OpenEuphoria

1. Suspicious behavior when calling functions described in dynamic libraries.

• Posted by kelen_ in June
• 482 views

A main program calls two procedures each defined in two separate dll files.

-- main.ex 
include std/dll.e 
sequence dll_extension 
ifdef LINUX then dll_extension = ".so" 
elsifdef WINDOWS then dll_extension = ".dll" 
end ifdef 
-- --- 
printf(1, "main : Begin\n") 
function_1() 
function_2() 
printf(1, "main : End\n") 
-- --- 
function function_1() 
    atom dll_id_1 = open_dll("./userdll_1" & dll_extension) 
    integer proc_rid_1 = define_c_proc(dll_id_1, "procedure_1", {}) 
    printf(1, "\tdll_id_1 : %d / proc_rid_1 : %d\n", {dll_id_1, proc_rid_1}) 
    c_proc(proc_rid_1, {}) 
    return(0) 
end function 
-- --- 
function function_2() 
    atom dll_id_2 = open_dll("./userdll_2" & dll_extension) 
    integer proc_rid_2 = define_c_proc(dll_id_2, "procedure_2", {}) 
    printf(1, "\tdll_id_2 : %d / proc_rid_2 : %d\n", {dll_id_2, proc_rid_2}) 
    c_proc(proc_rid_2, {}) 
    return(0) 
end function 

-- userdll_1.ex 
export procedure procedure_1() 
    printf(1, "\t--> Here userdll_1 / procedure_1()\n") 
end procedure 

-- userdll_2.ex 
export procedure procedure_2() 
    printf(1, "\t--> Here userdll_2 / procedure_2()\n") 
end procedure 

Under Windows euphoria-4.0.5-ow, euphoria-4.1.0-x86, euphoria-4.1.0-x64 the standard output gives this kind of things :

main : Begin 
    dll_id_1 : 14725352988672 / proc_rid_1 : 28 
    --> Here userdll_1 / procedure_1() 
    dll_id_2 : 14725352071168 / proc_rid_2 : 29 
    --> Here userdll_2 / procedure_2() 
main : End 

we see that everything is going well.

But under Linux euphoria-4.0.5-Linux-ix86, euphoria-4.1.0-Linux-x86, euphoria-4.1.0-Linux-x64 the standard output is :

main : Begin 
    dll_id_1 : 14387712 / proc_rid_1 : 19 
    --> Here userdll_1 / procedure_1() 
    dll_id_2 : 14384416 / proc_rid_2 : 20 
    --> Here userdll_1 / procedure_1() 
main : End 
free(): double free detected in tcache 2 
Aborted 

We can see that userdll_1 / procedure_1() is executed twice and program stops.
It seems that userdll_2 / procedure_2 is internally identified as userdll_1 / procedure_1 which can explain the detected double free.

This does not seem to be the expected behavior.

with all courtesy,
Philippe