On Mon, Dec 20 2021, Jeff Hostetler via GitGitGadget wrote:
> From: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx>
> [...]
> +static void tr2main_emit_summary_timers(uint64_t us_elapsed_absolute)
> +{
> + struct tr2_tgt *tgt_j;
> + int j;
> + struct tr2tmr_block merged;
> +
> + memset(&merged, 0, sizeof(merged));
Nit: just do a " = { 0 }" assignment above instead.
> + if (tid < 0 || tid >= TRACE2_NUMBER_OF_TIMERS)
> + BUG("invalid timer id: %d", tid);
> +
> + tr2tmr_start(tid);
> +}
> +
> +void trace2_timer_stop(enum trace2_timer_id tid)
> +{
> + if (!trace2_enabled)
> + return;
> +
> + if (tid < 0 || tid >= TRACE2_NUMBER_OF_TIMERS)
> + BUG("invalid timer id: %d", tid);
nit / style: maybe assert() instead for cases where assert() produces
better info than BUG(). I.e. it would quote the whole expression, and
show you what condition it violated....
> +void tr2tmr_stop(enum trace2_timer_id tid)
> +{
> + struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
> + struct tr2tmr_timer *t = &ctx->timers.timer[tid];
> + uint64_t us_now;
> + uint64_t us_interval;
> +
> + assert(t->recursion_count > 0);
...as you opted to do here.
> +
> + t->recursion_count--;
> + if (t->recursion_count > 0)
> + return; /* still in recursive call */
> +
> + us_now = getnanotime() / 1000;
> + us_interval = us_now - t->start_us;
> +
> + t->total_us += us_interval;
> +
> + if (!t->interval_count) {
> + t->min_us = us_interval;
> + t->max_us = us_interval;
> + } else {
> + if (us_interval < t->min_us)
> + t->min_us = us_interval;
> + if (us_interval > t->max_us)
> + t->max_us = us_interval;
> + }
Perhaps more readable/easily understood as just a (untested):
if (!t->interval_count || us_interval >= t->min_us)
t->min_us = us_interval;
if (!t->interval_count || us_interval >= t->max_us)
t->max_us = us_interval;
I.e. to avoid duplicating the identical assignment...
> [...]
> + if (!t->interval_count)
> + continue; /* this timer was not used by this thread. */
> +
> + t_merged->total_us += t->total_us;
> +
> + if (!t_merged->interval_count) {
> + t_merged->min_us = t->min_us;
> + t_merged->max_us = t->max_us;
> + } else {
> + if (t->min_us < t_merged->min_us)
> + t_merged->min_us = t->min_us;
> + if (t->max_us > t_merged->max_us)
> + t_merged->max_us = t->max_us;
> + }
...ditto, maybe since it's used at least twice factor it out to some
trivial "static" helper here (maybe not worth it..)>
> + /*
> + * Number of nested starts on the stack in this thread. (We
> + * ignore recursive starts and use this to track the recursive
> + * calls.)
> + */
> + unsigned int recursion_count;
Earlier we have various forms of:
if (t->recursion_count > 1)
But since it's unsigned can we just make those a:
if (t->recursion_count)
?
