Basic hashtable support for UST
[lttng-tools.git] / ltt-sessiond / trace-ust.c
index 957ac770b51eb9f9428ddbc3ea8648e49fad10ea..b1066072bf711bbffff2bf87a98bab3b1c359d48 100644 (file)
 #include <lttngerr.h>
 #include <lttng-share.h>
 
+#include "hashtable.h"
 #include "trace-ust.h"
 
 /*
- * Find the channel name for the given ust session.
+ * Find the channel in the hashtable.
  */
-struct ltt_ust_channel *trace_ust_get_channel_by_name(
-               char *name, struct ltt_ust_session *session)
+struct ltt_ust_channel *trace_ust_find_channel_by_name(struct cds_lfht *ht,
+               char *name)
 {
-       struct ltt_ust_channel *chan;
+       struct cds_lfht_node *node;
+       struct cds_lfht_iter iter;
 
-       if (session == NULL) {
-               ERR("Undefine session");
+       rcu_read_lock();
+       node = hashtable_lookup(ht, (void *) name, strlen(name), &iter);
+       if (node == NULL) {
+               rcu_read_unlock();
                goto error;
        }
+       rcu_read_unlock();
 
-       cds_list_for_each_entry(chan, &session->channels.head, list) {
-               if (strcmp(name, chan->name) == 0) {
-                       DBG("Found UST channel by name %s", name);
-                       return chan;
-               }
-       }
+       DBG2("Trace UST channel %s found by name", name);
+
+       return caa_container_of(node, struct ltt_ust_channel, node);
 
 error:
+       DBG2("Trace UST channel %s not found by name", name);
        return NULL;
 }
 
 /*
- * Find the event name for the given channel.
+ * Find the event in the hashtable.
  */
-struct ltt_ust_event *trace_ust_get_event_by_name(
-               char *name, struct ltt_ust_channel *channel)
+struct ltt_ust_event *trace_ust_find_event_by_name(struct cds_lfht *ht,
+               char *name)
 {
-       struct ltt_ust_event *ev;
+       struct cds_lfht_node *node;
+       struct cds_lfht_iter iter;
 
-       if (channel == NULL) {
-               ERR("Undefine channel");
+       rcu_read_lock();
+       node = hashtable_lookup(ht, (void *) name, strlen(name), &iter);
+       if (node == NULL) {
+               rcu_read_unlock();
                goto error;
        }
+       rcu_read_unlock();
 
-       cds_list_for_each_entry(ev, &channel->events.head, list) {
-               if (strcmp(name, ev->event->name) == 0) {
-                       DBG("Found UST event by name %s for channel %s", name,
-                                       channel->name);
-                       return ev;
-               }
-       }
+       DBG2("Found UST event by name %s", name);
+
+       return caa_container_of(node, struct ltt_ust_event, node);
 
 error:
        return NULL;
@@ -80,8 +83,10 @@ error:
  *
  * Return pointer to structure or NULL.
  */
-struct ltt_ust_session *trace_ust_create_session(void)
+struct ltt_ust_session *trace_ust_create_session(char *path, pid_t pid,
+               struct lttng_domain *domain)
 {
+       int ret;
        struct ltt_ust_session *lus;
 
        /* Allocate a new ltt ust session */
@@ -94,11 +99,24 @@ struct ltt_ust_session *trace_ust_create_session(void)
        /* Init data structure */
        lus->handle = -1;
        lus->enabled = 1;
-       lus->uconsumer_fds_sent = 0;
-       lus->path = NULL;
+       lus->consumer_fds_sent = 0;
        lus->metadata = NULL;
-       lus->channels.count = 0;
-       CDS_INIT_LIST_HEAD(&lus->channels.head);
+
+       /* Alloc UST domain hash tables */
+       lus->domain_pid = hashtable_new(0);
+       lus->domain_exec = hashtable_new_str(0);
+
+       /* Alloc UST global domain channels' HT */
+       lus->domain_global.channels = hashtable_new_str(0);
+
+       /* Set session path */
+       ret = snprintf(lus->path, PATH_MAX, "%s/ust_%d", path, pid);
+       if (ret < 0) {
+               PERROR("snprintf kernel traces path");
+               goto error;
+       }
+
+       DBG2("UST trace session create successful");
 
        return lus;
 
@@ -111,8 +129,8 @@ error:
  *
  * Return pointer to structure or NULL.
  */
-struct ltt_ust_channel *trace_ust_create_channel(char *name, char *path,
-               struct lttng_ust_channel *chan)
+struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
+               char *path)
 {
        int ret;
        struct ltt_ust_channel *luc;
@@ -123,29 +141,38 @@ struct ltt_ust_channel *trace_ust_create_channel(char *name, char *path,
                goto error;
        }
 
-       luc->attr = malloc(sizeof(struct lttng_ust_channel));
-       if (luc->attr == NULL) {
-               perror("lttng_ust_channel malloc");
-               goto error;
+       /* Copy UST channel attributes */
+       memcpy(&luc->attr, &chan->attr, sizeof(struct lttng_ust_channel));
+
+       /* Translate to UST output enum */
+       switch (luc->attr.output) {
+       default:
+               luc->attr.output = LTTNG_UST_MMAP;
+               break;
        }
-       memcpy(luc->attr, chan, sizeof(struct lttng_ust_channel));
 
        luc->handle = -1;
        luc->enabled = 1;
-       luc->ctx = NULL;
-       luc->events.count = 0;
-       CDS_INIT_LIST_HEAD(&luc->events.head);
 
        /* Copy channel name */
-       strncpy(luc->name, name, LTTNG_UST_SYM_NAME_LEN);
+       strncpy(luc->name, chan->name, sizeof(&luc->name));
        luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 
+       /* Init node */
+       hashtable_node_init(&luc->node, (void *) luc->name, strlen(luc->name));
+       /* Alloc hash tables */
+       luc->events = hashtable_new_str(0);
+       luc->ctx = hashtable_new_str(0);
+
        /* Set trace output path */
-       ret = asprintf(&luc->trace_path, "%s", path);
+       ret = snprintf(luc->trace_path, PATH_MAX, "%s", path);
        if (ret < 0) {
                perror("asprintf ust create channel");
                goto error;
        }
+       CDS_INIT_LIST_HEAD(&luc->stream_list.head);
+
+       DBG2("Trace UST channel %s created", luc->name);
 
        return luc;
 
@@ -161,27 +188,25 @@ error:
 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev)
 {
        struct ltt_ust_event *lue;
-       struct lttng_ust_event *event;
 
        lue = malloc(sizeof(struct ltt_ust_event));
-       event = malloc(sizeof(struct lttng_ust_event));
-       if (lue == NULL || event == NULL) {
-               perror("ust event malloc");
+       if (lue == NULL) {
+               PERROR("ust event malloc");
                goto error;
        }
 
        switch (ev->type) {
        case LTTNG_EVENT_PROBE:
-               event->instrumentation = LTTNG_UST_PROBE;
+               lue->attr.instrumentation = LTTNG_UST_PROBE;
                break;
        case LTTNG_EVENT_FUNCTION:
-               event->instrumentation = LTTNG_UST_FUNCTION;
+               lue->attr.instrumentation = LTTNG_UST_FUNCTION;
                break;
        case LTTNG_EVENT_FUNCTION_ENTRY:
-               event->instrumentation = LTTNG_UST_FUNCTION;
+               lue->attr.instrumentation = LTTNG_UST_FUNCTION;
                break;
        case LTTNG_EVENT_TRACEPOINT:
-               event->instrumentation = LTTNG_UST_TRACEPOINT;
+               lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
                break;
        default:
                ERR("Unknown ust instrumentation type (%d)", ev->type);
@@ -189,14 +214,18 @@ struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev)
        }
 
        /* Copy event name */
-       strncpy(event->name, ev->name, LTTNG_UST_SYM_NAME_LEN);
-       event->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
+       strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
+       lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
 
        /* Setting up a ust event */
        lue->handle = -1;
-       lue->event = event;
        lue->enabled = 1;
-       lue->ctx = NULL;
+
+       /* Init node */
+       hashtable_node_init(&lue->node, (void *) lue->attr.name,
+                       strlen(lue->attr.name));
+       /* Alloc context hash tables */
+       lue->ctx = hashtable_new_str(5);
 
        return lue;
 
@@ -213,27 +242,24 @@ struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
 {
        int ret;
        struct ltt_ust_metadata *lum;
-       struct lttng_ust_channel *attr;
 
        lum = malloc(sizeof(struct ltt_ust_metadata));
-       attr = malloc(sizeof(struct lttng_ust_channel));
-       if (lum == NULL || attr == NULL) {
+       if (lum == NULL) {
                perror("ust metadata malloc");
                goto error;
        }
 
        /* Set default attributes */
-       attr->overwrite = DEFAULT_CHANNEL_OVERWRITE;
-       attr->subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
-       attr->num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
-       attr->switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
-       attr->read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
-       attr->output = DEFAULT_UST_CHANNEL_OUTPUT;
-
-       lum->attr = attr;
+       lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
+       lum->attr.subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
+       lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
+       lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
+       lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
+       lum->attr.output = DEFAULT_UST_CHANNEL_OUTPUT;
+
        lum->handle = -1;
        /* Set metadata trace path */
-       ret = asprintf(&lum->trace_path, "%s/metadata", path);
+       ret = snprintf(lum->pathname, PATH_MAX, "%s/metadata", path);
        if (ret < 0) {
                perror("asprintf ust metadata");
                goto error;
@@ -245,20 +271,59 @@ error:
        return NULL;
 }
 
+/*
+ * RCU safe free context structure.
+ */
+static void destroy_context_rcu(struct rcu_head *head)
+{
+       struct cds_lfht_node *node =
+               caa_container_of(head, struct cds_lfht_node, head);
+       struct ltt_ust_context *ctx =
+               caa_container_of(node, struct ltt_ust_context, node);
+
+       free(ctx);
+}
+
+/*
+ * Cleanup UST context hash table.
+ */
+static void destroy_context(struct cds_lfht *ht)
+{
+       int ret;
+       struct cds_lfht_node *node;
+       struct cds_lfht_iter iter;
+
+       hashtable_get_first(ht, &iter);
+       while ((node = hashtable_iter_get_node(&iter)) != NULL) {
+               ret = hashtable_del(ht, &iter);
+               if (!ret) {
+                       call_rcu(&node->head, destroy_context_rcu);
+               }
+               hashtable_get_next(ht, &iter);
+       }
+}
+
 /*
  * Cleanup ust event structure.
  */
 void trace_ust_destroy_event(struct ltt_ust_event *event)
 {
-       DBG("[trace] Destroy ust event %s", event->event->name);
+       DBG2("Trace destroy UST event %s", event->attr.name);
+       destroy_context(event->ctx);
+       free(event);
+}
 
-       /* Free attributes */
-       free(event->event);
-       free(event->ctx);
+/*
+ * URCU intermediate call to complete destroy event.
+ */
+static void destroy_event_rcu(struct rcu_head *head)
+{
+       struct cds_lfht_node *node =
+               caa_container_of(head, struct cds_lfht_node, head);
+       struct ltt_ust_event *event =
+               caa_container_of(node, struct ltt_ust_event, node);
 
-       /* Remove from event list */
-       cds_list_del(&event->list);
-       free(event);
+       trace_ust_destroy_event(event);
 }
 
 /*
@@ -266,23 +331,41 @@ void trace_ust_destroy_event(struct ltt_ust_event *event)
  */
 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
 {
-       struct ltt_ust_event *event, *etmp;
+       int ret;
+       struct cds_lfht_node *node;
+       struct cds_lfht_iter iter;
 
-       DBG("[trace] Destroy ust channel %d", channel->handle);
+       DBG2("Trace destroy UST channel %s", channel->name);
 
-       free(channel->trace_path);
-       /* Free attributes structure */
-       free(channel->attr);
-       free(channel->ctx);
+       rcu_read_lock();
 
-       /* For each event in the channel list */
-       cds_list_for_each_entry_safe(event, etmp, &channel->events.head, list) {
-               trace_ust_destroy_event(event);
+       hashtable_get_first(channel->events, &iter);
+       while ((node = hashtable_iter_get_node(&iter)) != NULL) {
+               ret = hashtable_del(channel->events, &iter);
+               if (!ret) {
+                       call_rcu(&node->head, destroy_event_rcu);
+               }
+               hashtable_get_next(channel->events, &iter);
        }
 
-       /* Remove from channel list */
-       cds_list_del(&channel->list);
+       free(channel->events);
+       destroy_context(channel->ctx);
        free(channel);
+
+       rcu_read_unlock();
+}
+
+/*
+ * URCU intermediate call to complete destroy channel.
+ */
+static void destroy_channel_rcu(struct rcu_head *head)
+{
+       struct cds_lfht_node *node =
+               caa_container_of(head, struct cds_lfht_node, head);
+       struct ltt_ust_channel *channel =
+               caa_container_of(node, struct ltt_ust_channel, node);
+
+       trace_ust_destroy_channel(channel);
 }
 
 /*
@@ -290,37 +373,104 @@ void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
  */
 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
 {
-       DBG("[trace] Destroy ust metadata %d", metadata->handle);
-
-       /* Free attributes */
-       free(metadata->attr);
-       free(metadata->trace_path);
+       DBG2("Trace UST destroy metadata %d", metadata->handle);
 
        free(metadata);
 }
 
 /*
- * Cleanup ust session structure
+ * Iterate over a hash table containing channels and cleanup safely.
  */
-void trace_ust_destroy_session(struct ltt_ust_session *session)
+static void destroy_channels(struct cds_lfht *channels)
+{
+       int ret;
+       struct cds_lfht_node *node;
+       struct cds_lfht_iter iter;
+
+       hashtable_get_first(channels, &iter);
+       while ((node = hashtable_iter_get_node(&iter)) != NULL) {
+               ret = hashtable_del(channels, &iter);
+               if (!ret) {
+                       call_rcu(&node->head, destroy_channel_rcu);
+               }
+               hashtable_get_next(channels, &iter);
+       }
+}
+
+/*
+ * Cleanup UST pid domain.
+ */
+static void destroy_domain_pid(struct cds_lfht *ht)
+{
+       int ret;
+       struct cds_lfht_node *node;
+       struct cds_lfht_iter iter;
+       struct ltt_ust_domain_pid *d;
+
+       hashtable_get_first(ht, &iter);
+       while ((node = hashtable_iter_get_node(&iter)) != NULL) {
+               ret = hashtable_del(ht , &iter);
+               if (!ret) {
+                       d = caa_container_of(node, struct ltt_ust_domain_pid, node);
+                       destroy_channels(d->channels);
+               }
+               hashtable_get_next(ht, &iter);
+       }
+}
+
+/*
+ * Cleanup UST exec name domain.
+ */
+static void destroy_domain_exec(struct cds_lfht *ht)
 {
-       struct ltt_ust_channel *channel, *ctmp;
+       int ret;
+       struct cds_lfht_node *node;
+       struct cds_lfht_iter iter;
+       struct ltt_ust_domain_exec *d;
+
+       hashtable_get_first(ht, &iter);
+       while ((node = hashtable_iter_get_node(&iter)) != NULL) {
+               ret = hashtable_del(ht , &iter);
+               if (!ret) {
+                       d = caa_container_of(node, struct ltt_ust_domain_exec, node);
+                       destroy_channels(d->channels);
+               }
+               hashtable_get_next(ht, &iter);
+       }
+}
 
-       DBG("[trace] Destroy ust session %d", session->handle);
+/*
+ * Cleanup UST global domain.
+ */
+static void destroy_domain_global(struct ltt_ust_domain_global *dom)
+{
+       destroy_channels(dom->channels);
+}
 
+/*
+ * Cleanup ust session structure
+ */
+void trace_ust_destroy_session(struct ltt_ust_session *session)
+{
        /* Extra safety */
        if (session == NULL) {
                return;
        }
 
+       rcu_read_lock();
+
+       DBG2("Trace UST destroy session %d", session->handle);
+
        if (session->metadata != NULL) {
                trace_ust_destroy_metadata(session->metadata);
        }
 
-       cds_list_for_each_entry_safe(channel, ctmp, &session->channels.head, list) {
-               trace_ust_destroy_channel(channel);
-       }
+       /* Cleaning up UST domain */
+       destroy_domain_global(&session->domain_global);
+       destroy_domain_pid(session->domain_pid);
+       destroy_domain_exec(session->domain_exec);
 
-       free(session->path);
        free(session);
+
+       rcu_read_unlock();
 }
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