From: Thibault, Daniel Date: Tue, 31 Jan 2012 17:31:02 +0000 (-0500) Subject: Harmonise lttng.h and lttng-ctl.c documentation X-Git-Tag: v2.0-pre19~24 X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=1e46a50ff4c21c973767287bd6e79af04c81c283;p=lttng-tools.git Harmonise lttng.h and lttng-ctl.c documentation Fix comments alignment. Signed-off-by: Daniel U. Thibault Signed-off-by: David Goulet --- diff --git a/include/lttng/lttng.h b/include/lttng/lttng.h index 5e0a94123..433d2d804 100644 --- a/include/lttng/lttng.h +++ b/include/lttng/lttng.h @@ -5,19 +5,18 @@ * * Copyright (C) 2011 - David Goulet * - * 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. + * 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. * - * 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. + * 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 + * 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 @@ -38,7 +37,7 @@ */ /* - * Domain type are the different possible tracers. + * Domain types: the different possible tracers. */ enum lttng_domain_type { LTTNG_DOMAIN_KERNEL = 1, @@ -215,104 +214,117 @@ struct lttng_handle { /* * Public LTTng control API * - * For functions having a lttng domain type as parameter, if a bad value is + * 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. + * 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. */ /* - * Create an handle used as a context for every request made to the library. + * 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 on. + * 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); /* - * Destroy an handle. This will simply free(3) the data pointer returned by - * lttng_create_handle() and rendering it unsuable. + * 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); /* - * Create tracing session using a name and a path where trace will be written. + * Create a tracing session using a name and a path where the trace will be + * written. */ extern int lttng_create_session(const char *name, const char *path); /* - * Destroy tracing session. + * Destroy a tracing session. * - * The session will not be useable anymore, tracing will stopped for all - * registered trace and tracing buffers will be flushed. + * 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); /* - * List all tracing sessions. + * List all the tracing sessions. * - * Return the size of the "lttng_session" array. Caller must free(3). + * Return the size (number of entries) 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. + * List the registered domain(s) of a session. * - * Return the size of the "lttng_domain" array. Caller must free(3). + * 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); /* - * List channel(s) of a session. + * List the channel(s) of a session. * - * Return the size of the "lttng_channel" array. Caller must free(3). + * 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); /* - * List event(s) of a session channel. + * List the event(s) of a session channel. * - * Return the size of the "lttng_event" array. Caller must free(3). + * 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); /* - * List available tracepoints of a specific lttng domain. + * List the available tracepoints of a specific lttng domain. * - * Return the size of the "lttng_event" array. Caller must free(3). + * 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); /* * 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); /* - * Set tracing group for the *current* flow of execution. + * 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); /* - * Return a human readable error message of a lttng-tools error code. + * 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); /* - * 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). + * 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. @@ -321,32 +333,32 @@ extern int lttng_register_consumer(struct lttng_handle *handle, const char *socket_path); /* - * Start tracing for *all* registered trace (kernel and user-space). + * Start tracing for *all* registered traces (kernel and user-space). */ extern int lttng_start_tracing(const char *session_name); /* - * Stop tracing for *all* registered trace (kernel and user-space). + * Stop tracing for *all* registered traces (kernel and user-space). */ extern int lttng_stop_tracing(const char *session_name); /* - * Add context to event for a specific channel. + * Add context to event(s) for a specific channel (or for all). * - * If event_name is NULL, the context is applied to all event of the channel. + * 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 on all events of all channels. + * 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 a kernel event. + * Create or enable a kernel event (or events) for a channel. * * 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, @@ -354,15 +366,15 @@ extern int lttng_enable_event(struct lttng_handle *handle, /* * Create or enable a kernel channel. - * - * If name is NULL, the default channel is enabled (channel0). + * The channel name cannot be NULL. */ extern int lttng_enable_channel(struct lttng_handle *handle, struct lttng_channel *chan); /* - * Disable kernel event. + * Disable kernel event(s) of a channel and domain. * + * 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, @@ -371,7 +383,7 @@ extern int lttng_disable_event(struct lttng_handle *handle, /* * Disable kernel channel. * - * If channel_name is NULL, the default channel is disabled (channel0). + * The channel name cannot be NULL. */ extern int lttng_disable_channel(struct lttng_handle *handle, const char *name); @@ -385,6 +397,8 @@ extern int lttng_calibrate(struct lttng_handle *handle, /* * 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); diff --git a/src/lib/lttng-ctl/lttng-ctl.c b/src/lib/lttng-ctl/lttng-ctl.c index dfaa47f7d..1d92facf0 100644 --- a/src/lib/lttng-ctl/lttng-ctl.c +++ b/src/lib/lttng-ctl/lttng-ctl.c @@ -466,7 +466,10 @@ int lttng_stop_tracing(const char *session_name) } /* - * Add context to event or/and channel. + * Add context to event and/or channel. + * 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. * * Returns the size of the returned payload data or a negative error code. */