[RFC, v1 2/6] graph: introduce graph clone API for other worker core

[Zhirun Yan <zhirun.yan@intel.com>]

This patch adds graph API for supporting to clone the graph object for
a specified worker core. The new graph will also clone all nodes.

Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
Signed-off-by: Cunming Liang <cunming.liang@intel.com>
Signed-off-by: Zhirun Yan <zhirun.yan@intel.com>
---
 lib/graph/graph.c         | 115 ++++++++++++++++++++++++++++++++++++++
 lib/graph/graph_private.h |   4 ++
 lib/graph/rte_graph.h     |  32 +++++++++++
 lib/graph/version.map     |   1 +
 4 files changed, 152 insertions(+)

diff --git a/lib/graph/graph.c b/lib/graph/graph.c
index d61288647c..b4eb18175a 100644
--- a/lib/graph/graph.c
+++ b/lib/graph/graph.c
@@ -327,6 +327,8 @@ rte_graph_create(const char *name, struct rte_graph_param *prm)
 	graph->src_node_count = src_node_count;
 	graph->node_count = graph_nodes_count(graph);
 	graph->id = graph_id;
+	graph->parent_id = RTE_GRAPH_ID_INVALID;
+	graph->lcore_id = RTE_MAX_LCORE;
 
 	/* Allocate the Graph fast path memory and populate the data */
 	if (graph_fp_mem_create(graph))
@@ -387,6 +389,119 @@ rte_graph_destroy(rte_graph_t id)
 	return rc;
 }
 
+static int
+clone_name(struct graph *graph, struct graph *parent_graph, const char *name)
+{
+	ssize_t sz, rc;
+
+#define SZ RTE_GRAPH_NAMESIZE
+	rc = rte_strscpy(graph->name, parent_graph->name, SZ);
+	if (rc < 0)
+		goto fail;
+	sz = rc;
+	rc = rte_strscpy(graph->name + sz, "-", RTE_MAX((int16_t)(SZ - sz), 0));
+	if (rc < 0)
+		goto fail;
+	sz += rc;
+	sz = rte_strscpy(graph->name + sz, name, RTE_MAX((int16_t)(SZ - sz), 0));
+	if (sz < 0)
+		goto fail;
+
+	return 0;
+fail:
+	rte_errno = E2BIG;
+	return -rte_errno;
+}
+
+static rte_graph_t
+graph_clone(struct graph *parent_graph, const char *name,
+	    struct rte_graph_clone_param *prm)
+{
+	struct graph_node *graph_node;
+	struct graph *graph;
+
+	graph_spinlock_lock();
+
+	if (prm->lcore_id >= RTE_MAX_LCORE)
+		SET_ERR_JMP(EINVAL, fail, "Invalid lcore ID");
+
+	/* Don't allow to clone a node from a cloned graph */
+	if (parent_graph->parent_id != RTE_GRAPH_ID_INVALID)
+		SET_ERR_JMP(EEXIST, fail, "A cloned graph is not allowed to be cloned");
+
+	/* Create graph object */
+	graph = calloc(1, sizeof(*graph));
+	if (graph == NULL)
+		SET_ERR_JMP(ENOMEM, fail, "Failed to calloc cloned graph object");
+
+	/* Naming ceremony of the new graph. name is node->name + "-" + name */
+	if (clone_name(graph, parent_graph, name))
+		goto free;
+
+	/* Check for existence of duplicate graph */
+	if (rte_graph_from_name(graph->name) != RTE_GRAPH_ID_INVALID)
+		SET_ERR_JMP(EEXIST, free, "Found duplicate graph %s",
+			    graph->name);
+
+	/* Clone nodes from parent graph firstly */
+	STAILQ_INIT(&graph->node_list);
+	STAILQ_FOREACH(graph_node, &parent_graph->node_list, next) {
+		if (graph_node_add(graph, graph_node->node))
+			goto graph_cleanup;
+	}
+
+	/* Just update adjacency list of all nodes in the graph */
+	if (graph_adjacency_list_update(graph))
+		goto graph_cleanup;
+
+	/* Initialize the graph object */
+	graph->src_node_count = parent_graph->src_node_count;
+	graph->node_count = parent_graph->node_count;
+	graph->parent_id = parent_graph->id;
+	graph->lcore_id = prm->lcore_id;
+	graph->socket = rte_lcore_to_socket_id(prm->lcore_id);
+	graph->id = graph_id;
+
+	/* Allocate the Graph fast path memory and populate the data */
+	if (graph_fp_mem_create(graph))
+		goto graph_cleanup;
+
+	/* Call init() of the all the nodes in the graph */
+	if (graph_node_init(graph))
+		goto graph_mem_destroy;
+
+	/* All good, Lets add the graph to the list */
+	graph_id++;
+	STAILQ_INSERT_TAIL(&graph_list, graph, next);
+
+	graph_spinlock_unlock();
+	return graph->id;
+
+graph_mem_destroy:
+	graph_fp_mem_destroy(graph);
+graph_cleanup:
+	graph_cleanup(graph);
+free:
+	free(graph);
+fail:
+	graph_spinlock_unlock();
+	return RTE_GRAPH_ID_INVALID;
+}
+
+rte_graph_t
+rte_graph_clone(rte_graph_t id, const char *name, struct rte_graph_clone_param *prm)
+{
+	struct graph *graph;
+
+	GRAPH_ID_CHECK(id);
+	STAILQ_FOREACH(graph, &graph_list, next)
+		if (graph->id == id)
+			return graph_clone(graph, name, prm);
+
+fail:
+	return RTE_GRAPH_ID_INVALID;
+}
+
 rte_graph_t
 rte_graph_from_name(const char *name)
 {
diff --git a/lib/graph/graph_private.h b/lib/graph/graph_private.h
index 627090f802..d53ef289d4 100644
--- a/lib/graph/graph_private.h
+++ b/lib/graph/graph_private.h
@@ -97,8 +97,12 @@ struct graph {
 	/**< Circular buffer mask for wrap around. */
 	rte_graph_t id;
 	/**< Graph identifier. */
+	rte_graph_t parent_id;
+	/**< Parent graph identifier. */
 	size_t mem_sz;
 	/**< Memory size of the graph. */
+	unsigned int lcore_id;
+	/**< Lcore identifier where the grap runs on. */
 	int socket;
 	/**< Socket identifier where memory is allocated. */
 	STAILQ_HEAD(gnode_list, graph_node) node_list;
diff --git a/lib/graph/rte_graph.h b/lib/graph/rte_graph.h
index 9f84461dd8..27fd1e6cd0 100644
--- a/lib/graph/rte_graph.h
+++ b/lib/graph/rte_graph.h
@@ -166,6 +166,15 @@ struct rte_graph_param {
 	/**< Array of node patterns based on shell pattern. */
 };
 
+/**
+ * Structure to hold configuration parameters for cloning the graph.
+ *
+ * @see rte_graph_clone()
+ */
+struct rte_graph_clone_param {
+	unsigned int lcore_id; /**< Lcore id where the new graph is cloned to run. */
+};
+
 /**
  * Structure to hold configuration parameters for graph cluster stats create.
  *
@@ -242,6 +251,29 @@ rte_graph_t rte_graph_create(const char *name, struct rte_graph_param *prm);
 __rte_experimental
 int rte_graph_destroy(rte_graph_t id);
 
+/**
+ * Clone Graph.
+ *
+ * Clone a graph from static graph (graph created from rte_graph_create). And
+ * all cloned graphs attached to the parent graph MUST be destroied together
+ * for fast schedule design limitation (stop ALL graph walk firstly).
+ *
+ * @param id
+ *   Static graph id to clone from.
+ * @param name
+ *   Name of the new graph. The library prepends the parent graph name to the
+ * user-specified name. The final graph name will be,
+ * "parent graph name" + "-" + name.
+ * @param prm
+ *   Graph clone parameter, includes lcore ID.
+ *
+ * @return
+ *   Valid graph id on success, RTE_GRAPH_ID_INVALID otherwise.
+ */
+__rte_experimental
+rte_graph_t rte_graph_clone(rte_graph_t id, const char *name,
+			    struct rte_graph_clone_param *prm);
+
 /**
  * Get graph id from graph name.
  *
diff --git a/lib/graph/version.map b/lib/graph/version.map
index 6d40a74731..6fc43e4411 100644
--- a/lib/graph/version.map
+++ b/lib/graph/version.map
@@ -5,6 +5,7 @@ EXPERIMENTAL {
 	__rte_node_stream_alloc;
 	__rte_node_stream_alloc_size;
 
+	rte_graph_clone;
 	rte_graph_create;
 	rte_graph_destroy;
 	rte_graph_dump;
-- 
2.25.1