Dos16SysTrace

Dos16SysTrace writes a trace record to the system trace buffer. It provides a high speed event recording mechanism which may be used by PM and non-PM threads in ring 3 and ring 2 and by detached processes.

Syntax

APIRET16 APIENTRY16 Dos16SysTrace
       (USHORT major, USHORT cBuffer, USHORT minor, PCHAR pBuffer) 

Parameters

major (USHORT) input

Major code which identifies the trace record. Range reserved for user. :Use is 245-255.

Valid range 0-255

cBuffer (USHORT) input

Length of optional buffer. Valid range

• 0 - 512 (before 4.0 FP 10 and 3.0 FP 35)
• 0 - 4099 (from 3.0 FP35 and 4.0 FP10 onwards).

minor (USHORT) input

Minor code which identifies the trace record. Major-minor code pair should uniquely identify the trace record.

Valid range 1 - 255

pBuffer (PCHAR) input

Pointer to optional buffer. If cBuffer is 0, then pBuffer is ignored.

Return Code

ulrc (APIRET) returns

Dos16SysTrace returns one of the following values

• 0 NO_ERROR
• 150 ERROR_SYSTEM_TRACE

Remarks

Dos16SysTrace creates a trace record that includes the following items:

• Header Major code, minor code, time stamp, PID of logging process
• Optional System Data Controlled by the TRACE command
• Optional User Data Specified by the pBuffer parameter

If you use Dos16SysTrace, then you need to LINK specifying OS2386.LIB. If you use DosSysTrace, then you need to LINK specifying OS2286.LIB as an additional library file with the LINK386 command.

Example Code

int main(int argc, char *argv[], char *envp[]){
   APIRET16 rc=0;          /* default return code */
   USHORT major=255;       /* default major code */
   USHORT minor=1;         /* default minor code */
   USHORT cBuffer=0;       /* default buffer length */
   PCHAR  pBuffer=NULL;    /* default buffer address */

   if (argc>1)
   {
      pBuffer = argv[1];
      cBuffer = strlen(argv[1]);
   }

   if (argc>2) major = atol(argv[2]);
   if (argc>3) minor = atol(argv[3]);

   rc = Dos16SysTrace(major, cBuffer, minor, pBuffer);

   if (rc) printf("DosSysTrace retuned rc=%u\n", rc);

   return rc;
}

Related Functions

• DosDumpProcess
• DosForceSystemDump