get_pixel函数引发总线错误：10
#include #include #include #include #include #include #include #include #include #include #define FILE_MODE (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH) #ifndef MAP_FILE /* 44BSD defines this & requires it to mmap files */ #define MAP_FILE 0 /* to compile under systems other than 44BSD */ #endif #define SIZE 20 #define N 3 struct stat statbuf; struct pixel { char R; char G; char B; }; char * src; int size; struct pixel *get_pixel(char *buf, int *pos) { struct pixel pix; struct pixel *ppix = &pix; ppix->R = buf[*pos]; ppix->G = buf[(*pos)+1]; ppix->B = buf[(*pos)+2]; (*pos) += 3; return ppix; } void write_pixel(struct pixel *ppix, char *buf, int *pos) { buf[*pos] = ppix->G; buf[(*pos)+1] = ppix->B; buf[(*pos)+2] = ppix->R; (*pos) += 3; } void * do_rotation(void *rotation) { int fdout; char *dst; char fich[SIZE]; int counter,index, pos, x, y; int xmax = 0; int ymax = 0; int colormax = 0; /* Construção do nome do ficheiro de saída */ sprintf(fich, "rot%d.ppm", *((int*)rotation)); /* Zona #2 */ if ( (fdout = open(fich, O_RDWR | O_CREAT | O_TRUNC,FILE_MODE)) < 0) { fprintf(stderr,"can't creat %s for writing\n", fich); exit(1); } /* set size of output file */ if (lseek(fdout, size - 1, SEEK_SET) == -1) { fprintf(stderr,"lseek error\n"); exit(1); } if (write(fdout, "", 1) != 1) { fprintf(stderr,"write error\n"); exit(1); } if ( (dst = mmap(0, size, PROT_READ | PROT_WRITE,MAP_SHARED,fdout, 0)) == (caddr_t) -1) { fprintf(stderr,"mmap error for output\n"); exit(1); } /* Fim da Zona #2 */ sscanf(src,"P6\n%d %d\n%d\n",&xmax,&ymax,&colormax); struct pixel imagem [ymax][xmax]; for (counter=0, index=0; counter<3;index++) { if (src[index]=='\n') ++counter; } pos=index-1; for (y=0;y<ymax;y++) for (x=0;x<xmax;x++) imagem[y][x] = *(get_pixel(src,&pos)); pos=index; switch (*((int*)rotation)) { case 0 : //Rotação 90º clockwise sprintf(dst,"P6\n%d %d\n%d\n",ymax,xmax,colormax); for (x=0; x -1;y--) write_pixel(&(imagem[y][x]),dst,&pos); break; case 1: //Rotação 180º sprintf(dst,"P6\n%d %d\n%d\n",xmax,ymax,colormax); for (y=ymax-1;y>-1;y--) for (x = xmax-1; x>-1; x--) write_pixel(&(imagem[y][x]),dst,&pos); break; case 2: //Rotação 270º clockwise sprintf(dst,"P6\n%d %d\n%d\n",ymax,xmax,colormax); for (x=xmax-1; x>-1; x--) for (y=0; y<ymax;y++) write_pixel(&(imagem[y][x]),dst,&pos); break; } /* Zona #3 */ munmap(dst,size); close(fdout); /* Fim da Zona #3 */ pthread_exit(NULL); } int get_stat(int fdin) { struct stat pstatbuf; if (fstat(fdin, &pstatbuf) < 0) /* need size of input file */ { fprintf(stderr,"fstat error\n"); exit(1); } return pstatbuf.st_size; } int main(int argc, char *argv[]) { int id[N]; int fdin, i; if (argc != 2) { fprintf(stderr,"usage: trab11 \n"); exit(1); } if ( (fdin = open(argv[1], O_RDONLY)) < 0) { fprintf(stderr,"can't open %s for reading\n", argv[2]); exit(1); } size = get_stat(fdin); /* Zona # 1*/ if ( (src = mmap(0, size, PROT_READ, MAP_FILE | MAP_SHARED, fdin, 0)) == (caddr_t) -1) { fprintf(stderr,"mmap error for input\n"); exit(1); } /* Fim da Zona #1 */ /* Zona #5 */ pthread_t tid[N]; for (i=0; i<N; i++){ id[i]=i; pthread_create (&tid[i], NULL, do_rotation, &id[i]); } for (i=0; i<N; i++) pthread_join (tid[i], NULL); /* Fim da Zona #5 */ /* Zona #4 */ munmap(src,size); close(fdin); /* Fim da Zona #4 */ exit(0); } 每次我在Mac上运行它都会给我总线错误：10 ，但如果我在Linux上运行它不会给我任何错误，有人可以给我一个解决方案。
PS：错误是在get_pixel函数上，但我仍然无法弄明白。
在get_pixel您将返回一个指向自动变量的指针，该变量在此处退出函数时将不存在：
return ppix;
这声明了一个自动变量：
struct pixel pix;
其生命周期在函数结束时结束，因此从get_pixel返回后引用该内存是未定义的行为 。
您可以使用malloc动态分配：
struct pixel *ppix = malloc( sizeof( struct pixel ) ) ;
但是你必须记得在完成记忆后free打电话给记忆。