X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fust-registry-session.cpp;h=d0891fe9a87325a3d245e52cbe001c5a2c401c41;hb=HEAD;hp=bb678fe4da4c75763759c9b2e6e1fc5aeb213b54;hpb=b0f2e8db59fcadc8f4b06a94175792be3c431004;p=lttng-tools.git diff --git a/src/bin/lttng-sessiond/ust-registry-session.cpp b/src/bin/lttng-sessiond/ust-registry-session.cpp index bb678fe4d..d0891fe9a 100644 --- a/src/bin/lttng-sessiond/ust-registry-session.cpp +++ b/src/bin/lttng-sessiond/ust-registry-session.cpp @@ -5,6 +5,7 @@ * */ +#include "ctf2-trace-class-visitor.hpp" #include "field.hpp" #include "lttng-sessiond.hpp" #include "notification-thread-commands.hpp" @@ -19,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -28,6 +30,7 @@ #include #include +#include #include #include #include @@ -65,7 +68,9 @@ void clear_metadata_file(int fd) { const auto lseek_ret = lseek(fd, 0, SEEK_SET); if (lseek_ret < 0) { - LTTNG_THROW_POSIX("Failed to seek to the beginning of the metadata file while clearing it", errno); + LTTNG_THROW_POSIX( + "Failed to seek to the beginning of the metadata file while clearing it", + errno); } const auto ret = ftruncate(fd, 0); @@ -87,7 +92,7 @@ void destroy_channel_rcu(struct rcu_head *head) DIAGNOSTIC_PUSH DIAGNOSTIC_IGNORE_INVALID_OFFSETOF lsu::registry_channel *chan = - caa_container_of(head, lsu::registry_channel, _rcu_head); + lttng::utils::container_of(head, &lsu::registry_channel::_rcu_head); DIAGNOSTIC_POP delete chan; @@ -97,8 +102,10 @@ void destroy_channel_rcu(struct rcu_head *head) * Destroy every element of the registry and free the memory. This does NOT * free the registry pointer since it might not have been allocated before so * it's the caller responsability. + * + * Called from ~registry_session(), must not throw. */ -void destroy_channel(lsu::registry_channel *chan, bool notify) +void destroy_channel(lsu::registry_channel *chan, bool notify) noexcept { struct lttng_ht_iter iter; lttng::sessiond::ust::registry_event *event; @@ -108,8 +115,7 @@ void destroy_channel(lsu::registry_channel *chan, bool notify) if (notify) { cmd_ret = notification_thread_command_remove_channel( - the_notification_thread_handle, - chan->_consumer_key, LTTNG_DOMAIN_UST); + the_notification_thread_handle, chan->_consumer_key, LTTNG_DOMAIN_UST); if (cmd_ret != LTTNG_OK) { ERR("Failed to remove channel from notification thread"); } @@ -121,8 +127,7 @@ void destroy_channel(lsu::registry_channel *chan, bool notify) /* Destroy all event associated with this registry. */ DIAGNOSTIC_PUSH DIAGNOSTIC_IGNORE_INVALID_OFFSETOF - cds_lfht_for_each_entry( - chan->_events->ht, &iter.iter, event, _node.node) { + cds_lfht_for_each_entry (chan->_events->ht, &iter.iter, event, _node) { /* Delete the node from the ht and free it. */ ust_registry_channel_destroy_event(chan, event); } @@ -131,6 +136,92 @@ void destroy_channel(lsu::registry_channel *chan, bool notify) call_rcu(&chan->_rcu_head, destroy_channel_rcu); } + +void destroy_enum(lsu::registry_enum *reg_enum) +{ + if (!reg_enum) { + return; + } + + delete reg_enum; +} + +void destroy_enum_rcu(struct rcu_head *head) +{ + DIAGNOSTIC_PUSH + DIAGNOSTIC_IGNORE_INVALID_OFFSETOF + lsu::registry_enum *reg_enum = + lttng::utils::container_of(head, &lsu::registry_enum::rcu_head); + DIAGNOSTIC_POP + + destroy_enum(reg_enum); +} + +/* + * Hash table match function for enumerations in the session. Match is + * performed on enumeration name, and confirmed by comparing the enum + * entries. + */ +int ht_match_enum(struct cds_lfht_node *node, const void *_key) +{ + lsu::registry_enum *_enum; + const lsu::registry_enum *key; + + LTTNG_ASSERT(node); + LTTNG_ASSERT(_key); + + DIAGNOSTIC_PUSH + DIAGNOSTIC_IGNORE_INVALID_OFFSETOF + _enum = caa_container_of(node, lsu::registry_enum, node.node); + DIAGNOSTIC_POP + + LTTNG_ASSERT(_enum); + key = (lsu::registry_enum *) _key; + + return *_enum == *key; +} + +/* + * Hash table match function for enumerations in the session. Match is + * performed by enumeration ID. + */ +int ht_match_enum_id(struct cds_lfht_node *node, const void *_key) +{ + lsu::registry_enum *_enum; + const lsu::registry_enum *key = (lsu::registry_enum *) _key; + + LTTNG_ASSERT(node); + LTTNG_ASSERT(_key); + + DIAGNOSTIC_PUSH + DIAGNOSTIC_IGNORE_INVALID_OFFSETOF + _enum = caa_container_of(node, lsu::registry_enum, node.node); + DIAGNOSTIC_POP + + LTTNG_ASSERT(_enum); + + if (_enum->id != key->id) { + goto no_match; + } + + /* Match. */ + return 1; + +no_match: + return 0; +} + +/* + * Hash table hash function for enumerations in the session. The + * enumeration name is used for hashing. + */ +unsigned long ht_hash_enum(void *_key, unsigned long seed) +{ + lsu::registry_enum *key = (lsu::registry_enum *) _key; + + LTTNG_ASSERT(key); + return hash_key_str(key->name.c_str(), seed); +} } /* namespace */ void lsu::details::locked_registry_session_release(lsu::registry_session *session) @@ -139,52 +230,48 @@ void lsu::details::locked_registry_session_release(lsu::registry_session *sessio } lsu::registry_session::registry_session(const struct lst::abi& in_abi, - uint32_t major, - uint32_t minor, - const char *root_shm_path, - const char *shm_path, - uid_t euid, - gid_t egid, - uint64_t tracing_id) : + uint32_t major, + uint32_t minor, + const char *root_shm_path, + const char *shm_path, + uid_t euid, + gid_t egid, + uint64_t tracing_id) : lst::trace_class(in_abi, generate_uuid_or_throw()), - _uid{euid}, - _gid{egid}, - _app_tracer_version_major{major}, - _app_tracer_version_minor{minor}, - _tracing_id{tracing_id}, - _metadata_generating_visitor{lttng::make_unique( - abi, [this](const std::string& fragment) { - _append_metadata_fragment(fragment); - })} -{ - pthread_mutex_init(&_lock, NULL); - strncpy(_root_shm_path, root_shm_path, sizeof(_root_shm_path)); - _root_shm_path[sizeof(_root_shm_path) - 1] = '\0'; - if (shm_path[0]) { - strncpy(_shm_path, shm_path, sizeof(_shm_path)); - _shm_path[sizeof(_shm_path) - 1] = '\0'; - strncpy(_metadata_path, shm_path, sizeof(_metadata_path)); - _metadata_path[sizeof(_metadata_path) - 1] = '\0'; - strncat(_metadata_path, "/metadata", - sizeof(_metadata_path) - strlen(_metadata_path) - 1); - } - - if (_shm_path[0]) { - if (run_as_mkdir_recursive(_shm_path, S_IRWXU | S_IRWXG, euid, egid)) { + _root_shm_path{ root_shm_path ? root_shm_path : "" }, + _shm_path{ shm_path ? shm_path : "" }, + _metadata_path{ _shm_path.size() > 0 ? lttng::format("{}/metadata", _shm_path) : + std::string("") }, + _uid{ euid }, + _gid{ egid }, + _app_tracer_version{ .major = major, .minor = minor }, + _tracing_id{ tracing_id }, + _clock{ lttng::make_unique() }, + _metadata_generating_visitor{ lttng::make_unique( + abi, + [this](const std::string& fragment) { _append_metadata_fragment(fragment); }) }, + _packet_header{ _create_packet_header() } +{ + pthread_mutex_init(&_lock, nullptr); + if (_shm_path.size() > 0) { + if (run_as_mkdir_recursive(_shm_path.c_str(), S_IRWXU | S_IRWXG, euid, egid)) { LTTNG_THROW_POSIX("run_as_mkdir_recursive", errno); } } - if (_metadata_path[0]) { + if (_metadata_path.size() > 0) { /* Create metadata file. */ - const int ret = run_as_open(_metadata_path, O_WRONLY | O_CREAT | O_EXCL, - S_IRUSR | S_IWUSR, euid, egid); - + const int ret = run_as_open(_metadata_path.c_str(), + O_WRONLY | O_CREAT | O_EXCL, + S_IRUSR | S_IWUSR, + euid, + egid); if (ret < 0) { - std::stringstream ss; - - ss << "Opening metadata file '" << _metadata_path << "'"; - LTTNG_THROW_POSIX(ss.str(), errno); + LTTNG_THROW_POSIX( + lttng::format( + "Failed to open metadata file during registry session creation: path = {}", + _metadata_path), + errno); } _metadata_fd = ret; @@ -196,8 +283,8 @@ lsu::registry_session::registry_session(const struct lst::abi& in_abi, } /* hash/match functions are specified at call site. */ - _enums->match_fct = NULL; - _enums->hash_fct = NULL; + _enums->match_fct = nullptr; + _enums->hash_fct = nullptr; _channels.reset(lttng_ht_new(0, LTTNG_HT_TYPE_U64)); if (!_channels) { @@ -205,6 +292,85 @@ lsu::registry_session::registry_session(const struct lst::abi& in_abi, } } +lst::type::cuptr lsu::registry_session::_create_packet_header() const +{ + lst::structure_type::fields packet_header_fields; + + /* uint32_t magic */ + packet_header_fields.emplace_back(lttng::make_unique( + "magic", + lttng::make_unique( + abi.uint32_t_alignment, + abi.byte_order, + 32, + lst::integer_type::signedness::UNSIGNED, + lst::integer_type::base::HEXADECIMAL, + std::initializer_list( + { lst::integer_type::role::PACKET_MAGIC_NUMBER })))); + + /* uuid */ + packet_header_fields.emplace_back(lttng::make_unique( + "uuid", + lttng::make_unique( + 0, + 16, + std::initializer_list( + { lst::static_length_blob_type::role::METADATA_STREAM_UUID })))); + + /* uint32_t stream_id */ + packet_header_fields.emplace_back(lttng::make_unique( + "stream_id", + lttng::make_unique( + abi.uint32_t_alignment, + abi.byte_order, + 32, + lst::integer_type::signedness::UNSIGNED, + lst::integer_type::base::DECIMAL, + std::initializer_list( + { lst::integer_type::role::DATA_STREAM_CLASS_ID })))); + + /* uint64_t stream_instance_id */ + packet_header_fields.emplace_back(lttng::make_unique( + "stream_instance_id", + lttng::make_unique( + abi.uint64_t_alignment, + abi.byte_order, + 64, + lst::integer_type::signedness::UNSIGNED, + lst::integer_type::base::DECIMAL, + std::initializer_list( + { lst::integer_type::role::DATA_STREAM_ID })))); + + return lttng::make_unique(0, std::move(packet_header_fields)); +} + +const lst::type *lsu::registry_session::packet_header() const noexcept +{ + return _packet_header.get(); +} + +/* + * For a given enumeration in a registry, delete the entry and destroy + * the enumeration. + * + * Note that this is used by ~registry_session() and must not throw. + */ +void lsu::registry_session::_destroy_enum(lsu::registry_enum *reg_enum) noexcept +{ + int ret; + lttng::urcu::read_lock_guard read_lock_guard; + + LTTNG_ASSERT(reg_enum); + ASSERT_RCU_READ_LOCKED(); + + /* Delete the node first. */ + struct lttng_ht_iter iter; + iter.iter.node = ®_enum->node.node; + ret = lttng_ht_del(_enums.get(), &iter); + LTTNG_ASSERT(!ret); + call_rcu(®_enum->rcu_head, destroy_enum_rcu); +} + lsu::registry_session::~registry_session() { int ret; @@ -222,7 +388,7 @@ lsu::registry_session::~registry_session() /* Destroy all event associated with this registry. */ DIAGNOSTIC_PUSH DIAGNOSTIC_IGNORE_INVALID_OFFSETOF - cds_lfht_for_each_entry(_channels->ht, &iter.iter, chan, _node.node) { + cds_lfht_for_each_entry (_channels->ht, &iter.iter, chan, _node.node) { /* Delete the node from the ht and free it. */ ret = lttng_ht_del(_channels.get(), &iter); LTTNG_ASSERT(!ret); @@ -238,7 +404,7 @@ lsu::registry_session::~registry_session() PERROR("close"); } - ret = run_as_unlink(_metadata_path, _uid, _gid); + ret = run_as_unlink(_metadata_path.c_str(), _uid, _gid); if (ret) { PERROR("unlink"); } @@ -246,26 +412,27 @@ lsu::registry_session::~registry_session() if (_root_shm_path[0]) { /* Try to delete the directory hierarchy. */ - (void) run_as_rmdir_recursive(_root_shm_path, _uid, _gid, - LTTNG_DIRECTORY_HANDLE_SKIP_NON_EMPTY_FLAG); + (void) run_as_rmdir_recursive(_root_shm_path.c_str(), + _uid, + _gid, + LTTNG_DIRECTORY_HANDLE_SKIP_NON_EMPTY_FLAG); } /* Destroy the enum hash table */ if (_enums) { - rcu_read_lock(); + lttng::urcu::read_lock_guard read_lock_guard; + /* Destroy all enum entries associated with this registry. */ DIAGNOSTIC_PUSH DIAGNOSTIC_IGNORE_INVALID_OFFSETOF cds_lfht_for_each_entry (_enums->ht, &iter.iter, reg_enum, node.node) { - ust_registry_destroy_enum(this, reg_enum); + _destroy_enum(reg_enum); } DIAGNOSTIC_POP - - rcu_read_unlock(); } } -lsu::registry_session::locked_ptr lsu::registry_session::lock() +lsu::registry_session::locked_ptr lsu::registry_session::lock() noexcept { pthread_mutex_lock(&_lock); return locked_ptr(this); @@ -284,39 +451,41 @@ void lsu::registry_session::add_channel(uint64_t key) * the metadata can be dumped for that event. */ if (is_max_channel_id(_used_channel_id)) { - LTTNG_THROW_ERROR(fmt::format("Failed to allocate unique id for channel under session while adding channel")); + LTTNG_THROW_ERROR(lttng::format( + "Failed to allocate unique id for channel under session while adding channel")); } auto chan = new lsu::registry_channel( - _get_next_channel_id(), - /* Registered channel listener. */ - [this](const lsu::registry_channel& registered_channel) { - /* - * Channel registration completed, serialize it's layout's - * description. - */ - registered_channel.accept(*_metadata_generating_visitor); - }, - /* Added event listener. */ - [this](const lsu::registry_channel& channel, - const lsu::registry_event& added_event) { - /* - * The channel and its event classes will be dumped at once when - * it is registered. This check prevents event classes from being - * declared before their stream class. - */ - if (channel.is_registered()) { - added_event.accept(*_metadata_generating_visitor); - } - }); + _get_next_channel_id(), + abi, + _clock->name, + /* Registered channel listener. */ + [this](const lsu::registry_channel& registered_channel) { + /* + * Channel registration completed, serialize it's layout's + * description. + */ + registered_channel.accept(*_metadata_generating_visitor); + }, + /* Added event listener. */ + [this](const lsu::registry_channel& channel, + const lsu::registry_event& added_event) { + /* + * The channel and its event classes will be dumped at once when + * it is registered. This check prevents event classes from being + * declared before their stream class. + */ + if (channel.is_registered()) { + added_event.accept(*_metadata_generating_visitor); + } + }); lttng::urcu::read_lock_guard rcu_read_lock_guard; lttng_ht_node_init_u64(&chan->_node, key); lttng_ht_add_unique_u64(_channels.get(), &chan->_node); } -lttng::sessiond::ust::registry_channel& lsu::registry_session::get_channel( - uint64_t channel_key) const +lttng::sessiond::ust::registry_channel& lsu::registry_session::channel(uint64_t channel_key) const { lttng::urcu::read_lock_guard read_lock_guard; struct lttng_ht_node_u64 *node; @@ -327,13 +496,13 @@ lttng::sessiond::ust::registry_channel& lsu::registry_session::get_channel( lttng_ht_lookup(_channels.get(), &channel_key, &iter); node = lttng_ht_iter_get_node_u64(&iter); if (!node) { - LTTNG_THROW_INVALID_ARGUMENT_ERROR(fmt::format( - "Invalid channel key provided: channel key = {}", channel_key)); + LTTNG_THROW_INVALID_ARGUMENT_ERROR(lttng::format( + "Invalid channel key provided: channel key = {}", channel_key)); } DIAGNOSTIC_PUSH DIAGNOSTIC_IGNORE_INVALID_OFFSETOF - auto chan = caa_container_of(node, lsu::registry_channel, _node); + auto chan = lttng::utils::container_of(node, &lsu::registry_channel::_node); DIAGNOSTIC_POP return *chan; } @@ -345,25 +514,26 @@ void lsu::registry_session::remove_channel(uint64_t channel_key, bool notify) lttng::urcu::read_lock_guard read_lock_guard; ASSERT_LOCKED(_lock); - auto& channel = get_channel(channel_key); + auto& channel_to_remove = channel(channel_key); - iter.iter.node = &channel._node.node; + iter.iter.node = &channel_to_remove._node.node; ret = lttng_ht_del(_channels.get(), &iter); LTTNG_ASSERT(!ret); - destroy_channel(&channel, notify); + destroy_channel(&channel_to_remove, notify); } -void lsu::registry_session::_visit_environment( - lttng::sessiond::trace::trace_class_visitor& visitor) const +void lsu::registry_session::accept( + lttng::sessiond::trace::trace_class_environment_visitor& visitor) const { ASSERT_LOCKED(_lock); visitor.visit(lst::environment_field("domain", "ust")); visitor.visit(lst::environment_field("tracer_name", "lttng-ust")); - visitor.visit(lst::environment_field("tracer_major", _app_tracer_version_major)); - visitor.visit(lst::environment_field("tracer_minor", _app_tracer_version_minor)); - visitor.visit(lst::environment_field("tracer_buffering_scheme", - get_buffering_scheme() == LTTNG_BUFFER_PER_PID ? "pid" : "uid")); + visitor.visit(lst::environment_field("tracer_major", _app_tracer_version.major)); + visitor.visit(lst::environment_field("tracer_minor", _app_tracer_version.minor)); + visitor.visit(lst::environment_field( + "tracer_buffering_scheme", + buffering_scheme() == LTTNG_BUFFER_PER_PID ? "pid" : "uid")); visitor.visit(lst::environment_field("architecture_bit_width", abi.bits_per_long)); { @@ -374,11 +544,12 @@ void lsu::registry_session::_visit_environment( LTTNG_ASSERT(session); ASSERT_LOCKED(session->lock); - visitor.visit(lst::environment_field("trace_name", - session->has_auto_generated_name ? DEFAULT_SESSION_NAME : - session->name)); - visitor.visit(lst::environment_field("trace_creation_datetime", - lttng::utils::time_to_iso8601_str(session->creation_time))); + visitor.visit(lst::environment_field( + "trace_name", + session->has_auto_generated_name ? DEFAULT_SESSION_NAME : session->name)); + visitor.visit(lst::environment_field( + "trace_creation_datetime", + lttng::utils::time_to_iso8601_str(session->creation_time))); visitor.visit(lst::environment_field("hostname", session->hostname)); } } @@ -386,7 +557,7 @@ void lsu::registry_session::_visit_environment( void lsu::registry_session::_accept_on_clock_classes(lst::trace_class_visitor& visitor) const { ASSERT_LOCKED(_lock); - _clock.accept(visitor); + _clock->accept(visitor); } void lsu::registry_session::_accept_on_stream_classes(lst::trace_class_visitor& visitor) const @@ -402,17 +573,16 @@ void lsu::registry_session::_accept_on_stream_classes(lst::trace_class_visitor& DIAGNOSTIC_PUSH DIAGNOSTIC_IGNORE_INVALID_OFFSETOF - cds_lfht_for_each_entry(_channels->ht, &channel_it.iter, channel, _node.node) { + cds_lfht_for_each_entry (_channels->ht, &channel_it.iter, channel, _node.node) { sorted_stream_classes.emplace_back(channel); } DIAGNOSTIC_POP } - std::sort(sorted_stream_classes.begin(), sorted_stream_classes.end(), - [](const lttng::sessiond::ust::registry_channel *a, - const lttng::sessiond::ust::registry_channel *b) { - return a->id < b->id; - }); + std::sort(sorted_stream_classes.begin(), + sorted_stream_classes.end(), + [](const lttng::sessiond::ust::registry_channel *a, + const lttng::sessiond::ust::registry_channel *b) { return a->id < b->id; }); for (const auto stream_class : sorted_stream_classes) { stream_class->accept(visitor); @@ -446,17 +616,19 @@ void lsu::registry_session::_increase_metadata_size(size_t reservation_length) /* Rounding the new allocation length to the next power of 2 would overflow. */ if (new_alloc_len > (UINT32_MAX >> 1)) { - LTTNG_THROW_ERROR("Failed to reserve trace metadata storage as the new size would overflow"); + LTTNG_THROW_ERROR( + "Failed to reserve trace metadata storage as the new size would overflow"); } /* The current allocation length is already the largest we can afford. */ if ((old_alloc_len << 1) > (UINT32_MAX >> 1)) { - LTTNG_THROW_ERROR("Failed to reserve trace metadata storage as the max size was already reached"); + LTTNG_THROW_ERROR( + "Failed to reserve trace metadata storage as the max size was already reached"); } if (new_alloc_len > old_alloc_len) { - new_alloc_len = std::max( - 1U << get_count_order(new_alloc_len), old_alloc_len << 1); + new_alloc_len = + std::max(1U << get_count_order(new_alloc_len), old_alloc_len << 1); auto newptr = (char *) realloc(_metadata, new_alloc_len); if (!newptr) { @@ -482,11 +654,10 @@ void lsu::registry_session::_append_metadata_fragment(const std::string& fragmen if (_metadata_fd >= 0) { const auto bytes_written = - lttng_write(_metadata_fd, fragment.c_str(), fragment.size()); + lttng_write(_metadata_fd, fragment.c_str(), fragment.size()); if (bytes_written != fragment.size()) { - LTTNG_THROW_POSIX("Failed to write trace metadata fragment to file", - errno); + LTTNG_THROW_POSIX("Failed to write trace metadata fragment to file", errno); } } } @@ -505,14 +676,171 @@ void lsu::registry_session::_reset_metadata() void lsu::registry_session::_generate_metadata() { - accept(*_metadata_generating_visitor); + trace_class::accept(*_metadata_generating_visitor); } void lsu::registry_session::regenerate_metadata() { lttng::pthread::lock_guard registry_lock(_lock); + /* Resample the clock */ + _clock = lttng::make_unique(); + _metadata_version++; _reset_metadata(); _generate_metadata(); } + +/* + * Lookup enumeration by enum ID. + * + * Note that there is no need to lock the registry session as this only + * performs an RCU-protected look-up. The function also return an rcu-protected + * reference, which ensures that the caller keeps the RCU read lock until it + * disposes of the object. + */ +lsu::registry_enum::const_rcu_protected_reference +lsu::registry_session::enumeration(const char *enum_name, uint64_t enum_id) const +{ + lsu::registry_enum *reg_enum = nullptr; + struct lttng_ht_node_str *node; + struct lttng_ht_iter iter; + lttng::urcu::unique_read_lock rcu_lock; + /* + * Hack: only the name is used for hashing; the rest of the attributes + * can be fudged. + */ + lsu::registry_signed_enum reg_enum_lookup(enum_name, nullptr, 0); + + ASSERT_RCU_READ_LOCKED(); + + reg_enum_lookup.id = enum_id; + cds_lfht_lookup(_enums->ht, + ht_hash_enum((void *) ®_enum_lookup, lttng_ht_seed), + ht_match_enum_id, + ®_enum_lookup, + &iter.iter); + node = lttng_ht_iter_get_node_str(&iter); + if (!node) { + LTTNG_THROW_PROTOCOL_ERROR(lttng::format( + "Unknown enumeration referenced by application event field: enum name = `{}`, enum id = {}", + enum_name, + enum_id)); + } + + DIAGNOSTIC_PUSH + DIAGNOSTIC_IGNORE_INVALID_OFFSETOF + reg_enum = lttng::utils::container_of(node, &lsu::registry_enum::node); + DIAGNOSTIC_POP + + return lsu::registry_enum::const_rcu_protected_reference{ *reg_enum, std::move(rcu_lock) }; +} + +/* + * Lookup enumeration by name and comparing enumeration entries. + * Needs to be called from RCU read-side critical section. + */ +lsu::registry_enum * +lsu::registry_session::_lookup_enum(const lsu::registry_enum *reg_enum_lookup) const +{ + lsu::registry_enum *reg_enum = nullptr; + struct lttng_ht_node_str *node; + struct lttng_ht_iter iter; + + ASSERT_RCU_READ_LOCKED(); + + cds_lfht_lookup(_enums->ht, + ht_hash_enum((void *) reg_enum_lookup, lttng_ht_seed), + ht_match_enum, + reg_enum_lookup, + &iter.iter); + node = lttng_ht_iter_get_node_str(&iter); + if (!node) { + goto end; + } + + DIAGNOSTIC_PUSH + DIAGNOSTIC_IGNORE_INVALID_OFFSETOF + reg_enum = lttng::utils::container_of(node, &lsu::registry_enum::node); + DIAGNOSTIC_POP + +end: + return reg_enum; +} + +/* + * Create a lsu::registry_enum from the given parameters and add it to the + * registry hash table, or find it if already there. + * + * Should be called with session registry mutex held. + * + * We receive ownership of entries. + */ +void lsu::registry_session::create_or_find_enum(int session_objd, + const char *enum_name, + struct lttng_ust_ctl_enum_entry *raw_entries, + size_t nr_entries, + uint64_t *enum_id) +{ + struct cds_lfht_node *nodep; + lsu::registry_enum *reg_enum = nullptr, *old_reg_enum; + lttng::urcu::read_lock_guard read_lock_guard; + auto entries = lttng::make_unique_wrapper( + raw_entries); + + LTTNG_ASSERT(enum_name); + + /* + * This should not happen but since it comes from the UST tracer, an + * external party, don't assert and simply validate values. + */ + if (session_objd < 0) { + LTTNG_THROW_INVALID_ARGUMENT_ERROR(lttng::format( + "Invalid parameters used to create or look-up enumeration from registry session: session_objd = {}", + session_objd)); + } + if (nr_entries == 0) { + LTTNG_THROW_INVALID_ARGUMENT_ERROR(lttng::format( + "Invalid parameters used to create or look-up enumeration from registry session: nr_entries = {}", + nr_entries)); + } + if (lttng_strnlen(enum_name, LTTNG_UST_ABI_SYM_NAME_LEN) == LTTNG_UST_ABI_SYM_NAME_LEN) { + LTTNG_THROW_INVALID_ARGUMENT_ERROR( + "Invalid parameters used to create or look-up enumeration from registry session: enumeration name is not null terminated"); + } + + if (entries->start.signedness) { + reg_enum = new lsu::registry_signed_enum(enum_name, entries.get(), nr_entries); + } else { + reg_enum = new lsu::registry_unsigned_enum(enum_name, entries.get(), nr_entries); + } + + old_reg_enum = _lookup_enum(reg_enum); + if (old_reg_enum) { + DBG("enum %s already in sess_objd: %u", enum_name, session_objd); + /* Fall through. Use prior enum. */ + destroy_enum(reg_enum); + reg_enum = old_reg_enum; + } else { + DBG("UST registry creating enum: %s, sess_objd: %u", enum_name, session_objd); + if (_next_enum_id == -1ULL) { + destroy_enum(reg_enum); + LTTNG_THROW_ERROR( + "Failed to allocate unique enumeration ID as it would overflow"); + } + + reg_enum->id = _next_enum_id++; + nodep = cds_lfht_add_unique(_enums->ht, + ht_hash_enum(reg_enum, lttng_ht_seed), + ht_match_enum_id, + reg_enum, + ®_enum->node.node); + LTTNG_ASSERT(nodep == ®_enum->node.node); + } + + DBG("UST registry reply with enum %s with id %" PRIu64 " in sess_objd: %u", + enum_name, + reg_enum->id, + session_objd); + *enum_id = reg_enum->id; +}