tests/python/c_code@c_ext/cfile.xml
author Edouard Tisserant
Wed, 31 Jan 2018 11:21:08 +0100
changeset 1914 99f8cfa80b15
parent 1463 de311ffe3961
permissions -rw-r--r--
launcher : move call to ShowSplashScreen and BackgroundInitialization to PreStart()
It doesn't change behaviour of launcher in beremiz, but may have some impact on some customizations.
Some customizations need to squeeze some bitmap folder init in between app creation and ShowSplashScreen
<?xml version='1.0' encoding='utf-8'?>
<CFile xmlns:xhtml="http://www.w3.org/1999/xhtml">
  <includes>
    <xhtml:p><![CDATA[
]]></xhtml:p>
  </includes>
  <variables>
    <variable name="TestInput" type="SINT" initial="0"/>
    <variable name="TestOutput" type="SINT"/>
  </variables>
  <globals>
    <xhtml:p><![CDATA[
volatile long Lock=0;
volatile char PtoC=1,CtoP=2;

extern long AtomicCompareExchange(long*,long, long);
extern char *PLC_ID;

int Simple_C_Call(int val){
  return val+1;
}

int Python_to_C_Call(char toC, char *fromC){
  /* Code called by python should never touch to 
     variables modified by PLC thread directly

     AtomicCompareExchange comes from 
     beremiz' runtime implementation */

  int res = 0;
  if(!AtomicCompareExchange((long*)&Lock, 0, 1)){
    PtoC=toC;
    *fromC=CtoP;
    AtomicCompareExchange((long*)&Lock, 1, 0);
    res=1;
  }
  printf("C code called by Python: toC %d fromC %d\n",toC,*fromC);
  printf("PLC_ID id %s\n",PLC_ID);
  return res;
}

int PLC_C_Call(char fromPLC, char *toPLC){
  /* PLC also have to be realy carefull not to 
     conflict with asynchronous python access */
  if(!AtomicCompareExchange((long*)&Lock, 0, 1)){
      CtoP = fromPLC;
      *toPLC = PtoC;
      AtomicCompareExchange((long*)&Lock, 1, 0);
      return 1;
  }
  return 0;
}
]]></xhtml:p>
  </globals>
  <initFunction>
    <xhtml:p><![CDATA[
]]></xhtml:p>
  </initFunction>
  <cleanUpFunction>
    <xhtml:p><![CDATA[
]]></xhtml:p>
  </cleanUpFunction>
  <retrieveFunction>
    <xhtml:p><![CDATA[
]]></xhtml:p>
  </retrieveFunction>
  <publishFunction>
    <xhtml:p><![CDATA[
if(!AtomicCompareExchange((long*)&Lock, 0, 1)){
    TestInput = CtoP + PtoC + TestOutput;
    AtomicCompareExchange((long*)&Lock, 1, 0);
}
]]></xhtml:p>
  </publishFunction>
</CFile>