12     <xhtml:p><![CDATA[

    12     <xhtml:p><![CDATA[

    13 volatile long Lock=0;

    13 volatile long Lock=0;

    14 volatile char PtoC=1,CtoP=2;

    14 volatile char PtoC=1,CtoP=2;

    15 

    15 

    16 extern long AtomicCompareExchange(long*,long, long);

    16 extern long AtomicCompareExchange(long*,long, long);

    17 

    18 

    18 int Simple_C_Call(int val){

    19 int Simple_C_Call(int val){

    19   return val+1;

    20   return val+1;

    20 }

    21 }

    21 

    22 

    32     *fromC=CtoP;

    33     *fromC=CtoP;

    33     AtomicCompareExchange((long*)&Lock, 1, 0);

    34     AtomicCompareExchange((long*)&Lock, 1, 0);

    34     res=1;

    35     res=1;

    35   }

    36   }

    36   printf("C code called by Python: toC %d fromC %d\n",toC,*fromC);

    37   printf("C code called by Python: toC %d fromC %d\n",toC,*fromC);

    37   return res;

    39   return res;

    38 }

    40 }

    39 

    41 

    40 int PLC_C_Call(char fromPLC, char *toPLC){

    42 int PLC_C_Call(char fromPLC, char *toPLC){

    41   /* PLC also have to be realy carefull not to 

    43   /* PLC also have to be realy carefull not to