ltt-events.h

   1 #ifndef _LTT_EVENTS_H
   2 #define _LTT_EVENTS_H
   3
   4 /*
   5  * ltt-events.h
   6  *
   7  * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * Holds LTTng per-session event registry.
  10  */
  11
  12 #include <linux/list.h>
  13 #include "ltt-debugfs-abi.h"
  14
  15 struct ltt_channel;
  16 struct ltt_session;
  17 struct lib_ring_buffer_ctx;
  18
  19 /* Type description */
  20
  21 /* Update the astract_types name table in lttng-types.c along with this enum */
  22 enum abstract_types {
  23         atype_integer,
  24         atype_enum,
  25         atype_array,
  26         atype_sequence,
  27         atype_string,
  28         NR_ABSTRACT_TYPES,
  29 };
  30
  31 /* Update the string_encodings name table in lttng-types.c along with this enum */
  32 enum lttng_string_encodings {
  33         lttng_encode_UTF8 = 0,
  34         lttng_encode_ASCII = 1,
  35         NR_STRING_ENCODINGS,
  36 };
  37
  38 struct lttng_enum_entry {
  39         unsigned long long start, end;  /* start and end are inclusive */
  40         const char *string;
  41 };
  42
  43 #define __type_integer(_type, _byte_order)                      \
  44         {                                                       \
  45             .atype = atype_integer,                             \
  46             .u.basic.integer =                                  \
  47                 {                                               \
  48                   .size = sizeof(_type),                        \
  49                   .alignment = __alignof__(_type),              \
  50                   .signedness = is_signed_type(_type),          \
  51                   .reverse_byte_order = _byte_order != __BYTE_ORDER,    \
  52                 },                                              \
  53         }                                                       \
  54
  55 struct lttng_integer_type {
  56         unsigned int size;              /* in bits */
  57         unsigned short alignment;       /* in bits */
  58         unsigned int signedness:1;
  59         unsigned int reverse_byte_order:1;
  60 };
  61
  62 union _lttng_basic_type {
  63         struct lttng_integer_type integer;
  64         struct {
  65                 const char *name;
  66         } enumeration;
  67         struct {
  68                 enum lttng_string_encodings encoding;
  69         } string;
  70 };
  71
  72 struct lttng_basic_type {
  73         enum abstract_types atype;
  74         union {
  75                 union _lttng_basic_type basic;
  76         } u;
  77 };
  78
  79 struct lttng_type {
  80         enum abstract_types atype;
  81         union {
  82                 union _lttng_basic_type basic;
  83                 struct {
  84                         struct lttng_basic_type elem_type;
  85                         unsigned int length;            /* num. elems. */
  86                 } array;
  87                 struct {
  88                         struct lttng_basic_type length_type;
  89                         struct lttng_basic_type elem_type;
  90                 } sequence;
  91         } u;
  92 };
  93
  94 struct lttng_enum {
  95         const char *name;
  96         struct lttng_type container_type;
  97         const struct lttng_enum_entry *entries;
  98         unsigned int len;
  99 };
 100
 101 /* Event field description */
 102
 103 struct lttng_event_field {
 104         const char *name;
 105         const struct lttng_type type;
 106 };
 107
 108 struct lttng_event_desc {
 109         const struct lttng_event_field *fields;
 110         const char *name;
 111         void *probe_callback;
 112         unsigned int nr_fields;
 113 };
 114
 115 struct lttng_probe_desc {
 116         const struct lttng_event_desc *event_desc;
 117         unsigned int nr_events;
 118         struct list_head head;                  /* chain registered probes */
 119 };
 120
 121 /*
 122  * ltt_event structure is referred to by the tracing fast path. It must be
 123  * kept small.
 124  */
 125 struct ltt_event {
 126         unsigned int id;
 127         struct ltt_channel *chan;
 128         const struct lttng_event_desc *desc;
 129         void *filter;
 130         enum instrum_type itype;
 131         struct list_head list;          /* Event list */
 132         int metadata_dumped:1;
 133 };
 134
 135 struct ltt_channel_ops {
 136         struct channel *(*channel_create)(const char *name,
 137                                 struct ltt_session *session,
 138                                 void *buf_addr,
 139                                 size_t subbuf_size, size_t num_subbuf,
 140                                 unsigned int switch_timer_interval,
 141                                 unsigned int read_timer_interval);
 142         void (*channel_destroy)(struct channel *chan);
 143         struct lib_ring_buffer *(*buffer_read_open)(struct channel *chan);
 144         void (*buffer_read_close)(struct lib_ring_buffer *buf);
 145         int (*event_reserve)(struct lib_ring_buffer_ctx *ctx);
 146         void (*event_commit)(struct lib_ring_buffer_ctx *ctx);
 147         void (*event_write)(struct lib_ring_buffer_ctx *ctx, const void *src,
 148                             size_t len);
 149         wait_queue_head_t *(*get_reader_wait_queue)(struct ltt_channel *chan);
 150 };
 151
 152 struct ltt_channel {
 153         unsigned int id;
 154         struct channel *chan;           /* Channel buffers */
 155         /* Event ID management */
 156         struct ltt_session *session;
 157         struct file *file;              /* File associated to channel */
 158         unsigned int free_event_id;     /* Next event ID to allocate */
 159         struct list_head list;          /* Channel list */
 160         wait_queue_head_t notify_wait;  /* Channel addition notif. waitqueue */
 161         struct ltt_channel_ops *ops;
 162         int metadata_dumped:1;
 163         int header_type:2;              /* 0: unset, 1: compact, 2: large */
 164 };
 165
 166 struct ltt_session {
 167         int active;                     /* Is trace session active ? */
 168         struct file *file;              /* File associated to session */
 169         struct ltt_channel *metadata;   /* Metadata channel */
 170         struct list_head chan;          /* Channel list head */
 171         struct list_head events;        /* Event list head */
 172         struct list_head list;          /* Session list */
 173         unsigned int free_chan_id;      /* Next chan ID to allocate */
 174         int metadata_dumped:1;
 175 };
 176
 177 struct ltt_transport {
 178         char *name;
 179         struct module *owner;
 180         struct list_head node;
 181         struct ltt_channel_ops ops;
 182 };
 183
 184 struct ltt_session *ltt_session_create(void);
 185 int ltt_session_start(struct ltt_session *session);
 186 int ltt_session_stop(struct ltt_session *session);
 187 void ltt_session_destroy(struct ltt_session *session);
 188
 189 struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 190                                        const char *transport_name,
 191                                        void *buf_addr,
 192                                        size_t subbuf_size, size_t num_subbuf,
 193                                        unsigned int switch_timer_interval,
 194                                        unsigned int read_timer_interval);
 195 struct ltt_channel *ltt_global_channel_create(struct ltt_session *session,
 196                                        int overwrite, void *buf_addr,
 197                                        size_t subbuf_size, size_t num_subbuf,
 198                                        unsigned int switch_timer_interval,
 199                                        unsigned int read_timer_interval);
 200 void _ltt_channel_destroy(struct ltt_channel *chan);
 201
 202 struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 203                                    char *name,
 204                                    enum instrum_type itype,
 205                                    const struct lttng_event_desc *event_desc,
 206                                    void *filter);
 207 int _ltt_event_unregister(struct ltt_event *event);
 208 void _ltt_event_destroy(struct ltt_event *event);
 209
 210 void ltt_transport_register(struct ltt_transport *transport);
 211 void ltt_transport_unregister(struct ltt_transport *transport);
 212
 213 int ltt_debugfs_abi_init(void);
 214 void ltt_debugfs_abi_exit(void);
 215
 216 int ltt_probe_register(struct lttng_probe_desc *desc);
 217 void ltt_probe_unregister(struct lttng_probe_desc *desc);
 218 const struct lttng_event_desc *ltt_event_get(const char *name);
 219 void ltt_event_put(const struct lttng_event_desc *desc);
 220
 221 #endif /* _LTT_EVENTS_H */