如何使用C语言在Scilab / Xcos中开发自己的块

编程问答 2022-06-12

问题描述

我一直在使用CBLOCK4在Scilab / Xcos中开发自己的模块。 该块中的C语言代码如下：

#include <stdio.h>
#include "scicos_block4.h"

#define U  ((SCSREAL_cop *)GetRealInPortPtrs(block,1))
#define Y  ((SCSREAL_cop *)GetRealOutPortPtrs(block,1))
#define X  ((SCSREAL_cop *)GetState(block))
#define dX ((SCSREAL_cop *)GetDerState(block))
#define Xk ((SCSREAL_cop *)GetDstate(block))
#define W  ((SCSREAL_cop *)GetWorkPtrs(block))

// parameters
#define N (GetIparPtrs(block)[0])

typedef struct
{
    double *buffer;
    double *sum;
    int    *index;
}MovingAverage_t;

FILE *f;

void MovingAverage(scicos_block *block,int flag)
{

  MovingAverage_t *ptr;
  int bufferPos;

  if(flag == 4) 
  {
    /* init */

    f = fopen("Debug.txt","w");

    if((*(block->work) = (MovingAverage_t *)scicos_malloc(sizeof(MovingAverage_t))) == NULL)
    {
        set_block_error(-16);
        return;
    }
    ptr = (MovingAverage_t*)*block->work;       

    fprintf(f,"ptr: %ld \n",ptr);

    if((ptr->buffer = (double*)scicos_malloc(sizeof(double)*N)) == NULL)
    {
        scicos_free(*(block->work));
        fclose(f);
        set_block_error(-16);
        return;
    }
    
    if((ptr->sum = (double*)scicos_malloc(sizeof(double))) == NULL)
    {
        scicos_free(*(ptr->buffer));
        scicos_free(*(block->work));
        fclose(f);
        set_block_error(-16);
        return;
    }

    if((ptr->index  = (int*)scicos_malloc(sizeof(int))) == NULL)
    {
        scicos_free(*(ptr->buffer));
        scicos_free(*(ptr->sum));
        scicos_free(*(block->work));
        fclose(f);
        set_block_error(-16);
        return;
    }

    fprintf(f,"ptr->buffer: %ld \n",ptr->buffer);
    fprintf(f,"ptr->sum: %ld \n",ptr->sum);
    fprintf(f,"ptr->index: %ld \n",ptr->index);

    int i;
    for(i = 0; i < N; i++)
    {
        ptr->buffer[i] = 0;
    }
    *(ptr->sum) = 0;
    *(ptr->index) = 0;

    for(i = 0; i < N; i++)
    {
        fprintf(f,"buffer[%d]: %f\n",i,ptr->buffer[i]);
    }

    fprintf(f,"*(ptr->sum): %f\n",*(ptr->sum));
    fprintf(f,"*(ptr->index): %d\n",*(ptr->index));
        
  }
  else if(flag == 1) 
  {
    fprintf(f,"In: %f \n",U[0]);  

    ptr->buffer[0] = U[0];

    int i;
    for(i = 0; i < N; i++)
    {
        fprintf(f,ptr->buffer[i]);
    }
    
  } 
  else  if (flag == 5) 
  {
    /* ending */
    scicos_free(*(block->work));
    fclose(f);
  }
}

为了完整性，我还附加了scicos_block结构：

typedef struct
{
    int nevprt;
    voidg funpt;
    int type;
    int scsptr;
    int nz;
    double *z;
    int noz;
    int *ozsz;
    int *oztyp;
    void **ozptr;
    int nx;
    double *x;
    double *xd;
    double *res;
    int *xprop;
    int nin;
    int *insz;
    void **inptr;
    int nout;
    int *outsz;
    void **outptr;
    int nevout;
    double *evout;
    int nrpar;
    double *rpar;
    int nipar;
    int *ipar;
    int nopar;
    int *oparsz;
    int *opartyp;
    void **oparptr;
    int ng;
    double *g;
    int ztyp;
    int *jroot;
    char *label;
    void **work;
    int nmode;
    int *mode;
    char *uid;
}scicos_block;

我能够成功编译代码，但是如果我运行包含 我的CBLOCK4块我总是收到以下错误消息：

警告！！！ Scilab发现严重错误（EXCEPTION_ACCESS_VIOLATION） 具有“ scicosim”功能。 保存数据并重新启动Scilab。

并且模拟也不会开始。我发现，如果我删除了CBLOCK4块中的以下代码行，则模拟开始工作：

ptr->buffer[0] = U[0];

int i;
for(i = 0; i < N; i++)
{
    fprintf(f,ptr->buffer[i]);
}

我怀疑我的C代码中是否存在一些错误（可能与内存有关） 分配），但我找不到它。是否有人对Scilab / Xcos有经验 CBLOCK4的用法？

解决方法

我经历过很难在cblock4上获得良好的信息/示例，但是经过大量的搜索之后，我现在将以下内容用于缓冲区实现（采用实数输入，输出N个最后样本的向量）： 

#include "scicos_block4.h"

#define r_IN(n,i)  ((GetRealInPortPtrs(block,n+1))[(i)]) 
#define r_OUT(n,i) ((GetRealOutPortPtrs(block,n+1))[(i)]) 

#define in          (r_IN(0,0))                // input,single real
#define out(n)      (r_OUT(0,n))               // output,vector(1,N) real
#define nSamples    (GetOutPortSize(block,1,2))

#define setting0    (GetIparPtrs(block)[0])
#define X           (GetState(block)[0])        // state 
#define Xdot        (GetDerState(block)[0])     // derivative of the state 
#define surface0    (GetGPtrs(block)[0]) 
#define mode0       (GetModePtrs(block)[0]) 
#define wrk(i)      (((double*)GetWorkPtrs(block))[i])

void buffer(scicos_block *block,int flag)
{
    int i;
    switch(flag){
        case 0:            // calculate derivative
            break;
        case 1:            // calculate output
            for(i=1; i<nSamples; i++) out(i-1)=out(i);
            out(nSamples-1)=in;
            break;
        case 2:            // update states
            break;
        case 3:            // event
            break;
        case 4:            // init
            break;
        case 5:            // done,deinit
            break;
        case 6:            // re-initialization
            break;
        case 9:            // calculate surfaces and modes
            break;
    }
}

注意没有malloc，它只是将输出用作缓冲区...

cmemory-managementscilabxcos