src/bin/lttng-sessiond/buffer-registry.h

   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_BUFFER_REGISTRY_H
  19 #define LTTNG_BUFFER_REGISTRY_H
  20
  21 #include <stdint.h>
  22 #include <urcu/list.h>
  23
  24 #include <lttng/lttng.h>
  25 #include <common/hashtable/hashtable.h>
  26
  27 #include "consumer.h"
  28 #include "ust-ctl.h"
  29 #include "ust-registry.h"
  30
  31 struct buffer_reg_stream {
  32         struct cds_list_head lnode;
  33         union {
  34                 /* Original object data that MUST be copied over. */
  35                 struct lttng_ust_object_data *ust;
  36         } obj;
  37 };
  38
  39 struct buffer_reg_channel {
  40         /* This key is the same as a tracing channel key. */
  41         uint32_t key;
  42         /* Key of the channel on the consumer side. */
  43         uint64_t consumer_key;
  44         /* Stream registry object of this channel registry. */
  45         struct cds_list_head streams;
  46         /* Total number of stream in the list. */
  47         uint64_t stream_count;
  48         /* Used to ensure mutual exclusion to the stream's list. */
  49         pthread_mutex_t stream_list_lock;
  50         /* Node for hash table usage. */
  51         struct lttng_ht_node_u64 node;
  52         /* Size of subbuffers in this channel. */
  53         size_t subbuf_size;
  54         /* Number of subbuffers per stream. */
  55         size_t num_subbuf;
  56         union {
  57                 /* Original object data that MUST be copied over. */
  58                 struct lttng_ust_object_data *ust;
  59         } obj;
  60 };
  61
  62 struct buffer_reg_session {
  63         /* Registry per domain. */
  64         union {
  65                 struct ust_registry_session *ust;
  66         } reg;
  67
  68         /* Contains buffer registry channel indexed by tracing channel key. */
  69         struct lttng_ht *channels;
  70 };
  71
  72 /*
  73  * Registry object for per UID buffers.
  74  */
  75 struct buffer_reg_uid {
  76         /*
  77          * Keys to match this object in a hash table. The following three variables
  78          * identify a unique per UID buffer registry.
  79          */
  80         uint64_t session_id;    /* Unique tracing session id. */
  81         int bits_per_long;      /* ABI */
  82         uid_t uid;                      /* Owner. */
  83
  84         enum lttng_domain_type domain;
  85         struct buffer_reg_session *registry;
  86
  87         /* Indexed by session id. */
  88         struct lttng_ht_node_u64 node;
  89         /* Node of a linked list used to teardown object at a destroy session. */
  90         struct cds_list_head lnode;
  91
  92         char root_shm_path[PATH_MAX];
  93         char shm_path[PATH_MAX];
  94 };
  95
  96 /*
  97  * Registry object for per PID buffers.
  98  */
  99 struct buffer_reg_pid {
 100         uint64_t session_id;
 101
 102         struct buffer_reg_session *registry;
 103
 104         /* Indexed by session id. */
 105         struct lttng_ht_node_u64 node;
 106
 107         char root_shm_path[PATH_MAX];
 108         char shm_path[PATH_MAX];
 109 };
 110
 111 /* Buffer registry per UID. */
 112 void buffer_reg_init_uid_registry(void);
 113 int buffer_reg_uid_create(uint64_t session_id, uint32_t bits_per_long, uid_t uid,
 114                 enum lttng_domain_type domain, struct buffer_reg_uid **regp,
 115                 const char *root_shm_path, const char *shm_path);
 116 void buffer_reg_uid_add(struct buffer_reg_uid *reg);
 117 struct buffer_reg_uid *buffer_reg_uid_find(uint64_t session_id,
 118                 uint32_t bits_per_long, uid_t uid);
 119 void buffer_reg_uid_remove(struct buffer_reg_uid *regp);
 120 void buffer_reg_uid_destroy(struct buffer_reg_uid *regp,
 121                 struct consumer_output *consumer);
 122
 123 /* Buffer registry per PID. */
 124 void buffer_reg_init_pid_registry(void);
 125 int buffer_reg_pid_create(uint64_t session_id, struct buffer_reg_pid **regp,
 126                 const char *root_shm_path, const char *shm_path);
 127 void buffer_reg_pid_add(struct buffer_reg_pid *reg);
 128 struct buffer_reg_pid *buffer_reg_pid_find(uint64_t session_id);
 129 void buffer_reg_pid_remove(struct buffer_reg_pid *regp);
 130 void buffer_reg_pid_destroy(struct buffer_reg_pid *regp);
 131
 132 /* Channel */
 133 int buffer_reg_channel_create(uint64_t key, struct buffer_reg_channel **regp);
 134 void buffer_reg_channel_add(struct buffer_reg_session *session,
 135                 struct buffer_reg_channel *channel);
 136 struct buffer_reg_channel *buffer_reg_channel_find(uint64_t key,
 137                 struct buffer_reg_uid *reg);
 138 void buffer_reg_channel_remove(struct buffer_reg_session *session,
 139                 struct buffer_reg_channel *regp);
 140 void buffer_reg_channel_destroy(struct buffer_reg_channel *regp,
 141                 enum lttng_domain_type domain);
 142
 143 /* Stream */
 144 int buffer_reg_stream_create(struct buffer_reg_stream **regp);
 145 void buffer_reg_stream_add(struct buffer_reg_stream *stream,
 146                 struct buffer_reg_channel *channel);
 147 void buffer_reg_stream_destroy(struct buffer_reg_stream *regp,
 148                 enum lttng_domain_type domain);
 149
 150 /* Global registry. */
 151 void buffer_reg_destroy_registries(void);
 152
 153 #endif /* LTTNG_BUFFER_REGISTRY_H */