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/*
* Copyright (c) 2002-2005 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Nathan Binkert
*/
#include <sys/ioctl.h>
#include <sys/types.h>
#if defined(__sun__) || defined(__SUNPRO_CC)
#include <sys/file.h>
#endif
#include "base/pollevent.hh"
#include <fcntl.h>
#include <unistd.h>
#include <cerrno>
#include <csignal>
#include <cstring>
#include "base/misc.hh"
#include "base/types.hh"
#include "sim/async.hh"
#include "sim/core.hh"
#include "sim/eventq.hh"
#include "sim/serialize.hh"
using namespace std;
PollQueue pollQueue;
/////////////////////////////////////////////////////
//
PollEvent::PollEvent(int _fd, int _events)
: queue(NULL), enabled(true)
{
pfd.fd = _fd;
pfd.events = _events;
pfd.revents = 0;
}
PollEvent::~PollEvent()
{
if (queue)
queue->remove(this);
}
void
PollEvent::disable()
{
if (!enabled) return;
enabled = false;
if (queue)
queue->copy();
}
void
PollEvent::enable()
{
if (enabled) return;
enabled = true;
if (queue)
queue->copy();
}
void
PollEvent::serialize(CheckpointOut &cp) const
{
SERIALIZE_SCALAR(pfd.fd);
SERIALIZE_SCALAR(pfd.events);
SERIALIZE_SCALAR(enabled);
}
void
PollEvent::unserialize(CheckpointIn &cp)
{
UNSERIALIZE_SCALAR(pfd.fd);
UNSERIALIZE_SCALAR(pfd.events);
UNSERIALIZE_SCALAR(enabled);
}
/////////////////////////////////////////////////////
//
PollQueue::PollQueue()
: poll_fds(NULL), max_size(0), num_fds(0)
{ }
PollQueue::~PollQueue()
{
for (int i = 0; i < num_fds; i++)
setupAsyncIO(poll_fds[0].fd, false);
delete [] poll_fds;
}
void
PollQueue::copy()
{
eventvec_t::iterator i = events.begin();
eventvec_t::iterator end = events.end();
num_fds = 0;
while (i < end) {
if ((*i)->enabled)
poll_fds[num_fds++] = (*i)->pfd;
++i;
}
}
void
PollQueue::remove(PollEvent *event)
{
eventvec_t::iterator i = events.begin();
eventvec_t::iterator end = events.end();
while (i < end) {
if (*i == event) {
events.erase(i);
copy();
event->queue = NULL;
return;
}
++i;
}
panic("Event does not exist. Cannot remove.");
}
void
PollQueue::schedule(PollEvent *event)
{
if (event->queue)
panic("Event already scheduled!");
event->queue = this;
events.push_back(event);
setupAsyncIO(event->pfd.fd, true);
// if we ran out of space in the fd array, double the capacity
// if this is the first time that we've scheduled an event, create
// the array with an initial size of 16
if (++num_fds > max_size) {
if (max_size > 0) {
delete [] poll_fds;
max_size *= 2;
} else {
max_size = 16;
}
poll_fds = new pollfd[max_size];
}
copy();
}
void
PollQueue::service()
{
int ret = poll(poll_fds, num_fds, 0);
if (ret <= 0)
return;
for (int i = 0; i < num_fds; i++) {
int revents = poll_fds[i].revents;
if (revents) {
events[i]->process(revents);
if (--ret <= 0)
break;
}
}
}
template <class ArgT>
static int fcntlHelper(int fd, int cmd, ArgT arg)
{
int retval = fcntl(fd, cmd, arg);
if (retval == -1) {
char *errstr = strerror(errno);
panic("fcntl(%d, %d, %s): \"%s\" when setting up async IO.\n",
errstr, fd, cmd, arg);
}
return retval;
}
static int fcntlHelper(int fd, int cmd)
{
int retval = fcntl(fd, cmd);
if (retval == -1) {
char *errstr = strerror(errno);
panic("fcntl(%d, %d): \"%s\" when setting up async IO.\n",
errstr, fd, cmd);
}
return retval;
}
void
PollQueue::setupAsyncIO(int fd, bool set)
{
int flags = fcntlHelper(fd, F_GETFL);
if (set)
flags |= FASYNC;
else
flags &= ~(FASYNC);
if (set)
fcntlHelper(fd, F_SETOWN, getpid());
fcntlHelper(fd, F_SETFL, flags);
// The file descriptor might already have events pending. We won't
// see them if they occurred before we set the FASYNC
// flag. Simulate a SIGIO to ensure that the FD will be polled in
// next iteration of the simulation loop. We could just poll it,
// but this is much simpler.
if (set) {
async_event = true;
async_io = true;
/* Wake up some event queue to handle event */
getEventQueue(0)->wakeup();
}
}