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 "jhash.h"
  17
  18 static CDS_LIST_HEAD(lttng_transport_list);
  19 static CDS_LIST_HEAD(lttng_counter_transport_list);
  20
  21 struct lttng_transport *lttng_ust_transport_find(const char *name)
  22 {
  23         struct lttng_transport *transport;
  24
  25         cds_list_for_each_entry(transport, &lttng_transport_list, node) {
  26                 if (!strcmp(transport->name, name))
  27                         return transport;
  28         }
  29         return NULL;
  30 }
  31
  32 struct lttng_counter_transport *lttng_counter_transport_find(const char *name)
  33 {
  34         struct lttng_counter_transport *transport;
  35
  36         cds_list_for_each_entry(transport, &lttng_counter_transport_list, node) {
  37                 if (!strcmp(transport->name, name))
  38                         return transport;
  39         }
  40         return NULL;
  41 }
  42
  43 /**
  44  * lttng_transport_register - LTT transport registration
  45  * @transport: transport structure
  46  *
  47  * Registers a transport which can be used as output to extract the data out of
  48  * LTTng. Called with ust_lock held.
  49  */
  50 void lttng_transport_register(struct lttng_transport *transport)
  51 {
  52         cds_list_add_tail(&transport->node, &lttng_transport_list);
  53 }
  54
  55 /**
  56  * lttng_transport_unregister - LTT transport unregistration
  57  * @transport: transport structure
  58  * Called with ust_lock held.
  59  */
  60 void lttng_transport_unregister(struct lttng_transport *transport)
  61 {
  62         cds_list_del(&transport->node);
  63 }
  64
  65 /**
  66  * lttng_counter_transport_register - LTTng counter transport registration
  67  * @transport: transport structure
  68  *
  69  * Registers a counter transport which can be used as output to extract
  70  * the data out of LTTng. Called with ust_lock held.
  71  */
  72 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
  73 {
  74         cds_list_add_tail(&transport->node, &lttng_counter_transport_list);
  75 }
  76
  77 /**
  78  * lttng_counter_transport_unregister - LTTng counter transport unregistration
  79  * @transport: transport structure
  80  * Called with ust_lock held.
  81  */
  82 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
  83 {
  84         cds_list_del(&transport->node);
  85 }
  86
  87 /*
  88  * Needed by comm layer.
  89  */
  90 struct lttng_enum *lttng_ust_enum_get_from_desc(struct lttng_ust_session *session,
  91                 struct lttng_ust_enum_desc *enum_desc)
  92 {
  93         struct lttng_enum *_enum;
  94         struct cds_hlist_head *head;
  95         struct cds_hlist_node *node;
  96         size_t name_len = strlen(enum_desc->name);
  97         uint32_t hash;
  98
  99         hash = jhash(enum_desc->name, name_len, 0);
 100         head = &session->priv->enums_ht.table[hash & (LTTNG_UST_ENUM_HT_SIZE - 1)];
 101         cds_hlist_for_each_entry(_enum, node, head, hlist) {
 102                 assert(_enum->desc);
 103                 if (_enum->desc == enum_desc)
 104                         return _enum;
 105         }
 106         return NULL;
 107 }
 108
 109 size_t lttng_ust_dummy_get_size(struct lttng_ust_ctx_field *field, size_t offset)
 110 {
 111         size_t size = 0;
 112
 113         size += lttng_ust_lib_ring_buffer_align(offset, lttng_ust_rb_alignof(char));
 114         size += sizeof(char);           /* tag */
 115         return size;
 116 }
 117
 118 void lttng_ust_dummy_record(struct lttng_ust_ctx_field *field,
 119                  struct lttng_ust_lib_ring_buffer_ctx *ctx,
 120                  struct lttng_ust_channel_buffer *chan)
 121 {
 122         char sel_char = (char) LTTNG_UST_DYNAMIC_TYPE_NONE;
 123
 124         lttng_ust_lib_ring_buffer_align_ctx(ctx, lttng_ust_rb_alignof(sel_char));
 125         chan->ops->event_write(ctx, &sel_char, sizeof(sel_char));
 126 }
 127
 128 void lttng_ust_dummy_get_value(struct lttng_ust_ctx_field *field,
 129                 struct lttng_ust_ctx_value *value)
 130 {
 131         value->sel = LTTNG_UST_DYNAMIC_TYPE_NONE;
 132 }
 133
 134 int lttng_context_is_app(const char *name)
 135 {
 136         if (strncmp(name, "$app.", strlen("$app.")) != 0) {
 137                 return 0;
 138         }
 139         return 1;
 140 }
 141
 142 struct lttng_ust_channel_buffer *lttng_ust_alloc_channel_buffer(void)
 143 {
 144         struct lttng_ust_channel_buffer *lttng_chan_buf;
 145         struct lttng_ust_channel_common *lttng_chan_common;
 146         struct lttng_ust_channel_buffer_private *lttng_chan_buf_priv;
 147
 148         lttng_chan_buf = zmalloc(sizeof(struct lttng_ust_channel_buffer));
 149         if (!lttng_chan_buf)
 150                 goto lttng_chan_buf_error;
 151         lttng_chan_buf->struct_size = sizeof(struct lttng_ust_channel_buffer);
 152         lttng_chan_common = zmalloc(sizeof(struct lttng_ust_channel_common));
 153         if (!lttng_chan_common)
 154                 goto lttng_chan_common_error;
 155         lttng_chan_common->struct_size = sizeof(struct lttng_ust_channel_common);
 156         lttng_chan_buf_priv = zmalloc(sizeof(struct lttng_ust_channel_buffer_private));
 157         if (!lttng_chan_buf_priv)
 158                 goto lttng_chan_buf_priv_error;
 159         lttng_chan_buf->parent = lttng_chan_common;
 160         lttng_chan_common->type = LTTNG_UST_CHANNEL_TYPE_BUFFER;
 161         lttng_chan_common->child = lttng_chan_buf;
 162         lttng_chan_buf->priv = lttng_chan_buf_priv;
 163         lttng_chan_common->priv = &lttng_chan_buf_priv->parent;
 164         lttng_chan_buf_priv->pub = lttng_chan_buf;
 165         lttng_chan_buf_priv->parent.pub = lttng_chan_common;
 166
 167         return lttng_chan_buf;
 168
 169 lttng_chan_buf_priv_error:
 170         free(lttng_chan_common);
 171 lttng_chan_common_error:
 172         free(lttng_chan_buf);
 173 lttng_chan_buf_error:
 174         return NULL;
 175 }
 176
 177 void lttng_ust_free_channel_common(struct lttng_ust_channel_common *chan)
 178 {
 179         switch (chan->type) {
 180         case LTTNG_UST_CHANNEL_TYPE_BUFFER:
 181         {
 182                 struct lttng_ust_channel_buffer *chan_buf;
 183
 184                 chan_buf = (struct lttng_ust_channel_buffer *)chan->child;
 185                 free(chan_buf->parent);
 186                 free(chan_buf->priv);
 187                 free(chan_buf);
 188                 break;
 189         }
 190         default:
 191                 abort();
 192         }
 193 }