Provide thread-safety to functions that return pointers to meshlink_node_t.

  - The mesh->nodes tree can be updated by the library thread at any time,
    so it must be protected by a mutex or rwlock.

diff --git a/src/meshlink.c b/src/meshlink.c
index 72e27b0fe99cf3e956d3d125f093bc020e6c558d..fc8408ad1309843d9641df75a47323f0411b192d 100644 (file)
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -735,6 +735,7 @@ meshlink_handle_t *meshlink_open(const char *confbase, const char *name) {
        mesh->confbase = xstrdup(confbase);
        mesh->name = xstrdup(name);
        pthread_mutex_init ( &(mesh->outpacketqueue_mutex), NULL);
+       pthread_mutex_init ( &(mesh->nodes_mutex), NULL);
        event_loop_init(&mesh->loop);
        mesh->loop.data = mesh;
 
@@ -898,12 +899,17 @@ meshlink_node_t *meshlink_get_node(meshlink_handle_t *mesh, const char *name) {
 size_t meshlink_get_all_nodes(meshlink_handle_t *mesh, meshlink_node_t **nodes, size_t nmemb) {
        size_t i = 0;
 
+       //lock mesh->nodes
+       pthread_mutex_lock(&(mesh->nodes_mutex));
+
        for splay_each(node_t, n, mesh->nodes) {
                if(i < nmemb)
                        nodes[i] = (meshlink_node_t *)n;
                i++;
        }
 
+       pthread_mutex_unlock(&(mesh->nodes_mutex));
+
        return i;
 }
 

diff --git a/src/meshlink_internal.h b/src/meshlink_internal.h
index c58c477388620198143136e6603e274cbc129a3f..cb60416d838d02eb6eb5efa351cfbee8eaead149 100644 (file)
--- a/src/meshlink_internal.h
+++ b/src/meshlink_internal.h
@@ -61,6 +61,7 @@ struct meshlink_handle {
 
        pthread_t thread;
        pthread_mutex_t outpacketqueue_mutex;
+       pthread_mutex_t nodes_mutex;
        event_loop_t loop;
        listen_socket_t listen_socket[MAXSOCKETS];
        int listen_sockets;

diff --git a/src/node.c b/src/node.c
index 3e4dec957f98f410b3912dc9dcf9904dca64fc4c..0a7b4a5254921d9b3e263b3d62c21ff3fc2149d7 100644 (file)
--- a/src/node.c
+++ b/src/node.c
@@ -36,13 +36,17 @@ static int node_compare(const node_t *a, const node_t *b) {
 }
 
 void init_nodes(meshlink_handle_t *mesh) {
+       pthread_mutex_lock(&(mesh->nodes_mutex));
        mesh->nodes = splay_alloc_tree((splay_compare_t) node_compare, (splay_action_t) free_node);
        node_udp_cache = hash_alloc(0x100, sizeof(sockaddr_t));
+       pthread_mutex_unlock(&(mesh->nodes_mutex));
 }
 
 void exit_nodes(meshlink_handle_t *mesh) {
+       pthread_mutex_lock(&(mesh->nodes_mutex));
        hash_free(node_udp_cache);
        splay_delete_tree(mesh->nodes);
+       pthread_mutex_unlock(&(mesh->nodes_mutex));
 }
 
 node_t *new_node(void) {
@@ -81,25 +85,34 @@ void free_node(node_t *n) {
 }
 
 void node_add(meshlink_handle_t *mesh, node_t *n) {
+       pthread_mutex_lock(&(mesh->nodes_mutex));
        n->mesh = mesh;
        splay_insert(mesh->nodes, n);
+       pthread_mutex_unlock(&(mesh->nodes_mutex));
 }
 
 void node_del(meshlink_handle_t *mesh, node_t *n) {
+       pthread_mutex_lock(&(mesh->nodes_mutex));
        timeout_del(&mesh->loop, &n->mtutimeout);
 
        for splay_each(edge_t, e, n->edge_tree)
                edge_del(mesh, e);
 
        splay_delete(mesh->nodes, n);
+       pthread_mutex_unlock(&(mesh->nodes_mutex));
 }
 
 node_t *lookup_node(meshlink_handle_t *mesh, char *name) {
        node_t n = {NULL};
+       node_t* result;
 
        n.name = name;
 
-       return splay_search(mesh->nodes, &n);
+       pthread_mutex_lock(&(mesh->nodes_mutex));
+       result = splay_search(mesh->nodes, &n);
+       pthread_mutex_unlock(&(mesh->nodes_mutex));
+
+       return result;
 }
 
 node_t *lookup_node_udp(meshlink_handle_t *mesh, const sockaddr_t *sa) {