Docs: sessiond: document the role of an application's two sockets

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

diff --git a/src/bin/lttng-sessiond/ust-app.hpp b/src/bin/lttng-sessiond/ust-app.hpp
index f9238edc35c0830c28b6e6e9702358b3f9fed801..3200b654986596fb2eda518f96da35e2bccb097e 100644 (file)
--- a/src/bin/lttng-sessiond/ust-app.hpp
+++ b/src/bin/lttng-sessiond/ust-app.hpp
@@ -17,7 +17,9 @@
 
 #include "trace-ust.hpp"
 #include "ust-registry.hpp"
+#include "ust-registry-session.hpp"
 #include "session.hpp"
+#include "ust-field-convert.hpp"
 
 #define UST_APP_EVENT_LIST_SIZE 32
 
@@ -104,7 +106,7 @@ struct ust_app_ctx {
 };
 
 struct ust_app_event {
-       int enabled;
+       bool enabled;
        int handle;
        struct lttng_ust_abi_object_data *obj;
        struct lttng_ust_abi_event attr;
@@ -115,7 +117,7 @@ struct ust_app_event {
 };
 
 struct ust_app_event_notifier_rule {
-       int enabled;
+       bool enabled;
        uint64_t error_counter_index;
        int handle;
        struct lttng_ust_abi_object_data *obj;
@@ -143,7 +145,7 @@ struct ust_app_stream {
 };
 
 struct ust_app_channel {
-       int enabled;
+       bool enabled;
        int handle;
        /*
         * Unique key used to identify the channel on the consumer side.
@@ -194,9 +196,9 @@ struct ust_app_session {
         */
        pthread_mutex_t lock;
 
-       int enabled;
+       bool enabled;
        /* started: has the session been in started state at any time ? */
-       int started;  /* allows detection of start vs restart. */
+       bool started;  /* allows detection of start vs restart. */
        int handle;   /* used has unique identifier for app session */
 
        bool deleted;   /* Session deleted flag. Check with lock held. */
@@ -247,9 +249,11 @@ struct ust_app_session {
  * and a linked list is kept of all running traceable app.
  */
 struct ust_app {
+       /* Traffic initiated from the session daemon to the application. */
        int sock;
        pthread_mutex_t sock_lock;      /* Protects sock protocol. */
 
+       /* Traffic initiated from the application to the session daemon. */
        int notify_sock;
        pid_t pid;
        pid_t ppid;
@@ -323,21 +327,28 @@ struct ust_app {
         * (ust_app_event_notifier_rule) by their token's value.
         */
        struct lttng_ht *token_to_event_notifier_rule_ht;
+
+       lttng::sessiond::ust::ctl_field_quirks ctl_field_quirks() const;
 };
 
+/*
+ * Due to a bug in g++ < 7.1, this specialization must be enclosed in the fmt namespace,
+ * see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56480.
+ */
+namespace fmt {
 template <>
-struct fmt::formatter<ust_app> : fmt::formatter<std::string> {
-       template <typename FormatCtx>
-       typename FormatCtx::iterator format(const ust_app& app, FormatCtx& ctx)
+struct formatter<ust_app> : formatter<std::string> {
+       template <typename FormatContextType>
+       typename FormatContextType::iterator format(const ust_app& app, FormatContextType& ctx)
        {
-               return fmt::format_to(ctx.out(),
+               return format_to(ctx.out(),
                                "{{ procname = `{}`, ppid = {}, pid = {}, uid = {}, gid = {}, version = {}.{}, registration time = {} }}",
                                app.name, app.ppid, app.pid, app.uid, app.gid, app.v_major,
                                app.v_minor,
                                lttng::utils::time_to_iso8601_str(app.registration_time));
        }
 };
-
+} /* namespace fmt */
 
 #ifdef HAVE_LIBLTTNG_UST_CTL
 
@@ -365,18 +376,18 @@ int ust_app_add_ctx_channel_glb(struct ltt_ust_session *usess,
 void ust_app_global_update(struct ltt_ust_session *usess, struct ust_app *app);
 void ust_app_global_update_all(struct ltt_ust_session *usess);
 void ust_app_global_update_event_notifier_rules(struct ust_app *app);
-void ust_app_global_update_all_event_notifier_rules(void);
+void ust_app_global_update_all_event_notifier_rules();
 
-void ust_app_clean_list(void);
-int ust_app_ht_alloc(void);
+void ust_app_clean_list();
+int ust_app_ht_alloc();
 struct ust_app *ust_app_find_by_pid(pid_t pid);
-struct ust_app_stream *ust_app_alloc_stream(void);
+struct ust_app_stream *ust_app_alloc_stream();
 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(const ust_registry_session::locked_ptr& registry,
+ssize_t ust_app_push_metadata(const lttng::sessiond::ust::registry_session::locked_ptr& registry,
                struct consumer_socket *socket,
                int send_zero_data);
 void ust_app_destroy(struct ust_app *app);
@@ -407,7 +418,7 @@ enum lttng_error_code ust_app_open_packets(struct ltt_session *session);
 int ust_app_setup_event_notifier_group(struct ust_app *app);
 
 static inline
-int ust_app_supported(void)
+int ust_app_supported()
 {
        return 1;
 }
@@ -626,7 +637,7 @@ void ust_app_notify_sock_unregister(int sock __attribute__((unused)))
 
 static inline
 ssize_t ust_app_push_metadata(
-               ust_registry_session *registry __attribute__((unused)),
+               lttng::sessiond::ust::registry_session *registry __attribute__((unused)),
                struct consumer_socket *socket __attribute__((unused)),
                int send_zero_data __attribute__((unused)))
 {