src/common/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 <lttng/ust-ringbuffer-context.h>
  13
  14 #include "common/logging.h"
  15 #include "common/tracer.h"
  16 #include "common/jhash.h"
  17
  18
  19 /*
  20  * Each library using the transports will have its local lists.
  21  */
  22 static CDS_LIST_HEAD(lttng_transport_list);
  23 static CDS_LIST_HEAD(lttng_counter_transport_list);
  24
  25 struct lttng_transport *lttng_ust_transport_find(const char *name)
  26 {
  27         struct lttng_transport *transport;
  28
  29         cds_list_for_each_entry(transport, &lttng_transport_list, node) {
  30                 if (!strcmp(transport->name, name))
  31                         return transport;
  32         }
  33         return NULL;
  34 }
  35
  36 struct lttng_counter_transport *lttng_counter_transport_find(const char *name)
  37 {
  38         struct lttng_counter_transport *transport;
  39
  40         cds_list_for_each_entry(transport, &lttng_counter_transport_list, node) {
  41                 if (!strcmp(transport->name, name))
  42                         return transport;
  43         }
  44         return NULL;
  45 }
  46
  47 /**
  48  * lttng_transport_register - LTT transport registration
  49  * @transport: transport structure
  50  *
  51  * Registers a transport which can be used as output to extract the data out of
  52  * LTTng. Called with ust_lock held.
  53  */
  54 void lttng_transport_register(struct lttng_transport *transport)
  55 {
  56         cds_list_add_tail(&transport->node, &lttng_transport_list);
  57 }
  58
  59 /**
  60  * lttng_transport_unregister - LTT transport unregistration
  61  * @transport: transport structure
  62  * Called with ust_lock held.
  63  */
  64 void lttng_transport_unregister(struct lttng_transport *transport)
  65 {
  66         cds_list_del(&transport->node);
  67 }
  68
  69 /**
  70  * lttng_counter_transport_register - LTTng counter transport registration
  71  * @transport: transport structure
  72  *
  73  * Registers a counter transport which can be used as output to extract
  74  * the data out of LTTng. Called with ust_lock held.
  75  */
  76 void lttng_counter_transport_register(struct lttng_counter_transport *transport)
  77 {
  78         cds_list_add_tail(&transport->node, &lttng_counter_transport_list);
  79 }
  80
  81 /**
  82  * lttng_counter_transport_unregister - LTTng counter transport unregistration
  83  * @transport: transport structure
  84  * Called with ust_lock held.
  85  */
  86 void lttng_counter_transport_unregister(struct lttng_counter_transport *transport)
  87 {
  88         cds_list_del(&transport->node);
  89 }
  90
  91 size_t lttng_ust_dummy_get_size(void *priv __attribute__((unused)),
  92                 struct lttng_ust_probe_ctx *probe_ctx __attribute__((unused)),
  93                 size_t offset)
  94 {
  95         size_t size = 0;
  96
  97         size += lttng_ust_ring_buffer_align(offset, lttng_ust_rb_alignof(char));
  98         size += sizeof(char);           /* tag */
  99         return size;
 100 }
 101
 102 void lttng_ust_dummy_record(void *priv __attribute__((unused)),
 103                 struct lttng_ust_probe_ctx *probe_ctx __attribute__((unused)),
 104                 struct lttng_ust_ring_buffer_ctx *ctx,
 105                 struct lttng_ust_channel_buffer *chan)
 106 {
 107         char sel_char = (char) LTTNG_UST_DYNAMIC_TYPE_NONE;
 108
 109         chan->ops->event_write(ctx, &sel_char, sizeof(sel_char), lttng_ust_rb_alignof(sel_char));
 110 }
 111
 112 void lttng_ust_dummy_get_value(void *priv __attribute__((unused)),
 113                 struct lttng_ust_probe_ctx *probe_ctx __attribute__((unused)),
 114                 struct lttng_ust_ctx_value *value)
 115 {
 116         value->sel = LTTNG_UST_DYNAMIC_TYPE_NONE;
 117 }
 118
 119 int lttng_context_is_app(const char *name)
 120 {
 121         if (strncmp(name, "$app.", strlen("$app.")) != 0) {
 122                 return 0;
 123         }
 124         return 1;
 125 }
 126
 127 struct lttng_ust_channel_buffer *lttng_ust_alloc_channel_buffer(void)
 128 {
 129         struct lttng_ust_channel_buffer *lttng_chan_buf;
 130         struct lttng_ust_channel_common *lttng_chan_common;
 131         struct lttng_ust_channel_buffer_private *lttng_chan_buf_priv;
 132
 133         lttng_chan_buf = zmalloc(sizeof(struct lttng_ust_channel_buffer));
 134         if (!lttng_chan_buf)
 135                 goto lttng_chan_buf_error;
 136         lttng_chan_buf->struct_size = sizeof(struct lttng_ust_channel_buffer);
 137         lttng_chan_common = zmalloc(sizeof(struct lttng_ust_channel_common));
 138         if (!lttng_chan_common)
 139                 goto lttng_chan_common_error;
 140         lttng_chan_common->struct_size = sizeof(struct lttng_ust_channel_common);
 141         lttng_chan_buf_priv = zmalloc(sizeof(struct lttng_ust_channel_buffer_private));
 142         if (!lttng_chan_buf_priv)
 143                 goto lttng_chan_buf_priv_error;
 144         lttng_chan_buf->parent = lttng_chan_common;
 145         lttng_chan_common->type = LTTNG_UST_CHANNEL_TYPE_BUFFER;
 146         lttng_chan_common->child = lttng_chan_buf;
 147         lttng_chan_buf->priv = lttng_chan_buf_priv;
 148         lttng_chan_common->priv = &lttng_chan_buf_priv->parent;
 149         lttng_chan_buf_priv->pub = lttng_chan_buf;
 150         lttng_chan_buf_priv->parent.pub = lttng_chan_common;
 151
 152         return lttng_chan_buf;
 153
 154 lttng_chan_buf_priv_error:
 155         free(lttng_chan_common);
 156 lttng_chan_common_error:
 157         free(lttng_chan_buf);
 158 lttng_chan_buf_error:
 159         return NULL;
 160 }
 161
 162 void lttng_ust_free_channel_common(struct lttng_ust_channel_common *chan)
 163 {
 164         switch (chan->type) {
 165         case LTTNG_UST_CHANNEL_TYPE_BUFFER:
 166         {
 167                 struct lttng_ust_channel_buffer *chan_buf;
 168
 169                 chan_buf = (struct lttng_ust_channel_buffer *)chan->child;
 170                 free(chan_buf->parent);
 171                 free(chan_buf->priv);
 172                 free(chan_buf);
 173                 break;
 174         }
 175         default:
 176                 abort();
 177         }
 178 }
 179