xwords/xwords4/relay/crefmgr.h

/* -*-mode: C; fill-column: 78; c-basic-offset: 4; -*- */

/* 
 * Copyright 2005-2009 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.
 *
 * 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.
 */

#ifndef _CREFMGR_H_
#define _CREFMGR_H_

#include <list>

#include "cref.h"
#include "mlock.h"

typedef map<CookieID,CookieRef*> CookieMap;
class CookieMapIterator;
class SocketStuff;
typedef map< int, SocketStuff* > SocketMap;

class SocketsIterator {
 public:
    SocketsIterator( SocketMap::iterator iter, SocketMap::iterator end, 
                     pthread_mutex_t* mutex );
    ~SocketsIterator();
    int Next();
 private:
    SocketMap::iterator m_iter;
    SocketMap::iterator m_end;
    pthread_mutex_t* m_mutex; /* locked */
};

class CrefInfo {
 public:
    string m_cookie;
    string m_connName;
    CookieID m_cookieID;
    int m_totalSent;
    int m_nPlayersSought;
    int m_nPlayersHere;
    XW_RELAY_STATE m_curState;
    time_t m_startTime;
    int m_nHosts;
    string m_hostsIds;
    string m_hostSeeds;
    string m_hostIps;
};

class CrefMgrInfo {
 public:
    int m_nCrefsAll;
    int m_nCrefsCurrent;
    time_t m_startTimeSpawn;
    vector<CrefInfo> m_crefInfo;
};

class CRefMgr {
    /* Maintain access to CookieRef instances, ultimately to ensure that no
       single instance is being acted on by more than one thread at a time,
       and that once one is destroyed no additional threads attempt to access
       it.
     */

 public:
    static CRefMgr* Get();

    CRefMgr();
    ~CRefMgr();

    void CloseAll();

    CookieMapIterator GetCookieIterator();

    /* PENDING.  These need to go through SafeCref */
    void Recycle( CookieID id );
    void Recycle_locked( CookieRef* cref );
    void Recycle( const char* connName );
    CookieID CookieIdForName( const char* name );

    /* For use from ctrl only!!!! */
    void LockAll() { pthread_rwlock_wrlock( &m_cookieMapRWLock ); }
    void UnlockAll() { pthread_rwlock_unlock( &m_cookieMapRWLock ); }

    /* Track sockets independent of cookie refs */
    bool Associate( int socket, CookieRef* cref );
    void Disassociate( int socket, CookieRef* cref );
    pthread_mutex_t* GetWriteMutexForSocket( int socket );
    void RemoveSocketRefs( int socket );
    void PrintSocketInfo( int socket, string& out );
    SocketsIterator MakeSocketsIterator();

    int GetNumGamesSeen( void );
    int GetSize( void );

    time_t uptime();

    void GetStats( CrefMgrInfo& info );

 private:
    friend class SafeCref;

    /* We'll recycle cref instances rather than free and new them.  This
       solves, inelegantly, a problem where I want to free an instance (while
       holding its mutex) but can't know if other threads are trying to obtain
       that mutex.  It's illegal to destroy a mutex somebody's trying to lock.
       So we recycle, let the other thread succeed in locking but then quickly
       discover that the cref it got isn't what it wants.  See the SafeCref
       class.  */
    list<CookieRef*> m_freeList;
    pthread_mutex_t m_freeList_mutex;
    void addToFreeList( CookieRef* cref );
    CookieRef* getFromFreeList( void );

    CookieRef* getMakeCookieRef_locked( const char* cookie, const char* connName,
                                        HostID hid, int socket,
                                        int nPlayersH, int nPlayersT, int seed );
    CookieRef* getCookieRef( CookieID cookieID );
    CookieRef* getCookieRef( int socket );
    bool checkCookieRef_locked( CookieRef* cref );
    CookieRef* getCookieRef_impl( CookieID cookieID );
    CookieRef* AddNew( const char* cookie, const char* connName, int seed, 
                       CookieID id );
    CookieRef* FindOpenGameFor( const char* cookie, const char* connName,
                                HostID hid, int socket, int nPlayersH, 
                                int nPlayersT, int gameSeed, 
                                bool* alreadyHere );

    CookieID cookieIDForConnName( const char* connName );
    CookieID nextCID( const char* connName );

    static void heartbeatProc( void* closure );
    void checkHeartbeats( time_t now );

    pthread_mutex_t m_nextCIDMutex;
    CookieID m_nextCID;

    pthread_rwlock_t m_cookieMapRWLock;
    CookieMap m_cookieMap;

    pthread_mutex_t m_SocketStuffMutex;
    SocketMap m_SocketStuff;

    time_t m_startTime;

    friend class CookieMapIterator;
}; /* CRefMgr */


class SafeCref {

    /* Stack-based class that keeps more than one thread from accessing a
       CookieRef instance at a time. */

 public:
    SafeCref( const char* cookie, const char* connName, HostID hid, 
              int socket, int nPlayersH, int nPlayersT, 
              unsigned short gameSeed );
    SafeCref( CookieID cid, bool failOk = false );
    SafeCref( int socket );
    SafeCref( CookieRef* cref );
    ~SafeCref();

    bool Forward( HostID src, HostID dest, unsigned char* buf, int buflen ) {
        if ( IsValid() ) {
            m_cref->_Forward( src, dest, buf, buflen );
            return true;
        } else {
            return false;
        }
    }
    bool Connect( int socket, HostID srcID, int nPlayersH, int nPlayersT,
                  int seed ) {
        if ( IsValid() ) {
            m_cref->_Connect( socket, srcID, nPlayersH, nPlayersT, seed );
            return true;
        } else {
            return false;
        }
    }
    bool Reconnect( int socket, HostID srcID, int nPlayersH, int nPlayersT,
                    int seed ) {
        if ( IsValid() ) {
            m_cref->_Reconnect( socket, srcID, nPlayersH, nPlayersT, seed );
            return true;
        } else {
            return false;
        }
    }
    void Disconnect(int socket, HostID hostID ) {
        if ( IsValid() ) {
            m_cref->_Disconnect( socket, hostID );
        }
    }
    void Shutdown() {
        if ( IsValid() ) {
            m_cref->_Shutdown();
        }
    }
    void Remove( int socket ) {
        if ( IsValid() ) {
            m_cref->_Remove( socket );
        }
    }

#ifdef RELAY_HEARTBEAT
    bool HandleHeartbeat( HostID id, int socket ) {
        if ( IsValid() ) {
            m_cref->_HandleHeartbeat( id, socket );
            return true;
        } else {
            return false;
        }
    }
    void CheckHeartbeats( time_t now ) {
        if ( IsValid() ) {
            m_cref->_CheckHeartbeats( now );
        }
    }
#endif

    void PrintCookieInfo( string& out ) {
        if ( IsValid() ) {
            m_cref->_PrintCookieInfo( out );
        }
    }
    void CheckAllConnected() {
        if ( IsValid() ) {
            m_cref->_CheckAllConnected();
        }
    }
    const char* Cookie() { 
        if ( IsValid() ) {
            return m_cref->Cookie();
        } else {
            return "";          /* so don't crash.... */
        }
    }
    const char* ConnName() { 
        if ( IsValid() ) {
            return m_cref->ConnName();
        } else {
            return "";          /* so don't crash.... */
        }
    }
    
    CookieID GetCookieID() { 
        if ( IsValid() ) {
            return m_cref->GetCookieID();
        } else {
            return 0;          /* so don't crash.... */
        }
    }

    int GetTotalSent() { 
        if ( IsValid() ) {
            return m_cref->GetTotalSent();
        } else {
            return -1;          /* so don't crash.... */
        }
    }

    int GetPlayersTotal() { 
        if ( IsValid() ) {
            return m_cref->GetPlayersSought();
        } else {
            return -1;          /* so don't crash.... */
        }
    }
    int GetPlayersHere() { 
        if ( IsValid() ) {
            return m_cref->GetPlayersHere();
        } else {
            return -1;          /* so don't crash.... */
        }
    }

    const char* StateString() {
        if ( IsValid() ) {
            return stateString( m_cref->CurState() );
        } else {
            return "";
        }
    }

    void GetHostsConnected( string* hosts, string* seeds, string* addrs ) {
        if ( IsValid() ) {
            m_cref->_FormatHostInfo( hosts, seeds, addrs );
        }
    }

    time_t GetStartTime(void) {
        if ( IsValid() ) {
            return m_cref->GetStarttime();
        } else {
            return 0;
        }
    }

    bool IsValid()        { return m_isValid; }

 private:
    CookieRef* m_cref;
    CRefMgr* m_mgr;
    bool m_isValid;
    bool m_locked;
}; /* SafeCref class */


class CookieMapIterator {
 public:
    CookieMapIterator(pthread_rwlock_t* rwlock);
    ~CookieMapIterator() {}
    CookieID Next();
 private:
    RWReadLock m_rwl;
    CookieMap::const_iterator _iter;
};

#endif