From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Tue, 20 Oct 2015 14:45:28 +0000 (-0400)
Subject: Initialize lttng_ht_seed on hashtable creation
X-Git-Tag: v2.8.0-rc1~248
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=6dcd74cf9c4cce229b1c205ca05d8efcf4c4bceb;p=lttng-tools.git

Initialize lttng_ht_seed on hashtable creation

This is done to get rid of the need for constructors to be executed
such as in the case of a static build.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/src/common/hashtable/hashtable.c b/src/common/hashtable/hashtable.c
index 5b861c800..4fb19cffd 100644
--- a/src/common/hashtable/hashtable.c
+++ b/src/common/hashtable/hashtable.c
@@ -27,6 +27,9 @@
 #include "hashtable.h"
 #include "utils.h"
 
+/* seed_lock protects both seed_init and lttng_ht_seed. */
+static pthread_mutex_t seed_lock = PTHREAD_MUTEX_INITIALIZER;
+static bool seed_init;
 unsigned long lttng_ht_seed;
 
 static unsigned long min_hash_alloc_size = 1;
@@ -95,6 +98,13 @@ struct lttng_ht *lttng_ht_new(unsigned long size, int type)
 	if (!size)
 		size = DEFAULT_HT_SIZE;
 
+	pthread_mutex_lock(&seed_lock);
+	if (!seed_init) {
+		lttng_ht_seed = (unsigned long) time(NULL);
+		seed_init = true;
+	}
+	pthread_mutex_unlock(&seed_lock);
+
 	ht = zmalloc(sizeof(*ht));
 	if (ht == NULL) {
 		PERROR("zmalloc lttng_ht");
@@ -578,12 +588,3 @@ struct lttng_ht_node_two_u64 *lttng_ht_iter_get_node_two_u64(
 	}
 	return caa_container_of(node, struct lttng_ht_node_two_u64, node);
 }
-
-/*
- * lib constructor
- */
-static void __attribute__((constructor)) _init(void)
-{
-	/* Init hash table seed */
-	lttng_ht_seed = (unsigned long) time(NULL);
-}