[dpdk-dev] [PATCH 1/2] eal: add internal locks for timer lib into EAL

[Anatoly Burakov <anatoly.burakov@intel.com>]

Currently, timer library has a memory leak because there is no
way to concurrently initialize/deinitialize shared memory because
of race conditions [1].

Add a spinlock to the shared mem config to have a way to
exclusively initialize/deinitialize the timer library without
any races.

[1] See the following email thread:
https://mails.dpdk.org/archives/dev/2019-May/131498.html

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---
 lib/librte_eal/common/eal_common_mcfg.c        | 14 ++++++++++++++
 lib/librte_eal/common/eal_memcfg.h             |  2 ++
 .../common/include/rte_eal_memconfig.h         | 18 ++++++++++++++++++
 lib/librte_eal/rte_eal_version.map             |  2 ++
 4 files changed, 36 insertions(+)

diff --git a/lib/librte_eal/common/eal_common_mcfg.c b/lib/librte_eal/common/eal_common_mcfg.c
index 1825d9083..066549432 100644
--- a/lib/librte_eal/common/eal_common_mcfg.c
+++ b/lib/librte_eal/common/eal_common_mcfg.c
@@ -147,3 +147,17 @@ rte_mcfg_mempool_write_unlock(void)
 	struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
 	rte_rwlock_write_unlock(&mcfg->mplock);
 }
+
+void
+rte_mcfg_timer_lock(void)
+{
+	struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
+	rte_spinlock_lock(&mcfg->tlock);
+}
+
+void
+rte_mcfg_timer_unlock(void)
+{
+	struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
+	rte_spinlock_unlock(&mcfg->tlock);
+}
diff --git a/lib/librte_eal/common/eal_memcfg.h b/lib/librte_eal/common/eal_memcfg.h
index e1aae32df..00370cece 100644
--- a/lib/librte_eal/common/eal_memcfg.h
+++ b/lib/librte_eal/common/eal_memcfg.h
@@ -11,6 +11,7 @@
 #include <rte_memory.h>
 #include <rte_memzone.h>
 #include <rte_pause.h>
+#include <rte_spinlock.h>
 #include <rte_rwlock.h>
 #include <rte_tailq.h>
 
@@ -38,6 +39,7 @@ struct rte_mem_config {
 	rte_rwlock_t mlock;   /**< only used by memzone LIB for thread-safe. */
 	rte_rwlock_t qlock;   /**< used for tailq operation for thread safe. */
 	rte_rwlock_t mplock;  /**< only used by mempool LIB for thread-safe. */
+	rte_spinlock_t tlock; /**< needed for timer lib thread safety. */
 
 	rte_rwlock_t memory_hotplug_lock;
 	/**< indicates whether memory hotplug request is in progress. */
diff --git a/lib/librte_eal/common/include/rte_eal_memconfig.h b/lib/librte_eal/common/include/rte_eal_memconfig.h
index 1b615c892..05a32e12a 100644
--- a/lib/librte_eal/common/include/rte_eal_memconfig.h
+++ b/lib/librte_eal/common/include/rte_eal_memconfig.h
@@ -109,6 +109,24 @@ rte_mcfg_mempool_write_lock(void);
 void
 rte_mcfg_mempool_write_unlock(void);
 
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Lock the internal EAL Timer Library lock for exclusive access.
+ */
+void __rte_experimental
+rte_mcfg_timer_lock(void);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Unlock the internal EAL Timer Library lock for exclusive access.
+ */
+void __rte_experimental
+rte_mcfg_timer_unlock(void);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/librte_eal/rte_eal_version.map b/lib/librte_eal/rte_eal_version.map
index c28951f65..bc08fc4df 100644
--- a/lib/librte_eal/rte_eal_version.map
+++ b/lib/librte_eal/rte_eal_version.map
@@ -367,6 +367,8 @@ EXPERIMENTAL {
 	rte_malloc_heap_memory_detach;
 	rte_malloc_heap_memory_remove;
 	rte_malloc_heap_socket_is_external;
+	rte_mcfg_timer_lock;
+	rte_mcfg_timer_unlock;
 	rte_mem_alloc_validator_register;
 	rte_mem_alloc_validator_unregister;
 	rte_mem_check_dma_mask;
-- 
2.17.1