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

   1 /*
   2  * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #ifndef LTTNG_BUFFER_REGISTRY_H
   9 #define LTTNG_BUFFER_REGISTRY_H
  10
  11 #include <stdint.h>
  12 #include <urcu/list.h>
  13
  14 #include <lttng/lttng.h>
  15 #include <common/hashtable/hashtable.h>
  16
  17 #include "consumer.h"
  18 #include "lttng-ust-ctl.h"
  19 #include "ust-registry.h"
  20
  21 struct buffer_reg_stream {
  22         struct cds_list_head lnode;
  23         union {
  24                 /* Original object data that MUST be copied over. */
  25                 struct lttng_ust_object_data *ust;
  26         } obj;
  27 };
  28
  29 struct buffer_reg_channel {
  30         /* This key is the same as a tracing channel key. */
  31         uint32_t key;
  32         /* Key of the channel on the consumer side. */
  33         uint64_t consumer_key;
  34         /* Stream registry object of this channel registry. */
  35         struct cds_list_head streams;
  36         /* Total number of stream in the list. */
  37         uint64_t stream_count;
  38         /* Used to ensure mutual exclusion to the stream's list. */
  39         pthread_mutex_t stream_list_lock;
  40         /* Node for hash table usage. */
  41         struct lttng_ht_node_u64 node;
  42         /* Size of subbuffers in this channel. */
  43         size_t subbuf_size;
  44         /* Number of subbuffers per stream. */
  45         size_t num_subbuf;
  46         union {
  47                 /* Original object data that MUST be copied over. */
  48                 struct lttng_ust_object_data *ust;
  49         } obj;
  50 };
  51
  52 struct buffer_reg_session {
  53         /* Registry per domain. */
  54         union {
  55                 struct ust_registry_session *ust;
  56         } reg;
  57
  58         /* Contains buffer registry channel indexed by tracing channel key. */
  59         struct lttng_ht *channels;
  60 };
  61
  62 /*
  63  * Registry object for per UID buffers.
  64  */
  65 struct buffer_reg_uid {
  66         /*
  67          * Keys to match this object in a hash table. The following three variables
  68          * identify a unique per UID buffer registry.
  69          */
  70         uint64_t session_id;    /* Unique tracing session id. */
  71         int bits_per_long;      /* ABI */
  72         uid_t uid;                      /* Owner. */
  73
  74         enum lttng_domain_type domain;
  75         struct buffer_reg_session *registry;
  76
  77         /* Indexed by session id. */
  78         struct lttng_ht_node_u64 node;
  79         /* Node of a linked list used to teardown object at a destroy session. */
  80         struct cds_list_head lnode;
  81
  82         char root_shm_path[PATH_MAX];
  83         char shm_path[PATH_MAX];
  84 };
  85
  86 /*
  87  * Registry object for per PID buffers.
  88  */
  89 struct buffer_reg_pid {
  90         uint64_t session_id;
  91
  92         struct buffer_reg_session *registry;
  93
  94         /* Indexed by session id. */
  95         struct lttng_ht_node_u64 node;
  96
  97         char root_shm_path[PATH_MAX];
  98         char shm_path[PATH_MAX];
  99 };
 100
 101 /* Buffer registry per UID. */
 102 void buffer_reg_init_uid_registry(void);
 103 int buffer_reg_uid_create(uint64_t session_id, uint32_t bits_per_long, uid_t uid,
 104                 enum lttng_domain_type domain, struct buffer_reg_uid **regp,
 105                 const char *root_shm_path, const char *shm_path);
 106 void buffer_reg_uid_add(struct buffer_reg_uid *reg);
 107 struct buffer_reg_uid *buffer_reg_uid_find(uint64_t session_id,
 108                 uint32_t bits_per_long, uid_t uid);
 109 void buffer_reg_uid_remove(struct buffer_reg_uid *regp);
 110 void buffer_reg_uid_destroy(struct buffer_reg_uid *regp,
 111                 struct consumer_output *consumer);
 112
 113 /* Buffer registry per PID. */
 114 void buffer_reg_init_pid_registry(void);
 115 int buffer_reg_pid_create(uint64_t session_id, struct buffer_reg_pid **regp,
 116                 const char *root_shm_path, const char *shm_path);
 117 void buffer_reg_pid_add(struct buffer_reg_pid *reg);
 118 struct buffer_reg_pid *buffer_reg_pid_find(uint64_t session_id);
 119 void buffer_reg_pid_remove(struct buffer_reg_pid *regp);
 120 void buffer_reg_pid_destroy(struct buffer_reg_pid *regp);
 121
 122 /* Channel */
 123 int buffer_reg_channel_create(uint64_t key, struct buffer_reg_channel **regp);
 124 void buffer_reg_channel_add(struct buffer_reg_session *session,
 125                 struct buffer_reg_channel *channel);
 126 struct buffer_reg_channel *buffer_reg_channel_find(uint64_t key,
 127                 struct buffer_reg_uid *reg);
 128 void buffer_reg_channel_remove(struct buffer_reg_session *session,
 129                 struct buffer_reg_channel *regp);
 130 void buffer_reg_channel_destroy(struct buffer_reg_channel *regp,
 131                 enum lttng_domain_type domain);
 132
 133 /* Stream */
 134 int buffer_reg_stream_create(struct buffer_reg_stream **regp);
 135 void buffer_reg_stream_add(struct buffer_reg_stream *stream,
 136                 struct buffer_reg_channel *channel);
 137 void buffer_reg_stream_destroy(struct buffer_reg_stream *regp,
 138                 enum lttng_domain_type domain);
 139
 140 /* Global registry. */
 141 void buffer_reg_destroy_registries(void);
 142
 143 int buffer_reg_uid_consumer_channel_key(
 144                 struct cds_list_head *buffer_reg_uid_list,
 145                 uint64_t chan_key, uint64_t *consumer_chan_key);
 146
 147 #endif /* LTTNG_BUFFER_REGISTRY_H */