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Posted 13 Sep 2000


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Thread-safe Logger with Automatic Removing Log Messages from Release Version

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13 Sep 2000
A log file class for multi-threaded applications


This class makes it possible to use log file in multi-threaded applications and has several useful features widely used in my multi-threaded, time sensitive projects where Visual C++ integrated debugger has very limited usage.

CDebugPrintf class provides some useful features:

  1. Thread-safe logging in multi-threaded applications.
  2. Automatic removing log messages from release version of your application.
    You don't need anymore to remove or comment log messages in release version. Release version will not have any overhead or unused information in executable file.
  3. You can write log messages at the same time to same file from different applications.
    It is useful when it is necessary to explore interaction and timing issues between two or more applications.
  4. Using printfs style for format text: %s, %d, %4.1d, etc.
    Sorry, but there is no floating point support.
  5. Data and time stamps for each message in log file.
    Also, this class provides time difference stamp from application start.
  6. Console output and easy logging for error codes returned by GetLastError function.
  7. Saving old log files.
  8. Uses only Windows API functions. So it can be used even in non-MFC applications.

The class is easy to use.

  1. Include files dbg.h and dbg.cpp to your project.
  2. At any time you want to write something to the log file, use the PRINTF macro.

Example of Log File Output

0.000 08/25/2000 15:04:48  User name = KVA
0.015 08/25/2000 15:04:48  ISAPI = "TraxDataMgr.dll"
0.015 08/25/2000 15:04:48  CActionHandler constructor
0.015 08/25/2000 15:04:48  CDataMgrActionHandler constructor
5.123 08/25/2000 15:04:53  0   HttpExtensionProc: started
5.123 08/25/2000 15:04:53  Execute request 1 started.   
5.672 08/25/2000 15:04:53  CIndexer constructor: done
5.693 08/25/2000 15:04:53  Open:  D:\Data\Docs\customer
5.693 08/25/2000 15:04:53  Loading index table from 'D:\Data\Docs\customer.idx'
5.693 08/25/2000 15:04:53  Count: 93560
6.132 08/25/2000 15:04:54  Index loading finished ... OK
6.375 08/25/2000 15:04:54  Execute request 1 finished.   
6.375 08/25/2000 15:04:54  0   HttpExtensionProc: finished

Class Usage

void SomeFunction( char* arg1, int arg2, string& arg3 )
    // doing something
    PRINTF("Something happened by using %s and %d arguments", arg1, arg2);
    // doing something
    PRINTF("This message is visible on console and in log-file.");


All log messages must fit into one line of source code because of problem with transparent removing log messages from release version.

PRINTF("One line messages are supported.");
PRINTF("Multi-line messages %s %s",
           "are not",


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Comments and Discussions

Questioncan this be used in Linux Project Pin
pkuwgg8-Sep-08 16:25
pkuwgg8-Sep-08 16:25 
GeneralWorks great! Pin
Luckymmkay31-Aug-07 4:39
Luckymmkay31-Aug-07 4:39 
GeneralPossible memory corruption Pin
Tnarol6-Jul-06 2:17
Tnarol6-Jul-06 2:17 
GeneralAn enhancement to class Pin
Wes Jones13-Jun-01 9:31
Wes Jones13-Jun-01 9:31 
GeneralProblems w/ Console window Pin
Wes Jones24-May-01 15:25
Wes Jones24-May-01 15:25 
GeneralRe: Problems w/ Console window - half way fixed! Pin
Wes Jones25-May-01 13:33
Wes Jones25-May-01 13:33 
GeneralShouldn't CDebugPrintf::HideConsole() be... Pin
8-Feb-01 11:48
suss8-Feb-01 11:48 
GeneralFix for Multi-Line comment Pin
Brad Bruce14-Sep-00 12:10
Brad Bruce14-Sep-00 12:10 
GeneralAdd ThreadID Pin
Mark Findlay14-Sep-00 9:59
Mark Findlay14-Sep-00 9:59 
GeneralRe: Add ThreadID Pin
James Spibey21-Dec-00 22:25
James Spibey21-Dec-00 22:25 
GeneralRe: Add ThreadID Pin
17-Apr-01 3:43
suss17-Apr-01 3:43 
GeneralRe: Add ThreadID Pin
25-Nov-01 0:21
suss25-Nov-01 0:21 

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