Hello everyone! I want to create shared library that buffer some data and do some calculations, another program will use it. I wonder how this simplest code lead to crash (freeze) of dll:
---
// test_dll.d
import std.stdio;
import std.file;
import core.runtime;
import core.sys.windows.windows;
import std.exception;

version (test_dll) {
extern(C) {

export void TestFun() {
    double[int] T;
    foreach (i; 0..10000000) {
        writefln("i:%d",i);
        T[i] = i*1.0;
    }
}

} // extern(C)
} // version (test_dll)

version (test_exe) {
void main(string[] args) {
    if (!"test_dll.dll".exists) {
        writeln("test_dll.dll not exists");
    }

    HMODULE test_dll = cast(HMODULE) enforce(Runtime.loadLibrary("test_dll.dll"));

    alias extern(C) void function() Test_type;
    Test_type TestFun = cast(Test_type) enforce(GetProcAddress(test_dll, "TestFun"));
    TestFun();
} // main
} // version (stec_app)
---
Code compiled with options (version of dmd - 2.095.0, Windows 7 SP1, Intel Core i7 4790):
dmd -m64 -version=test_dll -shared -oftest_dll.dll -L/DLL test_dll.d dll.d
dmd -m64 -version=test_exe test_dll.d
Here dll.d - usual wrapper for DllMain (https://wiki.dlang.org/Win32_DLLs_in_D).

Any ideas? How to allocate memory in shared library properly?

On Monday, 25 January 2021 at 07:58:01 UTC, Vitalii wrote:
> Hello everyone! I want to create shared library that buffer some data and do some calculations, another program will use it. I wonder how this simplest code lead to crash (freeze) of dll:

Not tested your code but you have to use

import core.sys.windows.dll;
mixin SimpleDllMain;

Windows ist expecting a DllMain routine and runtime needs to attach the DLL thread.

On Monday, 25 January 2021 at 10:26:20 UTC, frame wrote:
> On Monday, 25 January 2021 at 07:58:01 UTC, Vitalii wrote:
>> Hello everyone! I want to create shared library that buffer some data and do some calculations, another program will use it. I wonder how this simplest code lead to crash (freeze) of dll:
>
> Not tested your code but you have to use
>
> import core.sys.windows.dll;
> mixin SimpleDllMain;
>
> Windows ist expecting a DllMain routine and runtime needs to attach the DLL thread.

Yes. I'm doing it whet add dll.d (https://wiki.dlang.org/Win32_DLLs_in_D) in compile line, it contents:
---
import core.sys.windows.windows;
import core.sys.windows.dll;

__gshared HINSTANCE g_hInst;

extern (Windows)
BOOL DllMain(HINSTANCE hInstance, ULONG ulReason, LPVOID pvReserved)
{
    switch (ulReason)
    {
	case DLL_PROCESS_ATTACH:
	    g_hInst = hInstance;
	    dll_process_attach( hInstance, true );
	    break;

	case DLL_PROCESS_DETACH:
	    dll_process_detach( hInstance, true );
	    break;

	case DLL_THREAD_ATTACH:
	    dll_thread_attach( true, true );
	    break;

	case DLL_THREAD_DETACH:
	    dll_thread_detach( true, true );
	    break;

        default:
    }
    return true;
}
---
Dll is starting ok. But after freeze after printing number around 64000 (~2^16). When I change assoc.array to simple array of double[] it freeze after number around 520000 (~2^19), int[] -- 1.000.000. So I conclude than dll freeze after exceed some memory limit about 4 Mb. But I still can't see what I'm doing wrong. Any ideas?

On Monday, 25 January 2021 at 11:30:45 UTC, Vitalii wrote:

> ---
> Dll is starting ok. But after freeze after printing number around 64000 (~2^16). When I change assoc.array to simple array of double[] it freeze after number around 520000 (~2^19), int[] -- 1.000.000. So I conclude than dll freeze after exceed some memory limit about 4 Mb. But I still can't see what I'm doing wrong. Any ideas?

I'm not an expert but it shouldn't freeze at all. Crashing maybe, but not freeze.
Sounds like a problem with the compiler and OS support. A memory limit makes not sense here.

On Monday, 25 January 2021 at 11:30:45 UTC, Vitalii wrote:
> On Monday, 25 January 2021 at 10:26:20 UTC, frame wrote:
>> [...]
>
> Yes. I'm doing it whet add dll.d (https://wiki.dlang.org/Win32_DLLs_in_D) in compile line, it contents:
> ---
> import core.sys.windows.windows;
> import core.sys.windows.dll;
>
> __gshared HINSTANCE g_hInst;
>
> extern (Windows)
> BOOL DllMain(HINSTANCE hInstance, ULONG ulReason, LPVOID pvReserved)
> {
>     switch (ulReason)
>     {
> 	case DLL_PROCESS_ATTACH:
> 	    g_hInst = hInstance;
> 	    dll_process_attach( hInstance, true );
> 	    break;
>
> 	case DLL_PROCESS_DETACH:
> 	    dll_process_detach( hInstance, true );
> 	    break;
>
> 	case DLL_THREAD_ATTACH:
> 	    dll_thread_attach( true, true );
> 	    break;
>
> 	case DLL_THREAD_DETACH:
> 	    dll_thread_detach( true, true );
> 	    break;
>
>         default:
>     }
>     return true;
> }
> ---

try replacing this with mixin SimpleDllMain (it initializes runtime for you IIRC). Runtime.LoadLibrary() is expected to call rt_init too, but Windows support for shared libs is too far from good.