windows-server-2003/admin/pchealth/core/trace/registry.c

/*----------------------------------------------------------------------
	REGISTRY.C
		Async tracing Registry reading routines

	Copyright (C) 1994 Microsoft Corporation
	All rights reserved.

	Authors:
		gordm          Gord Mangione

	History:
		01/30/95 gordm		Created.
----------------------------------------------------------------------*/

#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif

#include <windows.h>
#include "traceint.h"



char	szTraceFileName[MAX_PATH];
char 	szDebugAsyncTrace[] = "SOFTWARE\\Microsoft\\MosTrace\\CurrentVersion\\DebugAsyncTrace";


__inline BOOL GetRegDword( HKEY hKey, LPSTR pszValue, LPDWORD pdw )
{
	DWORD	cbData = sizeof( DWORD );
	DWORD	dwType = REG_DWORD;

	return	RegQueryValueEx(hKey,
							pszValue,
							NULL,
							&dwType,
							(LPBYTE)pdw,
							&cbData ) == ERROR_SUCCESS && dwType == REG_DWORD;
}



__inline BOOL GetRegString( HKEY hKey, LPSTR pszValue, LPBYTE buf, LPDWORD lpcbData )
{
	DWORD	dwType = REG_SZ;

	return	RegQueryValueEx(hKey,
							pszValue,
							NULL,
							&dwType,
							buf,
							lpcbData ) == ERROR_SUCCESS && dwType == REG_SZ;
}





BOOL GetTraceFlagsFromRegistry( void )
{
static char	szNewTraceFileName[MAX_PATH];
	DWORD	dwNewEnabledTraces;
	DWORD	dwNewTraceOutputType;
	DWORD	dwNewAsyncTraceFlag;
	DWORD	dwNewHeapIncrementCount;
	int		nNewThreadPriority;
	HKEY	hkConfig = NULL;
	BOOL	bRC = FALSE;
	DWORD	cbData;

	__try
	{
		if ( RegOpenKeyEx(	HKEY_LOCAL_MACHINE,
							szDebugAsyncTrace,
							0,
							KEY_READ,
							&hkConfig ) == ERROR_SUCCESS )
		{
			if ( GetRegDword(	hkConfig,
								"MaxTraceFileSize",
								&dwMaxFileSize ) == FALSE )
			{
				dwMaxFileSize = DEFAULT_MAX_FILE_SIZE;
			}

			//
			// determine threshold count based on how we can fit in the file
			//
			PendQ.dwThresholdCount = dwMaxFileSize / AVERAGE_TRACE_SIZE;
			INT_TRACE( "PendQ.dwThresholdCount: %d\n", PendQ.dwThresholdCount );
						
			if ( GetRegDword(	hkConfig,
								"EnabledTraces",
								&dwNewEnabledTraces ) == FALSE )
			{
				INT_TRACE( "GetRegDword: EnabledTraces failed: %d\n", GetLastError() );
				return	bRC = FALSE;
			}
						
			if ( GetRegDword(	hkConfig,
								"OutputTraceType",
								&dwNewTraceOutputType ) == FALSE )
			{
				INT_TRACE( "GetRegDword: OutputTraceType failed: %d\n", GetLastError() );
				return	bRC = FALSE;
			}
						
			if ( GetRegDword(	hkConfig,
								"AsyncTraceFlag",
								&dwNewAsyncTraceFlag ) == FALSE )
			{
				INT_TRACE( "GetRegDword: AsyncTraceFlag failed: %d\n", GetLastError() );
				return	bRC = FALSE;
			}
						
			if (GetRegDword(hkConfig,
							"HeapIncrementCount",
							(LPDWORD)&dwNewHeapIncrementCount ) == FALSE || 
				dwNewHeapIncrementCount == 0 )
			{
				//
				// optional reg entry
				// default is the number buffers in 64KB
				//
				dwNewHeapIncrementCount = 0x10000 / sizeof(TRACEBUF);
			}
			InterlockedExchange( (long *)&dwIncrementSize, (long)dwNewHeapIncrementCount );


			if ( GetRegDword(	hkConfig,
								"AsyncThreadPriority",
								(LPDWORD)&nNewThreadPriority ) == FALSE )
			{
			//
			// optional reg entry
			//
				nNewThreadPriority = THREAD_PRIORITY_BELOW_NORMAL;
			}
			else switch( nNewThreadPriority )
			{
			//
			// if successful verify the resulting value
			//
			case THREAD_PRIORITY_IDLE:
			case THREAD_PRIORITY_BELOW_NORMAL:
			case THREAD_PRIORITY_NORMAL:
			case THREAD_PRIORITY_ABOVE_NORMAL:
			case THREAD_PRIORITY_HIGHEST:
				break;

			default:
				ASSERT( FALSE );
				nNewThreadPriority = THREAD_PRIORITY_BELOW_NORMAL;
			}
						
			cbData = sizeof(szNewTraceFileName);
			if ( GetRegString(	hkConfig,
								"TraceFile",
								szNewTraceFileName,
								&cbData ) == FALSE )
			{	
				//
				// Only fail if user specifies FILE based tracing
				//
				if ( dwNewTraceOutputType & TRACE_OUTPUT_FILE )
				{
					INT_TRACE( "GetRegString: TraceFile failed: %d\n", GetLastError() );
					return	bRC = FALSE;
				}
			}
			bRC = TRUE;
		}
	}
	__finally
	{
		//
		// preserve the original error code
		//
		DWORD	dwLastError = GetLastError();
		BOOL	fLeaveCritSec = FALSE;

		if ( bRC == TRUE )
		{
			BOOL	bNewFileName = lstrcmpi( szNewTraceFileName, szTraceFileName ) != 0;
			BOOL	bNewTraces = dwNewEnabledTraces != *INTERNAL__dwEnabledTraces;
			BOOL	bNewFlags = dwNewAsyncTraceFlag != dwAsyncTraceFlag;
			BOOL	bNewOutput = dwNewTraceOutputType != dwTraceOutputType;

			INT_TRACE( "GetTraceFlags... 0x%08X, 0x%08X, 0x%08X, %s\n",
						dwNewAsyncTraceFlag,
						dwNewEnabledTraces,
						dwNewTraceOutputType,
						szNewTraceFileName );

			INT_TRACE( "bNewFileName:%d bNewTraces:%d bNewOutput:%d bNewFlags:%d\n",
						bNewFileName,
						bNewTraces,
						bNewOutput,
						bNewFlags );

			if ( bNewFileName || bNewTraces || bNewOutput || bNewFlags )
			{
				if ( *INTERNAL__dwEnabledTraces )
				{
					//
					// not the initial time thru
					//

					fLeaveCritSec = TRUE;

					if ( dwAsyncTraceFlag )
					{
						INTERNAL__FlushAsyncTrace();
					}
					EnterCriticalSection( &critSecWrite );
				}

				if ( PendQ.hFile !=	INVALID_HANDLE_VALUE )
				{
					//
					// if the file name changed or tracing was disabled or the
					// file tracing disabled, then close the currently open file
					//
					if(	bNewFileName ||
						dwNewEnabledTraces == 0 ||
						IsTraceFile( dwNewTraceOutputType ) == FALSE )
					{
						BOOL	bSuccess;

						EnterCriticalSection( &critSecWrite );
						bSuccess = CloseHandle( PendQ.hFile );
						INT_TRACE( "CloseHandle: %d, GetLastError: %d\n",
									bSuccess, GetLastError() );
						PendQ.hFile = INVALID_HANDLE_VALUE;
						LeaveCriticalSection( &critSecWrite );
					}
				}

				if ( IsTraceFile( dwNewTraceOutputType ) )
				{
					if (bNewFileName ||
						IsTraceFile( dwTraceOutputType ) == FALSE ||
						dwNewEnabledTraces != 0 &&
						PendQ.hFile == INVALID_HANDLE_VALUE )
					{
						PendQ.hFile = CreateFile(szNewTraceFileName,
												GENERIC_WRITE,
												FILE_SHARE_READ|FILE_SHARE_WRITE,
												NULL,
												OPEN_ALWAYS,
												FILE_ATTRIBUTE_NORMAL,
												NULL );

						if ( PendQ.hFile != INVALID_HANDLE_VALUE )
						{
							lstrcpy( szTraceFileName, szNewTraceFileName );
						}
						else
						{
							INT_TRACE( "CreateFile failed for %s 0x%X\n",
										szNewTraceFileName,
										GetLastError() );
						}
					}
				}

				//
				// set the new priority for the writer thread
				//
				if ( nNewThreadPriority != nAsyncThreadPriority )
				{
					nAsyncThreadPriority = nNewThreadPriority;
					SetThreadPriority( PendQ.hWriteThread, nAsyncThreadPriority );
				}

				dwTraceOutputType = dwNewTraceOutputType;
				dwAsyncTraceFlag = dwNewAsyncTraceFlag;

				InterlockedExchange( INTERNAL__dwEnabledTraces, dwNewEnabledTraces );

				if ( fLeaveCritSec )
				{
					//
					// not the initial time thru
					//
					LeaveCriticalSection( &critSecWrite );
				}
			}
		}

		if ( hkConfig != NULL )
		{
			RegCloseKey( hkConfig );
		}

		SetLastError( dwLastError );

    }

    return  bRC;
}




#define	NUM_REG_THREAD_OBJECTS	2

DWORD RegNotifyThread( LPDWORD lpdw )
{
	HANDLE	Handles[NUM_REG_THREAD_OBJECTS];
	HKEY	   hKey;
	DWORD	dw;

	Handles[0] = hShutdownEvent;

	INT_TRACE( "RegNotifyThread 0x%X\n", GetCurrentThreadId() );

	Handles[1] = CreateEvent( NULL, FALSE, FALSE, NULL );
	if ( Handles[1] == NULL )
	{
		ASSERT( FALSE );
		INT_TRACE( "RegNotifyThread CreateEvent failed 0x%X\n", GetLastError() );
		return	1;
	}

	if ( RegOpenKeyEx(	HKEY_LOCAL_MACHINE,
						szDebugAsyncTrace,
						0,
						KEY_READ,
						&hKey ) != ERROR_SUCCESS )
	{
		INT_TRACE( "RegNotifyThread RegOpenKeyEx failed 0x%X\n", GetLastError() );
		CloseHandle( Handles[1] );
		return	1;
	}

	for ( ;; )
	{
		if ( RegNotifyChangeKeyValue(hKey,
									FALSE,
									REG_NOTIFY_CHANGE_ATTRIBUTES |
									REG_NOTIFY_CHANGE_LAST_SET,
									Handles[1],
									TRUE ) != ERROR_SUCCESS )
		{
			INT_TRACE( "RegNotifyThread RegNotify... failed 0x%X\n", GetLastError() );
			RegCloseKey( hKey );
			CloseHandle( Handles[1] );
			return	1;
		}

		dw = WaitForMultipleObjects(NUM_REG_THREAD_OBJECTS,
									Handles,
									FALSE,
									INFINITE );

		switch( dw )
		{
		//
		// normal signalled event
		//
		case WAIT_OBJECT_0:
			RegCloseKey( hKey );
			CloseHandle( Handles[1] );
			INT_TRACE( "Exiting RegNotifyThread for hShutdownEvent\n" );
			return	0;

		//
		// signalled that our registry keys have changed
		//
		case WAIT_OBJECT_0+1:
			GetTraceFlagsFromRegistry();
			break;

		default:
			INT_TRACE( "RegNotifyThread WFMO: dw: 0x%X, Error: 0x%X\n", dw, GetLastError() );
			ASSERT( FALSE );
			RegCloseKey( hKey );
			CloseHandle( Handles[1] );
			return	1;
		}
	}

	INT_TRACE( "Exiting RegNotifyThread abnormally\n" );
	RegCloseKey( hKey );
	CloseHandle( Handles[1] );

	return	2;
}