Fix RCU-related hangs: incorrect lttng_ht_destroy use

[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.h

diff --git a/src/bin/lttng-sessiond/ust-app.h b/src/bin/lttng-sessiond/ust-app.h
index 00d2d5ae402f5204ab9774bf03155eb48bc9f248..6e6ff0203cdb9cc1ddf88a1d626f0cd96db5f033 100644 (file)
--- a/src/bin/lttng-sessiond/ust-app.h
+++ b/src/bin/lttng-sessiond/ust-app.h
@@ -24,20 +24,26 @@
 #include "trace-ust.h"
 #include "ust-registry.h"
 
-/* lttng-ust supported version. */
-//#define LTTNG_UST_COMM_MAJOR          2      /* comm protocol major version */
-//#define UST_APP_MAJOR_VERSION         3 /* Internal UST version supported */
-
 #define UST_APP_EVENT_LIST_SIZE 32
 
-/* Process name (short). Extra for the NULL byte. */
-#define UST_APP_PROCNAME_LEN   17
+/* Process name (short). */
+#define UST_APP_PROCNAME_LEN   16
 
 struct lttng_filter_bytecode;
 struct lttng_ust_filter_bytecode;
 
 extern int ust_consumerd64_fd, ust_consumerd32_fd;
 
+/*
+ * Object used to close the notify socket in a call_rcu(). Since the
+ * application might not be found, we need an independant object containing the
+ * notify socket fd.
+ */
+struct ust_app_notify_sock_obj {
+       int fd;
+       struct rcu_head head;
+};
+
 struct ust_app_ht_key {
        const char *name;
        const struct lttng_ust_filter_bytecode *filter;
@@ -124,7 +130,9 @@ struct ust_app_channel {
        /* Channel and streams were sent to the UST tracer. */
        int is_sent;
        /* Unique key used to identify the channel on the consumer side. */
-       unsigned long key;
+       uint64_t key;
+       /* Id of the tracing channel set on creation. */
+       uint64_t tracing_channel_id;
        /* Number of stream that this channel is expected to receive. */
        unsigned int expected_stream_count;
        char name[LTTNG_UST_SYM_NAME_LEN];
@@ -135,10 +143,8 @@ struct ust_app_channel {
        struct ust_app_session *session;
        struct lttng_ht *ctx;
        struct lttng_ht *events;
-       /*
-        * UST event registry. The ONLY writer is the application thread.
-        */
-       struct ust_registry_channel registry;
+       uint64_t tracefile_size;
+       uint64_t tracefile_count;
        /*
         * Node indexed by channel name in the channels' hash table of a session.
         */
@@ -148,6 +154,8 @@ struct ust_app_channel {
         * ust_objd hash table in the ust_app object.
         */
        struct lttng_ht_node_ulong ust_objd_node;
+       /* For delayed reclaim */
+       struct rcu_head rcu_head;
 };
 
 struct ust_app_session {
@@ -162,16 +170,33 @@ struct ust_app_session {
        /* started: has the session been in started state at any time ? */
        int started;  /* allows detection of start vs restart. */
        int handle;   /* used has unique identifier for app session */
-       int id;       /* session unique identifier */
-       struct ust_app_channel *metadata;
-       struct ust_registry_session registry;
+
+       /*
+        * Tracing session ID. Multiple ust app session can have the same tracing
+        * session id making this value NOT unique to the object.
+        */
+       int tracing_id;
+       uint64_t id;    /* Unique session identifier */
        struct lttng_ht *channels; /* Registered channels */
        struct lttng_ht_node_ulong node;
        char path[PATH_MAX];
-       /* UID/GID of the user owning the session */
+       /* UID/GID of the application owning the session */
        uid_t uid;
        gid_t gid;
+       /* Effective UID and GID. Same as the tracing session. */
+       uid_t euid;
+       gid_t egid;
        struct cds_list_head teardown_node;
+       /*
+        * Once at least *one* session is created onto the application, the
+        * corresponding consumer is set so we can use it on unregistration.
+        */
+       struct consumer_output *consumer;
+       enum lttng_buffer_type buffer_type;
+       /* ABI of the session. Same value as the application. */
+       uint32_t bits_per_long;
+       /* For delayed reclaim */
+       struct rcu_head rcu_head;
 };
 
 /*
@@ -201,7 +226,10 @@ struct ust_app {
        struct lttng_ust_tracer_version version;
        uint32_t v_major;    /* Version major number */
        uint32_t v_minor;    /* Version minor number */
-       char name[UST_APP_PROCNAME_LEN];
+       /* Extra for the NULL byte. */
+       char name[UST_APP_PROCNAME_LEN + 1];
+       /* Type of buffer this application uses. */
+       enum lttng_buffer_type buffer_type;
        struct lttng_ht *sessions;
        struct lttng_ht_node_ulong pid_n;
        struct lttng_ht_node_ulong sock_n;
@@ -233,8 +261,6 @@ int ust_app_register_done(int sock)
 int ust_app_version(struct ust_app *app);
 void ust_app_unregister(int sock);
 unsigned long ust_app_list_count(void);
-int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app);
-int ust_app_stop_trace(struct ltt_ust_session *usess, struct ust_app *app);
 int ust_app_start_trace_all(struct ltt_ust_session *usess);
 int ust_app_stop_trace_all(struct ltt_ust_session *usess);
 int ust_app_destroy_trace_all(struct ltt_ust_session *usess);
@@ -276,6 +302,9 @@ int ust_app_recv_registration(int sock, struct ust_register_msg *msg);
 int ust_app_recv_notify(int sock);
 void ust_app_add(struct ust_app *app);
 struct ust_app *ust_app_create(struct ust_register_msg *msg, int sock);
+void ust_app_notify_sock_unregister(int sock);
+ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
+               struct consumer_socket *socket, int send_zero_data);
 
 #else /* HAVE_LIBLTTNG_UST_CTL */
 
@@ -458,6 +487,16 @@ static inline
 void ust_app_add(struct ust_app *app)
 {
 }
+static inline
+void ust_app_notify_sock_unregister(int sock)
+{
+}
+static inline
+ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
+               struct consumer_socket *socket, int send_zero_data)
+{
+       return 0;
+}
 
 #endif /* HAVE_LIBLTTNG_UST_CTL */