| 1 | /* |
| 2 | * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU General Public License, version 2 only, as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 11 | * more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License along with |
| 14 | * this program; if not, write to the Free Software Foundation, Inc., 51 |
| 15 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 16 | */ |
| 17 | |
| 18 | #ifndef LTTNG_UST_REGISTRY_H |
| 19 | #define LTTNG_UST_REGISTRY_H |
| 20 | |
| 21 | #include <pthread.h> |
| 22 | #include <stdint.h> |
| 23 | #include <lttng/ust-ctl.h> |
| 24 | |
| 25 | #include <common/hashtable/hashtable.h> |
| 26 | #include <common/compat/uuid.h> |
| 27 | |
| 28 | #define CTF_SPEC_MAJOR 1 |
| 29 | #define CTF_SPEC_MINOR 8 |
| 30 | |
| 31 | struct ust_app; |
| 32 | |
| 33 | struct ust_registry_session { |
| 34 | /* |
| 35 | * With multiple writers and readers, use this lock to access |
| 36 | * the registry. Use defined macros above to lock it. |
| 37 | * Can nest within the ust app session lock. |
| 38 | */ |
| 39 | pthread_mutex_t lock; |
| 40 | /* Next channel ID available for a newly registered channel. */ |
| 41 | uint32_t next_channel_id; |
| 42 | /* Once this value reaches UINT32_MAX, no more id can be allocated. */ |
| 43 | uint32_t used_channel_id; |
| 44 | /* Universal unique identifier used by the tracer. */ |
| 45 | unsigned char uuid[UUID_LEN]; |
| 46 | |
| 47 | /* session ABI description */ |
| 48 | |
| 49 | /* Size of long, in bits */ |
| 50 | unsigned int bits_per_long; |
| 51 | /* Alignment, in bits */ |
| 52 | unsigned int uint8_t_alignment, |
| 53 | uint16_t_alignment, |
| 54 | uint32_t_alignment, |
| 55 | uint64_t_alignment, |
| 56 | long_alignment; |
| 57 | /* endianness */ |
| 58 | int byte_order; /* BIG_ENDIAN or LITTLE_ENDIAN */ |
| 59 | |
| 60 | /* Generated metadata. */ |
| 61 | char *metadata; /* NOT null-terminated ! Use memcpy. */ |
| 62 | size_t metadata_len, metadata_alloc_len; |
| 63 | /* Length of bytes sent to the consumer. */ |
| 64 | size_t metadata_len_sent; |
| 65 | }; |
| 66 | |
| 67 | struct ust_registry_channel { |
| 68 | /* Id set when replying to a register channel. */ |
| 69 | uint32_t chan_id; |
| 70 | enum ustctl_channel_header header_type; |
| 71 | |
| 72 | /* |
| 73 | * Hash table containing events sent by the UST tracer. MUST be accessed |
| 74 | * with a RCU read side lock acquired. |
| 75 | */ |
| 76 | struct lttng_ht *ht; |
| 77 | /* Next event ID available for a newly registered event. */ |
| 78 | uint32_t next_event_id; |
| 79 | /* Once this value reaches UINT32_MAX, no more id can be allocated. */ |
| 80 | uint32_t used_event_id; |
| 81 | /* |
| 82 | * Context fields of the registry. Context are per channel. Allocated by a |
| 83 | * register channel notification from the UST tracer. |
| 84 | */ |
| 85 | size_t nr_ctx_fields; |
| 86 | struct ustctl_field *ctx_fields; |
| 87 | }; |
| 88 | |
| 89 | /* |
| 90 | * Event registered from a UST tracer sent to the session daemon. This is |
| 91 | * indexed and matched by <event_name/signature>. |
| 92 | */ |
| 93 | struct ust_registry_event { |
| 94 | int id; |
| 95 | /* Both objd are set by the tracer. */ |
| 96 | int session_objd; |
| 97 | int channel_objd; |
| 98 | /* Name of the event returned by the tracer. */ |
| 99 | char name[LTTNG_UST_SYM_NAME_LEN]; |
| 100 | char *signature; |
| 101 | int loglevel; |
| 102 | size_t nr_fields; |
| 103 | struct ustctl_field *fields; |
| 104 | char *model_emf_uri; |
| 105 | /* |
| 106 | * Node in the ust-registry hash table. The event name is used to |
| 107 | * initialize the node and the event_name/signature for the match function. |
| 108 | */ |
| 109 | struct lttng_ht_node_str node; |
| 110 | }; |
| 111 | |
| 112 | /* |
| 113 | * Validate that the id has reached the maximum allowed or not. |
| 114 | * |
| 115 | * Return 0 if NOT else 1. |
| 116 | */ |
| 117 | static inline int ust_registry_is_max_id(uint32_t id) |
| 118 | { |
| 119 | return (id == UINT32_MAX) ? 1 : 0; |
| 120 | } |
| 121 | |
| 122 | /* |
| 123 | * Return next available event id and increment the used counter. The |
| 124 | * ust_registry_is_max_id function MUST be called before in order to validate |
| 125 | * if the maximum number of IDs have been reached. If not, it is safe to call |
| 126 | * this function. |
| 127 | * |
| 128 | * Return a unique channel ID. If max is reached, the used_event_id counter is |
| 129 | * returned. |
| 130 | */ |
| 131 | static inline uint32_t ust_registry_get_next_event_id( |
| 132 | struct ust_registry_channel *r) |
| 133 | { |
| 134 | if (ust_registry_is_max_id(r->used_event_id)) { |
| 135 | return r->used_event_id; |
| 136 | } |
| 137 | |
| 138 | r->used_event_id++; |
| 139 | return r->next_event_id++; |
| 140 | } |
| 141 | |
| 142 | /* |
| 143 | * Return next available channel id and increment the used counter. The |
| 144 | * ust_registry_is_max_id function MUST be called before in order to validate |
| 145 | * if the maximum number of IDs have been reached. If not, it is safe to call |
| 146 | * this function. |
| 147 | * |
| 148 | * Return a unique channel ID. If max is reached, the used_channel_id counter |
| 149 | * is returned. |
| 150 | */ |
| 151 | static inline uint32_t ust_registry_get_next_chan_id( |
| 152 | struct ust_registry_session *r) |
| 153 | { |
| 154 | if (ust_registry_is_max_id(r->used_channel_id)) { |
| 155 | return r->used_channel_id; |
| 156 | } |
| 157 | |
| 158 | r->used_channel_id++; |
| 159 | return r->next_channel_id++; |
| 160 | } |
| 161 | |
| 162 | /* |
| 163 | * Return registry event count. This is read atomically. |
| 164 | */ |
| 165 | static inline uint32_t ust_registry_get_event_count( |
| 166 | struct ust_registry_channel *r) |
| 167 | { |
| 168 | return (uint32_t) uatomic_read(&r->used_event_id); |
| 169 | } |
| 170 | |
| 171 | void ust_registry_channel_init(struct ust_registry_session *session, |
| 172 | struct ust_registry_channel *chan); |
| 173 | void ust_registry_channel_destroy(struct ust_registry_session *session, |
| 174 | struct ust_registry_channel *chan); |
| 175 | |
| 176 | int ust_registry_session_init(struct ust_registry_session *session, |
| 177 | struct ust_app *app, |
| 178 | uint32_t bits_per_long, |
| 179 | uint32_t uint8_t_alignment, |
| 180 | uint32_t uint16_t_alignment, |
| 181 | uint32_t uint32_t_alignment, |
| 182 | uint32_t uint64_t_alignment, |
| 183 | uint32_t long_alignment, |
| 184 | int byte_order); |
| 185 | |
| 186 | void ust_registry_session_destroy(struct ust_registry_session *session); |
| 187 | |
| 188 | int ust_registry_create_event(struct ust_registry_session *session, |
| 189 | struct ust_registry_channel *channel, |
| 190 | int session_objd, int channel_objd, char *name, char *sig, |
| 191 | size_t nr_fields, struct ustctl_field *fields, int loglevel, |
| 192 | char *model_emf_uri, uint32_t *event_id); |
| 193 | struct ust_registry_event *ust_registry_find_event( |
| 194 | struct ust_registry_channel *chan, char *name, char *sig); |
| 195 | void ust_registry_destroy_event(struct ust_registry_channel *chan, |
| 196 | struct ust_registry_event *event); |
| 197 | |
| 198 | /* app can be NULL for registry shared across applications. */ |
| 199 | int ust_metadata_session_statedump(struct ust_registry_session *session, |
| 200 | struct ust_app *app); |
| 201 | int ust_metadata_channel_statedump(struct ust_registry_session *session, |
| 202 | struct ust_registry_channel *chan); |
| 203 | int ust_metadata_event_statedump(struct ust_registry_session *session, |
| 204 | struct ust_registry_channel *chan, |
| 205 | struct ust_registry_event *event); |
| 206 | |
| 207 | #endif /* LTTNG_UST_REGISTRY_H */ |