Launch the application notification thread using lttng_thread

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

diff --git a/src/bin/lttng-sessiond/lttng-sessiond.h b/src/bin/lttng-sessiond/lttng-sessiond.h
index d0150123c8bcae1fbdc5c1ccd947db75fc7607d8..ae73507620a8b7ea02c7afdc1d75efa6a30c34bc 100644 (file)
--- a/src/bin/lttng-sessiond/lttng-sessiond.h
+++ b/src/bin/lttng-sessiond/lttng-sessiond.h
@@ -19,7 +19,6 @@
 #ifndef _LTT_SESSIOND_H
 #define _LTT_SESSIOND_H
 
-#define _LGPL_SOURCE
 #include <urcu.h>
 #include <urcu/wfcqueue.h>
 
@@ -29,7 +28,42 @@
 
 #include "session.h"
 #include "ust-app.h"
-#include "version.h"
+#include "notification-thread.h"
+#include "sessiond-config.h"
+
+/*
+ * Consumer daemon state which is changed when spawning it, killing it or in
+ * case of a fatal error.
+ */
+enum consumerd_state {
+       CONSUMER_STARTED = 1,
+       CONSUMER_STOPPED = 2,
+       CONSUMER_ERROR   = 3,
+};
+
+/*
+ * This consumer daemon state is used to validate if a client command will be
+ * able to reach the consumer. If not, the client is informed. For instance,
+ * doing a "lttng start" when the consumer state is set to ERROR will return an
+ * error to the client.
+ *
+ * The following example shows a possible race condition of this scheme:
+ *
+ * consumer thread error happens
+ *                                    client cmd arrives
+ *                                    client cmd checks state -> still OK
+ * consumer thread exit, sets error
+ *                                    client cmd try to talk to consumer
+ *                                    ...
+ *
+ * However, since the consumer is a different daemon, we have no way of making
+ * sure the command will reach it safely even with this state flag. This is why
+ * we consider that up to the state validation during command processing, the
+ * command is safe. After that, we can not guarantee the correctness of the
+ * client request vis-a-vis the consumer.
+ */
+extern enum consumerd_state ust_consumerd_state;
+extern enum consumerd_state kernel_consumerd_state;
 
 extern const char default_home_dir[],
        default_tracing_group[],
@@ -38,6 +72,11 @@ extern const char default_home_dir[],
 
 /* Set in main.c at boot time of the daemon */
 extern int kernel_tracer_fd;
+extern struct lttng_kernel_tracer_version kernel_tracer_version;
+extern struct lttng_kernel_tracer_abi_version kernel_tracer_abi_version;
+
+/* Notification thread handle. */
+extern struct notification_thread_handle *notification_thread_handle;
 
 /*
  * This contains extra data needed for processing a command received by the
@@ -59,7 +98,7 @@ struct ust_command {
 };
 
 /*
- * Queue used to enqueue UST registration request (ust_commant) and protected
+ * Queue used to enqueue UST registration request (ust_command) and synchronized
  * by a futex with a scheme N wakers / 1 waiters. See futex.c/.h
  */
 struct ust_cmd_queue {
@@ -86,12 +125,6 @@ struct ust_reg_wait_node {
        struct cds_list_head head;
 };
 
-/*
- * This pipe is used to inform the thread managing application notify
- * communication that a command is queued and ready to be processed.
- */
-extern int apps_cmd_notify_pipe[2];
-
 /*
  * Used to notify that a hash table needs to be destroyed by dedicated
  * thread. Required by design because we don't want to move destroy
@@ -101,29 +134,46 @@ extern int apps_cmd_notify_pipe[2];
  */
 extern int ht_cleanup_pipe[2];
 
+extern int kernel_poll_pipe[2];
+
 /*
  * Populated when the daemon starts with the current page size of the system.
+ * Set in main() with the current page size.
  */
 extern long page_size;
 
-/*
- * Global set once in main(). Agent TCP port for registration.
- */
-extern unsigned int agent_tcp_port;
+/* Application health monitoring */
+extern struct health_app *health_sessiond;
 
-/*
- * Section name to look for in the daemon configuration file.
- */
-extern const char * const config_section_name;
+extern struct sessiond_config config;
 
-/* Is this daemon root or not. */
-extern int is_root;
+extern int lttng_sessiond_ready;
 
-int sessiond_set_thread_pollset(struct lttng_poll_event *events, size_t size);
-int sessiond_check_thread_quit_pipe(int fd, uint32_t events);
+extern int ust_consumerd64_fd, ust_consumerd32_fd;
 
-void *thread_ht_cleanup(void *data);
+/* Parent PID for --sig-parent option */
+extern pid_t ppid;
+/* Internal parent PID use with daemonize. */
+extern pid_t child_ppid;
 
+/* Consumer daemon specific control data. */
+extern struct consumer_data ustconsumer32_data;
+extern struct consumer_data ustconsumer64_data;
+extern struct consumer_data kconsumer_data;
+
+int sessiond_init_thread_quit_pipe(void);
+int sessiond_check_thread_quit_pipe(int fd, uint32_t events);
+int sessiond_wait_for_quit_pipe(unsigned int timeout_us);
+int sessiond_notify_quit_pipe(void);
+void sessiond_close_quit_pipe(void);
+
+int sessiond_set_thread_pollset(struct lttng_poll_event *events, size_t size);
 void sessiond_notify_ready(void);
+void sessiond_signal_parents(void);
+
+void sessiond_set_client_thread_state(bool running);
+void sessiond_wait_client_thread_stopped(void);
+
+void *thread_manage_consumer(void *data);
 
 #endif /* _LTT_SESSIOND_H */