This is an old revision of the document!
Table of Contents
Dos16SysTrace
Brief
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 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
DosSysTrace 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
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; }