[v16,8/9] eal: implement functions for thread barrier management

diff --git a/lib/eal/common/rte_thread.c b/lib/eal/common/rte_thread.c
index 476a8a1c08..580448d8bf 100644
--- a/lib/eal/common/rte_thread.c
+++ b/lib/eal/common/rte_thread.c
@@ -364,6 +364,67 @@  rte_thread_mutex_destroy(rte_thread_mutex *mutex)
 	return ret;
 }
 
+int
+rte_thread_barrier_init(rte_thread_barrier *barrier, int count)
+{
+	int ret = 0;
+	pthread_barrier_t *pthread_barrier = NULL;
+
+	RTE_VERIFY(barrier != NULL);
+	RTE_VERIFY(count > 0);
+
+	pthread_barrier = calloc(1, sizeof(*pthread_barrier));
+	if (pthread_barrier == NULL) {
+		RTE_LOG(DEBUG, EAL, "Unable to initialize barrier. Insufficient memory!\n");
+		ret = ENOMEM;
+		goto cleanup;
+	}
+	ret = pthread_barrier_init(pthread_barrier, NULL, count);
+	if (ret != 0) {
+		RTE_LOG(DEBUG, EAL, "Failed to init barrier, ret = %d\n", ret);
+		goto cleanup;
+	}
+
+	barrier->barrier_id = pthread_barrier;
+	pthread_barrier = NULL;
+
+cleanup:
+	free(pthread_barrier);
+	return ret;
+}
+
+int
+rte_thread_barrier_wait(rte_thread_barrier *barrier)
+{
+	int ret = 0;
+
+	RTE_VERIFY(barrier != NULL);
+	RTE_VERIFY(barrier->barrier_id != NULL);
+
+	ret = pthread_barrier_wait(barrier->barrier_id);
+	if (ret == PTHREAD_BARRIER_SERIAL_THREAD)
+		ret = RTE_THREAD_BARRIER_SERIAL_THREAD;
+
+	return ret;
+}
+
+int
+rte_thread_barrier_destroy(rte_thread_barrier *barrier)
+{
+	int ret = 0;
+
+	RTE_VERIFY(barrier != NULL);
+
+	ret = pthread_barrier_destroy(barrier->barrier_id);
+	if (ret != 0)
+		RTE_LOG(DEBUG, EAL, "Failed to destroy barrier: %d\n", ret);
+
+	free(barrier->barrier_id);
+	barrier->barrier_id = NULL;
+
+	return ret;
+}
+
 int
 rte_thread_key_create(rte_thread_key *key, void (*destructor)(void *))
 {
diff --git a/lib/eal/include/rte_thread.h b/lib/eal/include/rte_thread.h
index b5782d396f..0adc854225 100644
--- a/lib/eal/include/rte_thread.h
+++ b/lib/eal/include/rte_thread.h
@@ -74,6 +74,18 @@  typedef struct rte_thread_mutex_tag {
 	void *mutex_id;  /**< mutex identifier */
 } rte_thread_mutex;
 
+/**
+ * Returned by rte_thread_barrier_wait() when call is successful.
+ */
+#define RTE_THREAD_BARRIER_SERIAL_THREAD -1
+
+/**
+ * Thread barrier representation.
+ */
+typedef struct rte_thread_barrier_tag {
+	void *barrier_id;  /**< barrrier identifier */
+} rte_thread_barrier;
+
 /**
  * TLS key type, an opaque pointer.
  */
@@ -410,6 +422,52 @@  int rte_thread_mutex_try_lock(rte_thread_mutex *mutex);
 __rte_experimental
 int rte_thread_mutex_destroy(rte_thread_mutex *mutex);
 
+/**
+ * Initializes a synchronization barrier.
+ *
+ * @param barrier
+ *    A pointer that references the newly created 'barrier' object.
+ *
+ * @param count
+ *    The number of threads that must enter the barrier before
+ *    the threads can continue execution.
+ *
+ * @return
+ *   On success, return 0.
+ *   On failure, return a positive errno-style error number.
+ */
+__rte_experimental
+int rte_thread_barrier_init(rte_thread_barrier *barrier, int count);
+
+/**
+ * Causes the calling thread to wait at the synchronization barrier 'barrier'.
+ *
+ * @param barrier
+ *    The barrier used for synchronizing the threads.
+ *
+ * @return
+ *   Return RTE_THREAD_BARRIER_SERIAL_THREAD for the thread synchronized
+ *      at the barrier.
+ *   Return 0 for all other threads.
+ *   Return a positive errno-style error number, in case of failure.
+ */
+__rte_experimental
+int rte_thread_barrier_wait(rte_thread_barrier *barrier);
+
+/**
+ * Releases all resources used by a synchronization barrier
+ * and uninitializes it.
+ *
+ * @param barrier
+ *    The barrier to be destroyed.
+ *
+ * @return
+ *   On success, return 0.
+ *   On failure, return a positive errno-style error number.
+ */
+__rte_experimental
+int rte_thread_barrier_destroy(rte_thread_barrier *barrier);
+
 /**
  * Create a TLS data key visible to all threads in the process.
  * the created key is later used to get/set a value.
diff --git a/lib/eal/version.map b/lib/eal/version.map
index 2506eb1587..ca05ba4f43 100644
--- a/lib/eal/version.map
+++ b/lib/eal/version.map
@@ -439,6 +439,9 @@  EXPERIMENTAL {
 	rte_thread_mutex_unlock;
 	rte_thread_mutex_try_lock;
 	rte_thread_mutex_destroy;
+	rte_thread_barrier_init;
+	rte_thread_barrier_wait;
+	rte_thread_barrier_destroy;
 };
 
 INTERNAL {
diff --git a/lib/eal/windows/rte_thread.c b/lib/eal/windows/rte_thread.c
index 188e25e02e..11b4863fe8 100644
--- a/lib/eal/windows/rte_thread.c
+++ b/lib/eal/windows/rte_thread.c
@@ -568,6 +568,62 @@  rte_thread_mutex_destroy(rte_thread_mutex *mutex)
 	return 0;
 }
 
+int
+rte_thread_barrier_init(rte_thread_barrier *barrier, int count)
+{
+	int ret = 0;
+	SYNCHRONIZATION_BARRIER *sync_barrier = NULL;
+
+	RTE_VERIFY(barrier != NULL);
+	RTE_VERIFY(count > 0);
+
+	sync_barrier = calloc(1, sizeof(*sync_barrier));
+	if (sync_barrier == NULL) {
+		RTE_LOG(DEBUG, EAL, "Unable to initialize barrier. Insufficient memory!\n");
+		ret = ENOMEM;
+		goto cleanup;
+	}
+	if (!InitializeSynchronizationBarrier(sync_barrier, count, -1)) {
+		ret = thread_log_last_error("InitializeSynchronizationBarrier()");
+		goto cleanup;
+	}
+
+	barrier->barrier_id = sync_barrier;
+	sync_barrier = NULL;
+
+cleanup:
+	free(sync_barrier);
+	return ret;
+}
+
+int
+rte_thread_barrier_wait(rte_thread_barrier *barrier)
+{
+	RTE_VERIFY(barrier != NULL);
+	RTE_VERIFY(barrier->barrier_id != NULL);
+
+	if (EnterSynchronizationBarrier(barrier->barrier_id,
+				SYNCHRONIZATION_BARRIER_FLAGS_BLOCK_ONLY)) {
+
+		return RTE_THREAD_BARRIER_SERIAL_THREAD;
+	}
+
+	return 0;
+}
+
+int
+rte_thread_barrier_destroy(rte_thread_barrier *barrier)
+{
+	RTE_VERIFY(barrier != NULL);
+
+	DeleteSynchronizationBarrier(barrier->barrier_id);
+
+	free(barrier->barrier_id);
+	barrier->barrier_id = NULL;
+
+	return 0;
+}
+
 int
 rte_thread_key_create(rte_thread_key *key,
 		__rte_unused void (*destructor)(void *))