Function SysPoll

Kernel/src/arch/x86_64/syscalls.cpp:1505–1625

* SysPoll (fds, nfds, timeout) - Wait for file descriptors * fds - Array of pollfd structs * nfds - Number of pollfd structs * timeout - timeout period * * On Success - return number of file descriptors * On Failure - return -1 */

 * On Failure - return -1
 */
long SysPoll(regs64_t* r){
	pollfd* fds = (pollfd*)SC_ARG0(r);
	unsigned nfds = SC_ARG1(r);
	long timeout = SC_ARG2(r);

	thread_t* thread = GetCPULocal()->currentThread;
	process_t* proc = Scheduler::GetCurrentProcess();
	if(!Memory::CheckUsermodePointer(SC_ARG0(r), nfds * sizeof(pollfd), proc->addressSpace)){
		Log::Warning("sys_poll: Invalid pointer to file descriptor array");
		return -EFAULT;
	}

	fs_fd_t* files[nfds];

	unsigned eventCount = 0; // Amount of fds with events
	for(unsigned i = 0; i < nfds; i++){
		fds[i].revents = 0;
		if(fds[i].fd < 0) continue;

		if((uint64_t)fds[i].fd >= Scheduler::GetCurrentProcess()->fileDescriptors.get_length()){
			Log::Warning("sys_poll: Invalid File Descriptor: %d", fds[i].fd);
			files[i] = 0;
			fds[i].revents |= POLLNVAL;
			eventCount++;
			continue;
		}

		fs_fd_t* handle = Scheduler::GetCurrentProcess()->fileDescriptors[fds[i].fd];

		if(!handle || !handle->node){
			Log::Warning("sys_poll: Invalid File Descriptor: %d", fds[i].fd);
			files[i] = 0;
			fds[i].revents |= POLLNVAL;
			eventCount++;
			continue;
		}

		files[i] = handle;

		bool hasEvent = 0;

		if((files[i]->node->flags & FS_NODE_TYPE) == FS_NODE_SOCKET){
			if(!((Socket*)files[i]->node)->IsConnected() && !((Socket*)files[i]->node)->IsListening()){
				fds[i].revents |= POLLHUP;
				hasEvent = true;
			}
			
			if(((Socket*)files[i]->node)->PendingConnections() && (fds[i].events & POLLIN)){
				fds[i].revents |= POLLIN;
				hasEvent = true;
			}
		}

		if(files[i]->node->CanRead() && (fds[i].events & POLLIN)) { // If readable and the caller requested POLLIN
			fds[i].revents |= POLLIN;
			hasEvent = true;
		}