[julia-users] Weird problem when I call a C function from a DLL library inside a loop

[Júlio Dias]

I really can´t understand what is going wrong. I would appreciate some help

At first, I defined a function which calls a simple C DLL function

function Study_create(iprt)
  ptr_pointer = ccall((:Study_create, "MyLibraryWin32"),Int32,(Int32,),iprt)
  return ptr_pointer
end

I have no problem to call my function Study_create. I can call it a number 
of times:

        imap2 = Study_create(0)
        imap3 = Study_create(0)
        imap4 = Study_create(0)

And if a watch imap2, imap3, imap4, the return values are ok.

But if I write a loop to run the same idea:

for test = 1:3
      imap = Study_create(0)
end

Julia crashes in the first iteration(test=1) with this output: 

Please submit a bug report with steps to reproduce this fault, and any 
error mes
sages that follow (in their entirety). Thanks.
Exception: EXCEPTION_ACCESS_VIOLATION at 0x654513ae -- jl_init_types at 
 (unknow
n line)
jl_init_types at D:\Julia-0.4.0_x86\bin\libjulia.dll (unknown line)
jl_init_types at D:\Julia-0.4.0_x86\bin\libjulia.dll (unknown line)
jl_apply_generic at D:\Julia-0.4.0_x86\bin\libjulia.dll (unknown line)
anonymous at D:\Julia-0.4.0_x86\examples\testepsrclasses\example1.jl:
27
jl_eval_with_compiler_p at D:\Julia-0.4.0_x86\bin\libjulia.dll (unknown 
line)
jl_parse_eval_all at D:\Julia-0.4.0_x86\bin\libjulia.dll (unknown line)
jl_load_ at D:\Julia-0.4.0_x86\bin\libjulia.dll (unknown line)
include at boot.jl:261
jl_apply_generic at D:\Julia-0.4.0_x86\bin\libjulia.dll (unknown line)
include_from_node1 at loading.jl:304
jl_apply_generic at D:\Julia-0.4.0_x86\bin\libjulia.dll (unknown line)
process_options at client.jl:308
_start at client.jl:410
jl_apply_generic at D:\Julia-0.4.0_x86\bin\libjulia.dll (unknown line)
jl_get_global at D:\Julia-0.4.0_x86\bin\libjulia.dll (unknown line)
unknown function (ip: 0040185B)
unknown function (ip: 004026B3)
unknown function (ip: 004013F0)
BaseThreadInitThunk at C:\Windows\SYSTEM32\KERNEL32.DLL (unknown line)
RtlInitializeExceptionChain at C:\Windows\SYSTEM32\ntdll.dll (unknown line)
RtlInitializeExceptionChain at C:\Windows\SYSTEM32\ntdll.dll (unknown line)

Even if I call directly ccall((:Study_create, 
"MyLibraryWin32"),Int32,(Int32,),0)I have the same problem
Any Idea?
Thank you.