我有一个主文件，它接收一个文件并将文件中的数字添加到矩阵中。我有一切工作，它打印出正确的答案，但在valgrind我得到泄漏，我肯定知道它，因为我没有在循环释放MatC：否则if（numOfMatrices＆gt; 2）。前面带箭头的线条是需要释放的线条。
这是主要功能：
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "mmult.h"
int main(int argc, char* argv[]){
(void) argc;
FILE* fp = fopen(argv[0], "r");
char *firstLine = NULL;
char *ptr;
if (!fp){
fprintf(stderr, "Can't Open File");
return EXIT_FAILURE;
} else{ // Gets the number of matrices
char *buf = NULL;
size_t len = 100;
while (getline(&buf, &len, stdin)){
char *pch;
pch = strtok(buf, " \n");
firstLine = buf;
(void) pch;
break;
}
}
int numOfMatrices = strtod(firstLine, &ptr);
free(firstLine);
// Gets the number of rows and columns of the matrix
for (int m = 0; m < numOfMatrices; m++){
int x, y, i, j;
Matrices MatA;
Matrices MatB;
Matrices MatC;
Matrices MatD;
if (numOfMatrices == 1){
MatA.Matrix = mread(stdin, &x, &y);
MatA.row = x;
MatA.col = y;
printf("%d %d\n", MatA.row, MatA.col);
mwrite(stdout, MatA.row, MatA.col, MatA.Matrix);
xfree(MatA.row, MatA.col, MatA.Matrix);
} else if (numOfMatrices >= 2){
if (numOfMatrices == 2){
if (m == 0){
MatA.Matrix = mread(stdin, &x, &y);
MatA.row = x;
MatA.col = y;
MatB.Matrix = mread(stdin, &i, &j);
MatB.row = i;
MatB.col = j;
MatC.Matrix = mmult(MatA.row, MatA.col, MatA.Matrix, MatB.row, MatB.col, MatB.Matrix);
MatC.row = MatA.row;
MatC.col = MatB.col;
xfree(MatA.row, MatA.col, MatA.Matrix);
xfree(MatB.row, MatB.col, MatB.Matrix);
printf("%d %d\n", MatC.row, MatC.col);
mwrite(stdout, MatC.row, MatC.col, MatC.Matrix);
xfree(MatC.row, MatC.col, MatC.Matrix);
}
} else if (numOfMatrices > 2){
if (m == 0){
MatA.Matrix = mread(stdin, &x, &y);
MatA.row = x;
MatA.col = y;
MatB.Matrix = mread(stdin, &i, &j);
MatB.row = i;
MatB.col = j;
-> MatC.Matrix = mmult(MatA.row, MatA.col, MatA.Matrix, MatB.row, MatB.col, MatB.Matrix);
MatC.row = MatA.row;
MatC.col = MatB.col;
xfree(MatA.row, MatA.col, MatA.Matrix);
xfree(MatB.row, MatB.col, MatB.Matrix);
for (int x = 2; x < numOfMatrices; x++){
MatD.Matrix = mread(stdin, &i, &j);
MatD.row = i;
MatD.col = j;
-> MatC.Matrix = mmult(MatC.row, MatC.col, MatC.Matrix, MatD.row, MatD.col, MatD.Matrix);
xfree(MatD.row, MatD.col, MatD.Matrix);
if (x == (numOfMatrices-1)){
printf("%d %d\n", MatC.row, MatC.col);
mwrite(stdout, MatC.row, MatC.col, MatC.Matrix);
xfree(MatC.row, MatC.col, MatC.Matrix);
}
}
}
}
}
}
fclose(fp);
}
另外，这是我的xfree函数，它是一个矩阵：
// Free all memory allocated for A
void xfree(int r, int c, double **A){
(void) c;
for (int y = 0; y < r; y++){
free(A[y]);
}
free(A);
}
我还为矩阵创建了一个结构：
typedef struct Matrices{
double **Matrix; // The matrix held in this node
int row; // Number of rows in the Matrix
int col; // Number of Columns in the Matrix
} Matrices;
Valgrind输出：
ShaolinGOD@comp:~/Desktop/Project2$ valgrind --leak-check=full --show-leak-kinds=all --track-origins=yes ./mmult < OneMatrix.txt
==7984== Memcheck, a memory error detector
==7984== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==7984== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==7984== Command: ./mmult
==7984==
2 2
52.00 52.00
80.00 80.00
==7984==
==7984== HEAP SUMMARY:
==7984== in use at exit: 144 bytes in 9 blocks
==7984== total heap usage: 30 allocs, 21 frees, 133,624 bytes allocated
==7984==
==7984== 32 bytes in 2 blocks are indirectly lost in loss record 1 of 4
==7984== at 0x4C2DB8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==7984== by 0x400D11: xalloc (mmult.c:83)
==7984== by 0x400BF7: mmult (mmult.c:65)
==7984== by 0x401111: main (mmult-driver.c:86)
==7984==
==7984== 48 (16 direct, 32 indirect) bytes in 1 blocks are definitely lost in loss record 2 of 4
==7984== at 0x4C2DB8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==7984== by 0x400CDE: xalloc (mmult.c:81)
==7984== by 0x400BF7: mmult (mmult.c:65)
==7984== by 0x401111: main (mmult-driver.c:86)
==7984==
==7984== 64 bytes in 4 blocks are indirectly lost in loss record 3 of 4
==7984== at 0x4C2DB8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==7984== by 0x400D11: xalloc (mmult.c:83)
==7984== by 0x400BF7: mmult (mmult.c:65)
==7984== by 0x4011A4: main (mmult-driver.c:98)
==7984==
==7984== 96 (32 direct, 64 indirect) bytes in 2 blocks are definitely lost in loss record 4 of 4
==7984== at 0x4C2DB8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==7984== by 0x400CDE: xalloc (mmult.c:81)
==7984== by 0x400BF7: mmult (mmult.c:65)
==7984== by 0x4011A4: main (mmult-driver.c:98)
==7984==
==7984== LEAK SUMMARY:
==7984== definitely lost: 48 bytes in 3 blocks
==7984== indirectly lost: 96 bytes in 6 blocks
==7984== possibly lost: 0 bytes in 0 blocks
==7984== still reachable: 0 bytes in 0 blocks
==7984== suppressed: 0 bytes in 0 blocks
==7984==
==7984== For counts of detected and suppressed errors, rerun with: -v
==7984== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 0 from 0)
ShaolinGOD@comp:~/Desktop/Project2$
答案 0 :(得分：1)
xfree功能没问题。问题是xfree
MatC.Matrix
您似乎正在尝试转换MatC.Matrix。为此，您可以分配一个临时矩阵，将旧矩阵复制到临时矩阵，释放旧矩阵，然后将旧矩阵指针设置为临时矩阵。
示例，请更改以下部分：
MatC.Matrix = mmult(MatA.row, MatA.col, MatA.Matrix, MatB.row, MatB.col, MatB.Matrix);
MatC.row = MatA.row;
MatC.col = MatB.col;
xfree(MatA.row, MatA.col, MatA.Matrix);
xfree(MatB.row, MatB.col, MatB.Matrix);
for (int x = 2; x < numOfMatrices; x++)
{
MatD.Matrix = mread(stdin, &i, &j);
MatD.row = i;
MatD.col = j;
MatC.Matrix = mmult(MatC.row, MatC.col, MatC.Matrix, MatD.row, MatD.col, MatD.Matrix);
xfree(MatD.row, MatD.col, MatD.Matrix);
if (x == (numOfMatrices - 1))
{
printf("%d %d\n", MatC.row, MatC.col);
mwrite(stdout, MatC.row, MatC.col, MatC.Matrix);
xfree(MatC.row, MatC.col, MatC.Matrix);
}
}
对此：
MatC.Matrix = mmult(MatA.row, MatA.col, MatA.Matrix, MatB.row, MatB.col, MatB.Matrix);
MatC.row = MatA.row;
MatC.col = MatB.col;
xfree(MatA.row, MatA.col, MatA.Matrix);
xfree(MatB.row, MatB.col, MatB.Matrix);
for (int x = 2; x < numOfMatrices; x++)
{
MatD.Matrix = mread(stdin, &i, &j);
MatD.row = i;
MatD.col = j;
Matrices temp;
temp.Matrix = mmult(MatC.row, MatC.col, MatC.Matrix, MatD.row, MatD.col, MatD.Matrix);
xfree(MatD.row, MatD.col, MatD.Matrix);
//free MatC.Matrix
xfree(MatC.row, MatC.col, MatC.Matrix);
//copy pointers from temp to MatC.Matrix
MatC.Matrix = temp.Matrix;
for (int k = 0; k < temp.row; k++)
MatC.Matrix[k] = temp.Matrix[k];
MatC.row = temp.row;//<== added (EDIT ***********)
MatC.col = temp.col;//<== added (EDIT ***********)
if (x == (numOfMatrices - 1))
{
printf("%d %d\n", MatC.row, MatC.col);
mwrite(stdout, MatC.row, MatC.col, MatC.Matrix);
}
}
//add xfree here:
xfree(MatC.row, MatC.col, MatC.Matrix);
现在分配数量和xfree应匹配。