nn::dbg::CTR::Instrument Class

class Instrument

Instrumentation class for tracing function calls.

Instrumentation Mechanism

If a program is compiled using the --gnu_instrument and --no_instrument_inline options of ARMCC, GCC (GNU Compiler Collection) format instrumentation code is inserted to the beginning and end of each function. The respective functions are _cyg_profile_func_enter and _cyg_profile_func_exit. With the Instrument instrumentation class, these functions are used to record when a function is called and also record system tick values.

Instrumentation Types

There are two recording modes: log mode and stack mode. You can also do things like record system ticks and use the instrumentation buffer as a ring buffer.

For details, see nn::dbg::CTR::Instrument::Initialize.

Starting and Stopping Instrumentation

Start instrumentation by calling nn::dbg::CTR::Instrument::Enable after initialization. Stop instrumentation by calling nn::dbg::CTR::Instrument::Disable.

Only thread calls on which nn::dbg::CTR::Instrument::Initialize was executed are measured. If nn::dbg::CTR::Instrument::Initialize is executed on more than one thread for different instrumentation buffers, measurements will be made for each.

Instrumentation Result Statistics

The instrumentation class only records calls to each function. The nn::dbg::CTR::Statistics class has been prepared for statistical analysis of this information.

Example

// Instrumentation buffer and instrumentation class instances
#define INST_BUF_SIZE  0x1000
u8 instBuffer[ INST_BUF_SIZE ];
nn::dbg::CTR::Instrument inst;

// Statistics buffer and statistics class instances
#define STAT_BUF_SIZE  0x1000
u8 statBuffer[ STAT_BUF_SIZE ];
nn::dbg::CTR::Statistics stat;

nnMain()
{
  // Initialization.
  inst.Initialize( instBuffer,
                   INST_BUF_SIZE,
                   nn::dbg::CTR::TRACE_LOG );
  stat.Initialize( statBuffer,
                   STAT_BUF_SIZE );

  // Start instrumentation
  inst.Enable();
    ...
    ...
    ...

  // Stop instrumentation
  inst.Disable();

  // Statistical buffer content display
  inst.Dump();

  // Statistics
  stat.Collect( &inst );

  // Statistical results display
  stat.Dump();

  // End instrumentation
  inst.Finalize();
}

2011/07/15

Added an example.

2011/07/12

Initial version.