ltt-events.h

   1 /*
   2  * ltt-events.h
   3  *
   4  * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  *
   6  * Holds LTTng per-session event registry.
   7  */
   8
   9 #include <linux/list.h>
  10
  11 struct ltt_channel;
  12 struct ltt_session;
  13
  14 enum instrum_type itype {
  15         INSTRUM_TRACEPOINTS,
  16 };
  17
  18 /*
  19  * ltt_event structure is referred to by the tracing fast path. It must be
  20  * kept small.
  21  */
  22 struct ltt_event {
  23         unsigned int id;
  24         struct ltt_channel *chan;
  25         void *probe;
  26         void *filter;
  27         char *name;
  28         enum instrum_type itype;
  29         struct list_head list;          /* Event list */
  30 };
  31
  32 struct ltt_channel {
  33         struct channel *chan;           /* Channel buffers */
  34         /* Event ID management */
  35         struct ltt_session *session;
  36         struct file *file;              /* File associated to channel */
  37         unsigned int free_event_id;     /* Next event ID to allocate */
  38         struct list_head list;          /* Channel list */
  39         wait_queue_head_t notify_wait;  /* Channel addition notif. waitqueue */
  40 };
  41
  42 struct ltt_session {
  43         int active;                     /* Is trace session active ? */
  44         struct file *file;              /* File associated to session */
  45         struct list_head chan;          /* Channel list head */
  46         struct list_head events;        /* Event list head */
  47         struct list_head list;          /* Session list */
  48 };
  49
  50 struct ltt_trace_ops {
  51         struct channel *(*channel_create)(const char *name,
  52                                 struct ltt_trace *trace,
  53                                 void *buf_addr,
  54                                 size_t subbuf_size, size_t num_subbuf,
  55                                 unsigned int switch_timer_interval,
  56                                 unsigned int read_timer_interval);
  57         void (*channel_destroy)(struct channel *chan);
  58         struct lib_ring_buffer *(*buffer_read_open)(struct channel *chan);
  59         struct lib_ring_buffer *(*buffer_read_close)(struct lib_ring_buffer *buf);
  60 };
  61
  62 struct ltt_transport {
  63         char *name;
  64         struct module *owner;
  65         struct list_head node;
  66         struct ltt_trace_ops ops;
  67 };
  68
  69 struct ltt_session *ltt_session_create(void);
  70 int ltt_session_start(struct ltt_session *session);
  71 int ltt_session_stop(struct ltt_session *session);
  72 int ltt_session_destroy(struct ltt_session *session);
  73
  74 struct ltt_channel *ltt_channel_create(struct ltt_session *session,
  75                                        int overwrite, void *buf_addr,
  76                                        size_t subbuf_size, size_t num_subbuf,
  77                                        unsigned int switch_timer_interval,
  78                                        unsigned int read_timer_interval);
  79 int _ltt_channel_destroy(struct ltt_channel *chan);
  80
  81 struct ltt_event *ltt_event_create(struct ltt_channel *chan,
  82                                    enum instrum_type itype,
  83                                    char *name,
  84                                    void *filter);
  85 int _ltt_event_destroy(struct ltt_event *event);
  86
  87 void ltt_transport_register(struct ltt_transport *transport);
  88 void ltt_transport_unregister(struct ltt_transport *transport);