+++ /dev/null
-/*
- * Copyright (c) 2000-2001,2003-2004 Apple Computer, Inc. All Rights Reserved.
- *
- * @APPLE_LICENSE_HEADER_START@
- *
- * This file contains Original Code and/or Modifications of Original Code
- * as defined in and that are subject to the Apple Public Source License
- * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
- *
- * The Original Code and all software distributed under the License are
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- * Please see the License for the specific language governing rights and
- * limitations under the License.
- *
- * @APPLE_LICENSE_HEADER_END@
- */
-
-
-//
-// selector - I/O stream multiplexing
-//
-#include "selector.h"
-#include <security_utilities/errors.h>
-#include <security_utilities/debugging.h>
-#include <algorithm> // min/max
-
-
-namespace Security {
-namespace UnixPlusPlus {
-
-
-//
-// construct a Selector object.
-//
-Selector::Selector() : fdMin(INT_MAX), fdMax(-1)
-{
- // initially allocate room for FD_SETSIZE file descriptors (usually good enough)
- fdSetSize = FD_SETSIZE / NFDBITS;
- inSet.grow(0, fdSetSize);
- outSet.grow(0, fdSetSize);
- errSet.grow(0, fdSetSize);
-}
-
-Selector::~Selector()
-{ }
-
-
-//
-// Add a Client to a Selector
-//
-void Selector::add(int fd, Client &client, Type type)
-{
- // plausibility checks
- assert(!client.isActive()); // one Selector per client, and no re-adding
- assert(fd >= 0);
-
- secdebug("selector", "add client %p fd %d type=%d", &client, fd, type);
-
- // grow FDSets if needed
- unsigned int pos = fd / NFDBITS;
- if (pos >= fdSetSize) {
- int newSize = (fd - 1) / NFDBITS + 2; // as much as needed + 1 spare word
- inSet.grow(fdSetSize, newSize);
- outSet.grow(fdSetSize, newSize);
- errSet.grow(fdSetSize, newSize);
- }
-
- // adjust boundaries
- if (fd < fdMin)
- fdMin = fd;
- if (fd > fdMax)
- fdMax = fd;
-
- // add client
- Client * &slot = clientMap[fd];
- assert(!slot);
- slot = &client;
- client.mFd = fd;
- client.mSelector = this;
- client.mEvents = type;
- set(fd, type);
-}
-
-
-//
-// Remove a Client from a Selector
-//
-void Selector::remove(int fd)
-{
- // sanity checks
- assert(fd >= 0);
- ClientMap::iterator it = clientMap.find(fd);
- assert(it != clientMap.end());
- assert(it->second->mSelector == this);
-
- secdebug("selector", "remove client %p fd %d", it->second, fd);
-
- // remove from FDSets
- set(fd, none);
-
- // remove client
- it->second->mSelector = NULL;
- clientMap.erase(it);
-
- // recompute fdMin/fdMax if needed
- if (isEmpty()) {
- fdMin = INT_MAX;
- fdMax = -1;
- } else if (fd == fdMin) {
- fdMin = clientMap.begin()->first;
- } else if (fd == fdMax) {
- fdMax = clientMap.rbegin()->first;
- }
-}
-
-
-//
-// Adjust the FDSets for a single given Client according to a new event Type mask.
-//
-void Selector::set(int fd, Type type)
-{
- assert(fd >= 0);
- inSet.set(fd, type & input);
- outSet.set(fd, type & output);
- errSet.set(fd, type & critical);
- secdebug("selector", "fd %d notifications 0x%x", fd, type);
-}
-
-
-void Selector::operator () ()
-{
- if (!clientMap.empty())
- singleStep(0);
-}
-
-
-void Selector::operator () (Time::Absolute stopTime)
-{
- if (!clientMap.empty())
- singleStep(stopTime - Time::now());
-}
-
-
-//
-// Perform a single pass through the Selector and notify all clients
-// that have selected I/O pending at this time.
-// There is not time limit on how long this may take; if the clients
-// are well written, it won't be too long.
-//
-void Selector::singleStep(Time::Interval maxWait)
-{
- assert(!clientMap.empty());
- secdebug("selector", "select(%d) [%d-%d] for %ld clients",
- fdMax + 1, fdMin, fdMax, clientMap.size());
- for (;;) { // pseudo-loop - only retries
- struct timeval duration = maxWait.timevalInterval();
-#if defined(__APPLE__)
- // ad-hoc fix: MacOS X's BSD rejects times of more than 100E6 seconds
- if (duration.tv_sec > 100000000)
- duration.tv_sec = 100000000;
-#endif
- const int size = FDSet::words(fdMax); // number of active words in sets
- switch (int hits = ::select(fdMax + 1,
- inSet.make(size), outSet.make(size), errSet.make(size),
- &duration)) {
- case -1: // error
- if (errno == EINTR)
- continue;
- secdebug("selector", "select failed: errno=%d", errno);
- UnixError::throwMe();
- case 0: // no events
- secdebug("selector", "select returned nothing");
- return;
- default: // some events
- secdebug("selector", "%d pending descriptors", hits);
- //@@@ This could be optimized as a word-merge scan.
- //@@@ The typical case doesn't benefit from this though, though browsers might
- //@@@ and integrated servers definitely would.
- for (int fd = fdMin; fd <= fdMax && hits > 0; fd++) {
- int types = 0;
- if (inSet[fd]) types |= input;
- if (outSet[fd]) types |= output;
- if (errSet[fd]) types |= critical;
- if (types) {
- secdebug("selector", "notify fd %d client %p type %d",
- fd, clientMap[fd], types);
- clientMap[fd]->notify(fd, types);
- hits--;
- }
- }
- return;
- }
- }
-}
-
-
-} // end namespace IPPlusPlus
-} // end namespace Security
projects / apple / security.git / blobdiff