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-rw-r--r--trace2/tr2_tmr.c183
1 files changed, 183 insertions, 0 deletions
diff --git a/trace2/tr2_tmr.c b/trace2/tr2_tmr.c
new file mode 100644
index 0000000..31d0e4d
--- /dev/null
+++ b/trace2/tr2_tmr.c
@@ -0,0 +1,183 @@
+#include "git-compat-util.h"
+#include "thread-utils.h"
+#include "trace2/tr2_tgt.h"
+#include "trace2/tr2_tls.h"
+#include "trace2/tr2_tmr.h"
+#include "trace.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);
+}