typedef struct wordCount {
    struct wordCount *self;
    int size;             // remaining file size
    int division_size;    // for each word count task
    int division_out_size;    
    int out_size;    
    int task_num;         // remaining task count
    int task_blocks;      // spawn task one at a time
    int status_num; 
    int task_spwaned;
    unsigned long long *o_data;
    unsigned long long *head_tail_flag;
    int out_task_num;
    int pad; 
    char * file_mmap;
    HTaskPtr t_print;
} WordCount;