Re: [PATCH 1/2] tools lib traceevent: Man page for tep_add_plugin_path() API

[Steven Rostedt]

[ Added Michael to the Cc ]

On Tue, 29 Sep 2020 20:36:32 +0300
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx> wrote:

> Add documentation of tep_add_plugin_path() API in the libtraceevent plugin man page.


Nit, but the above should be no more than 74 (I do 76) characters wide.

> 
> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
> ---
>  .../Documentation/libtraceevent-plugins.txt   | 22 +++++++++++++++++--
>  1 file changed, 20 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/lib/traceevent/Documentation/libtraceevent-plugins.txt b/tools/lib/traceevent/Documentation/libtraceevent-plugins.txt
> index 4d6394397d92..e584b8c777ad 100644
> --- a/tools/lib/traceevent/Documentation/libtraceevent-plugins.txt
> +++ b/tools/lib/traceevent/Documentation/libtraceevent-plugins.txt
> @@ -3,7 +3,7 @@ libtraceevent(3)
>  
>  NAME
>  ----
> -tep_load_plugins, tep_unload_plugins, tep_load_plugins_hook - Load / unload traceevent plugins.
> +tep_load_plugins, tep_unload_plugins, tep_load_plugins_hook, tep_add_plugin_path - Load / unload traceevent plugins.
>  
>  SYNOPSIS
>  --------
> @@ -19,6 +19,8 @@ void *tep_load_plugins_hook*(struct tep_handle pass:[*]_tep_, const char pass:[*
>  					       const char pass:[*]name,
>  					       void pass:[*]data),
>  			   void pass:[*]_data_);
> +int *tep_add_plugin_path*(struct tep_handle pass:[*]tep, char pass:[*]path,
> +			  enum tep_plugin_load_priority prio);
>  --
>  
>  DESCRIPTION
> @@ -52,16 +54,30 @@ _tep_load_plugins()_. The _tep_ argument is trace event parser context. The
>  _plugin_list_ is the list of loaded plugins, returned by
>  the _tep_load_plugins()_ function.
>  
> -The _tep_load_plugins_hook_ function walks through all directories with plugins
> +The _tep_load_plugins_hook()_ function walks through all directories with plugins
>  and calls user specified _load_plugin()_ hook for each plugin file. Only files
>  with given _suffix_ are considered to be plugins. The _data_ is a user specified
>  context, passed to _load_plugin()_. Directories and the walk order are the same
>  as in _tep_load_plugins()_ API.
>  
> +The _tep_add_plugin_path()_ functions adds additional directories with plugins in
> +the _tep_->plugins_dir list. It must be called before _tep_load_plugins()_ in order
> +the plugins from the new directories to be loaded. The _tep_ argument is trace event

"in order for the plugins" .. "is the trace event parser"


> +parser context. The _path_ is the full path to the new plugin directory. The _prio_
> +argument specifies the loading priority of plugins from the new directory. The loading

"specifies the loading priority order for the new directory of plugins"

> +priority is important in case of different versions of the same plugin located in
> +multiple plugin directories.The last loaded plugin wins. The priority can be:
> +[verse]
> +--
> +	_TEP_PLUGIN_FIRST_	- Load plugins from this directory first
> +	_TEP_PLUGIN_LAST_	- Load plugins from this directory last
> +--

"Where the plugins in TEP_PLUGIN_LAST" will take precedence over the
plugins in the other directories."

> +
>  RETURN VALUE
>  ------------
>  The _tep_load_plugins()_ function returns a list of successfully loaded plugins,
>  or NULL in case no plugins are loaded.
> +The _tep_add_plugin_path()_ function returns -1 in case of an error, 0 otherwise.
>  

-- Steve

>  EXAMPLE
>  -------
> @@ -71,6 +87,8 @@ EXAMPLE
>  ...
>  struct tep_handle *tep = tep_alloc();
>  ...
> +tep_add_plugin_path(tep, "~/dev_plugins", TEP_PLUGIN_LAST);
> +...
>  struct tep_plugin_list *plugins = tep_load_plugins(tep);
>  if (plugins == NULL) {
>  	/* no plugins are loaded */