please do so. Otherwise we can't learn from others' issues. :)

> well, i wish i could describe in details without code

Can you show it with a short program without using platform specific definitions?

Ali

On Jul 18, 2013, at 8:29 AM, evilrat <evilrat666@gmail.com> wrote:
> 
> shortly speaking, WINDOW is pointer to window in C library so it's "shared", and i need it in another thread to make opengl context current in that thread, but compiler simply doesn't allow me to do anything with that, and i can't change definition since it's 3rd party bindings. any suggestions?

In short, you're trying to send a pointer via std.concurrency.  The easiest way is to cast it to/from shared.  Otherwise, you'd need to make it an opaque type like a size_t rather than a type D can tell is a reference.

On Thursday, 18 July 2013 at 17:23:20 UTC, Ali Çehreli wrote:
> On 07/18/2013 08:29 AM, evilrat wrote:
>
> > i hate asking for help
>
> Please do so. Otherwise we can't learn from others' issues. :)
>
that's who i am. long story, but in short, people hated when i ask something and after few minutes i find solution. i bother everyone ;(

> > well, i wish i could describe in details without code
>
> Can you show it with a short program without using platform specific definitions?

here is reduced example without platform-specific stuff,  requires derelict3 and glfw.
http://pastebin.com/rhB14YNs

On Thursday, 18 July 2013 at 23:36:34 UTC, Sean Kelly wrote:
> In short, you're trying to send a pointer via std.concurrency.  The easiest way is to cast it to/from shared.  Otherwise, you'd need to make it an opaque type like a size_t rather than a type D can tell is a reference.

sure cast to size_t and back works, but can shoot in the leg later anytime :(

On Friday, 19 July 2013 at 15:16:23 UTC, evilrat wrote:
> On Thursday, 18 July 2013 at 17:23:20 UTC, Ali Çehreli wrote:
>> On 07/18/2013 08:29 AM, evilrat wrote:
>>
>> > i hate asking for help
>>
>> Please do so. Otherwise we can't learn from others' issues. :)
>>
> that's who i am. long story, but in short, people hated when i ask something and after few minutes i find solution. i bother everyone ;(
>
>> > well, i wish i could describe in details without code
>>
>> Can you show it with a short program without using platform specific definitions?
>
> here is reduced example without platform-specific stuff,  requires derelict3 and glfw.
> http://pastebin.com/rhB14YNs

I can't get that to compile, I keep getting Derelict3/import/derelict/glfw3/types.d(290): Error: struct derelict.glfw3.types.GLFWwindow unknown size

I suspect I'm compiling wrong somehow.

On 07/19/2013 08:16 AM, evilrat wrote:

> here is reduced example without platform-specific stuff, requires
> derelict3 and glfw.
> http://pastebin.com/rhB14YNs

Further reduced by removing the need for derelict3 and glfw:

import std.stdio;
import std.concurrency;
import core.thread;

alias GLFWwindow = void;

struct Window {
    void create() {
        auto tid = spawn(&runNewView);
        send(tid, _wnd );        // <-- ERROR

        thread_joinAll();
    }

    GLFWwindow* _wnd;
}

void runNewView() {
    while ( true ) {
        receive (
            (string msg) { writeln(msg); },
            (const(GLFWwindow*) window) { }
                 );
    }
}

void main() {
    auto window = Window();
    // runs main loop
    window.create();
}

Error: static assert  "Aliases to mutable thread-local data not allowed."
       instantiated from here: send!(void*)

Is that the problem? (If so, why don't you say so? ;))

Then there are two solutions:

a) Make _wnd a shared(GLFWwindow):

struct Window {
    // ...

    shared(GLFWwindow)* _wnd;
}

The code now compiles.

b) As Sean Kelly said, cast to shared before sending:

        send(tid, cast(shared(GLFWwindow)*)_wnd );

With the b option you may need to change the definition of the receiving delegate to shared as well:

            (const(shared(GLFWwindow)*) window) { }

But that change is not needed in that simple code.

Ali

P.S. Additionally, the const on the receiving side probably should apply only to what is being pointed at (as opposed to the pointer itself):

            (const(GLFWwindow)* window) { }

On Friday, 19 July 2013 at 15:36:33 UTC, Ali Çehreli wrote:
>
> Error: static assert  "Aliases to mutable thread-local data not allowed."
>        instantiated from here: send!(void*)
>
> Is that the problem? (If so, why don't you say so? ;))
>
> Then there are two solutions:
>
> a) Make _wnd a shared(GLFWwindow):
>
> struct Window {
>     // ...
>
>     shared(GLFWwindow)* _wnd;
> }
>
> The code now compiles.
>
> b) As Sean Kelly said, cast to shared before sending:
>
>         send(tid, cast(shared(GLFWwindow)*)_wnd );
>
> With the b option you may need to change the definition of the receiving delegate to shared as well:
>
>             (const(shared(GLFWwindow)*) window) { }
>
> But that change is not needed in that simple code.

unfortunately both variants fails for me, i think this is because GLFWwindow is (pre)defined as struct instead alias void :(

maybe there is something to override type definition without modifying 3rd party libraries code?

/Users/evilrat/Documents/prog/Derelict3/import/derelict/glfw3/types.d(290): Error: struct derelict.glfw3.types.GLFWwindow unknown size
/Users/evilrat/Documents/prog/Derelict3/import/derelict/glfw3/types.d(290): Error: struct derelict.glfw3.types.GLFWwindow no size yet for forward reference

anyway thanks to both authors, now i could avoid such problems in the future \0/
>
> P.S. Additionally, the const on the receiving side probably should apply only to what is being pointed at (as opposed to the pointer itself):
>
>             (const(GLFWwindow)* window) { }

ah yes, such a shame. i'm sometimes forgot about this little detail :(

On Friday, 19 July 2013 at 15:35:27 UTC, John Colvin wrote:
> On Friday, 19 July 2013 at 15:16:23 UTC, evilrat wrote:
>> here is reduced example without platform-specific stuff,  requires derelict3 and glfw.
>> http://pastebin.com/rhB14YNs
>
> I can't get that to compile, I keep getting Derelict3/import/derelict/glfw3/types.d(290): Error: struct derelict.glfw3.types.GLFWwindow unknown size
>
> I suspect I'm compiling wrong somehow.

no you don't. this is because of the definition of GLFWwindow in derelict3 (it's really predefined as struct, not void*)

On 07/19/2013 09:00 AM, evilrat wrote:

> i think this is because GLFWwindow is (pre)defined as struct instead alias
> void :(

Further reduced:

import std.concurrency;

struct S;

void main()
{
    receive((S * p){});
}

Error: struct deneme.S is forward referenced when looking for 'toHash'
Error: struct deneme.S is forward referenced when looking for 'opCmp'
Error: struct deneme.S is forward referenced when looking for 'toString'
Error: struct deneme.S unknown size
Error: struct deneme.S no size yet for forward reference
Error: struct deneme.S unknown size
Error: struct deneme.S no size yet for forward reference

Ali