From 802bbf87524e7d1952b36cfa35444f7be129fbe6 Mon Sep 17 00:00:00 2001
From: George Joseph <gjoseph@digium.com>
Date: Tue, 25 Oct 2016 10:20:16 -0600
Subject: [PATCH] test_astobj2_thrash: Fix multithreaded issues
The test uses 4 threads to grow, count, lookup and shrink 15K objects
in a container. If there's only 1 execution engine available, the test
will complete in <50ms. If each threads gets its own execution engine,
the test may timeout after 60 seconds because the count thread does a
locked ao2_callback on the whole container in a tight loop with only
a sched_yield to give up time. The lock contention makes the test
execution times wildly variable and mostly timeout. 2 execution
engines are OK, 3 results in about 33% failure rate and >=4 causes
a 80% failure rate.
To fix, the sched_yield was changed to a usleep(500).
Also, the number of buckets specified for the container was an even
number so that was changed to the next prime number greater than
(MAX_HASH_ENTRIES / 100). That's 151 currently.
Change-Id: I50cd2344161ea61bfe4b96d2a29a6ccf88385c77
---
tests/test_astobj2_thrash.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/tests/test_astobj2_thrash.c b/tests/test_astobj2_thrash.c
index eaadbb6475..ef0da44ca5 100644
--- a/tests/test_astobj2_thrash.c
+++ b/tests/test_astobj2_thrash.c
@@ -46,6 +46,13 @@ ASTERISK_REGISTER_FILE()
#include "asterisk/utils.h"
#define MAX_HASH_ENTRIES 15000
+/*
+ * Use one of the online calculators to find the first prime number
+ * greater than MAX_HASH_ENTRIES / 100.
+ */
+#define HASH_BUCKETS 151
+
+#define COUNT_SLEEP_US 500
#define MAX_TEST_SECONDS 60
struct hash_test {
@@ -207,7 +214,7 @@ static void *hash_test_count(void *d)
if (last_count == count) {
/* Allow other threads to run. */
- sched_yield();
+ usleep(COUNT_SLEEP_US);
} else if (last_count > count) {
/* Make sure the ao2 container never shrinks */
return "ao2 container unexpectedly shrank";
@@ -261,7 +268,7 @@ AST_TEST_DEFINE(hash_test)
data.preload = MAX_HASH_ENTRIES / 2;
data.max_grow = MAX_HASH_ENTRIES - data.preload;
data.deadline = ast_tvadd(ast_tvnow(), ast_tv(MAX_TEST_SECONDS, 0));
- data.to_be_thrashed = ao2_container_alloc(MAX_HASH_ENTRIES / 100, hash_string,
+ data.to_be_thrashed = ao2_container_alloc(HASH_BUCKETS, hash_string,
compare_strings);
if (data.to_be_thrashed == NULL) {
--
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