gtpp1m0u | Program Development Support Reference |
Real-time trace (RTT) is a system utility (referred to as the RTT utility in the remainder of this book) that counts or traces the use of specific macros and related system activity. The RTT utility is activated by commands issued from computer room agent set (CRAS) consoles. These commands may be included in the inputs to the program test vehicle (PTV) utility. For the trace option, the RTT utility traces any macros, including fast wait and fast link (non SVC) macros. The amount of trace data collected is determined by the options specified with the activating command. For the count option, the RTT utility creates a list of the selected macros providing a total of executions for each macro during the count period.
When the RTT utility is activated, it dynamically overlays the system code at several points. This enables the RTT utility to get control when:
When an ECB is created, the RTT utility determines whether you requested any macro tracing that could apply to the new entry. If so, the RTT utility sets indicators in the ECB to show the macro whose activity is to be traced in the entry, and the output required when the entry issues such a macro. If the ECB has a message block attached and the trace option is active, then the RTT utility writes a copy of the input message to the real-time tape.
When an application program issues a macro, the RTT utility checks the indicator bytes in the ECB (CE1REC) to see if tracing was requested. If tracing was requested for the entry and the macro just issued is among those to be traced, then the RTT utility collects the output you specified and writes it to tape.
When a system error macro is issued, the system error routines force system error dumps to the real-time tape. Any queued real-time tape output is bypassed. When system error macros are processed, the RTT utility sends a message indicating when the dump occurred so that the out of sequence RTT information can be understood.
At WAIT COMPLETE, the RTT utility intercepts the ECB for combination input/output (I/O) macros (FINWC, FIWHC, and Fast Wait) so that conditions at I/O completion time are recorded.
TPF application programming interface (API) library functions called by dynamic load modules (DLMs) issue TPF macros intercepted by the RTT utility from the macro decoder in the same way as those macros issued from basic assembler language (BAL) programs. However, there is no facility in the RTT utility to trace library function Enters or Exits.