gem5/base/pollevent.cc
Steve Reinhardt d5a187dd5a Miscellaneous minor fixes/improvements.
Most notable is that the rundiff trace-output lossage is fixed!

base/pollevent.cc:
    Use SA_RESTART to keep blocked write() calls from failing
    with EINTR when signals happen.
base/trace.hh:
    Make TRACING_ON depend on NDEBUG not being set (instead of
    DEBUG being set) so m5.opt/m5.fast do what we want.
util/rundiff:
    Print header lines showing file/cmd names.

--HG--
extra : convert_revision : 4966814ad65aedb6d62a5a62a6ad3e3f326d61b8
2003-12-17 09:43:03 -08:00

273 lines
5.9 KiB
C++

/*
* Copyright (c) 2003 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.
*/
#include <sys/ioctl.h>
#include <sys/types.h>
#include <fcntl.h>
#include <signal.h>
#include <unistd.h>
#include "sim/async.hh"
#include "sim/host.hh"
#include "base/misc.hh"
#include "base/pollevent.hh"
#include "sim/universe.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;
}
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(ostream &os)
{
SERIALIZE_SCALAR(pfd.fd);
SERIALIZE_SCALAR(pfd.events);
SERIALIZE_SCALAR(enabled);
}
void
PollEvent::unserialize(Checkpoint *cp, const std::string &section)
{
UNSERIALIZE_SCALAR(pfd.fd);
UNSERIALIZE_SCALAR(pfd.events);
UNSERIALIZE_SCALAR(enabled);
}
/////////////////////////////////////////////////////
//
PollQueue::PollQueue()
: poll_fds(NULL), max_size(0), num_fds(0)
{ }
PollQueue::~PollQueue()
{
removeHandler();
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;
setupHandler();
}
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;
}
}
}
struct sigaction PollQueue::oldio;
struct sigaction PollQueue::oldalrm;
bool PollQueue::handler = false;
void
PollQueue::setupAsyncIO(int fd, bool set)
{
int flags = fcntl(fd, F_GETFL);
if (flags == -1)
panic("Could not set up async IO");
if (set)
flags |= FASYNC;
else
flags &= ~(FASYNC);
if (fcntl(fd, F_SETFL, flags) == -1)
panic("Could not set up async IO");
if (set) {
if (fcntl(fd, F_SETOWN, getpid()) == -1)
panic("Could not set up async IO");
}
}
void
PollQueue::setupHandler()
{
struct sigaction act;
act.sa_handler = handleIO;
sigemptyset(&act.sa_mask);
act.sa_flags = SA_RESTART;
if (sigaction(SIGIO, &act, &oldio) == -1)
panic("could not do sigaction");
act.sa_handler = handleALRM;
sigemptyset(&act.sa_mask);
act.sa_flags = SA_RESTART;
if (sigaction(SIGALRM, &act, &oldalrm) == -1)
panic("could not do sigaction");
alarm(1);
handler = true;
}
void
PollQueue::removeHandler()
{
if (sigaction(SIGIO, &oldio, NULL) == -1)
panic("could not remove handler");
if (sigaction(SIGIO, &oldalrm, NULL) == -1)
panic("could not remove handler");
}
void
PollQueue::handleIO(int sig)
{
if (sig != SIGIO)
panic("Wrong Handler");
async_event = true;
async_io = true;
}
void
PollQueue::handleALRM(int sig)
{
if (sig != SIGALRM)
panic("Wrong Handler");
async_event = true;
async_alarm = true;
alarm(1);
}