Fix: race between statedump and library destructor

[lttng-ust.git] / libringbuffer / shm.h

diff --git a/libringbuffer/shm.h b/libringbuffer/shm.h
index 3d22a31305d1268d4ede5604415f236d589aa9b9..1f293e3847e44d70fb06f97cb361abf7a2832144 100644 (file)
--- a/libringbuffer/shm.h
+++ b/libringbuffer/shm.h
@@ -29,7 +29,7 @@
 /* channel_handle_create - for UST. */
 extern
 struct lttng_ust_shm_handle *channel_handle_create(void *data,
-                               uint64_t memory_map_size);
+                               uint64_t memory_map_size, int wakeup_fd);
 /* channel_handle_add_stream - for UST. */
 extern
 int channel_handle_add_stream(struct lttng_ust_shm_handle *handle,
@@ -88,14 +88,16 @@ void _set_shmp(struct shm_ref *ref, struct shm_ref src)
 struct shm_object_table *shm_object_table_create(size_t max_nb_obj);
 struct shm_object *shm_object_table_alloc(struct shm_object_table *table,
                        size_t memory_map_size,
-                       enum shm_object_type type);
+                       enum shm_object_type type,
+                       const int stream_fd,
+                       int cpu);
 struct shm_object *shm_object_table_append_shm(struct shm_object_table *table,
                        int shm_fd, int wakeup_fd, uint32_t stream_nr,
                        size_t memory_map_size);
 /* mem ownership is passed to shm_object_table_append_mem(). */
 struct shm_object *shm_object_table_append_mem(struct shm_object_table *table,
-                       void *mem, size_t memory_map_size);
-void shm_object_table_destroy(struct shm_object_table *table);
+                       void *mem, size_t memory_map_size, int wakeup_fd);
+void shm_object_table_destroy(struct shm_object_table *table, int consumer);
 
 /*
  * zalloc_shm - allocate memory within a shm object.
@@ -141,6 +143,7 @@ int shm_close_wait_fd(struct lttng_ust_shm_handle *handle,
 {
        struct shm_object_table *table = handle->table;
        struct shm_object *obj;
+       int wait_fd;
        size_t index;
        int ret;
 
@@ -148,14 +151,15 @@ int shm_close_wait_fd(struct lttng_ust_shm_handle *handle,
        if (caa_unlikely(index >= table->allocated_len))
                return -EPERM;
        obj = &table->objects[index];
-       if (obj->wait_fd[0] < 0)
+       wait_fd = obj->wait_fd[0];
+       if (wait_fd < 0)
                return -ENOENT;
-       ret = close(obj->wait_fd[0]);
+       obj->wait_fd[0] = -1;
+       ret = close(wait_fd);
        if (ret) {
                ret = -errno;
                return ret;
        }
-       obj->wait_fd[0] = -1;
        return 0;
 }
 
@@ -165,6 +169,7 @@ int shm_close_wakeup_fd(struct lttng_ust_shm_handle *handle,
 {
        struct shm_object_table *table = handle->table;
        struct shm_object *obj;
+       int wakeup_fd;
        size_t index;
        int ret;
 
@@ -172,14 +177,15 @@ int shm_close_wakeup_fd(struct lttng_ust_shm_handle *handle,
        if (caa_unlikely(index >= table->allocated_len))
                return -EPERM;
        obj = &table->objects[index];
-       if (obj->wait_fd[1] < 0)
+       wakeup_fd = obj->wait_fd[1];
+       if (wakeup_fd < 0)
                return -ENOENT;
-       ret = close(obj->wait_fd[1]);
+       obj->wait_fd[1] = -1;
+       ret = close(wakeup_fd);
        if (ret) {
                ret = -errno;
                return ret;
        }
-       obj->wait_fd[1] = -1;
        return 0;
 }