liblttng-ust/ust-core.c

   1 /*
   2  * SPDX-License-Identifier: LGPL-2.1-only
   3  *
   4  * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  */
   6
   7 #define _LGPL_SOURCE
   8 #include <stdint.h>
   9 #include <stddef.h>
  10 #include <stdlib.h>
  11
  12 #include "context-internal.h"
  13 #include "ust-events-internal.h"
  14 #include <usterr-signal-safe.h>
  15 #include "lttng-tracer-core.h"
  16 #include "lttng-rb-clients.h"
  17 #include "lttng-counter-client.h"
  18 #include "jhash.h"
  19
  20 static CDS_LIST_HEAD(lttng_transport_list);
  21 static CDS_LIST_HEAD(lttng_counter_transport_list);
  22
  23 struct lttng_transport *lttng_ust_transport_find(const char *name)
  24 {
  25         struct lttng_transport *transport;
  26
  27         cds_list_for_each_entry(transport, &lttng_transport_list, node) {
  28                 if (!strcmp(transport->name, name))
  29                         return transport;
  30         }
  31         return NULL;
  32 }
  33
  34 struct lttng_counter_transport *lttng_counter_transport_find(const char *name)
  35 {
  36         struct lttng_counter_transport *transport;
  37
  38         cds_list_for_each_entry(transport, &lttng_counter_transport_list, node) {
  39                 if (!strcmp(transport->name, name))
  40                         return transport;
  41         }
  42         return NULL;
  43 }
  44
  45 /**
  46  * lttng_transport_register - LTT transport registration
  47  * @transport: transport structure
  48  *
  49  * Registers a transport which can be used as output to extract the data out of
  50  * LTTng. Called with ust_lock held.
  51  */
  52 void lttng_transport_register(struct lttng_transport *transport)
  53 {
  54         cds_list_add_tail(&transport->node, &lttng_transport_list);
  55 }
  56
  57 /**
  58  * lttng_transport_unregister - LTT transport unregistration
  59  * @transport: transport structure
  60  * Called with ust_lock held.
  61  */
  62 void lttng_transport_unregister(struct lttng_transport *transport)
  63 {
  64         cds_list_del(&transport->node);
  65 }
  66
  67 /**
  68  * lttng_counter_transport_register - LTTng counter transport registration
  69  * @transport: transport structure
  70  *
  71  * Registers a counter transport which can be used as output to extract
  72  * the data out of LTTng. Called with ust_lock held.
  73  */
  74 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
  75 {
  76         cds_list_add_tail(&transport->node, &lttng_counter_transport_list);
  77 }
  78
  79 /**
  80  * lttng_counter_transport_unregister - LTTng counter transport unregistration
  81  * @transport: transport structure
  82  * Called with ust_lock held.
  83  */
  84 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
  85 {
  86         cds_list_del(&transport->node);
  87 }
  88
  89 /*
  90  * Needed by comm layer.
  91  */
  92 struct lttng_enum *lttng_ust_enum_get_from_desc(struct lttng_ust_session *session,
  93                 struct lttng_ust_enum_desc *enum_desc)
  94 {
  95         struct lttng_enum *_enum;
  96         struct cds_hlist_head *head;
  97         struct cds_hlist_node *node;
  98         size_t name_len = strlen(enum_desc->name);
  99         uint32_t hash;
 100
 101         hash = jhash(enum_desc->name, name_len, 0);
 102         head = &session->priv->enums_ht.table[hash & (LTTNG_UST_ENUM_HT_SIZE - 1)];
 103         cds_hlist_for_each_entry(_enum, node, head, hlist) {
 104                 assert(_enum->desc);
 105                 if (_enum->desc == enum_desc)
 106                         return _enum;
 107         }
 108         return NULL;
 109 }
 110
 111 size_t lttng_ust_dummy_get_size(struct lttng_ust_ctx_field *field, size_t offset)
 112 {
 113         size_t size = 0;
 114
 115         size += lttng_ust_lib_ring_buffer_align(offset, lttng_ust_rb_alignof(char));
 116         size += sizeof(char);           /* tag */
 117         return size;
 118 }
 119
 120 void lttng_ust_dummy_record(struct lttng_ust_ctx_field *field,
 121                  struct lttng_ust_lib_ring_buffer_ctx *ctx,
 122                  struct lttng_ust_channel_buffer *chan)
 123 {
 124         char sel_char = (char) LTTNG_UST_DYNAMIC_TYPE_NONE;
 125
 126         chan->ops->event_write(ctx, &sel_char, sizeof(sel_char), lttng_ust_rb_alignof(sel_char));
 127 }
 128
 129 void lttng_ust_dummy_get_value(struct lttng_ust_ctx_field *field,
 130                 struct lttng_ust_ctx_value *value)
 131 {
 132         value->sel = LTTNG_UST_DYNAMIC_TYPE_NONE;
 133 }
 134
 135 int lttng_context_is_app(const char *name)
 136 {
 137         if (strncmp(name, "$app.", strlen("$app.")) != 0) {
 138                 return 0;
 139         }
 140         return 1;
 141 }
 142
 143 struct lttng_ust_channel_buffer *lttng_ust_alloc_channel_buffer(void)
 144 {
 145         struct lttng_ust_channel_buffer *lttng_chan_buf;
 146         struct lttng_ust_channel_common *lttng_chan_common;
 147         struct lttng_ust_channel_buffer_private *lttng_chan_buf_priv;
 148
 149         lttng_chan_buf = zmalloc(sizeof(struct lttng_ust_channel_buffer));
 150         if (!lttng_chan_buf)
 151                 goto lttng_chan_buf_error;
 152         lttng_chan_buf->struct_size = sizeof(struct lttng_ust_channel_buffer);
 153         lttng_chan_common = zmalloc(sizeof(struct lttng_ust_channel_common));
 154         if (!lttng_chan_common)
 155                 goto lttng_chan_common_error;
 156         lttng_chan_common->struct_size = sizeof(struct lttng_ust_channel_common);
 157         lttng_chan_buf_priv = zmalloc(sizeof(struct lttng_ust_channel_buffer_private));
 158         if (!lttng_chan_buf_priv)
 159                 goto lttng_chan_buf_priv_error;
 160         lttng_chan_buf->parent = lttng_chan_common;
 161         lttng_chan_common->type = LTTNG_UST_CHANNEL_TYPE_BUFFER;
 162         lttng_chan_common->child = lttng_chan_buf;
 163         lttng_chan_buf->priv = lttng_chan_buf_priv;
 164         lttng_chan_common->priv = &lttng_chan_buf_priv->parent;
 165         lttng_chan_buf_priv->pub = lttng_chan_buf;
 166         lttng_chan_buf_priv->parent.pub = lttng_chan_common;
 167
 168         return lttng_chan_buf;
 169
 170 lttng_chan_buf_priv_error:
 171         free(lttng_chan_common);
 172 lttng_chan_common_error:
 173         free(lttng_chan_buf);
 174 lttng_chan_buf_error:
 175         return NULL;
 176 }
 177
 178 void lttng_ust_free_channel_common(struct lttng_ust_channel_common *chan)
 179 {
 180         switch (chan->type) {
 181         case LTTNG_UST_CHANNEL_TYPE_BUFFER:
 182         {
 183                 struct lttng_ust_channel_buffer *chan_buf;
 184
 185                 chan_buf = (struct lttng_ust_channel_buffer *)chan->child;
 186                 free(chan_buf->parent);
 187                 free(chan_buf->priv);
 188                 free(chan_buf);
 189                 break;
 190         }
 191         default:
 192                 abort();
 193         }
 194 }
 195
 196 void lttng_ust_ring_buffer_clients_init(void)
 197 {
 198         lttng_ring_buffer_metadata_client_init();
 199         lttng_ring_buffer_client_overwrite_init();
 200         lttng_ring_buffer_client_overwrite_rt_init();
 201         lttng_ring_buffer_client_discard_init();
 202         lttng_ring_buffer_client_discard_rt_init();
 203 }
 204
 205 void lttng_ust_ring_buffer_clients_exit(void)
 206 {
 207         lttng_ring_buffer_client_discard_rt_exit();
 208         lttng_ring_buffer_client_discard_exit();
 209         lttng_ring_buffer_client_overwrite_rt_exit();
 210         lttng_ring_buffer_client_overwrite_exit();
 211         lttng_ring_buffer_metadata_client_exit();
 212 }
 213
 214 void lttng_ust_counter_clients_init(void)
 215 {
 216         lttng_counter_client_percpu_64_modular_init();
 217         lttng_counter_client_percpu_32_modular_init();
 218 }
 219
 220 void lttng_ust_counter_clients_exit(void)
 221 {
 222         lttng_counter_client_percpu_32_modular_exit();
 223         lttng_counter_client_percpu_64_modular_exit();
 224 }