X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fust-registry.hpp;fp=src%2Fbin%2Flttng-sessiond%2Fust-registry.hpp;h=3bf439f238174e9770d7d2faf31cde2664be4995;hp=0000000000000000000000000000000000000000;hb=c9e313bc594f40a86eed237dce222c0fc99c957f;hpb=4878de5c7deb512bbdac4fdfc498907efa06fb7c diff --git a/src/bin/lttng-sessiond/ust-registry.hpp b/src/bin/lttng-sessiond/ust-registry.hpp new file mode 100644 index 000000000..3bf439f23 --- /dev/null +++ b/src/bin/lttng-sessiond/ust-registry.hpp @@ -0,0 +1,462 @@ +/* + * Copyright (C) 2013 David Goulet + * + * SPDX-License-Identifier: GPL-2.0-only + * + */ + +#ifndef LTTNG_UST_REGISTRY_H +#define LTTNG_UST_REGISTRY_H + +#include +#include + +#include +#include + +#include "lttng-ust-ctl.hpp" + +#define CTF_SPEC_MAJOR 1 +#define CTF_SPEC_MINOR 8 + +struct ust_app; + +struct ust_registry_session { + /* + * With multiple writers and readers, use this lock to access + * the registry. Can nest within the ust app session lock. + * Also acts as a registry serialization lock. Used by registry + * readers to serialize the registry information sent from the + * sessiond to the consumerd. + * The consumer socket lock nests within this lock. + */ + pthread_mutex_t lock; + /* Next channel ID available for a newly registered channel. */ + uint32_t next_channel_id; + /* Once this value reaches UINT32_MAX, no more id can be allocated. */ + uint32_t used_channel_id; + /* Next enumeration ID available. */ + uint64_t next_enum_id; + /* Universal unique identifier used by the tracer. */ + unsigned char uuid[LTTNG_UUID_LEN]; + + /* session ABI description */ + + /* Size of long, in bits */ + unsigned int bits_per_long; + /* Alignment, in bits */ + unsigned int uint8_t_alignment, + uint16_t_alignment, + uint32_t_alignment, + uint64_t_alignment, + long_alignment; + /* endianness */ + int byte_order; /* BIG_ENDIAN or LITTLE_ENDIAN */ + + /* Generated metadata. */ + char *metadata; /* NOT null-terminated ! Use memcpy. */ + size_t metadata_len, metadata_alloc_len; + /* Length of bytes sent to the consumer. */ + size_t metadata_len_sent; + /* Current version of the metadata. */ + uint64_t metadata_version; + + /* + * Those fields are only used when a session is created with + * the --shm-path option. In this case, the metadata is output + * twice: once to the consumer, as ususal, but a second time + * also in the shm path directly. This is done so that a copy + * of the metadata that is as fresh as possible is available + * on the event of a crash. + * + * root_shm_path contains the shm-path provided by the user, along with + * the session's name and timestamp: + * e.g. /tmp/my_shm/my_session-20180612-135822 + * + * shm_path contains the full path of the memory buffers: + * e.g. /tmp/my_shm/my_session-20180612-135822/ust/uid/1000/64-bit + * + * metadata_path contains the full path to the metadata file that + * is kept for the "crash buffer" extraction: + * e.g. /tmp/my_shm/my_session-20180612-135822/ust/uid/1000/64-bit/metadata + * + * Note that this is not the trace's final metadata file. It is + * only meant to be used to read the contents of the ring buffers + * in the event of a crash. + * + * metadata_fd is a file descriptor that points to the file at + * 'metadata_path'. + */ + char root_shm_path[PATH_MAX]; + char shm_path[PATH_MAX]; + char metadata_path[PATH_MAX]; + int metadata_fd; /* file-backed metadata FD */ + + /* + * Hash table containing channels sent by the UST tracer. MUST + * be accessed with a RCU read side lock acquired. + */ + struct lttng_ht *channels; + /* + * Unique key to identify the metadata on the consumer side. + */ + uint64_t metadata_key; + /* + * Indicates if the metadata is closed on the consumer side. This is to + * avoid double close of metadata when an application unregisters AND + * deletes its sessions. + */ + unsigned int metadata_closed; + + /* User and group owning the session. */ + uid_t uid; + gid_t gid; + + /* Enumerations table. */ + struct lttng_ht *enums; + + /* + * Copy of the tracer version when the first app is registered. + * It is used if we need to regenerate the metadata. + */ + uint32_t major; + uint32_t minor; + + /* The id of the parent session */ + uint64_t tracing_id; + uid_t tracing_uid; +}; + +struct ust_registry_channel { + uint64_t key; + uint64_t consumer_key; + /* Id set when replying to a register channel. */ + uint32_t chan_id; + enum lttng_ust_ctl_channel_header header_type; + + /* + * Flag for this channel if the metadata was dumped once during + * registration. 0 means no, 1 yes. + */ + unsigned int metadata_dumped; + /* Indicates if this channel registry has already been registered. */ + unsigned int register_done; + + /* + * Hash table containing events sent by the UST tracer. MUST be accessed + * with a RCU read side lock acquired. + */ + struct lttng_ht *ht; + /* Next event ID available for a newly registered event. */ + uint32_t next_event_id; + /* Once this value reaches UINT32_MAX, no more id can be allocated. */ + uint32_t used_event_id; + /* + * Context fields of the registry. Context are per channel. Allocated by a + * register channel notification from the UST tracer. + */ + size_t nr_ctx_fields; + struct lttng_ust_ctl_field *ctx_fields; + struct lttng_ht_node_u64 node; + /* For delayed reclaim */ + struct rcu_head rcu_head; +}; + +/* + * Event registered from a UST tracer sent to the session daemon. This is + * indexed and matched by . + */ +struct ust_registry_event { + int id; + /* Both objd are set by the tracer. */ + int session_objd; + int channel_objd; + /* Name of the event returned by the tracer. */ + char name[LTTNG_UST_ABI_SYM_NAME_LEN]; + char *signature; + int loglevel_value; + size_t nr_fields; + struct lttng_ust_ctl_field *fields; + char *model_emf_uri; + /* + * Flag for this channel if the metadata was dumped once during + * registration. 0 means no, 1 yes. + */ + unsigned int metadata_dumped; + /* + * Node in the ust-registry hash table. The event name is used to + * initialize the node and the event_name/signature for the match function. + */ + struct lttng_ht_node_u64 node; +}; + +struct ust_registry_enum { + char name[LTTNG_UST_ABI_SYM_NAME_LEN]; + struct lttng_ust_ctl_enum_entry *entries; + size_t nr_entries; + uint64_t id; /* enum id in session */ + /* Enumeration node in session hash table. */ + struct lttng_ht_node_str node; + /* For delayed reclaim. */ + struct rcu_head rcu_head; +}; + +/* + * Validate that the id has reached the maximum allowed or not. + * + * Return 0 if NOT else 1. + */ +static inline int ust_registry_is_max_id(uint32_t id) +{ + return (id == UINT32_MAX) ? 1 : 0; +} + +/* + * Return next available event id and increment the used counter. The + * ust_registry_is_max_id function MUST be called before in order to validate + * if the maximum number of IDs have been reached. If not, it is safe to call + * this function. + * + * Return a unique channel ID. If max is reached, the used_event_id counter is + * returned. + */ +static inline uint32_t ust_registry_get_next_event_id( + struct ust_registry_channel *r) +{ + if (ust_registry_is_max_id(r->used_event_id)) { + return r->used_event_id; + } + + r->used_event_id++; + return r->next_event_id++; +} + +/* + * Return next available channel id and increment the used counter. The + * ust_registry_is_max_id function MUST be called before in order to validate + * if the maximum number of IDs have been reached. If not, it is safe to call + * this function. + * + * Return a unique channel ID. If max is reached, the used_channel_id counter + * is returned. + */ +static inline uint32_t ust_registry_get_next_chan_id( + struct ust_registry_session *r) +{ + if (ust_registry_is_max_id(r->used_channel_id)) { + return r->used_channel_id; + } + + r->used_channel_id++; + return r->next_channel_id++; +} + +/* + * Return registry event count. This is read atomically. + */ +static inline uint32_t ust_registry_get_event_count( + struct ust_registry_channel *r) +{ + return (uint32_t) uatomic_read(&r->used_event_id); +} + +#ifdef HAVE_LIBLTTNG_UST_CTL + +void ust_registry_channel_destroy(struct ust_registry_session *session, + struct ust_registry_channel *chan); +struct ust_registry_channel *ust_registry_channel_find( + struct ust_registry_session *session, uint64_t key); +int ust_registry_channel_add(struct ust_registry_session *session, + uint64_t key); +void ust_registry_channel_del_free(struct ust_registry_session *session, + uint64_t key, bool notif); + +int ust_registry_session_init(struct ust_registry_session **sessionp, + struct ust_app *app, + uint32_t bits_per_long, + uint32_t uint8_t_alignment, + uint32_t uint16_t_alignment, + uint32_t uint32_t_alignment, + uint32_t uint64_t_alignment, + uint32_t long_alignment, + int byte_order, + 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, + uid_t tracing_uid); +void ust_registry_session_destroy(struct ust_registry_session *session); + +int ust_registry_create_event(struct ust_registry_session *session, + uint64_t chan_key, int session_objd, int channel_objd, char *name, + char *sig, size_t nr_fields, struct lttng_ust_ctl_field *fields, + int loglevel_value, char *model_emf_uri, int buffer_type, + uint32_t *event_id_p, struct ust_app *app); +struct ust_registry_event *ust_registry_find_event( + struct ust_registry_channel *chan, char *name, char *sig); +void ust_registry_destroy_event(struct ust_registry_channel *chan, + struct ust_registry_event *event); + +/* app can be NULL for registry shared across applications. */ +int ust_metadata_session_statedump(struct ust_registry_session *session, + struct ust_app *app, uint32_t major, uint32_t minor); +int ust_metadata_channel_statedump(struct ust_registry_session *session, + struct ust_registry_channel *chan); +int ust_metadata_event_statedump(struct ust_registry_session *session, + struct ust_registry_channel *chan, + struct ust_registry_event *event); +int ust_registry_create_or_find_enum(struct ust_registry_session *session, + int session_objd, char *name, + struct lttng_ust_ctl_enum_entry *entries, size_t nr_entries, + uint64_t *enum_id); +struct ust_registry_enum * + ust_registry_lookup_enum_by_id(struct ust_registry_session *session, + const char *name, uint64_t id); + +#else /* HAVE_LIBLTTNG_UST_CTL */ + +static inline +void ust_registry_channel_destroy( + struct ust_registry_session *session __attribute__((unused)), + struct ust_registry_channel *chan __attribute__((unused))) +{} + +static inline +struct ust_registry_channel *ust_registry_channel_find( + struct ust_registry_session *session __attribute__((unused)), + uint64_t key __attribute__((unused))) +{ + return NULL; +} + +static inline +int ust_registry_channel_add( + struct ust_registry_session *session __attribute__((unused)), + uint64_t key __attribute__((unused))) +{ + return 0; +} + +static inline +void ust_registry_channel_del_free( + struct ust_registry_session *session __attribute__((unused)), + uint64_t key __attribute__((unused)), + bool notif __attribute__((unused))) +{} + +static inline +int ust_registry_session_init( + struct ust_registry_session **sessionp __attribute__((unused)), + struct ust_app *app __attribute__((unused)), + uint32_t bits_per_long __attribute__((unused)), + uint32_t uint8_t_alignment __attribute__((unused)), + uint32_t uint16_t_alignment __attribute__((unused)), + uint32_t uint32_t_alignment __attribute__((unused)), + uint32_t uint64_t_alignment __attribute__((unused)), + uint32_t long_alignment __attribute__((unused)), + int byte_order __attribute__((unused)), + uint32_t major __attribute__((unused)), + uint32_t minor __attribute__((unused)), + const char *root_shm_path __attribute__((unused)), + const char *shm_path __attribute__((unused)), + uid_t euid __attribute__((unused)), + gid_t egid __attribute__((unused)), + uint64_t tracing_id __attribute__((unused)), + uid_t tracing_uid __attribute__((unused))) +{ + return 0; +} + +static inline +void ust_registry_session_destroy( + struct ust_registry_session *session __attribute__((unused))) +{} + +static inline +int ust_registry_create_event( + struct ust_registry_session *session __attribute__((unused)), + uint64_t chan_key __attribute__((unused)), + int session_objd __attribute__((unused)), + int channel_objd __attribute__((unused)), + char *name __attribute__((unused)), + char *sig __attribute__((unused)), + size_t nr_fields __attribute__((unused)), + struct lttng_ust_ctl_field *fields __attribute__((unused)), + int loglevel_value __attribute__((unused)), + char *model_emf_uri __attribute__((unused)), + int buffer_type __attribute__((unused)), + uint32_t *event_id_p __attribute__((unused))) +{ + return 0; +} +static inline +struct ust_registry_event *ust_registry_find_event( + struct ust_registry_channel *chan __attribute__((unused)), + char *name __attribute__((unused)), + char *sig __attribute__((unused))) +{ + return NULL; +} + +static inline +void ust_registry_destroy_event( + struct ust_registry_channel *chan __attribute__((unused)), + struct ust_registry_event *event __attribute__((unused))) +{} + +/* The app object can be NULL for registry shared across applications. */ +static inline +int ust_metadata_session_statedump( + struct ust_registry_session *session __attribute__((unused)), + struct ust_app *app __attribute__((unused)), + uint32_t major __attribute__((unused)), + uint32_t minor __attribute__((unused))) +{ + return 0; +} + +static inline +int ust_metadata_channel_statedump( + struct ust_registry_session *session __attribute__((unused)), + struct ust_registry_channel *chan __attribute__((unused))) +{ + return 0; +} + +static inline +int ust_metadata_event_statedump( + struct ust_registry_session *session __attribute__((unused)), + struct ust_registry_channel *chan __attribute__((unused)), + struct ust_registry_event *event __attribute__((unused))) +{ + return 0; +} + +static inline +int ust_registry_create_or_find_enum( + struct ust_registry_session *session __attribute__((unused)), + int session_objd __attribute__((unused)), + char *name __attribute__((unused)), + struct lttng_ust_ctl_enum_entry *entries __attribute__((unused)), + size_t nr_entries __attribute__((unused)), + uint64_t *enum_id __attribute__((unused))) +{ + return 0; +} + +static inline +struct ust_registry_enum * + ust_registry_lookup_enum_by_id( + struct ust_registry_session *session __attribute__((unused)), + const char *name __attribute__((unused)), + uint64_t id __attribute__((unused))) +{ + return NULL; +} + +#endif /* HAVE_LIBLTTNG_UST_CTL */ + +#endif /* LTTNG_UST_REGISTRY_H */