xwords/xwords4/relay/addrinfo.cpp
Eric House 811c8f535e add socket refcounting
AddrInfo now has ref()/unref() and keeps a global socket->refcount map
(since actual AddrInfo instances come and go.) When the
count drops to 0, the existing CloseSocket() method is called. This
seems to fix a bunch of race conditions that had a socket being closed
and reused while old code was still expecting to write to the device
attached to the socket the first time (along with lots of calls to close()
already-closed sockets, attempts to write() to closed sockets, etc.)
2017-12-07 07:18:09 -08:00

124 lines
3.6 KiB
C++

/* -*-mode: C; fill-column: 78; c-basic-offset: 4; -*- */
/*
* Copyright 2005-2011 by Eric House (xwords@eehouse.org). All rights
* reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <assert.h>
#include <errno.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "addrinfo.h"
#include "xwrelay_priv.h"
#include "tpool.h"
#include "udpager.h"
#include "mlock.h"
// static uint32_t s_prevCreated = 0L;
void
AddrInfo::construct( int sock, const AddrUnion* saddr, bool isTCP )
{
memset( this, 0, sizeof(*this) );
struct timespec tp;
clock_gettime( CLOCK_MONOTONIC, &tp );
/* convert to milliseconds */
m_createdMillis = (tp.tv_sec * 1000) + (tp.tv_nsec / 1000000);
/* assert( m_created >= s_prevCreated ); */
/* s_prevCreated = m_created; */
m_socket = sock;
m_isTCP = isTCP;
memcpy( &m_saddr, saddr, sizeof(m_saddr) );
m_isValid = true;
}
bool
AddrInfo::isCurrent() const
{
bool result;
if ( isTCP() ) {
result = XWThreadPool::GetTPool()->IsCurrent( this );
} else {
result = UDPAger::Get()->IsCurrent( this );
}
return result;
}
bool
AddrInfo::equals( const AddrInfo& other ) const
{
bool equal = other.isTCP() == isTCP();
if ( equal ) {
if ( isTCP() ) {
equal = m_socket == other.m_socket;
if ( equal && created() != other.created() ) {
logf( XW_LOGINFO, "%s(): rejecting on time mismatch (%lx vs %lx)",
__func__, created(), other.created() );
equal = false;
}
} else {
// assert( m_socket == other.m_socket ); /* both same UDP socket */
/* what does equal mean on udp addresses? Same host, or same host AND game */
equal = m_clientToken == other.m_clientToken
&& 0 == memcmp( &m_saddr, &other.m_saddr, sizeof(m_saddr) );
}
}
return equal;
}
static pthread_mutex_t s_refMutex = PTHREAD_MUTEX_INITIALIZER;
static map<int, int > s_socketRefs;
void AddrInfo::ref() const
{
// logf( XW_LOGVERBOSE0, "%s(socket=%d)", __func__, m_socket );
MutexLock ml( &s_refMutex );
++s_socketRefs[m_socket];
printRefMap();
}
void
AddrInfo::unref() const
{
// logf( XW_LOGVERBOSE0, "%s(socket=%d)", __func__, m_socket );
MutexLock ml( &s_refMutex );
assert( s_socketRefs[m_socket] > 0 );
--s_socketRefs[m_socket];
if ( s_socketRefs[m_socket] == 0 ) {
XWThreadPool::GetTPool()->CloseSocket( this );
}
printRefMap();
}
/* private, and assumes have mutex */
void
AddrInfo::printRefMap() const
{
/* for ( map<int,int>::const_iterator iter = s_socketRefs.begin(); */
/* iter != s_socketRefs.end(); ++iter ) { */
/* int count = iter->second; */
/* if ( count > 0 ) { */
/* logf( XW_LOGVERBOSE0, "socket: %d; count: %d", iter->first, count ); */
/* } */
/* } */
}