git/trace2/tr2_tmr.c

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#include "cache.h"
#include "thread-utils.h"
#include "trace2/tr2_tgt.h"
#include "trace2/tr2_tls.h"
#include "trace2/tr2_tmr.h"
#define MY_MAX(a, b) ((a) > (b) ? (a) : (b))
#define MY_MIN(a, b) ((a) < (b) ? (a) : (b))
/*
* A global timer block to aggregate values from the partial sums from
* each thread.
*/
static struct tr2_timer_block final_timer_block; /* access under tr2tls_mutex */
/*
* Define metadata for each stopwatch timer.
*
* This array must match "enum trace2_timer_id" and the values
* in "struct tr2_timer_block.timer[*]".
*/
static struct tr2_timer_metadata tr2_timer_metadata[TRACE2_NUMBER_OF_TIMERS] = {
[TRACE2_TIMER_ID_TEST1] = {
.category = "test",
.name = "test1",
.want_per_thread_events = 0,
},
[TRACE2_TIMER_ID_TEST2] = {
.category = "test",
.name = "test2",
.want_per_thread_events = 1,
},
/* Add additional metadata before here. */
};
void tr2_start_timer(enum trace2_timer_id tid)
{
struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
struct tr2_timer *t = &ctx->timer_block.timer[tid];
t->recursion_count++;
if (t->recursion_count > 1)
return; /* ignore recursive starts */
t->start_ns = getnanotime();
}
void tr2_stop_timer(enum trace2_timer_id tid)
{
struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
struct tr2_timer *t = &ctx->timer_block.timer[tid];
uint64_t ns_now;
uint64_t ns_interval;
assert(t->recursion_count > 0);
t->recursion_count--;
if (t->recursion_count)
return; /* still in recursive call(s) */
ns_now = getnanotime();
ns_interval = ns_now - t->start_ns;
t->total_ns += ns_interval;
/*
* min_ns was initialized to zero (in the xcalloc()) rather
* than UINT_MAX when the block of timers was allocated,
* so we should always set both the min_ns and max_ns values
* the first time that the timer is used.
*/
if (!t->interval_count) {
t->min_ns = ns_interval;
t->max_ns = ns_interval;
} else {
t->min_ns = MY_MIN(ns_interval, t->min_ns);
t->max_ns = MY_MAX(ns_interval, t->max_ns);
}
t->interval_count++;
ctx->used_any_timer = 1;
if (tr2_timer_metadata[tid].want_per_thread_events)
ctx->used_any_per_thread_timer = 1;
}
void tr2_update_final_timers(void)
{
struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
enum trace2_timer_id tid;
if (!ctx->used_any_timer)
return;
/*
* Accessing `final_timer_block` requires holding `tr2tls_mutex`.
* We assume that our caller is holding the lock.
*/
for (tid = 0; tid < TRACE2_NUMBER_OF_TIMERS; tid++) {
struct tr2_timer *t_final = &final_timer_block.timer[tid];
struct tr2_timer *t = &ctx->timer_block.timer[tid];
if (t->recursion_count) {
/*
* The current thread is exiting with
* timer[tid] still running.
*
* Technically, this is a bug, but I'm going
* to ignore it.
*
* I don't think it is worth calling die()
* for. I don't think it is worth killing the
* process for this bookkeeping error. We
* might want to call warning(), but I'm going
* to wait on that.
*
* The downside here is that total_ns won't
* include the current open interval (now -
* start_ns). I can live with that.
*/
}
if (!t->interval_count)
continue; /* this timer was not used by this thread */
t_final->total_ns += t->total_ns;
/*
* final_timer_block.timer[tid].min_ns was initialized to
* was initialized to zero rather than UINT_MAX, so we should
* always set both the min_ns and max_ns values the first time
* that we add a partial sum into it.
*/
if (!t_final->interval_count) {
t_final->min_ns = t->min_ns;
t_final->max_ns = t->max_ns;
} else {
t_final->min_ns = MY_MIN(t_final->min_ns, t->min_ns);
t_final->max_ns = MY_MAX(t_final->max_ns, t->max_ns);
}
t_final->interval_count += t->interval_count;
}
}
void tr2_emit_per_thread_timers(tr2_tgt_evt_timer_t *fn_apply)
{
struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
enum trace2_timer_id tid;
if (!ctx->used_any_per_thread_timer)
return;
/*
* For each timer, if the timer wants per-thread events and
* this thread used it, emit it.
*/
for (tid = 0; tid < TRACE2_NUMBER_OF_TIMERS; tid++)
if (tr2_timer_metadata[tid].want_per_thread_events &&
ctx->timer_block.timer[tid].interval_count)
fn_apply(&tr2_timer_metadata[tid],
&ctx->timer_block.timer[tid],
0);
}
void tr2_emit_final_timers(tr2_tgt_evt_timer_t *fn_apply)
{
enum trace2_timer_id tid;
/*
* Accessing `final_timer_block` requires holding `tr2tls_mutex`.
* We assume that our caller is holding the lock.
*/
for (tid = 0; tid < TRACE2_NUMBER_OF_TIMERS; tid++)
if (final_timer_block.timer[tid].interval_count)
fn_apply(&tr2_timer_metadata[tid],
&final_timer_block.timer[tid],
1);
}