Question

我正在学习c和ncurses，并用halfdelay（1）编写了一个简单的蛇游戏来半自动化它。当我添加线程时，它停止工作，我无法从键盘获得任何输入。

所以我编写了一个简短的程序来尝试thread / ncurses和mutex锁定。代码有2个线程，各自有函数（fn和fn2）。当我在相应的函数调用中使用wmove / wprint运行它时它工作（好吧，它打印到屏幕！）我试图实现互斥锁定并将代码移动到另一个名为print_to_screen（）的函数，但没有任何反应。

我添加了if(thread_id == pthread_self())来切换线程但仍然没有任何反应。我添加了一些注释掉的行，显示了2个线程到达print_to_screen（）函数，但是if循环中的代码根本没有运行。

请帮助我，我在我的智慧结束 - 我甚至尝试阅读usr/inc.ncurses.h而男人是无益的！这是代码。如果您注释掉2个函数中的wmove / wprint位并取消注释print_to_screen（）调用，则可以看到差异。 ncurses设置来自隐形岛教程，如果有人知道为什么他把（无效）放在他的ncurses电话前请告诉我。 TIA可以提供任何帮助。

#include <stdlib.h>
#include <curses.h>
#include <signal.h>
#include <string.h> 
#include <time.h>
#include <pthread.h>
#include <sys/types.h>
#include <unistd.h>

void *myfunction(void *);
void *myfunction2(void *);

void print_to_screen(void);
static void finish(int);

pthread_t thread1, thread2;
pthread_mutex_t mx = PTHREAD_MUTEX_INITIALIZER;

int thread1_id, thread2_id, count, count2;
int done;   
int ch;

WINDOW *mywin;

int main(void){

    (void) signal(SIGINT, finish);      /* arrange interrupts to terminate */

    (void) initscr();      /* initialize the curses library */
    keypad(stdscr, TRUE);  /* enable keyboard mapping */
    (void) nonl();         /* tell curses not to do NL->CR/NL on output */
    (void) cbreak();       /* take input chars one at a time, no wait for \n */
    (void) echo();         /* echo input - in color */

      if (has_colors())
        {
        start_color();

        /*
         * Simple color assignment, often all we need.  Color pair 0 cannot
         * be redefined.  This example uses the same value for the color
         * pair as for the foreground color, though of course that is not
         * necessary:
         */
        init_pair(1, COLOR_RED,     COLOR_BLACK);
        init_pair(2, COLOR_GREEN,   COLOR_BLACK);
        init_pair(3, COLOR_YELLOW,  COLOR_BLACK);
        init_pair(4, COLOR_BLUE,    COLOR_BLACK);
        init_pair(5, COLOR_CYAN,    COLOR_BLACK);
        init_pair(6, COLOR_MAGENTA, COLOR_BLACK);
        init_pair(7, COLOR_WHITE,   COLOR_BLACK);
    }
    count = count2 = 0;
    done = 0;

    mywin = newwin(LINES, COLS, 0,0);
    keypad(mywin, TRUE);

    pthread_create( &thread1, NULL, myfunction, NULL);
    pthread_create( &thread2, NULL, myfunction2, NULL);

    pthread_join(thread1,  NULL);
    pthread_join(thread2,  NULL);

    finish(0);
    exit(0);
}

void *myfunction(void *ptr){

    thread1_id =  pthread_self();
    halfdelay(-1);

    while(1){
        ch = getch();
        if(ch == 'q') break;

        wmove(mywin, 5,2);
        wprintw(mywin, "Thread 1 at print");
        wmove(mywin, 10,count);
        waddch(mywin, ch);
        wrefresh(mywin);

        //print_to_screen();
        if(count++ >70) count = 0;
        nanosleep((struct timespec[]){{0, 250000000}}, NULL);
    }
    done = 1;
}

void *myfunction2(void *ptr){
    thread2_id =  pthread_self();

    while(1){
        if(done == 1) break;
        if(count++ >24) count = 0;
        wmove(mywin, 6,2);
        wprintw(mywin, "Thread 2 at print");
        wmove(mywin, count, 10);
        wprintw(mywin, "hello from thread 2");
        wrefresh(mywin); 

        //print_to_screen();
        nanosleep((struct timespec[]){{0, 250000000}}, NULL);
    }
}

void print_to_screen(){
    pthread_mutex_lock(&mx);

    //printw("PTHREAD ID = %d : ", pthread_self());
    //printw("thread1_id = %d : thread2_id = %d\n", thread1_id, thread2_id);

    if(pthread_self() == thread1_id){
        wmove(mywin, 5,2);
        wprintw(mywin, "Thread 1 at print");
        wmove(mywin, 10,count);
        waddch(mywin, ch);
        wrefresh(mywin);
    }


    if(pthread_self() == thread2_id){
        wmove(mywin, 6,2);
        wprintw(mywin, "Thread 2 at print");
        wmove(mywin, count, 10);
        wprintw(mywin, "hello from thread 2");
        wrefresh(mywin);
    }

    pthread_mutex_unlock(&mx);
}

static void finish(int sig)
{
    endwin();
    /* do your non-curses wrapup here */
}

Answer 1

首先：

int thread1_id, thread2_id, count, count2;

应该是

int count, count2;
pthread_t thread1_id, thread2_id;

永远不会调用print_to_screen()。

pthread和ncurses - 为什么这个锁不起作用？

1 个答案: