[lttng-modules.git] / ltt-events.c

/*
 * ltt-events.c
 *
 * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * Holds LTTng per-session event registry.
 */

#include <linux/module.h>
#include "ltt-events.h"

static LIST_HEAD(sessions);
static DEFINE_MUTEX(sessions_mutex);
static struct kmem_cache *event_cache;

struct ltt_session *ltt_session_create(char *name)
{
	struct ltt_session *session;

	mutex_lock(&sessions_mutex);
	list_for_each_entry(session, &sessions, list)
		if (!strcmp(session->name, name))
			goto exist;
	session = kmalloc(sizeof(struct ltt_session) + strlen(name) + 1);
	if (!session)
		return NULL;
	strcpy(session->name, name);
	INIT_LIST_HEAD(&session->chan);
	list_add(&session->list, &sessions);
	mutex_unlock(&sessions_mutex);
	return session;

exist:
	mutex_unlock(&sessions_mutex);
	return NULL;
}

int ltt_session_destroy(struct ltt_session *session)
{
	struct ltt_channel *chan, *tmpchan;
	struct ltt_event *event, *tmpevent;

	mutex_lock(&sessions_mutex);
	list_for_each_entry_safe(event, tmpevent, &session->events, list)
		_ltt_event_destroy(event);
	list_for_each_entry_safe(chan, tmpchan, &session->chan, list)
		_ltt_channel_destroy(chan);
	list_del(&session->list);
	mutex_unlock(&sessions_mutex);
	kfree(session);
}

struct ltt_channel *ltt_channel_create(struct ltt_session *session, char *name,
				       int overwrite, void *buf_addr,
				       size_t subbuf_size, size_t num_subbuf,
				       unsigned int switch_timer_interval,
				       unsigned int read_timer_interval)
{
	struct ltt_channel *chan;

	mutex_lock(&sessions_mutex);
	list_for_each_entry(chan, &session->chan, list)
		if (!strcmp(chan->name, name))
			goto exist;
	chan = kmalloc(sizeof(struct ltt_channel) + strlen(name) + 1, GFP_KERNEL);
	if (!chan)
		return NULL;
	strcpy(chan->name, name);
	chan->session = session;

	/* TODO: create rb channel */
	list_add(&chan->list, &session->chan);
	mutex_unlock(&sessions_mutex);
	return chan;

exist:
	mutex_unlock(&sessions_mutex);
	return NULL;
}

/*
 * Only used internally at session destruction.
 */
int _ltt_channel_destroy(struct ltt_channel *chan)
{
	list_del(&chan->list);
	kfree(chan);
}

struct ltt_event *ltt_event_create(struct ltt_channel *chan, char *name,
				   void *filter)
{
	struct ltt_event *event;

	mutex_lock(&sessions_mutex);
	/*
	 * This is O(n^2) (for each event loop called at event creation).
	 * Might require a hash if we have lots of events.
	 */
	list_for_each_entry(event, &chan->session->events, list)
		if (!strcmp(event->name, name))
			goto exist;
	event = kmem_cache_zalloc(events_cache, GFP_KERNEL);
	if (!event)
		goto cache_error;
	event->name = kmalloc(strlen(name) + 1, GFP_KERNEL);
	if (!event->name)
		goto error;
	strcpy(event->name, name);
	event->chan = chan;
	event->filter = filter;
	event->id = atomic_inc_return(&chan->free_event_id) - 1;
	/* TODO register to tracepoint */
	mutex_unlock(&sessions_mutex);
	return event;

error:
	kmem_cache_free(event);
cache_error:
exist:
	mutex_unlock(&sessions_mutex);
	return NULL;
}

/*
 * Only used internally at session destruction.
 */
int _ltt_event_destroy(struct ltt_event *event)
{
	/* TODO unregister from tracepoint */
	kfree(event->name);
	kmem_cache_free(event);
}

static int __init ltt_events_init(void)
{
	int ret;

	events_cache = KMEM_CACHE(ltt_event, 0);
	if (!events_cache)
		return -ENOMEM;
	return 0;
}

static void __exit ltt_events_exit(void)
{
	kmem_cache_destroy(events_cache);
}
Commit	Line	Data
4e3c1b9b MD	1	/*
	2	* ltt-events.c
	3	*
	4	* Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	5	*
	6	* Holds LTTng per-session event registry.
	7	*/
	8
	9	#include <linux/module.h>
	10	#include "ltt-events.h"
	11
	12	static LIST_HEAD(sessions);
	13	static DEFINE_MUTEX(sessions_mutex);
	14	static struct kmem_cache *event_cache;
	15
	16	struct ltt_session ltt_session_create(char name)
	17	{
	18	struct ltt_session *session;
	19
	20	mutex_lock(&sessions_mutex);
	21	list_for_each_entry(session, &sessions, list)
	22	if (!strcmp(session->name, name))
	23	goto exist;
	24	session = kmalloc(sizeof(struct ltt_session) + strlen(name) + 1);
	25	if (!session)
	26	return NULL;
	27	strcpy(session->name, name);
	28	INIT_LIST_HEAD(&session->chan);
	29	list_add(&session->list, &sessions);
	30	mutex_unlock(&sessions_mutex);
	31	return session;
	32
	33	exist:
	34	mutex_unlock(&sessions_mutex);
	35	return NULL;
	36	}
	37
	38	int ltt_session_destroy(struct ltt_session *session)
	39	{
	40	struct ltt_channel chan, tmpchan;
	41	struct ltt_event event, tmpevent;
	42
	43	mutex_lock(&sessions_mutex);
	44	list_for_each_entry_safe(event, tmpevent, &session->events, list)
	45	_ltt_event_destroy(event);
	46	list_for_each_entry_safe(chan, tmpchan, &session->chan, list)
	47	_ltt_channel_destroy(chan);
	48	list_del(&session->list);
	49	mutex_unlock(&sessions_mutex);
	50	kfree(session);
	51	}
	52
	53	struct ltt_channel ltt_channel_create(struct ltt_session session, char *name,
	54	int overwrite, void *buf_addr,
	55	size_t subbuf_size, size_t num_subbuf,
	56	unsigned int switch_timer_interval,
	57	unsigned int read_timer_interval)
	58	{
	59	struct ltt_channel *chan;
	60
	61	mutex_lock(&sessions_mutex);
	62	list_for_each_entry(chan, &session->chan, list)
	63	if (!strcmp(chan->name, name))
	64	goto exist;
65	chan = kmalloc(sizeof(struct ltt_channel) + strlen(name) + 1, GFP_KERNEL);
66	if (!chan)
67	return NULL;
68	strcpy(chan->name, name);
69	chan->session = session;
70
71	/* TODO: create rb channel */
72	list_add(&chan->list, &session->chan);
73	mutex_unlock(&sessions_mutex);
74	return chan;
75
76	exist:
77	mutex_unlock(&sessions_mutex);
78	return NULL;
79	}
80
81	/*
82	* Only used internally at session destruction.
83	*/
84	int _ltt_channel_destroy(struct ltt_channel *chan)
85	{
86	list_del(&chan->list);
87	kfree(chan);
88	}
89
90	struct ltt_event ltt_event_create(struct ltt_channel chan, char *name,
91	void *filter)
92	{
93	struct ltt_event *event;
94
95	mutex_lock(&sessions_mutex);
96	/*
97	* This is O(n^2) (for each event loop called at event creation).
98	* Might require a hash if we have lots of events.
99	*/
100	list_for_each_entry(event, &chan->session->events, list)
101	if (!strcmp(event->name, name))
102	goto exist;
103	event = kmem_cache_zalloc(events_cache, GFP_KERNEL);
104	if (!event)
105	goto cache_error;
106	event->name = kmalloc(strlen(name) + 1, GFP_KERNEL);
107	if (!event->name)
108	goto error;
109	strcpy(event->name, name);
110	event->chan = chan;
111	event->filter = filter;
112	event->id = atomic_inc_return(&chan->free_event_id) - 1;
113	/* TODO register to tracepoint */
114	mutex_unlock(&sessions_mutex);
115	return event;
116
117	error:
118	kmem_cache_free(event);
119	cache_error:
120	exist:
121	mutex_unlock(&sessions_mutex);
122	return NULL;
123	}
124
125	/*
126	* Only used internally at session destruction.
127	*/
128	int _ltt_event_destroy(struct ltt_event *event)
129	{
130	/* TODO unregister from tracepoint */
131	kfree(event->name);
132	kmem_cache_free(event);
133	}
134
135	static int __init ltt_events_init(void)
136	{
137	int ret;
138
139	events_cache = KMEM_CACHE(ltt_event, 0);
140	if (!events_cache)
141	return -ENOMEM;
142	return 0;
143	}
144
145	static void __exit ltt_events_exit(void)
146	{
147	kmem_cache_destroy(events_cache);
148	}