Question

编辑：我明白了。当deflateReadOut（）实例化时，数组太大而无法进入堆栈，因此在调用时会抛出EXC_BAD_ACCESS错误。有用的链接：link

这个EXC_BAD_ACCESS错误令我难过。到目前为止，我的程序所做的是制作一个包含四个大型无符号字符数组的二维矢量数组，用100s填充位置0处的一个，并尝试将指向该指针的指针传递给所有100个。但是，当它进入函数调用时，会发生EXC_BAD_ACCESS错误。我通过打印检查了阵列的完整性，它打印得很好。代码如下。

#include <stdint.h>
#include <map>
#include <stdio.h>
#include <iostream>
#include <time.h>
#include <string.h>
#include <assert.h>
#include <cstdlib>
#include <sstream>
#include <zlib.h>
#include "Hash.h"

#define CHUNK 16777216

using namespace std;

class WSUMap {
public:

    vector<vector <unsigned char> > chunk;
    int xComp[4];
    int yComp[4];
    vector<int> priority;
    Hash hashChunk;

    WSUMap() {
        chunk.reserve(4);
        chunk[0] = vector<unsigned char>(CHUNK);
        chunk[1] = vector<unsigned char>(CHUNK);
        chunk[2] = vector<unsigned char>(CHUNK);
        chunk[3] = vector<unsigned char>(CHUNK);
        priority.push_back(0);
        priority.push_back(1);
        priority.push_back(2);
        priority.push_back(3);
        xComp[0] = -1;
        xComp[1] = -1;
        xComp[2] = -1;
        xComp[3] = -1;
        yComp[0] = -1;
        yComp[1] = -1;
        yComp[2] = -1;
        yComp[3] = -1;
    }

    //Important part starts here:

    void generate() {
        for (int i = 0; i<CHUNK; i++) {
            chunk[0][i]=100;
        }
        for (int i = 0; i < 16; i++) {
            for (int j = 0; j < 16; j++) {
                cout << chunk[0][0] << endl;
                unsigned char* ch = &chunk[0][0];
                cout << ch[0] << endl;
                deflateReadOut(i, j, ch); //EXC_BAD_ACCESS Here
            }
        }
    }

    void deflateReadOut(int x, int y, unsigned char* chunk) {


        int ret, flush;
        unsigned have;
        z_stream strm;
        unsigned char out[CHUNK];

        /* allocate deflate state */
        strm.zalloc = Z_NULL;
        strm.zfree = Z_NULL;
        strm.opaque = Z_NULL;
        ret = deflateInit(&strm, 1);
        if (ret != Z_OK);
        //return ret;

        ostringstream oss;
        oss << "map/" << x << "x" << y;
        string str = oss.str();
        FILE* dest = fopen(str.c_str(), "w");

        /* run deflate() on input until output buffer not full, finish
           compression if all of source has been read in */
        do {
            strm.avail_out = CHUNK;
            strm.next_in = chunk;
            strm.next_out = out;

            ret = deflate(&strm, flush); /* no bad return value */
            assert(ret != Z_STREAM_ERROR); /* state not clobbered */

            have = CHUNK - strm.avail_out;
            if (fwrite(out, 1, have, dest) != have || ferror(dest)) {
                (void) deflateEnd(&strm);
                //return Z_ERRNO;
            }

        } while (strm.avail_out == 0);
        assert(strm.avail_in == 0); /* all input will be used */

        /* clean up and return */
        (void) deflateEnd(&strm);
    }

感谢您提供任何帮助。

Answer 1

此：

chunk.reserve(4);

应该是：

chunk.resize(4);

否则，您只是增加容量而不是实际的矢量大小。

您还可以初始化初始化列表中的向量：

WSUMap() 
: chunk(4, vector<unsigned char>(CHUNK)) 
{

}

这相当于增加大小并初始化各个向量。

C ++：传递从向量中获取的数组指针时的EXC_BAD_ACCESS

1 个答案: