Tracing Session Manager API return information

SESMGR APIs

SESMGR APIs are entered either directly or indirectly via a SESMGR thunking layer as shown below:

     Direct call:

             APPL ────────────────────> SESMGR
                  <────────────────────


     Thunked call:

             APPL ────> SESMGR Thunk Layer ─────> SESMGR
                  <──── SESMGR Thunk Layer <─────

Direct Calls:

Used for 16-bit APIs. Use TRACE ON SESMGR(....) for tracing APIs and return information.

Thunked Calls:

Used for 32-bit SESMGR APIs. Trace the 16-bit SESMGR API with the 32-bit SESMGR API to record the return information to the original 32-bit caller. For example, to trace the return information and parameters to DosStartSession from a 32-bit caller use: TRACE ON SESMGR(20,34,32788). The following is an example of the traced output:

(OS) DosStartSession Post-Invocation
Event [8]  Major [23/0x0017]  Minor [32788/0x8014]  PID [62/0x003e]  Length [12]  Time [10:44:23.01]
     New Process Id           = 0000
     New Session              = f0000
     Return Code              = 0000

(OS) DosStartSession Pre-Invocation
Event [16]  Major [23/0x0017]  Minor [20/0x0014]  PID [62/0x003e]  Length [60]  Time [10:44:22.77]
Return address = DFD7:BD0C
     Start Data               = 0032 0000 0000 0000 62D4 004F 2B54 004F CA10 045F 0000 0000 0000 0000 0001 0000
0000 0000 0000 0000 0000 0000 0000 0000 0000

(OS) Dos32StartSession Pre-Invocation
Event [17]  Major [23/0x0017]  Minor [34/0x0022]  PID [62/0x003e]  Length [7]  Time [10:44:22.77]
Return address = 0002E7E2

In this example the return address to the 32-bit application is given in minor code 34.

For a list of indirected SESMR APIs see: Indirected Session Manager API Tracepoints.

---

[Back: Tracing Kernel API Return Information]
[Next: Tracing Queue Calls API return information]