X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=include%2Flttng%2Flttng.h;h=825b6682bbee9f39cbaaf2c0093cc1ba3984cdca;hp=9e2d4d129894878631d38452f05bc5ffc25c946a;hb=HEAD;hpb=178191b3899f114001f000c2e7f46909969f9c6f diff --git a/include/lttng/lttng.h b/include/lttng/lttng.h index 9e2d4d129..6ae331bda 100644 --- a/include/lttng/lttng.h +++ b/include/lttng/lttng.h @@ -3,606 +3,496 @@ * * Linux Trace Toolkit Control Library Header File * - * Copyright (C) 2011 - David Goulet + * Copyright (C) 2011 EfficiOS Inc. * - * This library is free software; you can redistribute it and/or modify it - * under the terms of the GNU Lesser General Public License, version 2.1 only, - * as published by the Free Software Foundation. + * SPDX-License-Identifier: LGPL-2.1-only * - * This library is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License - * for more details. - * - * You should have received a copy of the GNU Lesser General Public License - * along with this library; if not, write to the Free Software Foundation, - * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef LTTNG_H #define LTTNG_H -#include -#include -#include +#include /* Error codes that can be returned by API calls */ #include +/* Include every LTTng ABI/API available. */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + #ifdef __cplusplus extern "C" { #endif -/* - * Event symbol length. Copied from LTTng kernel ABI. - */ -#define LTTNG_SYMBOL_NAME_LEN 256 - -/* - * Every lttng_event_* structure both apply to kernel event and user-space - * event. - */ - -/* - * Domain types: the different possible tracers. - */ -enum lttng_domain_type { - LTTNG_DOMAIN_KERNEL = 1, - LTTNG_DOMAIN_UST = 2, - - /* - * For now, the domains below are not implemented. However, we keep them - * here in order to retain their enum values for future development. Note - * that it is on the roadmap to implement them. - * - LTTNG_DOMAIN_UST_EXEC_NAME = 3, - LTTNG_DOMAIN_UST_PID = 4, - LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN = 5, - */ -}; - -/* - * Instrumentation type of tracing event. - */ -enum lttng_event_type { - LTTNG_EVENT_ALL = -1, - LTTNG_EVENT_TRACEPOINT = 0, - LTTNG_EVENT_PROBE = 1, - LTTNG_EVENT_FUNCTION = 2, - LTTNG_EVENT_FUNCTION_ENTRY = 3, - LTTNG_EVENT_NOOP = 4, - LTTNG_EVENT_SYSCALL = 5, -}; - -/* - * Loglevel information. - */ -enum lttng_loglevel_type { - LTTNG_EVENT_LOGLEVEL_ALL = 0, - LTTNG_EVENT_LOGLEVEL_RANGE = 1, - LTTNG_EVENT_LOGLEVEL_SINGLE = 2, -}; - -/* - * Available loglevels. - */ -enum lttng_loglevel { - LTTNG_LOGLEVEL_EMERG = 0, - LTTNG_LOGLEVEL_ALERT = 1, - LTTNG_LOGLEVEL_CRIT = 2, - LTTNG_LOGLEVEL_ERR = 3, - LTTNG_LOGLEVEL_WARNING = 4, - LTTNG_LOGLEVEL_NOTICE = 5, - LTTNG_LOGLEVEL_INFO = 6, - LTTNG_LOGLEVEL_DEBUG_SYSTEM = 7, - LTTNG_LOGLEVEL_DEBUG_PROGRAM = 8, - LTTNG_LOGLEVEL_DEBUG_PROCESS = 9, - LTTNG_LOGLEVEL_DEBUG_MODULE = 10, - LTTNG_LOGLEVEL_DEBUG_UNIT = 11, - LTTNG_LOGLEVEL_DEBUG_FUNCTION = 12, - LTTNG_LOGLEVEL_DEBUG_LINE = 13, - LTTNG_LOGLEVEL_DEBUG = 14, -}; - -/* - * LTTng consumer mode - */ -enum lttng_event_output { - LTTNG_EVENT_SPLICE = 0, - LTTNG_EVENT_MMAP = 1, -}; - -/* Event context possible type */ -enum lttng_event_context_type { - LTTNG_EVENT_CONTEXT_PID = 0, - LTTNG_EVENT_CONTEXT_PERF_COUNTER = 1, - LTTNG_EVENT_CONTEXT_PROCNAME = 2, - LTTNG_EVENT_CONTEXT_PRIO = 3, - LTTNG_EVENT_CONTEXT_NICE = 4, - LTTNG_EVENT_CONTEXT_VPID = 5, - LTTNG_EVENT_CONTEXT_TID = 6, - LTTNG_EVENT_CONTEXT_VTID = 7, - LTTNG_EVENT_CONTEXT_PPID = 8, - LTTNG_EVENT_CONTEXT_VPPID = 9, - LTTNG_EVENT_CONTEXT_PTHREAD_ID = 10, - LTTNG_EVENT_CONTEXT_HOSTNAME = 11, -}; - enum lttng_calibrate_type { - LTTNG_CALIBRATE_FUNCTION = 0, + LTTNG_CALIBRATE_FUNCTION = 0, }; -/* Health component for the health check function. */ -enum lttng_health_component { - LTTNG_HEALTH_CMD, - LTTNG_HEALTH_APP_MANAGE, - LTTNG_HEALTH_APP_REG, - LTTNG_HEALTH_KERNEL, - LTTNG_HEALTH_CONSUMER, - LTTNG_HEALTH_ALL, +/* Machine interface output type */ +enum lttng_mi_output_type { + LTTNG_MI_XML = 1 /* XML output */ }; -/* - * The structures should be initialized to zero before use. - */ -#define LTTNG_DOMAIN_PADDING1 16 -#define LTTNG_DOMAIN_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32 -struct lttng_domain { - enum lttng_domain_type type; - char padding[LTTNG_DOMAIN_PADDING1]; - - union { - pid_t pid; - char exec_name[NAME_MAX]; - char padding[LTTNG_DOMAIN_PADDING2]; - } attr; -}; - -/* - * Perf counter attributes - * - * The structures should be initialized to zero before use. - */ -#define LTTNG_PERF_EVENT_PADDING1 16 -struct lttng_event_perf_counter_ctx { - uint32_t type; - uint64_t config; - char name[LTTNG_SYMBOL_NAME_LEN]; - - char padding[LTTNG_PERF_EVENT_PADDING1]; -}; - -/* - * Event/channel context - * - * The structures should be initialized to zero before use. - */ -#define LTTNG_EVENT_CONTEXT_PADDING1 16 -#define LTTNG_EVENT_CONTEXT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32 -struct lttng_event_context { - enum lttng_event_context_type ctx; - char padding[LTTNG_EVENT_CONTEXT_PADDING1]; - - union { - struct lttng_event_perf_counter_ctx perf_counter; - char padding[LTTNG_EVENT_CONTEXT_PADDING2]; - } u; -}; - -/* - * Event probe. - * - * Either addr is used or symbol_name and offset. - * - * The structures should be initialized to zero before use. - */ -#define LTTNG_EVENT_PROBE_PADDING1 16 -struct lttng_event_probe_attr { - uint64_t addr; - - uint64_t offset; - char symbol_name[LTTNG_SYMBOL_NAME_LEN]; - - char padding[LTTNG_EVENT_PROBE_PADDING1]; -}; - -/* - * Function tracer - * - * The structures should be initialized to zero before use. - */ -#define LTTNG_EVENT_FUNCTION_PADDING1 16 -struct lttng_event_function_attr { - char symbol_name[LTTNG_SYMBOL_NAME_LEN]; - - char padding[LTTNG_EVENT_FUNCTION_PADDING1]; -}; - -/* - * Generic lttng event - * - * The structures should be initialized to zero before use. - */ -#define LTTNG_EVENT_PADDING1 15 -#define LTTNG_EVENT_PADDING2 LTTNG_SYMBOL_NAME_LEN + 32 -struct lttng_event { - enum lttng_event_type type; - char name[LTTNG_SYMBOL_NAME_LEN]; - - enum lttng_loglevel_type loglevel_type; - int loglevel; - - int32_t enabled; /* Does not apply: -1 */ - pid_t pid; - unsigned char filter; /* filter enabled ? */ - - char padding[LTTNG_EVENT_PADDING1]; - - /* Per event type configuration */ - union { - struct lttng_event_probe_attr probe; - struct lttng_event_function_attr ftrace; - - char padding[LTTNG_EVENT_PADDING2]; - } attr; -}; - -enum lttng_event_field_type { - LTTNG_EVENT_FIELD_OTHER = 0, - LTTNG_EVENT_FIELD_INTEGER = 1, - LTTNG_EVENT_FIELD_ENUM = 2, - LTTNG_EVENT_FIELD_FLOAT = 3, - LTTNG_EVENT_FIELD_STRING = 4, -}; - -#define LTTNG_EVENT_FIELD_PADDING LTTNG_SYMBOL_NAME_LEN + 32 -struct lttng_event_field { - char field_name[LTTNG_SYMBOL_NAME_LEN]; - enum lttng_event_field_type type; - char padding[LTTNG_EVENT_FIELD_PADDING]; - struct lttng_event event; - int nowrite; -}; - -/* - * Tracer channel attributes. For both kernel and user-space. - * - * The structures should be initialized to zero before use. - */ -#define LTTNG_CHANNEL_ATTR_PADDING1 LTTNG_SYMBOL_NAME_LEN + 32 -struct lttng_channel_attr { - int overwrite; /* 1: overwrite, 0: discard */ - uint64_t subbuf_size; /* bytes */ - uint64_t num_subbuf; /* power of 2 */ - unsigned int switch_timer_interval; /* usec */ - unsigned int read_timer_interval; /* usec */ - enum lttng_event_output output; /* splice, mmap */ - - char padding[LTTNG_CHANNEL_ATTR_PADDING1]; -}; - -/* - * Channel information structure. For both kernel and user-space. - * - * The structures should be initialized to zero before use. - */ -#define LTTNG_CHANNEL_PADDING1 16 -struct lttng_channel { - char name[LTTNG_SYMBOL_NAME_LEN]; - uint32_t enabled; - struct lttng_channel_attr attr; - - char padding[LTTNG_CHANNEL_PADDING1]; -}; - -#define LTTNG_CALIBRATE_PADDING1 16 +#define LTTNG_CALIBRATE_PADDING1 16 struct lttng_calibrate { enum lttng_calibrate_type type; char padding[LTTNG_CALIBRATE_PADDING1]; }; -/* - * Basic session information. - * - * This is an 'output data' meaning that it only comes *from* the session - * daemon *to* the lttng client. It's basically a 'human' representation of - * tracing entities (here a session). - * - * The structures should be initialized to zero before use. - */ -#define LTTNG_SESSION_PADDING1 16 -struct lttng_session { - char name[NAME_MAX]; - /* The path where traces are written */ - char path[PATH_MAX]; - uint32_t enabled; /* enabled/started: 1, disabled/stopped: 0 */ - - char padding[LTTNG_SESSION_PADDING1]; -}; - -/* - * Handle used as a context for commands. - * - * The structures should be initialized to zero before use. - */ -#define LTTNG_HANDLE_PADDING1 16 -struct lttng_handle { - char session_name[NAME_MAX]; - struct lttng_domain domain; - - char padding[LTTNG_HANDLE_PADDING1]; -}; - -/* - * Public LTTng control API - * - * For functions having an lttng domain type as parameter, if a bad value is - * given, NO default is applied and an error is returned. - * - * On success, all functions of the API return 0 or the size of the allocated - * array (in bytes). - * - * On error, a negative value is returned being a specific lttng-tools error - * code which can be humanly interpreted with lttng_strerror(err). - * - * Exceptions to this are noted below. - */ +/*! +@brief + Returns whether or not liblttng-ctl is able to connect to a + listening session daemon. -/* - * Create a handle used as a context for every request made to the library. - * - * This handle contains the session name and lttng domain on which the command - * will be executed. - * The returned pointer will be NULL in case of malloc() error. - */ -extern struct lttng_handle *lttng_create_handle(const char *session_name, - struct lttng_domain *domain); +@ingroup api_gen -/* - * Destroy a handle. This will simply free(3) the data pointer returned by - * lttng_create_handle(), rendering it unusable. - */ -extern void lttng_destroy_handle(struct lttng_handle *handle); +How this function tries to +\ref api-gen-sessiond-conn "connect to a session daemon" depends on the +current Unix tracing group (initially \c tracing) of the library. Set +the tracing group with lttng_set_tracing_group(). -/* - * Create a tracing session using a name and an optional URL. - * - * If _url_ is NULL, no consumer is created for the session. - */ -extern int lttng_create_session(const char *name, const char *url); +@returns + @parblock + One of: -/* - * Destroy a tracing session. - * - * The session will not be usable anymore, tracing will be stopped for all - * registered traces, and the tracing buffers will be flushed. - */ -extern int lttng_destroy_session(const char *name); +
+
1
+
+ liblttng-ctl is able to connect to a session daemon. -/* - * List all the tracing sessions. - * - * Return the size (number of entries) of the "lttng_session" array. Caller - * must free(3). - */ -extern int lttng_list_sessions(struct lttng_session **sessions); +
0 +
+ liblttng-ctl isn't able to connect to a session daemon. -/* - * List the registered domain(s) of a session. - * - * Return the size (number of entries) of the "lttng_domain" array. Caller - * must free(3). - */ -extern int lttng_list_domains(const char *session_name, - struct lttng_domain **domains); +
Negative value +
+ Error: a negative #lttng_error_code enumerator. +
+ @endparblock -/* - * List the channel(s) of a session. - * - * Return the size (number of entries) of the "lttng_channel" array. Caller - * must free(3). - */ -extern int lttng_list_channels(struct lttng_handle *handle, - struct lttng_channel **channels); +@sa lttng_set_tracing_group() -- + Sets the current Unix tracing group of liblttng-ctl. +*/ +LTTNG_EXPORT extern int lttng_session_daemon_alive(void); -/* - * List the event(s) of a session channel. - * - * Return the size (number of entries) of the "lttng_event" array. - * Caller must free(3). - */ -extern int lttng_list_events(struct lttng_handle *handle, - const char *channel_name, struct lttng_event **events); +/*! +@brief + Sets the current Unix tracing group of liblttng-ctl to \lt_p{group}. -/* - * List the available tracepoints of a specific lttng domain. - * - * Return the size (number of entries) of the "lttng_event" array. - * Caller must free(3). - */ -extern int lttng_list_tracepoints(struct lttng_handle *handle, - struct lttng_event **events); +@ingroup api_gen -/* - * List the available tracepoints fields of a specific lttng domain. - * - * Return the size (number of entries) of the "lttng_event_field" array. - * Caller must free(3). - */ -extern int lttng_list_tracepoint_fields(struct lttng_handle *handle, - struct lttng_event_field **fields); +How the liblttng-ctl functions +\ref api-gen-sessiond-conn "connect to a session daemon" depends on +the current Unix tracing group (initially \c tracing) of the library. -/* - * Check if a session daemon is alive. - * - * Return 1 if alive or 0 if not. On error returns a negative value. - */ -extern int lttng_session_daemon_alive(void); +@param[in] group + New Unix tracing group of liblttng-ctl. -/* - * Set the tracing group for the *current* flow of execution. - * - * On success, returns 0, on error, returns -1 (null name) or -ENOMEM. - */ -extern int lttng_set_tracing_group(const char *name); +@returns + 0 on success, or a \em negative #lttng_error_code enumerator + otherwise. -/* - * Return a human-readable error message for an lttng-tools error code. - * - * Parameter MUST be a negative value or else you'll get a generic message. - */ -extern const char *lttng_strerror(int code); +@lt_pre_not_null{group} +@pre + \lt_p{group} names an existing Unix group. +*/ +LTTNG_EXPORT extern int lttng_set_tracing_group(const char *group); /* * This call registers an "outside consumer" for a session and an lttng domain. * No consumer will be spawned and all fds/commands will go through the socket * path given (socket_path). * - * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the - * command socket. The error socket is not supported yet for roaming consumers. - */ -extern int lttng_register_consumer(struct lttng_handle *handle, - const char *socket_path); - -/* - * Start tracing for *all* registered traces (kernel and user-space). - */ -extern int lttng_start_tracing(const char *session_name); + * NOTE that this is not recommended unless you absolutely know what you are + * doing. + * + * Return 0 on success else a negative LTTng error code. + */ +LTTNG_EXPORT extern int lttng_register_consumer(struct lttng_handle *handle, + const char *socket_path); + +/*! +@brief + Makes the recording session named \lt_p{session_name} active, + starting all the tracers for its + \ref api-channel-channel "channels". + +@ingroup api_session + +@note + An #LTTNG_ACTION_TYPE_START_SESSION trigger action can also activate + (start) a recording session. + +@param[in] session_name + Name of the recording session to activate/start. + +@returns + 0 on success, or a \em negative #lttng_error_code enumerator + otherwise. + +@lt_pre_conn +@lt_pre_not_null{session_name} +@lt_pre_sess_exists{session_name} +@lt_pre_sess_inactive{session_name} + +@sa lttng_stop_tracing() -- + Stops a recording session. +@sa \lt_man{lttng-start,1} +*/ +LTTNG_EXPORT extern int lttng_start_tracing(const char *session_name); + +/*! +@brief + Makes the recording session named \lt_p{session_name} inactive, + stopping all the tracers for its + \ref api-channel-channel "channels", blocking until the operation + completes. + +@ingroup api_session + +This function blocks until the trace data of the +recording session named \lt_p{session_name} is valid. Use +lttng_stop_tracing_no_wait() to avoid a blocking call. + +If LTTng \ref api_session_rotation "archived the current trace chunk" +of the recording session named \lt_p{session_name} at least +once during its lifetime, then this function renames the current trace +chunk subdirectory. Although it's safe to +read the content of this renamed subdirectory while the recording +session remains inactive, it's \em not a trace chunk archive: you need to +\link lttng_destroy_session_ext() destroy\endlink the recording session +or a rotation needs to occur to archive it. + +@note + An #LTTNG_ACTION_TYPE_STOP_SESSION trigger action can also + deactivate (stop) a recording session. + +@param[in] session_name + Name of the recording session to deactivate/stop. + +@returns + 0 on success, or a \em negative #lttng_error_code enumerator + otherwise. + +@lt_pre_conn +@lt_pre_not_null{session_name} +@lt_pre_sess_exists{session_name} +@lt_pre_sess_active{session_name} + +@sa lttng_stop_tracing_no_wait() -- + Deactivates a recording session without waiting for the operation + to complete. +@sa lttng_start_tracing() -- + Starts a recording session. +@sa \lt_man{lttng-stop,1} +*/ +LTTNG_EXPORT extern int lttng_stop_tracing(const char *session_name); + +/*! +@brief + Makes the recording session named \lt_p{session_name} inactive, + stopping all the tracers for its + \ref api-channel-channel "channels" without waiting for the + operation to complete. + +@ingroup api_session + +Unlike lttng_stop_tracing(), this function does \em not block until +the operation is complete: it returns immediately. This +means the traces(s) of the recording session might not be valid when +this function returns, and there's no way to know when it/they become +valid. + +@note + An #LTTNG_ACTION_TYPE_STOP_SESSION trigger action can also + deactivate (stop) a recording session. + +@param[in] session_name + Name of the recording session to deactivate/stop. + +@returns + 0 on success, or a \em negative #lttng_error_code enumerator + otherwise. + +@lt_pre_conn +@lt_pre_not_null{session_name} +@lt_pre_sess_exists{session_name} +@lt_pre_sess_active{session_name} +@pre + No deactivation operation is in progress for the recording session + named \lt_p{session_name}. + +@sa lttng_stop_tracing() -- + Deactivates a recording session, blocking until the operation + completes. +@sa lttng_start_tracing() -- + Starts a recording session. +@sa \lt_man{lttng-stop,1} +*/ +LTTNG_EXPORT extern int lttng_stop_tracing_no_wait(const char *session_name); + +/* + * Deprecated: As of LTTng 2.9, this function always returns + * -LTTNG_ERR_UND. + */ +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wshadow" +LTTNG_EXPORT extern int lttng_calibrate(struct lttng_handle *handle, + struct lttng_calibrate *calibrate); +#pragma GCC diagnostic pop /* - * Stop tracing for *all* registered traces (kernel and user-space). + * Set URL for a consumer for a session and domain. * - * This call will wait for data availability for each domain of the session so - * this can take an abritrary amount of time. However, when returning you have - * the guarantee that the data is ready to be read and analyse. Use the - * _no_wait call below to avoid this behavior. - */ -extern int lttng_stop_tracing(const char *session_name); - -/* - * Behave exactly like lttng_stop_tracing but does not wait for data - * availability. - */ -extern int lttng_stop_tracing_no_wait(const char *session_name); - -/* - * Add context to event(s) for a specific channel (or for all). + * Both data and control URL must be defined. If both URLs are the same, only + * the control URL is used even for network streaming. * - * If event_name is NULL, the context is applied to all events of the channel. - * If channel_name is NULL, a lookup of the event's channel is done. - * If both are NULL, the context is applied to all events of all channels. - */ -extern int lttng_add_context(struct lttng_handle *handle, - struct lttng_event_context *ctx, const char *event_name, - const char *channel_name); - -/* - * Create or enable an event (or events) for a channel. + * Default port are 5342 and 5343 respectively for control and data which uses + * the TCP protocol. * - * If the event you are trying to enable does not exist, it will be created, - * else it is enabled. - * If event_name is NULL, all events are enabled. - * If channel_name is NULL, the default channel is used (channel0). - */ -extern int lttng_enable_event(struct lttng_handle *handle, - struct lttng_event *ev, const char *channel_name); - -/* - * Apply a filter expression to an event. + * URL format: proto://[HOST|IP][:PORT1[:PORT2]][/TRACE_PATH] * - * If event is NULL, the filter is applied to all events of the channel. - * If channel_name is NULL, a lookup of the event's channel is done. - * If both are NULL, the filter is applied to all events of all channels. - */ -extern int lttng_set_event_filter(struct lttng_handle *handle, - struct lttng_event *event, const char *channel_name, - const char *filter_expression); - -/* - * Create or enable a channel. - * The channel name cannot be NULL. - */ -extern int lttng_enable_channel(struct lttng_handle *handle, - struct lttng_channel *chan); - -/* - * Disable event(s) of a channel and domain. + * Possible protocols are: + * > file://... + * Local filesystem full path. * - * If event_name is NULL, all events are disabled. - * If channel_name is NULL, the default channel is used (channel0). - */ -extern int lttng_disable_event(struct lttng_handle *handle, - const char *name, const char *channel_name); - -/* - * Disable channel. + * > net[6]://... + * This will use the default network transport layer which is TCP for both + * control (PORT1) and data port (PORT2). * - * The channel name cannot be NULL. + * > tcp[6]://... + * TCP only streaming. For this one, both data and control URL must be given. + * + * Return 0 on success else a negative LTTng error code. */ -extern int lttng_disable_channel(struct lttng_handle *handle, - const char *name); +LTTNG_EXPORT extern int +lttng_set_consumer_url(struct lttng_handle *handle, const char *control_url, const char *data_url); -/* - * Calibrate LTTng overhead. - */ -extern int lttng_calibrate(struct lttng_handle *handle, - struct lttng_calibrate *calibrate); +/*! +@brief + Returns whether or not you may read the traces of the recording + session named \lt_p{session_name}. -/* - * Set the default channel attributes for a specific domain and an allocated - * lttng_channel_attr pointer. - * - * If either or both of the arguments are NULL, nothing happens. - */ -extern void lttng_channel_set_default_attr(struct lttng_domain *domain, - struct lttng_channel_attr *attr); +@ingroup api_session -/* - * Set URL for a consumer for a session and domain. - * - * Both data and control URL must be defined. If both URLs are the same, only - * the control URL is used even for network streaming. - * - * Default port are 5342 and 5343 respectively for control and data which uses - * the TCP protocol. - */ -extern int lttng_set_consumer_url(struct lttng_handle *handle, - const char *control_url, const char *data_url); +It's not safe to read the traces of a recording session while +LTTng is still consuming data from the tracers for its +\ref api-channel-channel "channels". -/* - * Enable the consumer for a session and domain. - */ -extern int lttng_enable_consumer(struct lttng_handle *handle); +This function makes it possible to know when LTTng is done consuming +trace data from tracers for the channels of the recording session +named \lt_p{session_name}. -/* - * Disable consumer for a session and domain. - */ -extern int lttng_disable_consumer(struct lttng_handle *handle); +@param[in] session_name + Name of the recording session of which get whether or not + you may read its traces. -/* - * Check session daemon health for a specific component. - * - * Return 0 if health is OK or 1 if BAD. A returned value of -1 indicate that - * the control library was not able to connect to the session daemon health - * socket. - * - * Any other positive value is an lttcomm error which can be translate with - * lttng_strerror(). - */ -extern int lttng_health_check(enum lttng_health_component c); +@returns + @parblock + One of: -/* - * For a given session name, this call checks if the data is ready to be read - * or is still being extracted by the consumer(s) (pending) hence not ready to - * be used by any readers. - * - * Return 0 if there is _no_ data pending in the buffers thus having a - * guarantee that the data can be read safely. Else, return 1 if there is still - * traced data is pending. On error, a negative value is returned and readable - * by lttng_strerror(). - */ -extern int lttng_data_pending(const char *session_name); +
+
0 +
+ You may read the traces of the recording session named + \lt_p{session_name}. + + This remains true as long as the recording session remains + \link lttng_session::enabled inactive\endlink (stopped). + +
1
+
+ You may \em not read the traces of the recording session named + \lt_p{session_name}. + +
Negative value +
+ Error: a negative #lttng_error_code enumerator. +
+ @endparblock + +@lt_pre_conn +@lt_pre_not_null{session_name} +@lt_pre_sess_exists{session_name} +@lt_pre_sess_inactive{session_name} +*/ +LTTNG_EXPORT extern int lttng_data_pending(const char *session_name); + +/* + * Gets the status of the kernel tracer. + * + * Sets the value of the argument, which must not be null. + */ +LTTNG_EXPORT extern enum lttng_error_code +lttng_get_kernel_tracer_status(enum lttng_kernel_tracer_status *status); + +/*! +@brief + Regenerates the metadata streams of the recording session named + \lt_p{session_name}. + +@ingroup api_session + +@deprecated + Use lttng_regenerate_metadata(). + +@param[in] session_name + Name of the recording session of which to regenerate the metadata + streams. + +@returns + 0 on success, or a \em negative #lttng_error_code enumerator + otherwise. + +@lt_pre_conn +@lt_pre_not_null{session_name} +@lt_pre_sess_exists{session_name} +*/ +/// @cond DEPRECATED +LTTNG_DEPRECATED() +/// @endcond +LTTNG_EXPORT extern int lttng_metadata_regenerate(const char *session_name); + +/*! +@brief + Regenerates the metadata streams of the recording session named + \lt_p{session_name}. + +@ingroup api_session + +Use this function to resample the offset between the monotonic clock and +the wall time of the system, and then regenerate (overwrite) all the +metadata stream files (local or remote) of the recording session +named \lt_p{session_name}. + +More specifically, you may want to resample the wall time following a +major NTP +correction. As such, LTTng can trace a system booting with an incorrect +wall time before its wall time is NTP-corrected. Regenerating the +metadata of a recording session ensures that trace readers +can accurately determine the event record timestamps relative to the +Unix epoch. + +Note that if you plan to \ref api_session_rotation "rotate" the +recording session named \lt_p{session_name}, this function only +regenerates the metadata stream files of the \em current and \em next +trace chunks. + +See the preconditions of this function which show important limitations. + +@param[in] session_name + Name of the recording session of which to regenerate the metadata + streams. + +@returns + 0 on success, or a \em negative #lttng_error_code enumerator + otherwise. + +@lt_pre_conn +@lt_pre_not_null{session_name} +@lt_pre_sess_exists{session_name} +@pre + The recording session named \lt_p{session_name} was \em not created + in \ref api-session-live-mode "live mode". +@pre + All the \ref api-channel-channel "channels" of the recording session + named \lt_p{session_name} use a + \ref api-channel-per-user-buf "per-user buffering scheme". + +@sa lttng_regenerate_statedump() -- + Regenerates the state dump event records of a recording session. +@sa \lt_man{lttng-regenerate,1} +*/ +LTTNG_EXPORT extern int lttng_regenerate_metadata(const char *session_name); + +/*! +@brief + Regenerates the state dump event records of the recording session + named \lt_p{session_name}. + +@ingroup api_session + +Use this function to collect up-to-date state dump information and +append corresponding event records to the +\ref api-channel-channel "sub-buffers" of the recording session named +\lt_p{session_name}. + +This is particularly useful if you created the recording session in +\ref api-session-snapshot-mode "snapshot mode" +or if LTTng \ref api_session_rotation "rotates" trace files for one of +its \ref api-channel-channel "channels": in both cases, the state dump +information may be lost. + +@param[in] session_name + Name of the recording session of which to regenerate the + state dump event records. + +@returns + 0 on success, or a \em negative #lttng_error_code enumerator + otherwise. + +@lt_pre_conn +@lt_pre_not_null{session_name} +@lt_pre_sess_exists{session_name} + +@sa lttng_regenerate_metadata() -- + Regenerates the metadata streams of a recording session. +@sa \lt_man{lttng-regenerate,1} +*/ +LTTNG_EXPORT extern int lttng_regenerate_statedump(const char *session_name); #ifdef __cplusplus }