ioqueue.cc

一个mips虚拟机非常好代码,使用C++来编写的,希望大家多学学,

#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include "sulima.hh"
#include "ioqueue.hh"

IOQueue *ioqueue;

extern "C" void
sigio_handler(int signo)
{
	ioqueue->poll();
}

void
Sulima::create_io_subsystem()
{
	struct sigaction sa;

	ioqueue = new IOQueue();

	memset(&sa, 0, sizeof(sa));
	sa.sa_handler = sigio_handler;
	sigaction(SIGIO, &sa, NULL);
}

void
Sulima::destroy_io_subsystem()
{
	
}

IOQueue::IOQueue(void)
{
	queue = NULL;
	FD_ZERO(&fds);
	max_fd = -1;
}

void
IOQueue::insert(IOListener *listener)
{
	listener->io_next = queue;
	queue = listener;

	fcntl(listener->io_fd, F_SETOWN, getpid());
	fcntl(listener->io_fd, F_SETFL, fcntl(listener->io_fd, F_GETFL) | O_ASYNC);

	FD_SET(listener->io_fd, &fds);
	if (listener->io_fd > max_fd)
		max_fd = listener->io_fd;
}

void
IOQueue::remove(IOListener *listener)
{
	IOListener **prev;

	for (prev = &queue; prev != NULL; prev = &((*prev)->io_next))
	{
		if (*prev == listener)
		{
			*prev = listener->io_next;
			break;
		}
	}

	FD_CLR(listener->io_fd, &fds);
	fcntl(listener->io_fd, F_SETFL, fcntl(listener->io_fd, F_GETFL) & ~O_ASYNC);
}

void
IOQueue::poll(void)
{
	IOListener *listener;
	fd_set readfds;
	struct timeval tv;

	readfds = fds;
	tv.tv_sec = tv.tv_usec = 0;

	if (select(max_fd+1, &readfds, NULL, NULL, &tv) <= 0)
		return;

	for (listener = queue; listener != NULL; listener = listener->io_next)
	{
		if (FD_ISSET(listener->io_fd, &readfds))
			listener->io_poll();
	}
}