From 24d65432e0514044965e066d426a5cac3d603972 Mon Sep 17 00:00:00 2001
From: Samy Al Bahra <sbahra@appnexus.com>
Date: Thu, 17 Apr 2014 15:36:53 -0400
Subject: [PATCH] regressions: Benchmark coverage for latchlock operations.

---
 regressions/ck_rwlock/benchmark/latency.c    | 26 ++++++++
 regressions/ck_rwlock/benchmark/throughput.c | 66 ++++++++++++++++++++
 2 files changed, 92 insertions(+)

diff --git a/regressions/ck_rwlock/benchmark/latency.c b/regressions/ck_rwlock/benchmark/latency.c
index 34dc406..6808a8b 100644
--- a/regressions/ck_rwlock/benchmark/latency.c
+++ b/regressions/ck_rwlock/benchmark/latency.c
@@ -55,6 +55,19 @@ main(void)
 	e_b = rdtsc();
 	printf("                WRITE: rwlock   %15" PRIu64 "\n", (e_b - s_b) / STEPS);
 
+	for (i = 0; i < STEPS; i++) {
+		ck_rwlock_write_latch(&rwlock);
+		ck_rwlock_write_unlatch(&rwlock);
+	}
+
+	s_b = rdtsc();
+	for (i = 0; i < STEPS; i++) {
+		ck_rwlock_write_latch(&rwlock);
+		ck_rwlock_write_unlatch(&rwlock);
+	}
+	e_b = rdtsc();
+	printf("           LATCHWRITE: rwlock   %15" PRIu64 "\n", (e_b - s_b) / STEPS);
+
 #ifdef CK_F_PR_RTM
 	struct ck_elide_config config = CK_ELIDE_CONFIG_DEFAULT_INITIALIZER;
 	struct ck_elide_stat st = CK_ELIDE_STAT_INITIALIZER;
@@ -99,6 +112,19 @@ main(void)
 	e_b = rdtsc();
 	printf("                READ:  rwlock   %15" PRIu64 "\n", (e_b - s_b) / STEPS);
 
+	for (i = 0; i < STEPS; i++) {
+		ck_rwlock_read_latchlock(&rwlock);
+		ck_rwlock_read_unlock(&rwlock);
+	}
+
+	s_b = rdtsc();
+	for (i = 0; i < STEPS; i++) {
+		ck_rwlock_read_latchlock(&rwlock);
+		ck_rwlock_read_unlock(&rwlock);
+	}
+	e_b = rdtsc();
+	printf("           LATCHREAD:  rwlock   %15" PRIu64 "\n", (e_b - s_b) / STEPS);
+
 #ifdef CK_F_PR_RTM
 	ck_elide_stat_init(&st);
 
diff --git a/regressions/ck_rwlock/benchmark/throughput.c b/regressions/ck_rwlock/benchmark/throughput.c
index 908348d..45caf0e 100644
--- a/regressions/ck_rwlock/benchmark/throughput.c
+++ b/regressions/ck_rwlock/benchmark/throughput.c
@@ -181,6 +181,71 @@ thread_lock(void *pun)
 	return NULL;
 }
 
+static void *
+thread_lock_latch(void *pun)
+{
+	uint64_t s_b, e_b, a, i;
+	uint64_t *value = pun;
+
+	if (aff_iterate(&affinity) != 0) {
+		perror("ERROR: Could not affine thread");
+		exit(EXIT_FAILURE);
+	}
+
+	ck_pr_inc_int(&barrier);
+	while (ck_pr_load_int(&barrier) != threads)
+		ck_pr_stall();
+
+	for (i = 1, a = 0;; i++) {
+		s_b = rdtsc();
+		ck_rwlock_read_latchlock(&rw.lock);
+		ck_rwlock_read_unlock(&rw.lock);
+		ck_rwlock_read_latchlock(&rw.lock);
+		ck_rwlock_read_unlock(&rw.lock);
+		ck_rwlock_read_latchlock(&rw.lock);
+		ck_rwlock_read_unlock(&rw.lock);
+		ck_rwlock_read_latchlock(&rw.lock);
+		ck_rwlock_read_unlock(&rw.lock);
+		ck_rwlock_read_latchlock(&rw.lock);
+		ck_rwlock_read_unlock(&rw.lock);
+		ck_rwlock_read_latchlock(&rw.lock);
+		ck_rwlock_read_unlock(&rw.lock);
+		ck_rwlock_read_latchlock(&rw.lock);
+		ck_rwlock_read_unlock(&rw.lock);
+		ck_rwlock_read_latchlock(&rw.lock);
+		ck_rwlock_read_unlock(&rw.lock);
+		ck_rwlock_read_latchlock(&rw.lock);
+		ck_rwlock_read_unlock(&rw.lock);
+		ck_rwlock_read_latchlock(&rw.lock);
+		ck_rwlock_read_unlock(&rw.lock);
+		ck_rwlock_read_latchlock(&rw.lock);
+		ck_rwlock_read_unlock(&rw.lock);
+		ck_rwlock_read_latchlock(&rw.lock);
+		ck_rwlock_read_unlock(&rw.lock);
+		ck_rwlock_read_latchlock(&rw.lock);
+		ck_rwlock_read_unlock(&rw.lock);
+		ck_rwlock_read_latchlock(&rw.lock);
+		ck_rwlock_read_unlock(&rw.lock);
+		ck_rwlock_read_latchlock(&rw.lock);
+		ck_rwlock_read_unlock(&rw.lock);
+		ck_rwlock_read_latchlock(&rw.lock);
+		ck_rwlock_read_unlock(&rw.lock);
+		e_b = rdtsc();
+
+		a += (e_b - s_b) >> 4;
+
+		if (ck_pr_load_uint(&flag) == 1)
+			break;
+	}
+
+	ck_pr_inc_int(&barrier);
+	while (ck_pr_load_int(&barrier) != threads * 2)
+		ck_pr_stall();
+
+	*value = (a / i);
+	return NULL;
+}
+
 static void
 rwlock_test(pthread_t *p, int d, uint64_t *latency, void *(*f)(void *), const char *label)
 {
@@ -244,6 +309,7 @@ main(int argc, char *argv[])
 
 	d = atoi(argv[1]);
 	rwlock_test(p, d, latency, thread_lock, "rwlock");
+	rwlock_test(p, d, latency, thread_lock_latch, "rwlock, latch");
 
 #ifdef CK_F_PR_RTM
 	rwlock_test(p, d, latency, thread_lock_rtm, "rwlock, rtm");