common.c

quakeIII源码这个不用我多说吧

#ifndef DEDICATED
	CL_ShutdownCGame();
	CL_ShutdownUI();
#endif
	SV_ShutdownGameProgs();
#ifndef DEDICATED
	CIN_CloseAllVideos();
#endif
	hunk_low.mark = 0;
	hunk_low.permanent = 0;
	hunk_low.temp = 0;
	hunk_low.tempHighwater = 0;

	hunk_high.mark = 0;
	hunk_high.permanent = 0;
	hunk_high.temp = 0;
	hunk_high.tempHighwater = 0;

	hunk_permanent = &hunk_low;
	hunk_temp = &hunk_high;

	Com_Printf( "Hunk_Clear: reset the hunk ok\n" );
	VM_Clear();
#ifdef HUNK_DEBUG
	hunkblocks = NULL;
#endif
}

static void Hunk_SwapBanks( void ) {
	hunkUsed_t	*swap;

	// can't swap banks if there is any temp already allocated
	if ( hunk_temp->temp != hunk_temp->permanent ) {
		return;
	}

	// if we have a larger highwater mark on this side, start making
	// our permanent allocations here and use the other side for temp
	if ( hunk_temp->tempHighwater - hunk_temp->permanent >
		hunk_permanent->tempHighwater - hunk_permanent->permanent ) {
		swap = hunk_temp;
		hunk_temp = hunk_permanent;
		hunk_permanent = swap;
	}
}

/*
=================
Hunk_Alloc

Allocate permanent (until the hunk is cleared) memory
=================
*/
#ifdef HUNK_DEBUG
void *Hunk_AllocDebug( int size, ha_pref preference, char *label, char *file, int line ) {
#else
void *Hunk_Alloc( int size, ha_pref preference ) {
#endif
	void	*buf;

	if ( s_hunkData == NULL)
	{
		Com_Error( ERR_FATAL, "Hunk_Alloc: Hunk memory system not initialized" );
	}

	// can't do preference if there is any temp allocated
	if (preference == h_dontcare || hunk_temp->temp != hunk_temp->permanent) {
		Hunk_SwapBanks();
	} else {
		if (preference == h_low && hunk_permanent != &hunk_low) {
			Hunk_SwapBanks();
		} else if (preference == h_high && hunk_permanent != &hunk_high) {
			Hunk_SwapBanks();
		}
	}

#ifdef HUNK_DEBUG
	size += sizeof(hunkblock_t);
#endif

	// round to cacheline
	size = (size+31)&~31;

	if ( hunk_low.temp + hunk_high.temp + size > s_hunkTotal ) {
#ifdef HUNK_DEBUG
		Hunk_Log();
		Hunk_SmallLog();
#endif
		Com_Error( ERR_DROP, "Hunk_Alloc failed on %i", size );
	}

	if ( hunk_permanent == &hunk_low ) {
		buf = (void *)(s_hunkData + hunk_permanent->permanent);
		hunk_permanent->permanent += size;
	} else {
		hunk_permanent->permanent += size;
		buf = (void *)(s_hunkData + s_hunkTotal - hunk_permanent->permanent );
	}

	hunk_permanent->temp = hunk_permanent->permanent;

	Com_Memset( buf, 0, size );

#ifdef HUNK_DEBUG
	{
		hunkblock_t *block;

		block = (hunkblock_t *) buf;
		block->size = size - sizeof(hunkblock_t);
		block->file = file;
		block->label = label;
		block->line = line;
		block->next = hunkblocks;
		hunkblocks = block;
		buf = ((byte *) buf) + sizeof(hunkblock_t);
	}
#endif
	return buf;
}

/*
=================
Hunk_AllocateTempMemory

This is used by the file loading system.
Multiple files can be loaded in temporary memory.
When the files-in-use count reaches zero, all temp memory will be deleted
=================
*/
void *Hunk_AllocateTempMemory( int size ) {
	void		*buf;
	hunkHeader_t	*hdr;

	// return a Z_Malloc'd block if the hunk has not been initialized
	// this allows the config and product id files ( journal files too ) to be loaded
	// by the file system without redunant routines in the file system utilizing different 
	// memory systems
	if ( s_hunkData == NULL )
	{
		return Z_Malloc(size);
	}

	Hunk_SwapBanks();

	size = ( (size+3)&~3 ) + sizeof( hunkHeader_t );

	if ( hunk_temp->temp + hunk_permanent->permanent + size > s_hunkTotal ) {
		Com_Error( ERR_DROP, "Hunk_AllocateTempMemory: failed on %i", size );
	}

	if ( hunk_temp == &hunk_low ) {
		buf = (void *)(s_hunkData + hunk_temp->temp);
		hunk_temp->temp += size;
	} else {
		hunk_temp->temp += size;
		buf = (void *)(s_hunkData + s_hunkTotal - hunk_temp->temp );
	}

	if ( hunk_temp->temp > hunk_temp->tempHighwater ) {
		hunk_temp->tempHighwater = hunk_temp->temp;
	}

	hdr = (hunkHeader_t *)buf;
	buf = (void *)(hdr+1);

	hdr->magic = HUNK_MAGIC;
	hdr->size = size;

	// don't bother clearing, because we are going to load a file over it
	return buf;
}


/*
==================
Hunk_FreeTempMemory
==================
*/
void Hunk_FreeTempMemory( void *buf ) {
	hunkHeader_t	*hdr;

	  // free with Z_Free if the hunk has not been initialized
	  // this allows the config and product id files ( journal files too ) to be loaded
	  // by the file system without redunant routines in the file system utilizing different 
	  // memory systems
	if ( s_hunkData == NULL )
	{
		Z_Free(buf);
		return;
	}


	hdr = ( (hunkHeader_t *)buf ) - 1;
	if ( hdr->magic != HUNK_MAGIC ) {
		Com_Error( ERR_FATAL, "Hunk_FreeTempMemory: bad magic" );
	}

	hdr->magic = HUNK_FREE_MAGIC;

	// this only works if the files are freed in stack order,
	// otherwise the memory will stay around until Hunk_ClearTempMemory
	if ( hunk_temp == &hunk_low ) {
		if ( hdr == (void *)(s_hunkData + hunk_temp->temp - hdr->size ) ) {
			hunk_temp->temp -= hdr->size;
		} else {
			Com_Printf( "Hunk_FreeTempMemory: not the final block\n" );
		}
	} else {
		if ( hdr == (void *)(s_hunkData + s_hunkTotal - hunk_temp->temp ) ) {
			hunk_temp->temp -= hdr->size;
		} else {
			Com_Printf( "Hunk_FreeTempMemory: not the final block\n" );
		}
	}
}


/*
=================
Hunk_ClearTempMemory

The temp space is no longer needed.  If we have left more
touched but unused memory on this side, have future
permanent allocs use this side.
=================
*/
void Hunk_ClearTempMemory( void ) {
	if ( s_hunkData != NULL ) {
		hunk_temp->temp = hunk_temp->permanent;
	}
}

/*
=================
Hunk_Trash
=================
*/
void Hunk_Trash( void ) {
	int length, i, rnd;
	char *buf, value;

	return;

	if ( s_hunkData == NULL )
		return;

#ifdef _DEBUG
	Com_Error(ERR_DROP, "hunk trashed\n");
	return;
#endif

	Cvar_Set("com_jp", "1");
	Hunk_SwapBanks();

	if ( hunk_permanent == &hunk_low ) {
		buf = (void *)(s_hunkData + hunk_permanent->permanent);
	} else {
		buf = (void *)(s_hunkData + s_hunkTotal - hunk_permanent->permanent );
	}
	length = hunk_permanent->permanent;

	if (length > 0x7FFFF) {
		//randomly trash data within buf
		rnd = random() * (length - 0x7FFFF);
		value = 31;
		for (i = 0; i < 0x7FFFF; i++) {
			value *= 109;
			buf[rnd+i] ^= value;
		}
	}
}

/*
===================================================================

EVENTS AND JOURNALING

In addition to these events, .cfg files are also copied to the
journaled file
===================================================================
*/

// bk001129 - here we go again: upped from 64
// FIXME TTimo blunt upping from 256 to 1024
// https://zerowing.idsoftware.com/bugzilla/show_bug.cgi?id=5
#define	MAX_PUSHED_EVENTS	            1024
// bk001129 - init, also static
static int com_pushedEventsHead = 0;
static int com_pushedEventsTail = 0;
// bk001129 - static
static sysEvent_t	com_pushedEvents[MAX_PUSHED_EVENTS];

/*
=================
Com_InitJournaling
=================
*/
void Com_InitJournaling( void ) {
	Com_StartupVariable( "journal" );
	com_journal = Cvar_Get ("journal", "0", CVAR_INIT);
	if ( !com_journal->integer ) {
		return;
	}

	if ( com_journal->integer == 1 ) {
		Com_Printf( "Journaling events\n");
		com_journalFile = FS_FOpenFileWrite( "journal.dat" );
		com_journalDataFile = FS_FOpenFileWrite( "journaldata.dat" );
	} else if ( com_journal->integer == 2 ) {
		Com_Printf( "Replaying journaled events\n");
		FS_FOpenFileRead( "journal.dat", &com_journalFile, qtrue );
		FS_FOpenFileRead( "journaldata.dat", &com_journalDataFile, qtrue );
	}

	if ( !com_journalFile || !com_journalDataFile ) {
		Cvar_Set( "com_journal", "0" );
		com_journalFile = 0;
		com_journalDataFile = 0;
		Com_Printf( "Couldn't open journal files\n" );
	}
}

/*
=================
Com_GetRealEvent
=================
*/
sysEvent_t	Com_GetRealEvent( void ) {
	int			r;
	sysEvent_t	ev;

	// either get an event from the system or the journal file
	if ( com_journal->integer == 2 ) {
		r = FS_Read( &ev, sizeof(ev), com_journalFile );
		if ( r != sizeof(ev) ) {
			Com_Error( ERR_FATAL, "Error reading from journal file" );
		}
		if ( ev.evPtrLength ) {
			ev.evPtr = Z_Malloc( ev.evPtrLength );
			r = FS_Read( ev.evPtr, ev.evPtrLength, com_journalFile );
			if ( r != ev.evPtrLength ) {
				Com_Error( ERR_FATAL, "Error reading from journal file" );
			}
		}
	} else {
		ev = Sys_GetEvent();

		// write the journal value out if needed
		if ( com_journal->integer == 1 ) {
			r = FS_Write( &ev, sizeof(ev), com_journalFile );
			if ( r != sizeof(ev) ) {
				Com_Error( ERR_FATAL, "Error writing to journal file" );
			}
			if ( ev.evPtrLength ) {
				r = FS_Write( ev.evPtr, ev.evPtrLength, com_journalFile );
				if ( r != ev.evPtrLength ) {
					Com_Error( ERR_FATAL, "Error writing to journal file" );
				}
			}
		}
	}

	return ev;
}


/*
=================
Com_InitPushEvent
=================
*/
// bk001129 - added
void Com_InitPushEvent( void ) {
  // clear the static buffer array
  // this requires SE_NONE to be accepted as a valid but NOP event
  memset( com_pushedEvents, 0, sizeof(com_pushedEvents) );
  // reset counters while we are at it
  // beware: GetEvent might still return an SE_NONE from the buffer
  com_pushedEventsHead = 0;
  com_pushedEventsTail = 0;
}


/*
=================
Com_PushEvent
=================
*/
void Com_PushEvent( sysEvent_t *event ) {
	sysEvent_t		*ev;
	static int printedWarning = 0; // bk001129 - init, bk001204 - explicit int

	ev = &com_pushedEvents[ com_pushedEventsHead & (MAX_PUSHED_EVENTS-1) ];

	if ( com_pushedEventsHead - com_pushedEventsTail >= MAX_PUSHED_EVENTS ) {

		// don't print the warning constantly, or it can give time for more...
		if ( !printedWarning ) {
			printedWarning = qtrue;
			Com_Printf( "WARNING: Com_PushEvent overflow\n" );
		}

		if ( ev->evPtr ) {
			Z_Free( ev->evPtr );
		}
		com_pushedEventsTail++;
	} else {
		printedWarning = qfalse;
	}

	*ev = *event;
	com_pushedEventsHead++;
}

/*
=================
Com_GetEvent
=================
*/
sysEvent_t	Com_GetEvent( void ) {
	if ( com_pushedEventsHead > com_pushedEventsTail ) {
		com_pushedEventsTail++;
		return com_pushedEvents[ (com_pushedEventsTail-1) & (MAX_PUSHED_EVENTS-1) ];
	}
	return Com_GetRealEvent();
}

/*
=================
Com_RunAndTimeServerPacket
=================
*/
void Com_RunAndTimeServerPacket( netadr_t *evFrom, msg_t *buf ) {
	int		t1, t2, msec;

	t1 = 0;

	if ( com_speeds->integer ) {
		t1 = Sys_Milliseconds ();
	}

	SV_PacketEvent( *evFrom, buf );

	if ( com_speeds->integer ) {
		t2 = Sys_Milliseconds ();
		msec = t2 - t1;
		if ( com_speeds->integer == 3 ) {
			Com_Printf( "SV_PacketEvent time: %i\n", msec );
		}
	}
}

/*
=================
Com_EventLoop

Returns last event time
=================
*/
int Com_EventLoop( void ) {
	sysEvent_t	ev;
	netadr_t	evFrom;
	byte		bufData[MAX_MSGLEN];
	msg_t		buf;

	MSG_Init( &buf, bufData, sizeof( bufData ) );

	while ( 1 ) {
		ev = Com_GetEvent();

		// if no more events are available
		if ( ev.evType == SE_NONE ) {
			// manually send packet events for the loopback channel
			while ( NET_GetLoopPacket( NS_CLIENT, &evFrom, &buf ) ) {
				CL_PacketEvent( evFrom, &buf );
			}

			while ( NET_GetLoopPacket( NS_SERVER, &evFrom, &buf ) ) {
				// if the server just shut down, flush the events
				if ( com_sv_running->integer ) {
					Com_RunAndTimeServerPacket( &evFrom, &buf );
				}
			}

			return ev.evTime;
		}


		switch ( ev.evType ) {
		default:
		  // bk001129 - was ev.evTime
			Com_Error( ERR_FATAL, "Com_EventLoop: bad event type %i", ev.evType );
			break;
        case SE_NONE:
            break;
		case SE_KEY:
			CL_KeyEvent( ev.evValue, ev.evValue2, ev.evTime );
			break;
		case SE_CHAR:
			CL_CharEvent( ev.evValue );
			break;
		case SE_MOUSE:
			CL_MouseEvent( ev.evValue, ev.evValue2, ev.evTime );
			break;
		case SE_JOYSTICK_AXIS:
			CL_JoystickEvent( ev.evValue, ev.evValue2, ev.evTime );
			break;
		case SE_CONSOLE:
			Cbuf_AddText( (char *)ev.evPtr );
			Cbuf_AddText( "\n" );
			break;
		case SE_PACKET:
			// this cvar allows simulation of connections that
			// drop a lot of packets.  Note that loopback connections
			// don't go through here at all.
			if ( com_dropsim->value > 0 ) {
				static int seed;

				if ( Q_random( &seed ) < com_dropsim->value ) {
					break;		// drop this packet
				}
			}

			evFrom = *(netadr_t *)ev.evPtr;
			buf.cursize = ev.evPtrLength - sizeof( evFrom );

			// we must copy the contents of the message out, because
			// the event buffers are only large enough to hold the
			// exact payload, but channel messages need to be large
			// enough to hold fragment reassembly
			if ( (unsigned)buf.cursize > buf.maxsize ) {
				Com_Printf("Com_EventLoop: oversize packet\n");
				continue;
			}
			Com_Memcpy( buf.data, (byte *)((netadr_t *)ev.evPtr + 1), buf.cursize );