在信号处理程序中使用sem_post()是否依赖于未定义的行为?
/*
* excerpted from the 2017-09-15 Linux man page for sem_wait(3)
* http://man7.org/linux/man-pages/man3/sem_wait.3.html
*/
...
sem_t sem;
...
static void
handler(int sig)
{
write(STDOUT_FILENO, "sem_post() from handler\n", 24);
if (sem_post(&
我是否可以区分信号,直接传递给进程和通过调试器传递。
案例1:
$ ./process1
process1 (not ptraced)
//set up handler
alarm(5);
....
//signal is handled and I can parse handler parameters
案例2:
$ debugger1 ./process1
process1 (is ptraced by debugger1)
//set up handler
alarm(5);
...
//signal is catched by debugger1. It re
我使用的是serial port,在与此通信时,我必须使用tcsetattr()和TCSDRAIN模式更改配置。
TCSADRAIN
The change should take place after all output written to fd has been read by the master pseudoterminal. Use this value when changing terminal attributes that affect output.
当使用tcsetattr()调用TCSDRAIN时,如果缓冲区中仍然保留输出数据,则Linux似乎被阻塞,并在中