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);
+}