Small exercise of process and signal

 Create a subprocess ,
	 Subprocess interval 7s send out 2 A signal to the parent process ,
	 Parent process registration 2 A signal response function ,
	 Create a signal set , Add all signals to the signal set ,
	 Judge 2 Whether the signals are in the signal set , Set the signal in the signal set to block ,
	 Time delay 10s relieve 1 Blocking of signals ,
	 stay 5s Then unblock another signal ,
	 Signal response function   Printing process pid And signal value 

#include <stdio.h>

#include <sys/types.h>
#include <unistd.h>

#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>

void func1(int sig)
{
    
	printf("pid=%d, received %d The signal ,  Execute the response function 1\n",getpid(),sig);
}
void func2(int sig)
{
    
	printf("pid=%d, received %d The signal ,  Execute the response function 2\n",getpid(),sig);
}

int main(int argc, char const *argv[])
{
    

	pid_t pid=fork();
	if (pid > 0)
	{
    
		printf(" The parent process pid=%d\n",getpid());

		signal(10, func1);// Register response function 
		signal(12, func2);

		sigset_t myset;
		// sigemptyset(&myset); // Clear the signal set 
		sigaddset(&myset,10);		// Add signal SIGUSR1 To signal set  10
		sigaddset(&myset,12);		// Add signal SIGUSR2 To signal set  12

		if (sigismember(&myset, 10))	// Judge 10 Whether the signal is myset Signal concentration 
		{
    
			printf("10 The signal is myset Signal concentration \n");
		}
		else
		{
    
			printf("10 The signal is not myset Signal concentration \n");
		}
		if (sigismember(&myset, 12))	// Judge 12 Whether the signal is myset Signal concentration 
		{
    
			printf("12 The signal is myset Signal concentration \n");
		}
		else
		{
    
			printf("12 The signal is not myset Signal concentration \n");
		}

		sigprocmask(SIG_BLOCK, &myset, NULL);		// Set up myset The signals in the signal set are blocking 
		sigprocmask(SIG_UNBLOCK, &myset, NULL);		// relieve myset A signal in a signal set   Blocking 
		sigemptyset(&myset);		// Clear the signal set 
		int a=10;
		while(a--)
		{
    
			sleep(1);
			printf(" The parent process  %d  The signal 10\n", a);		
			
			sigaddset(&myset,10);		// Add signal SIGUSR1 To signal set  10 
			sigprocmask(SIG_UNBLOCK, &myset, NULL);		// relieve myset A signal in a signal set   Blocking 
		}
		sigemptyset(&myset);		// Clear the signal set 
		a=5;
		while(a--)	
		{
    	
			sleep(1);
			printf(" The parent process  %d  The signal 12\n", a);
			
			sigaddset(&myset,12);		// Add signal SIGUSR2 To signal set  12
			sigprocmask(SIG_UNBLOCK, &myset, NULL);		// relieve myset A signal in a signal set   Blocking 
		}
		
	}
	else if (pid == 0)
	{
    
		int a=7;
		while(a--)
		{
    	
			sleep(1);
			printf(" Subprocesses  %d  The signal 10\n", a);
		}
		kill(getppid(), 10);
		a=7;
		while(a--)
		{
    
			sleep(1);
			printf(" Subprocesses  %d  The signal 12\n", a);			
		}
		kill(getppid(), 12);
	}	
	return 0;
}