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 struct lttng_enum {
  44         const struct lttng_enum_entry *entries;
  45         unsigned int len;
  46 };
  47
  48 struct lttng_type {
  49         enum abstract_types atype;
  50         const char *name;
  51         union {
  52                 struct {
  53                         unsigned int size;              /* in bits */
  54                         unsigned short alignment;       /* in bits */
  55                         unsigned int signedness:1;
  56                         unsigned int reverse_byte_order:1;
  57                 } integer;
  58                 struct {
  59                         const char *parent_type;
  60                         const struct lttng_enum def;
  61                 } enumeration;
  62                 struct {
  63                         const char *elem_type;
  64                         unsigned int length;            /* num. elems. */
  65                 } array;
  66                 struct {
  67                         const char *elem_type;
  68                         const char *length_type;
  69                 } sequence;
  70                 struct {
  71                         enum lttng_string_encodings encoding;
  72                 } string;
  73         } u;
  74 } __attribute__((packed));
  75
  76 /* Event field description */
  77
  78 struct lttng_event_field {
  79         const char *name;
  80         const struct lttng_type type;
  81 };
  82
  83 struct lttng_event_desc {
  84         const struct lttng_event_field *fields;
  85         const char *name;
  86         void *probe_callback;
  87         unsigned int nr_fields;
  88 };
  89
  90 struct lttng_probe_desc {
  91         const struct lttng_event_desc *event_desc;
  92         unsigned int nr_events;
  93         struct list_head head;                  /* chain registered probes */
  94 };
  95
  96 /*
  97  * ltt_event structure is referred to by the tracing fast path. It must be
  98  * kept small.
  99  */
 100 struct ltt_event {
 101         unsigned int id;
 102         struct ltt_channel *chan;
 103         const struct lttng_event_desc *desc;
 104         void *filter;
 105         enum instrum_type itype;
 106         struct list_head list;          /* Event list */
 107 };
 108
 109 struct ltt_channel_ops {
 110         struct channel *(*channel_create)(const char *name,
 111                                 struct ltt_session *session,
 112                                 void *buf_addr,
 113                                 size_t subbuf_size, size_t num_subbuf,
 114                                 unsigned int switch_timer_interval,
 115                                 unsigned int read_timer_interval);
 116         void (*channel_destroy)(struct channel *chan);
 117         struct lib_ring_buffer *(*buffer_read_open)(struct channel *chan);
 118         void (*buffer_read_close)(struct lib_ring_buffer *buf);
 119         int (*event_reserve)(struct lib_ring_buffer_ctx *ctx);
 120         void (*event_commit)(struct lib_ring_buffer_ctx *ctx);
 121         void (*event_write)(struct lib_ring_buffer_ctx *ctx, const void *src,
 122                             size_t len);
 123 };
 124
 125 struct ltt_channel {
 126         struct channel *chan;           /* Channel buffers */
 127         /* Event ID management */
 128         struct ltt_session *session;
 129         struct file *file;              /* File associated to channel */
 130         unsigned int free_event_id;     /* Next event ID to allocate */
 131         struct list_head list;          /* Channel list */
 132         wait_queue_head_t notify_wait;  /* Channel addition notif. waitqueue */
 133         struct ltt_channel_ops *ops;
 134 };
 135
 136 struct ltt_session {
 137         int active;                     /* Is trace session active ? */
 138         struct file *file;              /* File associated to session */
 139         struct list_head chan;          /* Channel list head */
 140         struct list_head events;        /* Event list head */
 141         struct list_head list;          /* Session list */
 142 };
 143
 144 struct ltt_transport {
 145         char *name;
 146         struct module *owner;
 147         struct list_head node;
 148         struct ltt_channel_ops ops;
 149 };
 150
 151 struct ltt_session *ltt_session_create(void);
 152 int ltt_session_start(struct ltt_session *session);
 153 int ltt_session_stop(struct ltt_session *session);
 154 void ltt_session_destroy(struct ltt_session *session);
 155
 156 struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 157                                        const char *transport_name,
 158                                        void *buf_addr,
 159                                        size_t subbuf_size, size_t num_subbuf,
 160                                        unsigned int switch_timer_interval,
 161                                        unsigned int read_timer_interval);
 162 struct ltt_channel *ltt_global_channel_create(struct ltt_session *session,
 163                                        int overwrite, void *buf_addr,
 164                                        size_t subbuf_size, size_t num_subbuf,
 165                                        unsigned int switch_timer_interval,
 166                                        unsigned int read_timer_interval);
 167 void _ltt_channel_destroy(struct ltt_channel *chan);
 168
 169 struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 170                                    char *name,
 171                                    enum instrum_type itype,
 172                                    const struct lttng_event_desc *event_desc,
 173                                    void *filter);
 174 int _ltt_event_unregister(struct ltt_event *event);
 175 void _ltt_event_destroy(struct ltt_event *event);
 176
 177 void ltt_transport_register(struct ltt_transport *transport);
 178 void ltt_transport_unregister(struct ltt_transport *transport);
 179
 180 int ltt_debugfs_abi_init(void);
 181 void ltt_debugfs_abi_exit(void);
 182
 183 int ltt_probe_register(struct lttng_probe_desc *desc);
 184 void ltt_probe_unregister(struct lttng_probe_desc *desc);
 185 const struct lttng_event_desc *ltt_event_get(const char *name);
 186 void ltt_event_put(const struct lttng_event_desc *desc);
 187
 188 #endif /* _LTT_EVENTS_H */