X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=include%2Flttng%2Flttng.h;h=929ce014e10b752f133c87589ff492bfb27e7efd;hb=HEAD;hp=ebcdd2b58e94ca83484b3b7fad4972f9d3e91b74;hpb=330be774319277f86ecf9445603bf97dc3249ca3;p=lttng-tools.git diff --git a/include/lttng/lttng.h b/include/lttng/lttng.h index ebcdd2b58..6ae331bda 100644 --- a/include/lttng/lttng.h +++ b/include/lttng/lttng.h @@ -3,381 +3,499 @@ * * 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 as published by the Free Software Foundation; only - * version 2.1 of the License. + * 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 - -/* Default unix group name for tracing. */ -#define LTTNG_DEFAULT_TRACING_GROUP "tracing" - -/* Environment variable to set session daemon binary path. */ -#define LTTNG_SESSIOND_PATH_ENV "LTTNG_SESSIOND_PATH" - -/* Default trace output directory name */ -#define LTTNG_DEFAULT_TRACE_DIR_NAME "lttng-traces" - -/* - * Event symbol length. Copied from LTTng kernel ABI. - */ -#define LTTNG_SYMBOL_NAME_LEN 256 +#ifndef LTTNG_H +#define LTTNG_H + +#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 -/* - * Every lttng_event_* structure both apply to kernel event and user-space - * event. - */ - -/* - * Domain type are the different possible tracers. - */ -enum lttng_domain_type { - LTTNG_DOMAIN_KERNEL = 1, - LTTNG_DOMAIN_UST = 2, - LTTNG_DOMAIN_UST_EXEC_NAME = 3, - LTTNG_DOMAIN_UST_PID = 4, - LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN = 5, +enum lttng_calibrate_type { + LTTNG_CALIBRATE_FUNCTION = 0, }; -/* - * 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, - LTTNG_EVENT_TRACEPOINT_LOGLEVEL = 6, +/* Machine interface output type */ +enum lttng_mi_output_type { + LTTNG_MI_XML = 1 /* XML output */ }; -/* - * LTTng consumer mode - */ -enum lttng_event_output { - LTTNG_EVENT_SPLICE = 0, - LTTNG_EVENT_MMAP = 1, -}; +#define LTTNG_CALIBRATE_PADDING1 16 +struct lttng_calibrate { + enum lttng_calibrate_type type; -/* Event context possible type */ -enum lttng_event_context_type { - LTTNG_EVENT_CONTEXT_PID = 0, - LTTNG_EVENT_CONTEXT_PERF_COUNTER = 1, - LTTNG_EVENT_CONTEXT_COMM = 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, + char padding[LTTNG_CALIBRATE_PADDING1]; }; -enum lttng_calibrate_type { - LTTNG_CALIBRATE_FUNCTION = 0, -}; +/*! +@brief + Returns whether or not liblttng-ctl is able to connect to a + listening session daemon. -struct lttng_domain { - enum lttng_domain_type type; - union { - pid_t pid; - char exec_name[NAME_MAX]; - } attr; -}; +@ingroup api_gen -/* Perf counter attributes */ -struct lttng_event_perf_counter_ctx { - uint32_t type; - uint64_t config; - char name[LTTNG_SYMBOL_NAME_LEN]; -}; +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(). -/* Event/Channel context */ -struct lttng_event_context { - enum lttng_event_context_type ctx; - union { - struct lttng_event_perf_counter_ctx perf_counter; - } u; -}; +@returns + @parblock + One of: -/* - * Event probe. - * - * Either addr is used or symbol_name and offset. - */ -struct lttng_event_probe_attr { - uint64_t addr; +
+
1
+
+ liblttng-ctl is able to connect to a session daemon. - uint64_t offset; - char symbol_name[LTTNG_SYMBOL_NAME_LEN]; -}; +
0 +
+ liblttng-ctl isn't able to connect to a session daemon. -/* - * Function tracer - */ -struct lttng_event_function_attr { - char symbol_name[LTTNG_SYMBOL_NAME_LEN]; -}; +
Negative value +
+ Error: a negative #lttng_error_code enumerator. +
+ @endparblock -/* - * Generic lttng event - */ -struct lttng_event { - char name[LTTNG_SYMBOL_NAME_LEN]; - char loglevel[LTTNG_SYMBOL_NAME_LEN]; - int64_t loglevel_value; - enum lttng_event_type type; - uint32_t enabled; - pid_t pid; - /* Per event type configuration */ - union { - struct lttng_event_probe_attr probe; - struct lttng_event_function_attr ftrace; - } attr; -}; +@sa lttng_set_tracing_group() -- + Sets the current Unix tracing group of liblttng-ctl. +*/ +LTTNG_EXPORT extern int lttng_session_daemon_alive(void); -/* - * Tracer channel attributes. For both kernel and user-space. - */ -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 */ -}; +/*! +@brief + Sets the current Unix tracing group of liblttng-ctl to \lt_p{group}. -/* - * Channel information structure. For both kernel and user-space. - */ -struct lttng_channel { - char name[NAME_MAX]; - uint32_t enabled; - struct lttng_channel_attr attr; -}; +@ingroup api_gen -struct lttng_calibrate { - enum lttng_calibrate_type type; -}; +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. -/* - * 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). - */ -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 */ -}; +@param[in] group + New Unix tracing group of liblttng-ctl. -/* - * Handle used as a context for commands. - */ -struct lttng_handle { - char session_name[NAME_MAX]; - struct lttng_domain domain; -}; +@returns + 0 on success, or a \em negative #lttng_error_code enumerator + otherwise. + +@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); /* - * Public LTTng control API + * 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). * - * For functions having a lttng domain type as parameter, if a bad value is - * given, NO default is applied and an error is returned. + * NOTE that this is not recommended unless you absolutely know what you are + * doing. * - * On success, all functions of the API return 0 or the size of the allocated - * array. + * 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 + +/* + * Set URL for a consumer for a session and domain. * - * On error, a negative value is returned being a specific lttng-tools error - * code which can be humanly interpreted with lttng_strerror(err). - */ - -/* - * Create an handle used as a context for every request made to the library. + * Both data and control URL must be defined. If both URLs are the same, only + * the control URL is used even for network streaming. * - * This handle contains the session name and lttng domain on which the command - * will be executed on. - */ -extern struct lttng_handle *lttng_create_handle(const char *session_name, - struct lttng_domain *domain); - -/* - * Destroy an handle. This will simply free(3) the data pointer returned by - * lttng_create_handle() and rendering it unsuable. - */ -extern void lttng_destroy_handle(struct lttng_handle *handle); - -/* - * Create tracing session using a name and a path where trace will be written. - */ -extern int lttng_create_session(const char *name, const char *path); - -/* - * Destroy tracing session. + * Default port are 5342 and 5343 respectively for control and data which uses + * the TCP protocol. * - * The session will not be useable anymore, tracing will stopped for all - * registered trace and tracing buffers will be flushed. - */ -extern int lttng_destroy_session(const char *name); - -/* - * List all tracing sessions. + * URL format: proto://[HOST|IP][:PORT1[:PORT2]][/TRACE_PATH] * - * Return the size of the "lttng_session" array. Caller must free(3). - */ -extern int lttng_list_sessions(struct lttng_session **sessions); - -/* - * List registered domain(s) of a session. + * Possible protocols are: + * > file://... + * Local filesystem full path. * - * Return the size of the "lttng_domain" array. Caller must free(3). - */ -extern int lttng_list_domains(const char *session_name, - struct lttng_domain **domains); - -/* - * List channel(s) of a session. + * > net[6]://... + * This will use the default network transport layer which is TCP for both + * control (PORT1) and data port (PORT2). * - * Return the size of the "lttng_channel" array. Caller must free(3). - */ -extern int lttng_list_channels(struct lttng_handle *handle, - struct lttng_channel **channels); - -/* - * List event(s) of a session channel. + * > tcp[6]://... + * TCP only streaming. For this one, both data and control URL must be given. * - * Return the size of the "lttng_event" array. Caller must free(3). + * Return 0 on success else a negative LTTng error code. */ -extern int lttng_list_events(struct lttng_handle *handle, - const char *channel_name, struct lttng_event **events); +LTTNG_EXPORT extern int +lttng_set_consumer_url(struct lttng_handle *handle, const char *control_url, const char *data_url); -/* - * List available tracepoints of a specific lttng domain. - * - * Return the size of the "lttng_event" array. Caller must free(3). - */ -extern int lttng_list_tracepoints(struct lttng_handle *handle, - struct lttng_event **events); +/*! +@brief + Returns whether or not you may read the traces of the recording + session named \lt_p{session_name}. -/* - * Check if a session daemon is alive. - */ -extern int lttng_session_daemon_alive(void); +@ingroup api_session -/* - * Set tracing group for the *current* flow of execution. - */ -extern int lttng_set_tracing_group(const char *name); +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". -/* - * Return a human readable error message of a 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); +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}. -/* - * This call permits to register an "outside consumer" to a session and a 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); +@param[in] session_name + Name of the recording session of which get whether or not + you may read its traces. -/* - * Start tracing for *all* registered trace (kernel and user-space). - */ -extern int lttng_start_tracing(const char *session_name); +@returns + @parblock + One of: -/* - * Stop tracing for *all* registered trace (kernel and user-space). - */ -extern int lttng_stop_tracing(const char *session_name); +
+
0 +
+ You may read the traces of the recording session named + \lt_p{session_name}. -/* - * Add context to event for a specific channel. - * - * If event_name is NULL, the context is applied to all event 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 on 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); + This remains true as long as the recording session remains + \link lttng_session::enabled inactive\endlink (stopped). -/* - * Create or enable a kernel event. - * - * If the event you are trying to enable does not exist, it will be created, - * else it is 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); +
1
+
+ You may \em not read the traces of the recording session named + \lt_p{session_name}. -/* - * Create or enable a kernel channel. - * - * If name is NULL, the default channel is enabled (channel0). - */ -extern int lttng_enable_channel(struct lttng_handle *handle, - struct lttng_channel *chan); +
Negative value +
+ Error: a negative #lttng_error_code enumerator. +
+ @endparblock -/* - * Disable kernel event. - * - * 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); +@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); /* - * Disable kernel channel. + * Gets the status of the kernel tracer. * - * If channel_name is NULL, the default channel is disabled (channel0). - */ -extern int lttng_disable_channel(struct lttng_handle *handle, - const char *name); - -/* - * Calibrate LTTng overhead. - */ -extern int lttng_calibrate(struct lttng_handle *handle, - struct lttng_calibrate *calibrate); - -/* - * Set the default channel attributes for a specific domain and an allocated - * lttng_channel_attr pointer. - */ -extern void lttng_channel_set_default_attr(struct lttng_domain *domain, - struct lttng_channel_attr *attr); - -#endif /* _LTTNG_H */ + * 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 +} +#endif + +#endif /* LTTNG_H */