pollevent.cc revision 10476
1/* 2 * Copyright (c) 2002-2005 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Nathan Binkert 29 */ 30 31#include <sys/ioctl.h> 32#include <sys/types.h> 33#if defined(__sun__) || defined(__SUNPRO_CC) 34#include <sys/file.h> 35#endif 36 37#include <fcntl.h> 38#include <unistd.h> 39 40#include <csignal> 41 42#include "base/misc.hh" 43#include "base/pollevent.hh" 44#include "base/types.hh" 45#include "sim/async.hh" 46#include "sim/core.hh" 47#include "sim/eventq.hh" 48#include "sim/serialize.hh" 49 50using namespace std; 51 52PollQueue pollQueue; 53 54///////////////////////////////////////////////////// 55// 56PollEvent::PollEvent(int _fd, int _events) 57 : queue(NULL), enabled(true) 58{ 59 pfd.fd = _fd; 60 pfd.events = _events; 61 pfd.revents = 0; 62} 63 64PollEvent::~PollEvent() 65{ 66 if (queue) 67 queue->remove(this); 68} 69 70void 71PollEvent::disable() 72{ 73 if (!enabled) return; 74 enabled = false; 75 76 if (queue) 77 queue->copy(); 78} 79 80void 81PollEvent::enable() 82{ 83 if (enabled) return; 84 enabled = true; 85 86 if (queue) 87 queue->copy(); 88} 89 90void 91PollEvent::serialize(ostream &os) 92{ 93 SERIALIZE_SCALAR(pfd.fd); 94 SERIALIZE_SCALAR(pfd.events); 95 SERIALIZE_SCALAR(enabled); 96} 97 98void 99PollEvent::unserialize(Checkpoint *cp, const std::string §ion) 100{ 101 UNSERIALIZE_SCALAR(pfd.fd); 102 UNSERIALIZE_SCALAR(pfd.events); 103 UNSERIALIZE_SCALAR(enabled); 104} 105 106///////////////////////////////////////////////////// 107// 108PollQueue::PollQueue() 109 : poll_fds(NULL), max_size(0), num_fds(0) 110{ } 111 112PollQueue::~PollQueue() 113{ 114 for (int i = 0; i < num_fds; i++) 115 setupAsyncIO(poll_fds[0].fd, false); 116 117 delete [] poll_fds; 118} 119 120void 121PollQueue::copy() 122{ 123 eventvec_t::iterator i = events.begin(); 124 eventvec_t::iterator end = events.end(); 125 126 num_fds = 0; 127 128 while (i < end) { 129 if ((*i)->enabled) 130 poll_fds[num_fds++] = (*i)->pfd; 131 ++i; 132 } 133} 134 135void 136PollQueue::remove(PollEvent *event) 137{ 138 eventvec_t::iterator i = events.begin(); 139 eventvec_t::iterator end = events.end(); 140 141 while (i < end) { 142 if (*i == event) { 143 events.erase(i); 144 copy(); 145 event->queue = NULL; 146 return; 147 } 148 149 ++i; 150 } 151 152 panic("Event does not exist. Cannot remove."); 153} 154 155void 156PollQueue::schedule(PollEvent *event) 157{ 158 if (event->queue) 159 panic("Event already scheduled!"); 160 161 event->queue = this; 162 events.push_back(event); 163 setupAsyncIO(event->pfd.fd, true); 164 165 // if we ran out of space in the fd array, double the capacity 166 // if this is the first time that we've scheduled an event, create 167 // the array with an initial size of 16 168 if (++num_fds > max_size) { 169 if (max_size > 0) { 170 delete [] poll_fds; 171 max_size *= 2; 172 } else { 173 max_size = 16; 174 } 175 176 poll_fds = new pollfd[max_size]; 177 } 178 179 copy(); 180} 181 182void 183PollQueue::service() 184{ 185 int ret = poll(poll_fds, num_fds, 0); 186 187 if (ret <= 0) 188 return; 189 190 for (int i = 0; i < num_fds; i++) { 191 int revents = poll_fds[i].revents; 192 if (revents) { 193 events[i]->process(revents); 194 if (--ret <= 0) 195 break; 196 } 197 } 198} 199 200void 201PollQueue::setupAsyncIO(int fd, bool set) 202{ 203 int flags = fcntl(fd, F_GETFL); 204 if (flags == -1) 205 panic("Could not set up async IO"); 206 207 if (set) 208 flags |= FASYNC; 209 else 210 flags &= ~(FASYNC); 211 212 if (set) { 213 if (fcntl(fd, F_SETOWN, getpid()) == -1) 214 panic("Could not set up async IO"); 215 } 216 217 if (fcntl(fd, F_SETFL, flags) == -1) 218 panic("Could not set up async IO"); 219 220 // The file descriptor might already have events pending. We won't 221 // see them if they occurred before we set the FASYNC 222 // flag. Simulate a SIGIO to ensure that the FD will be polled in 223 // next iteration of the simulation loop. We could just poll it, 224 // but this is much simpler. 225 if (set) { 226 async_event = true; 227 async_io = true; 228 /* Wake up some event queue to handle event */ 229 getEventQueue(0)->wakeup(); 230 } 231} 232