struct metrics
{
+ /* Flag to indicate first frame is being processed. */
+ bool first_frame;
+
/* Description of all available peformance counters, counter
* groups, their names and IDs, etc. */
metrics_info_t *info;
struct timespec cpu_time_ts;
};
+/* Return (a - b) while accounting for the fact that between a and b,
+ * the counter may have wrapped around (with a maximum number of bits
+ * in the counter of GL_QUERY_COUNTER_BITS). */
+static uint64_t
+subtract_timestamp (uint64_t a, uint64_t b)
+{
+ GLint timestamp_bits;
+
+ glGetQueryiv (GL_TIMESTAMP, GL_QUERY_COUNTER_BITS, ×tamp_bits);
+
+ /* Note: "<<" isn't defined for the number of bits in the
+ * type, and the compiler will punish you.
+ */
+ if (timestamp_bits == 64)
+ return a - b;
+
+ if (b > a)
+ return (1ull << timestamp_bits) + a - b;
+ else
+ return a - b;
+}
+
metrics_t *
metrics_create (metrics_info_t *info)
{
metrics->info = info;
+ metrics->first_frame = true;
+
metrics->op = 0;
metrics->timer_begun_id = 0;
/* Get the first frame timestamp started immediately. */
glQueryCounter (metrics->swap_end_timestamp_id, GL_TIMESTAMP);
+ /* As well as the initial CPU time. */
+ clock_gettime (CLOCK_PROCESS_CPUTIME_ID, &metrics->cpu_time_ts);
+
return metrics;
}
{ \
fprintf (stderr, "Unexpected end-of-buffer while " \
"parsing results\n"); \
+ value = 0.0; \
break; \
} \
(var) = *((typeof(var) *) p); \
}
}
-/* Return the difference from ts0 to ts1 as floating-point seconds. */
-#define TIMESPEC_DIFF(ts0, ts1) (double) (ts1.tv_sec - ts0.tv_sec + \
- (ts1.tv_nsec - ts0.tv_nsec) / 1e9)
+/* Subtract timespec values: Return (a - b) in seconds as a double. */
+#define SUBTRACT_TIMESPEC(a, b) (double) (a.tv_sec - b.tv_sec + \
+ (a.tv_nsec - b.tv_nsec) / 1e9)
void
metrics_end_frame_pre_swap (metrics_t *metrics)
glGetQueryObjectui64v (metrics->swap_end_timestamp_id,
GL_QUERY_RESULT, &swap_end_timestamp);
-
- if (frames == 0) {
+
+ if (metrics->first_frame) {
/* Print header */
- printf ("# frame: Frame_Number Frame_Time_milliseconds Frame_latency_milliseconds CPU_load\n");
+ printf ("# frame: Frame_Number Frame_Time_milliseconds Frame_latency_milliseconds CPU_load GPU_load\n");
+
+ metrics->first_frame = false;
} else {
/* Subtract previous frame's times to get frame times. */
- frame_time_ns = swap_end_timestamp - metrics->previous_swap_end_timestamp;
+ frame_time_ns = subtract_timestamp (swap_end_timestamp,
+ metrics->previous_swap_end_timestamp);
- latency_ns = swap_end_timestamp - metrics->swap_begin_timestamp;
+ latency_ns = subtract_timestamp (swap_end_timestamp,
+ metrics->swap_begin_timestamp);
- cpu_time = TIMESPEC_DIFF (metrics->previous_cpu_time_ts, metrics->cpu_time_ts);
+ cpu_time = SUBTRACT_TIMESPEC (metrics->cpu_time_ts,
+ metrics->previous_cpu_time_ts);
/* We've waited one frame to ensure we have a timestamp
* result. So the time we've actually measured here is
* for the previous frame. */
- printf ("frame: %d %g %g %g\n",
+ printf ("frame: %d %g %g %g %g\n",
frames - 1,
(double) frame_time_ns / 1e6,
(double) latency_ns / 1e6,
- cpu_time / (frame_time_ns / 1e9));
+ cpu_time / (frame_time_ns / 1e9),
+ 0.0);
}
metrics->previous_swap_end_timestamp = swap_end_timestamp;