beremiz

Added native (not a plugin) asynchronous python eval function block - Beta. Code cleanup in C code templates.

2008-12-23, etisserant
f2ef79f3dba0
Parents 47d29c4b55a3
Children 3f0fc8de99b0
Added native (not a plugin) asynchronous python eval function block - Beta. Code cleanup in C code templates.
10 files changed, 658 insertions(+), 69 deletions(-)
  • +20 -1
    plugger.py
  • +82 -0
    pous.xml
  • +29 -2
    runtime/PLCObject.py
  • +46 -16
    targets/Linux/plc_Linux_main.c
  • +77 -20
    targets/Win32/plc_Win32_main.c
  • +29 -26
    targets/plc_common_main.c
  • +1 -4
    targets/plc_debug.c
  • +179 -0
    targets/plc_python.c
  • +6 -0
    tests/python/beremiz.xml
  • +189 -0
    tests/python/plc.xml
    • --- a/plugger.py Tue Dec 23 19:31:28 2008 +0100
    +++ b/plugger.py Tue Dec 23 19:37:44 2008 +0100
    @@ -1078,6 +1078,23 @@
    return debug_code
    + def Generate_plc_python(self):
    + """
    + Generate trace/debug code out of PLC variable list
    + """
    + self.GetIECProgramsAndVariables()
    +
    + python_eval_fb_list = []
    + for v in self._VariablesList :
    + if v["vartype"] == "FB" and v["type"] == "PYTHON_EVAL":
    + python_eval_fb_list.append(v)
    + python_eval_fb_count = len(python_eval_fb_list)
    +
    + # prepare debug code
    + python_code = targets.code("plc_python") % {
    + "python_eval_fb_count": python_eval_fb_count}
    + return python_code
    +
    def Generate_plc_common_main(self):
    """
    Use plugins layout given in LocationCFilesAndCFLAGS to
    @@ -1175,6 +1192,8 @@
    for generator, filename, name in [
    # debugger code
    (self.Generate_plc_debugger, "plc_debugger.c", "Debugger"),
    + # IEC<->python gateway code
    + (self.Generate_plc_python, "plc_python.c", "IEC-Python gateway"),
    # init/cleanup/retrieve/publish, run and align code
    (self.Generate_plc_common_main,"plc_common_main.c","Common runtime")]:
    try:
    @@ -1408,7 +1427,7 @@
    # This will block thread if more than one call is waiting
    elif debug_vars is not None:
    wx.CallAfter(self.logger.write_warning,
    - "debug data not coherent %d != %d"%(len(debug_vars), len(self.TracedIECPath)))
    + "Debug data not coherent %d != %d\n"%(len(debug_vars), len(self.TracedIECPath)))
    elif debug_tick == -1:
    #wx.CallAfter(self.logger.write, "Debugger unavailable\n")
    pass
    --- /dev/null Thu Jan 01 00:00:00 1970 +0000
    +++ b/pous.xml Tue Dec 23 19:37:44 2008 +0100
    @@ -0,0 +1,82 @@
    +<?xml version="1.0" encoding="UTF-8"?>
    +<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    + xmlns="http://www.plcopen.org/xml/tc6.xsd"
    + xmlns:xhtml="http://www.w3.org/1999/xhtml"
    + xsi:schemaLocation="http://www.plcopen.org/xml/tc6.xsd">
    + <fileHeader companyName="LOLITECH"
    + productName="Beremiz"
    + productVersion="0.0"
    + creationDateTime="2008-12-14T16:53:26"/>
    + <contentHeader name="Beremiz non-standard POUs library"
    + modificationDateTime="2008-12-18T18:41:34">
    + <coordinateInfo>
    + <fbd>
    + <scaling x="0" y="0"/>
    + </fbd>
    + <ld>
    + <scaling x="0" y="0"/>
    + </ld>
    + <sfc>
    + <scaling x="0" y="0"/>
    + </sfc>
    + </coordinateInfo>
    + </contentHeader>
    + <types>
    + <dataTypes/>
    + <pous>
    + <pou name="python_eval" pouType="functionBlock">
    + <interface>
    + <inputVars>
    + <variable name="TRIG">
    + <type>
    + <BOOL/>
    + </type>
    + </variable>
    + <variable name="CODE">
    + <type>
    + <string/>
    + </type>
    + </variable>
    + </inputVars>
    + <outputVars>
    + <variable name="ACK">
    + <type>
    + <BOOL/>
    + </type>
    + </variable>
    + <variable name="RESULT">
    + <type>
    + <string/>
    + </type>
    + </variable>
    + </outputVars>
    + <localVars>
    + <variable name="STATE">
    + <type>
    + <DWORD/>
    + </type>
    + </variable>
    + <variable name="BUFFER">
    + <type>
    + <string/>
    + </type>
    + </variable>
    + <variable name="TRIGM1">
    + <type>
    + <BOOL/>
    + </type>
    + </variable>
    + </localVars>
    + </interface>
    + <body>
    + <ST>
    +<![CDATA[{extern void __PythonEvalFB(PYTHON_EVAL*);__PythonEvalFB(data__);}]]>
    + </ST>
    + </body>
    + </pou>
    + </pous>
    + </types>
    + <instances>
    + <configurations/>
    + </instances>
    +</project>
    --- a/runtime/PLCObject.py Tue Dec 23 19:31:28 2008 +0100
    +++ b/runtime/PLCObject.py Tue Dec 23 19:37:44 2008 +0100
    @@ -23,8 +23,9 @@
    #Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
    import Pyro.core as pyro
    -from threading import Timer
    +from threading import Timer, Thread
    import ctypes, os, commands
    +import time
    if os.name in ("nt", "ce"):
    from _ctypes import LoadLibrary as dlopen
    @@ -107,6 +108,10 @@
    self._resumeDebug = self.PLClibraryHandle.resumeDebug
    self._resumeDebug.restype = None
    +
    + self._PythonIterator = self.PLClibraryHandle.PythonIterator
    + self._PythonIterator.restype = ctypes.c_char_p
    + self._PythonIterator.argtypes = [ctypes.c_char_p]
    return True
    except:
    @@ -128,6 +133,7 @@
    self._WaitDebugData = lambda:-1
    self._suspendDebug = lambda:None
    self._resumeDebug = lambda:None
    + self._PythonIterator = lambda:""
    self.PLClibraryHandle = None
    # Unload library explicitely
    if getattr(self,"_PLClibraryHandle",None) is not None:
    @@ -163,6 +169,18 @@
    return True
    return False
    + def PythonThreadProc(self):
    + res = ""
    + print "PythonThreadProc started"
    + while self.PLCStatus == "Started":
    + cmd = self._PythonIterator(res)
    + print "_PythonIterator(", res, ") -> ", cmd
    + try :
    + res = eval(cmd)
    + except Exception,e:
    + res = "#EXCEPTION : "+str(e)
    + print res
    + print "PythonThreadProc finished"
    def StartPLC(self, debug=False):
    print "StartPLC"
    @@ -174,6 +192,8 @@
    self.PLCStatus = "Started"
    if self.statuschange is not None:
    self.statuschange(self.PLCStatus)
    + self.PythonThread = Thread(target=self.PythonThreadProc)
    + self.PythonThread.start()
    return True
    else:
    print "_StartPLC did not return 0 !"
    @@ -270,6 +290,13 @@
    for idx in idxs:
    self._RegisterDebugVariable(idx)
    self._resumeDebug()
    +
    + class IEC_STRING(ctypes.Structure):
    + """
    + Must be changed according to changes in iec_types.h
    + """
    + _fields_ = [("len", ctypes.c_uint8),
    + ("body", ctypes.c_char * 40)]
    TypeTranslator = {"BOOL" : (ctypes.c_uint8, lambda x:x.value!=0),
    "STEP" : (ctypes.c_uint8, lambda x:x.value),
    @@ -278,7 +305,7 @@
    "SINT" : (ctypes.c_int8, lambda x:x.value),
    "USINT" : (ctypes.c_uint8, lambda x:x.value),
    "BYTE" : (ctypes.c_uint8, lambda x:x.value),
    - "STRING" : (None, None),#TODO
    + "STRING" : (IEC_STRING, lambda x:x.body[:x.len]),
    "INT" : (ctypes.c_int16, lambda x:x.value),
    "UINT" : (ctypes.c_uint16, lambda x:x.value),
    "WORD" : (ctypes.c_uint16, lambda x:x.value),
    --- a/targets/Linux/plc_Linux_main.c Tue Dec 23 19:31:28 2008 +0100
    +++ b/targets/Linux/plc_Linux_main.c Tue Dec 23 19:37:44 2008 +0100
    @@ -1,3 +1,7 @@
    +/**
    + * Linux specific code
    + **/
    +
    #include <stdio.h>
    #include <string.h>
    #include <time.h>
    @@ -5,16 +9,14 @@
    #include <stdlib.h>
    #include <pthread.h>
    +/* provided by POUS.C */
    +extern int common_ticktime__;
    +
    long AtomicCompareExchange(long* atomicvar,long compared, long exchange)
    {
    return __sync_val_compare_and_swap(atomicvar, compared, exchange);
    }
    -//long AtomicExchange(long* atomicvar,long exchange)
    -//{
    -// return __sync_lock_test_and_set(atomicvar, exchange);
    -//}
    -
    void PLC_GetTime(IEC_TIME *CURRENT_TIME)
    {
    clock_gettime(CLOCK_REALTIME, CURRENT_TIME);
    @@ -64,9 +66,12 @@
    static int __debug_tick;
    -static pthread_mutex_t wait_mutex = PTHREAD_MUTEX_INITIALIZER;
    +static pthread_mutex_t python_wait_mutex = PTHREAD_MUTEX_INITIALIZER;
    +static pthread_mutex_t python_mutex = PTHREAD_MUTEX_INITIALIZER;
    +static pthread_mutex_t debug_wait_mutex = PTHREAD_MUTEX_INITIALIZER;
    static pthread_mutex_t debug_mutex = PTHREAD_MUTEX_INITIALIZER;
    +#define maxval(a,b) ((a>b)?a:b)
    int startPLC(int argc,char **argv)
    {
    struct sigevent sigev;
    @@ -79,7 +84,8 @@
    sigev.sigev_notify_attributes = NULL;
    sigev.sigev_notify_function = PLC_timer_notify;
    - pthread_mutex_lock(&wait_mutex);
    + pthread_mutex_lock(&debug_wait_mutex);
    + pthread_mutex_lock(&python_wait_mutex);
    timer_create (CLOCK_REALTIME, &sigev, &PLC_timer);
    if( __init(argc,argv) == 0 ){
    @@ -111,7 +117,7 @@
    timer_delete (PLC_timer);
    __cleanup();
    __debug_tick = -1;
    - pthread_mutex_unlock(&wait_mutex);
    + pthread_mutex_unlock(&debug_wait_mutex);
    }
    extern int __tick;
    @@ -119,7 +125,7 @@
    int WaitDebugData()
    {
    /* Wait signal from PLC thread */
    - pthread_mutex_lock(&wait_mutex);
    + pthread_mutex_lock(&debug_wait_mutex);
    return __debug_tick;
    }
    @@ -127,25 +133,49 @@
    * This is supposed to unlock debugger thread in WaitDebugData*/
    void InitiateDebugTransfer()
    {
    - /* Leave debugger section */
    - pthread_mutex_unlock(&debug_mutex);
    /* remember tick */
    __debug_tick = __tick;
    /* signal debugger thread it can read data */
    - pthread_mutex_unlock(&wait_mutex);
    + pthread_mutex_unlock(&debug_wait_mutex);
    }
    -void suspendDebug()
    +void suspendDebug(void)
    {
    - __DEBUG = 0;
    /* Prevent PLC to enter debug code */
    pthread_mutex_lock(&debug_mutex);
    }
    -void resumeDebug()
    +void resumeDebug(void)
    {
    - __DEBUG = 1;
    /* Let PLC enter debug code */
    pthread_mutex_unlock(&debug_mutex);
    }
    +/* from plc_python.c */
    +int WaitPythonCommands(void)
    +{
    + /* Wait signal from PLC thread */
    + pthread_mutex_lock(&python_wait_mutex);
    +}
    +
    +/* Called by PLC thread on each new python command*/
    +void UnBlockPythonCommands(void)
    +{
    + /* signal debugger thread it can read data */
    + pthread_mutex_unlock(&python_wait_mutex);
    +}
    +
    +int TryLockPython(void)
    +{
    + return pthread_mutex_trylock(&python_mutex) == 0;
    +}
    +
    +void UnLockPython(void)
    +{
    + pthread_mutex_unlock(&python_mutex);
    +}
    +
    +void LockPython(void)
    +{
    + pthread_mutex_lock(&python_mutex);
    +}
    --- a/targets/Win32/plc_Win32_main.c Tue Dec 23 19:31:28 2008 +0100
    +++ b/targets/Win32/plc_Win32_main.c Tue Dec 23 19:37:44 2008 +0100
    @@ -1,18 +1,20 @@
    +/**
    + * Win32 specific code
    + **/
    +
    #include <stdio.h>
    #include <sys/timeb.h>
    #include <time.h>
    #include <windows.h>
    +/* provided by POUS.C */
    +extern int common_ticktime__;
    +
    long AtomicCompareExchange(long* atomicvar, long compared, long exchange)
    {
    return InterlockedCompareExchange(atomicvar, exchange, compared);
    }
    -//long AtomicExchange(long* atomicvar,long exchange)
    -//{
    -// return InterlockedExchange(atomicvar, exchange);
    -//}
    -
    struct _timeb timetmp;
    void PLC_GetTime(IEC_TIME *CURRENT_TIME)
    {
    @@ -64,9 +66,11 @@
    HANDLE PLC_thread;
    HANDLE debug_sem;
    -HANDLE wait_sem;
    -#define MAX_SEM_COUNT 1
    +HANDLE debug_wait_sem;
    +HANDLE python_sem;
    +HANDLE python_wait_sem;
    +#define maxval(a,b) ((a>b)?a:b)
    int startPLC(int argc,char **argv)
    {
    unsigned long thread_id = 0;
    @@ -76,25 +80,50 @@
    debug_sem = CreateSemaphore(
    NULL, // default security attributes
    1, // initial count
    - MAX_SEM_COUNT, // maximum count
    + 1, // maximum count
    NULL); // unnamed semaphore
    if (debug_sem == NULL)
    {
    - printf("CreateMutex error: %d\n", GetLastError());
    + printf("startPLC CreateSemaphore debug_sem error: %d\n", GetLastError());
    return;
    }
    - wait_sem = CreateSemaphore(
    + debug_wait_sem = CreateSemaphore(
    NULL, // default security attributes
    0, // initial count
    - MAX_SEM_COUNT, // maximum count
    + 1, // maximum count
    + NULL); // unnamed semaphore
    +
    + if (debug_wait_sem == NULL)
    + {
    + printf("startPLC CreateSemaphore debug_wait_sem error: %d\n", GetLastError());
    + return;
    + }
    +
    + python_sem = CreateSemaphore(
    + NULL, // default security attributes
    + 1, // initial count
    + 1, // maximum count
    NULL); // unnamed semaphore
    - if (wait_sem == NULL)
    + if (python_sem == NULL)
    {
    - printf("CreateMutex error: %d\n", GetLastError());
    + printf("startPLC CreateSemaphore python_sem error: %d\n", GetLastError());
    return;
    }
    + python_wait_sem = CreateSemaphore(
    + NULL, // default security attributes
    + 0, // initial count
    + 1, // maximum count
    + NULL); // unnamed semaphore
    +
    +
    + if (python_wait_sem == NULL)
    + {
    + printf("startPLC CreateSemaphore python_wait_sem error: %d\n", GetLastError());
    + return;
    + }
    +
    /* Create a waitable timer */
    PLC_timer = CreateWaitableTimer(NULL, FALSE, "WaitableTimer");
    @@ -133,9 +162,9 @@
    WaitForSingleObject(PLC_thread, INFINITE);
    __cleanup();
    __debug_tick = -1;
    - ReleaseSemaphore(wait_sem, 1, NULL);
    + ReleaseSemaphore(debug_wait_sem, 1, NULL);
    CloseHandle(debug_sem);
    - CloseHandle(wait_sem);
    + CloseHandle(debug_wait_sem);
    CloseHandle(PLC_timer);
    CloseHandle(PLC_thread);
    }
    @@ -143,30 +172,58 @@
    /* from plc_debugger.c */
    int WaitDebugData()
    {
    - WaitForSingleObject(wait_sem, INFINITE);
    + WaitForSingleObject(debug_wait_sem, INFINITE);
    return __debug_tick;
    }
    -/* Called by PLC thread when debug_pu//blish finished
    +/* Called by PLC thread when debug_publish finished
    * This is supposed to unlock debugger thread in WaitDebugData*/
    void InitiateDebugTransfer()
    {
    /* remember tick */
    __debug_tick = __tick;
    /* signal debugger thread it can read data */
    - ReleaseSemaphore(wait_sem, 1, NULL);
    + ReleaseSemaphore(debug_wait_sem, 1, NULL);
    }
    void suspendDebug()
    {
    - __DEBUG = 0;
    /* Prevent PLC to enter debug code */
    WaitForSingleObject(debug_sem, INFINITE);
    }
    void resumeDebug()
    {
    - __DEBUG = 1;
    /* Let PLC enter debug code */
    ReleaseSemaphore(debug_sem, 1, NULL);
    }
    +
    +/* from plc_python.c */
    +int WaitPythonCommands(void)
    +{
    + /* Wait signal from PLC thread */
    + WaitForSingleObject(python_wait_sem, INFINITE);
    +}
    +
    +/* Called by PLC thread on each new python command*/
    +void UnBlockPythonCommands(void)
    +{
    + /* signal debugger thread it can read data */
    + ReleaseSemaphore(python_wait_sem, 1, NULL);
    +}
    +
    +int TryLockPython(void)
    +{
    + return WaitForSingleObject(python_sem, 0) == WAIT_OBJECT_0;
    +}
    +
    +void UnLockPython(void)
    +{
    + ReleaseSemaphore(python_sem, 1, NULL);
    +}
    +
    +void LockPython(void)
    +{
    + WaitForSingleObject(python_sem, INFINITE);
    +}
    +
    --- a/targets/plc_common_main.c Tue Dec 23 19:31:28 2008 +0100
    +++ b/targets/plc_common_main.c Tue Dec 23 19:37:44 2008 +0100
    @@ -1,41 +1,35 @@
    -/*
    - * Prototypes for function provided by arch-specific code (main)
    - * concatained after this template
    - ** /
    +/**
    + * Code common to all C targets
    + **/
    -
    -/*
    - * Functions and variables provied by generated C softPLC
    - **/
    -extern int common_ticktime__;
    +#include "iec_types.h"
    /*
    - * Functions and variables provied by plc.c
    - **/
    -void run(long int tv_sec, long int tv_nsec);
    -
    -#define maxval(a,b) ((a>b)?a:b)
    -
    -#include "iec_types.h"
    -/*#include "stdio.h" /* For debug */
    -
    -/*
    - * Functions and variables provied by generated C softPLC
    + * Prototypes of functions provied by generated C softPLC
    **/
    void config_run__(int tick);
    void config_init__(void);
    -void __init_debug(void);
    -void __cleanup_debug(void);
    -
    /*
    - * Functions and variables to export to generated C softPLC and plugins
    + * Prototypes of functions provied by generated target C code
    + * */
    +void __init_debug(void);
    +void __cleanup_debug(void);
    +/*void __retrieve_debug(void);*/
    +void __publish_debug(void);
    +
    +void __init_python(void);
    +void __cleanup_python(void);
    +void __retrieve_python(void);
    +void __publish_python(void);
    +
    +/*
    + * Variables used by generated C softPLC and plugins
    **/
    -
    IEC_TIME __CURRENT_TIME;
    -IEC_BOOL __DEBUG;
    int __tick = -1;
    +/* Help to quit cleanly when init fail at a certain level */
    static int init_level = 0;
    /*
    @@ -52,10 +46,14 @@
    %(retrieve_calls)s
    + __retrieve_python();
    +
    /*__retrieve_debug();*/
    config_run__(__tick);
    + __publish_python();
    +
    __publish_debug();
    %(publish_calls)s
    @@ -169,3 +167,8 @@
    }
    }
    }
    +
    +/**
    + * Prototypes for function provided by arch-specific code (main)
    + * is concatained hereafter
    + **/
    \ No newline at end of file
    --- a/targets/plc_debug.c Tue Dec 23 19:31:28 2008 +0100
    +++ b/targets/plc_debug.c Tue Dec 23 19:37:44 2008 +0100
    @@ -53,10 +53,7 @@
    void __init_debug()
    {
    %(variables_pointer_type_table_initializer)s
    -AtomicCompareExchange(
    - &buffer_state,
    - BUFFER_BUSY,
    - BUFFER_FREE);
    + buffer_state = BUFFER_FREE;
    }
    void __cleanup_debug()
    --- /dev/null Thu Jan 01 00:00:00 1970 +0000
    +++ b/targets/plc_python.c Tue Dec 23 19:37:44 2008 +0100
    @@ -0,0 +1,179 @@
    +/*
    + * Python Asynchronous execution code
    + *
    + * PLC put python commands in a fifo, respecting execution order
    + * with the help of C pragmas inserted in python_eval FB code
    + *
    + * Buffer content is read asynchronously, (from non real time part),
    + * commands are executed and result stored for later use by PLC.
    + *
    + * In this implementation, fifo is a list of pointer to python_eval
    + * function blocks structures. Some local variables have been added in
    + * python_eval interface. We use those local variables as buffer and state
    + * flags.
    + *
    + * */
    +
    +#include "iec_types_all.h"
    +#include "POUS.h"
    +#include <string.h>
    +
    +/* The fifo (fixed size, as number of FB is fixed) */
    +static PYTHON_EVAL* EvalFBs[%(python_eval_fb_count)d];
    +/* Producer and consumer cursors */
    +static long Current_PLC_EvalFB;
    +static long Current_Python_EvalFB;
    +
    +/* A global IEC-Python gateway state, for use inside python_eval FBs*/
    +static int PythonState;
    +#define PYTHON_LOCKED_BY_PYTHON 0
    +#define PYTHON_LOCKED_BY_PLC 1
    +#define PYTHON_MUSTWAKEUP 2
    +
    +/* Each python_eval FunctionBlock have it own state */
    +#define PYTHON_FB_FREE 0
    +#define PYTHON_FB_REQUESTED 1
    +#define PYTHON_FB_PROCESSING 2
    +#define PYTHON_FB_ANSWERED 3
    +
    +int WaitPythonCommands(void);
    +void UnBlockPythonCommands(void);
    +int TryLockPython(void);
    +void UnLockPython(void);
    +void LockPython(void);
    +
    +void __init_python()
    +{
    + int i;
    + /* Initialize cursors */
    + Current_Python_EvalFB = 0;
    + Current_PLC_EvalFB = 0;
    + PythonState = PYTHON_LOCKED_BY_PYTHON;
    + for(i = 0; i < %(python_eval_fb_count)d; i++)
    + EvalFBs[i] = NULL;
    +}
    +
    +void __cleanup_python()
    +{
    +}
    +
    +void __retrieve_python()
    +{
    + /* Check Python thread is not being
    + * modifying internal python_eval data */
    + PythonState = TryLockPython() ?
    + PYTHON_LOCKED_BY_PLC :
    + PYTHON_LOCKED_BY_PYTHON;
    + /* If python thread _is_ in, then PythonState remains PYTHON_LOCKED_BY_PYTHON
    + * and python_eval will no do anything */
    +}
    +
    +void __publish_python()
    +{
    + if(PythonState & PYTHON_LOCKED_BY_PLC){
    + /* If runnig PLC did push something in the fifo*/
    + if(PythonState & PYTHON_MUSTWAKEUP){
    + /* WakeUp python thread */
    + UnBlockPythonCommands();
    + }
    + UnLockPython();
    + }
    +}
    +/**
    + * Called by the PLC, each time a python_eval
    + * FB instance is executed
    + */
    +void __PythonEvalFB(PYTHON_EVAL* data__)
    +{
    + /* python thread is not in ? */
    + if( PythonState & PYTHON_LOCKED_BY_PLC){
    + /* Rising edge on TRIG */
    + if(data__->TRIG && !data__->TRIGM1 &&
    + /* and not already being processed */
    + data__->STATE == PYTHON_FB_FREE)
    + {
    + /* Get a new line */
    + Current_PLC_EvalFB = (Current_PLC_EvalFB + 1) %% %(python_eval_fb_count)d;
    + /* Enter the block in the fifo
    + /* Don't have to check if fifo cell is free
    + * as fifo size == FB count, and a FB cannot
    + * be requested twice */
    + EvalFBs[Current_PLC_EvalFB] = data__;
    + /* copy CODE in variable into BUFFER local*/
    + data__->BUFFER = data__->CODE;
    + /* Set ACK pin to low so that we can set a rising edge on result */
    + data__->ACK = 0;
    + /* Mark FB busy */
    + data__->STATE = PYTHON_FB_REQUESTED;
    + /* Have to wakeup python thread in case he was asleep */
    + PythonState |= PYTHON_MUSTWAKEUP;
    + //printf("__PythonEvalFB push %%*s\n",data__->BUFFER.len, data__->BUFFER.body);
    + }else if(data__->STATE == PYTHON_FB_ANSWERED){
    + data__->RESULT = data__->BUFFER;
    + data__->ACK = 1;
    + data__->STATE = PYTHON_FB_FREE;
    + //printf("__PythonEvalFB pop %%*s\n",data__->BUFFER.len, data__->BUFFER.body);
    + }
    + /* retain value for trig
    + * do this only when PYTHON_LOCKED_BY_PLC
    + * to avoid missed rising edge due to asynchronism */
    + data__->TRIGM1 = data__->TRIG;
    + }
    +}
    +
    +char* PythonIterator(char* result)
    +{
    + char* next_command;
    + PYTHON_EVAL* data__;
    + //printf("PythonIterator result %%s\n", result);
    + /* take python mutex to prevent changing PLC data while PLC running */
    + LockPython();
    + /* Get current FB */
    + data__ = EvalFBs[Current_Python_EvalFB];
    + if(data__ && /* may be null at first run */
    + data__->STATE == PYTHON_FB_PROCESSING){ /* some answer awaited*/
    + /* If result not None */
    + if(result){
    + /* Get results len */
    + data__->BUFFER.len = strlen(result);
    + /* prevent results overrun */
    + if(data__->BUFFER.len > STR_MAX_LEN)
    + {
    + data__->BUFFER.len = STR_MAX_LEN;
    + /* TODO : signal error */
    + }
    + /* Copy results to buffer */
    + strncpy(data__->BUFFER.body, result, data__->BUFFER.len);
    + }else{
    + data__->BUFFER.len = 0;
    + }
    + /* remove block from fifo*/
    + EvalFBs[Current_Python_EvalFB] = NULL;
    + /* Mark block as answered */
    + data__->STATE = PYTHON_FB_ANSWERED;
    + /* Get a new line */
    + Current_Python_EvalFB = (Current_Python_EvalFB + 1) %% %(python_eval_fb_count)d;
    + }
    + /* while next slot is empty */
    + while(((data__ = EvalFBs[Current_Python_EvalFB]) == NULL) ||
    + /* or doesn't contain command */
    + data__->STATE != PYTHON_FB_REQUESTED)
    + {
    + UnLockPython();
    + /* wait next FB to eval */
    + WaitPythonCommands();
    + LockPython();
    + }
    + /* Mark block as processing */
    + data__->STATE = PYTHON_FB_PROCESSING;
    + //printf("PythonIterator\n");
    + /* make BUFFER a null terminated string */
    + data__->BUFFER.body[data__->BUFFER.len] = 0;
    + /* next command is BUFFER */
    + next_command = data__->BUFFER.body;
    + /* free python mutex */
    + UnLockPython();
    + /* return the next command to eval */
    + return next_command;
    +}
    +
    --- /dev/null Thu Jan 01 00:00:00 1970 +0000
    +++ b/tests/python/beremiz.xml Tue Dec 23 19:37:44 2008 +0100
    @@ -0,0 +1,6 @@
    +<?xml version="1.0" encoding="UTF-8"?>
    +<BeremizRoot URI_location="PYRO://127.0.0.1:3000">
    + <TargetType>
    + <Linux CFLAGS="-g" LDFLAGS="-g"/>
    + </TargetType>
    +</BeremizRoot>
    --- /dev/null Thu Jan 01 00:00:00 1970 +0000
    +++ b/tests/python/plc.xml Tue Dec 23 19:37:44 2008 +0100
    @@ -0,0 +1,189 @@
    +<?xml version="1.0" encoding="UTF-8"?>
    +<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    + xmlns="http://www.plcopen.org/xml/tc6.xsd"
    + xmlns:xhtml="http://www.w3.org/1999/xhtml"
    + xsi:schemaLocation="http://www.plcopen.org/xml/tc6.xsd">
    + <fileHeader companyName="LOLITECH"
    + productName="Beremiz"
    + productVersion="0.0"
    + creationDateTime="2008-12-14T16:21:19"/>
    + <contentHeader name="Beremiz Python Support Tests"
    + modificationDateTime="2008-12-22T23:58:02">
    + <coordinateInfo>
    + <pageSize x="1024" y="1024"/>
    + <fbd>
    + <scaling x="5" y="5"/>
    + </fbd>
    + <ld>
    + <scaling x="5" y="5"/>
    + </ld>
    + <sfc>
    + <scaling x="5" y="5"/>
    + </sfc>
    + </coordinateInfo>
    + </contentHeader>
    + <types>
    + <dataTypes/>
    + <pous>
    + <pou name="main_pytest" pouType="program">
    + <interface>
    + <localVars>
    + <variable name="pytest_var1">
    + <type>
    + <string/>
    + </type>
    + <initialValue>
    + <simpleValue value="time.sleep(1)"/>
    + </initialValue>
    + </variable>
    + <variable name="pytest_var2">
    + <type>
    + <BOOL/>
    + </type>
    + </variable>
    + <variable name="pytest_var3">
    + <type>
    + <string/>
    + </type>
    + </variable>
    + <variable name="pytest_var4">
    + <type>
    + <BOOL/>
    + </type>
    + </variable>
    + <variable name="py1">
    + <type>
    + <derived name="python_eval"/>
    + </type>
    + </variable>
    + </localVars>
    + </interface>
    + <body>
    + <FBD>
    + <outVariable localId="2" height="30" width="120">
    + <position x="760" y="150"/>
    + <connectionPointIn>
    + <relPosition x="0" y="15"/>
    + <connection refLocalId="5" formalParameter="RESULT">
    + <position x="760" y="165"/>
    + <position x="515" y="165"/>
    + </connection>
    + </connectionPointIn>
    + <expression>pytest_var3</expression>
    + </outVariable>
    + <inVariable localId="4" height="30" width="120">
    + <position x="35" y="150"/>
    + <connectionPointOut>
    + <relPosition x="120" y="15"/>
    + </connectionPointOut>
    + <expression>pytest_var1</expression>
    + </inVariable>
    + <block localId="5" width="125" height="80" typeName="python_eval" instanceName="py1">
    + <position x="390" y="100"/>
    + <inputVariables>
    + <variable formalParameter="TRIG">
    + <connectionPointIn>
    + <relPosition x="0" y="35"/>
    + <connection refLocalId="7" formalParameter="OUT">
    + <position x="390" y="135"/>
    + <position x="190" y="135"/>
    + <position x="190" y="55"/>
    + <position x="130" y="55"/>
    + </connection>
    + </connectionPointIn>
    + </variable>
    + <variable formalParameter="CODE">
    + <connectionPointIn>
    + <relPosition x="0" y="65"/>
    + <connection refLocalId="4">
    + <position x="390" y="165"/>
    + <position x="155" y="165"/>
    + </connection>
    + </connectionPointIn>
    + </variable>
    + </inputVariables>
    + <inOutVariables/>
    + <outputVariables>
    + <variable formalParameter="ACK">
    + <connectionPointOut>
    + <relPosition x="125" y="35"/>
    + </connectionPointOut>
    + </variable>
    + <variable formalParameter="RESULT">
    + <connectionPointOut>
    + <relPosition x="125" y="65"/>
    + </connectionPointOut>
    + </variable>
    + </outputVariables>
    + </block>
    + <outVariable localId="6" height="30" width="120">
    + <position x="760" y="120"/>
    + <connectionPointIn>
    + <relPosition x="0" y="15"/>
    + <connection refLocalId="5" formalParameter="ACK">
    + <position x="760" y="135"/>
    + <position x="515" y="135"/>
    + </connection>
    + </connectionPointIn>
    + <expression>pytest_var4</expression>
    + </outVariable>
    + <block localId="7" width="70" height="45" typeName="NOT">
    + <position x="60" y="25"/>
    + <inputVariables>
    + <variable formalParameter="IN">
    + <connectionPointIn>
    + <relPosition x="0" y="30"/>
    + <connection refLocalId="3">
    + <position x="60" y="55"/>
    + <position x="45" y="55"/>
    + <position x="45" y="85"/>
    + <position x="165" y="85"/>
    + <position x="165" y="120"/>
    + <position x="155" y="120"/>
    + </connection>
    + </connectionPointIn>
    + </variable>
    + </inputVariables>
    + <inOutVariables/>
    + <outputVariables>
    + <variable formalParameter="OUT">
    + <connectionPointOut>
    + <relPosition x="70" y="30"/>
    + </connectionPointOut>
    + </variable>
    + </outputVariables>
    + </block>
    + <inOutVariable localId="3" height="30" width="120">
    + <position x="35" y="105"/>
    + <connectionPointIn>
    + <relPosition x="0" y="15"/>
    + <connection refLocalId="7" formalParameter="OUT">
    + <position x="35" y="120"/>
    + <position x="25" y="120"/>
    + <position x="25" y="15"/>
    + <position x="210" y="15"/>
    + <position x="210" y="55"/>
    + <position x="130" y="55"/>
    + </connection>
    + </connectionPointIn>
    + <connectionPointOut>
    + <relPosition x="120" y="15"/>
    + </connectionPointOut>
    + <expression>pytest_var2</expression>
    + </inOutVariable>
    + </FBD>
    + </body>
    + </pou>
    + </pous>
    + </types>
    + <instances>
    + <configurations>
    + <configuration name="conf_pytest">
    + <resource name="res_pytest">
    + <task name="pytest_task" interval="00:00:00.100000" priority="0"/>
    + <pouInstance name="pytest_instance" type="main_pytest"/>
    + </resource>
    + </configuration>
    + </configurations>
    + </instances>
    +</project>