Hello everyone, I'm creating my coursework project and I should create my own C++ library for easier GPIO usage. I'm struggling with using epoll in my code, because it doesn't register edge events, that I specified. My code looks like this:

void somePollingFunc(std::string path) {
	int epollFD = epoll_create1(0);
	if(epollFD == -1){
		throw std::runtime_error("Failed to create epoll");
	}

	int socketToRead = open(path.c_str(), O_RDONLY | O_NONBLOCK);
	if(socketToRead < 0) {
		throw std::runtime_error(std::string("Failed to open file\nPath: ") + path.data());
	}

	// Creating epoll struct
	struct epoll_event gpioPollFD;
	gpioPollFD.data.fd = socketToRead;
	gpioPollFD.events = EPOLLET;

	// Adding gpio fd to epoll
	if(epoll_ctl(epollFD, EPOLL_CTL_ADD, socketToRead, &gpioPollFD) == -1) {
		throw std::runtime_error("Failed to add custom file descriptor to epoll");
	}
	
	char readByte;
	bool callbackStop = false;
	int pollValue;

	do {
		pollValue = epoll_wait(epollFD, &gpioPollFD, 1, 100);
		if(pollValue == 0){ continue; }
			
		if(::read(gpioPollFD.data.fd, &readByte, 1)){
			callbackStop = callback(readByte);
		}
		lseek(gpioPollFD.data.fd, 0, SEEK_SET);
	} while(!callbackStop);
	close(epollFD);
}

I checked my edge file, its value is set right, also I experimented using EPOLLIN or EPOLLPRI, they both works for every action that happen to socket

Am I missing something or such functionality doesn't work?

Edited November 29, 20214 yr by Casi

There is no Orange Pi Lite 3.

On 11/30/2021 at 4:31 AM, Werner said:

There is no Orange Pi Lite 3.

I'm sorry, I've meant Orange PI Lite with H3 processor. Sorry for long reply. As a newbie I have limitations for posts

I've found my error, I've found my error, I filtered all events with EPOLLET flag that is input-only, so it newer occured in output