From 70eab54181d99cf166f237df5e733fa22797e673 Mon Sep 17 00:00:00 2001
From: Stathis Kamperis <ekamperi@auth.gr>
Date: Mon, 30 Jul 2007 00:19:55 +0300
Subject: [PATCH] Add some sanity checks in freemat()  * The program leaks like
 hell (potentially). It will go under major rearrangements.

---
 pthreads/matrixmul.c | 383 +++++++++++++++++++++++++++------------------------
 1 file changed, 200 insertions(+), 183 deletions(-)
 rewrite pthreads/matrixmul.c (80%)

diff --git a/pthreads/matrixmul.c b/pthreads/matrixmul.c
dissimilarity index 80%
index 7224ae3..275c4c4 100755
--- a/pthreads/matrixmul.c
+++ b/pthreads/matrixmul.c
@@ -1,183 +1,200 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <pthread.h>
-
-struct matrix {   
-   unsigned int rows;
-   unsigned int cols;
-   int **data;
-};
-
-struct matrix_index {
-   unsigned int row;
-   unsigned int col;
-};
-
-struct matrix *mat1 = NULL;
-struct matrix *mat2 = NULL;
-struct matrix *mat3 = NULL;
-
-/* function prototypes */
-void allocmat(struct matrix **mat, int rows, int cols);
-void freemat(struct matrix **mat);
-void readmat(const char *path, struct matrix **mat);
-void printmat(const struct matrix *mat);
-void *mulvect(void *arg);
-
-int main(int argc, char *argv[]) {
-   pthread_t *tid;
-   struct matrix_index *v;
-   unsigned int i, j, k, numthreads;
-
-   /* arguments validations */
-   if (argc != 3) {
-      fprintf(stderr, "Incorrect num of args.\nUsage: ./matrixmul matfile1 matfile2\n");
-      exit(EXIT_FAILURE);
-   }
-
-   /* read matrix data from files */
-   readmat(argv[1], &mat1);
-   readmat(argv[2], &mat2);
-
-   /* Is the multiplication feasible by definition? */
-   if (mat1->cols != mat2->rows) {
-      fprintf(stderr, "Matrices' dimensions size must satisfy (NxM)(MxK)=(NxK)\n");
-      exit(EXIT_FAILURE);
-   }
-
-   /* allocate memory for the result */
-   allocmat(&mat3, mat1->rows, mat2->cols);
-
-   /* How many threads do we need ?*/
-   numthreads = mat1->rows * mat2->cols;
-
-   /* v[k] holds the (i, j) pair in the k-th computation */
-   v = malloc(numthreads * sizeof(struct matrix_index));
-
-   /* allocate memory for the threads' ids */
-   tid = malloc(numthreads * sizeof(pthread_t));
-   if (!tid) {
-      fprintf(stderr, "Error allocating memory\n");
-      exit(EXIT_FAILURE);
-   }
-
-   /* create the threads */
-   for (i=0; i<mat1->rows; i++) {
-      for (j=0; j<mat2->cols; j++) {
-	 k = i*mat1->rows + j;
-	 v[k].row = i;
-	 v[k].col = j;
-	 if (pthread_create(&tid[k], NULL, mulvect, (void *)&v[k])) {
-	    fprintf(stderr, "pthtrad_create() error\n");
-	    exit(EXIT_FAILURE);
-	 }
-      }
-   }
-
-   /* make sure all threads are done  */
-   for (i=0; i<numthreads; i++)
-      if (pthread_join(tid[i], NULL)) {
-	 fprintf(stderr, "pthread_join() error\n");
-	 exit(EXIT_FAILURE);
-      }
-
-   /* print the result */
-   printmat(mat3);
-
-   /* free matrices */
-   freemat(&mat1);
-   freemat(&mat2);
-   freemat(&mat3);
-
-   return EXIT_SUCCESS;
-}
-
-void allocmat(struct matrix **mat, int rows, int cols) {
-   int i;
-
-   *mat = malloc(sizeof(struct matrix));
-   if (!*mat) {
-      fprintf(stderr, "Error allocating memory\n");
-      exit(EXIT_FAILURE);
-   }
-
-   (*mat)->rows = rows;
-   (*mat)->cols = cols;
-
-   (*mat)->data = malloc(rows * sizeof(int *));
-   if (!(*mat)->data) {
-      fprintf(stderr, "Error allocating memory\n");
-      exit(EXIT_FAILURE);
-   }
-
-   for (i=0; i<rows; i++) {
-      (*mat)->data[i] = malloc(cols * sizeof(int));
-      if (!(*mat)->data[i]) {
-	 fprintf(stderr, "Error allocating memory\n");
-	 exit(EXIT_FAILURE);
-      }
-   }
-}
-
-void freemat(struct matrix **mat) {
-   unsigned int i;
-
-   for (i=0; i<(*mat)->rows; i++) {
-      free((*mat)->data[i]);
-   }
-   free(*mat);
-   *mat = NULL;
-}
-
-void readmat(const char *path, struct matrix **mat) {
-   FILE *fp;
-   unsigned int i, j, rows, cols;
-
-   /* open file */
-   if (!(fp = fopen(path, "r"))) {
-      fprintf(stderr, "Error opening file: %s\n", path);
-      exit(EXIT_FAILURE);
-   }
-
-   /* read matrix dimensions */
-   fscanf(fp, "%u%u", &rows, &cols);
-
-   /* allocate memory for matrix */
-   allocmat(mat, rows, cols);
-
-   /* read matrix elements */
-   for (i=0; i<(*mat)->rows; i++) {
-      for (j=0; j<(*mat)->cols; j++) {
-	 fscanf(fp, "%d", &(*mat)->data[i][j]);
-      }
-   }
-
-   /* close file */
-   fclose(fp);
-}
-
-
-void printmat(const struct matrix *mat) {
-   unsigned int i, j;
-
-   for (i=0; i<mat->rows; i++) {
-      for (j=0; j<mat->cols; j++) {
-	 printf("%d ", mat->data[i][j]);
-      }
-      printf("\n");
-   }
-}
-
-
-void *mulvect(void *arg) {
-   unsigned int i, row, col;
-
-   row = *((int *)arg + 0);
-   col = *((int *)arg + 1);
-
-   mat3->data[row][col] = 0;
-   for (i=0; i<mat1->cols; i++)
-      mat3->data[row][col] += mat1->data[row][i] * mat2->data[i][col];
-
-   pthread_exit(NULL);
-}
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+
+struct matrix {
+   unsigned int rows;
+   unsigned int cols;
+   int **data;
+};
+
+struct matrix_index {
+   unsigned int row;
+   unsigned int col;
+};
+
+struct matrix *mat1 = NULL;
+struct matrix *mat2 = NULL;
+struct matrix *mat3 = NULL;
+
+/* function prototypes */
+void allocmat(struct matrix **mat, unsigned int rows, unsigned int cols);
+void freemat(struct matrix **mat);
+void readmat(const char *path, struct matrix **mat);
+void printmat(const struct matrix *mat);
+void *mulvect(void *arg);
+void diep(const char *s);
+
+int main(int argc, char *argv[])
+{
+    pthread_t *tid;
+    struct matrix_index *v;
+    unsigned int i, j, k, numthreads;
+
+    /* check argument count */
+    if (argc != 3) {
+        fprintf(stderr, "Usage: %s matfile1 matfile2\n", argv[0]);
+        exit(EXIT_FAILURE);
+    }
+
+    /* read matrix data from files */
+    readmat(argv[1], &mat1);
+    readmat(argv[2], &mat2);
+
+    /* is the multiplication feasible by definition? */
+    if (mat1->cols != mat2->rows) {
+        fprintf(stderr, "Matrices' dimensions size must satisfy (NxM)(MxK)=(NxK)\n");
+        exit(EXIT_FAILURE);
+    }
+
+    /* allocate memory for the result */
+    allocmat(&mat3, mat1->rows, mat2->cols);
+
+    /* how many threads do we need ?*/
+    numthreads = mat1->rows * mat2->cols;
+
+    /* v[k] holds the (i, j) pair in the k-th computation */
+    if ((v = malloc(numthreads * sizeof(struct matrix_index))) == NULL)
+        diep("malloc");
+
+    /* allocate memory for the threads' ids */
+    tid = malloc(numthreads * sizeof(pthread_t));
+    if (!tid) {
+        fprintf(stderr, "Error allocating memory\n");
+        exit(EXIT_FAILURE);
+    }
+
+    /* create the threads */
+    for (i = 0; i < mat1->rows; i++) {
+        for (j = 0; j < mat2->cols; j++) {
+            k = i*mat1->rows + j;
+            v[k].row = i;
+            v[k].col = j;
+            if (pthread_create(&tid[k], NULL, mulvect, (void *)&v[k])) {
+                fprintf(stderr, "pthtrad_create() error\n");
+                exit(EXIT_FAILURE);
+            }
+        }
+    }
+
+    /* make sure all threads are done  */
+    for (i = 0; i < numthreads; i++)
+        if (pthread_join(tid[i], NULL)) {
+            fprintf(stderr, "pthread_join() error\n");
+            exit(EXIT_FAILURE);
+        }
+
+    /* print the result */
+    printmat(mat3);
+
+    /* free matrices */
+    freemat(&mat1);
+    freemat(&mat2);
+    freemat(&mat3);
+
+    return EXIT_SUCCESS;
+}
+
+void allocmat(struct matrix **mat, unsigned int rows, unsigned int cols)
+{
+    int i;
+
+    *mat = malloc(sizeof(struct matrix));
+    if (!*mat) {
+        fprintf(stderr, "Error allocating memory\n");
+        exit(EXIT_FAILURE);
+    }
+
+    (*mat)->rows = rows;
+    (*mat)->cols = cols;
+
+    (*mat)->data = malloc(rows * sizeof(int *));
+    if (!(*mat)->data) {
+        fprintf(stderr, "Error allocating memory\n");
+        exit(EXIT_FAILURE);
+    }
+
+    for (i = 0; i < rows; i++) {
+        (*mat)->data[i] = malloc(cols * sizeof(int));
+        if (!(*mat)->data[i]) {
+            fprintf(stderr, "Error allocating memory\n");
+            exit(EXIT_FAILURE);
+        }
+    }
+}
+
+void freemat(struct matrix **mat)
+{
+    unsigned int i;
+
+    for (i = 0; i < (*mat)->rows; i++) {
+        if ((*mat)->data[i] != NULL)
+            free((*mat)->data[i]);
+    }
+
+    if (*mat != NULL)
+        free(*mat);
+
+    *mat = NULL;
+}
+
+void readmat(const char *path, struct matrix **mat)
+{
+    FILE *fp;
+    unsigned int i, j, rows, cols;
+
+    /* open file */
+    if (!(fp = fopen(path, "r"))) {
+        fprintf(stderr, "Error opening file: %s\n", path);
+        exit(EXIT_FAILURE);
+    }
+
+    /* read matrix dimensions */
+    fscanf(fp, "%u%u", &rows, &cols);
+
+    /* allocate memory for matrix */
+    allocmat(mat, rows, cols);
+
+    /* read matrix elements */
+    for (i = 0; i < (*mat)->rows; i++) {
+        for (j = 0; j < (*mat)->cols; j++) {
+            fscanf(fp, "%d", &(*mat)->data[i][j]);
+        }
+   }
+
+    /* close file */
+    fclose(fp);
+}
+
+
+void printmat(const struct matrix *mat)
+{
+    unsigned int i, j;
+
+    for (i = 0; i < mat->rows; i++) {
+        for (j = 0; j < mat->cols; j++) {
+            printf("%d ", mat->data[i][j]);
+        }
+        printf("\n");
+    }
+}
+
+
+void *mulvect(void *arg) {
+   unsigned int i, row, col;
+
+   row = *((int *)arg + 0);
+   col = *((int *)arg + 1);
+
+   mat3->data[row][col] = 0;
+   for (i=0; i<mat1->cols; i++)
+      mat3->data[row][col] += mat1->data[row][i] * mat2->data[i][col];
+
+   pthread_exit(NULL);
+}
+
+void diep(const char *s)
+{
+    perror(s);
+    exit(EXIT_FAILURE);
+}
-- 
2.11.4.GIT