libprof/libprof.h

//---
//	libprof: A manual profiling library for gint
//---

#ifndef LIBPROF_LIBPROF
#define LIBPROF_LIBPROF

#include <stdint.h>

//---
//	Initialization
//---

/* prof_init(): Initialize the profiler's data and timer

   Initializes [prof_rec] and [prof_time] (see below) with enough elements to
   hold all the context IDs. Context IDs should be numbered from 0 to [n-1];
   due to speed requirements array bounds are not checked so be careful.

   Also starts a timer to count time. The timer ID must be set to 0, 1 or 2 as
   the standard TMU is the most tweakable and precise. libprof automatically
   selects an accurate timer configuration.

   @n      Number of different contexts (functions) that will be measured
   @timer  Timer ID, see <gint/timer.h> to select one
   Returns non-zero if a setup error occurs. */
int prof_init(int n, int timer);

/* prof_quit(): Free the profiler's data and timer */
void prof_quit(void);

//---
//	Runtime time measurement
//---

/* Recursion depth of each function currently being executed */
extern uint8_t *prof_rec;
/* Time that has elapsed within each function; the value for a given function
   is only relevant when it is not executing, due to optimizations */
extern uint32_t *prof_elapsed;
/* Timer counter */
extern uint32_t volatile *prof_tcnt;

/* prof_enter(): Start counting time for a function
   This macro should be called at the start of the context scope. If the
   function was already executing then the deepest instance in the stack is
   used instead of creating a new counter. */
#define prof_enter(ctx) {					\
	if(!prof_rec[ctx]++) prof_elapsed[ctx] += *prof_tcnt;	\
}

/* prof_leave(): Stop counting time for a function
   This should be called at the end of the context scope; it only actually
   stops if there is no deeper instance of the context in the stack. If there
   are not as exactly as many prof_leave()'s as prof_enter()'s then the
   resulting time measure will not be relevant at all. */
#define prof_leave(ctx) {					\
	if(!--prof_rec[ctx]) prof_elapsed[ctx] -= *prof_tcnt;	\
}

/* prof_clear(): Clear a context's counter
   This operation is defined only if the context is not being profiled. */
#define prof_clear(ctx) {		\
	prof_elapsed[ctx] = 0;		\
}

//---
//	Post-measurement analysis
//---

/* prof_time(): Time spent in a given context, in microseconds
   Should only be called when the context is not currently executing. */
uint32_t prof_time(int ctx);

#endif /* LIBPROF_LIBPROF */