Add wildcard support
authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Tue, 6 Dec 2011 19:58:27 +0000 (14:58 -0500)
committerMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Tue, 6 Dec 2011 19:58:27 +0000 (14:58 -0500)
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
include/lttng/ust-events.h
liblttng-ust/ltt-events.c
liblttng-ust/ltt-probes.c
liblttng-ust/lttng-ust-abi.c

index 7f5cff846f52dd2b2099023007421759ad9fa3d6..b74a176755af19f0bc12da564035a14db5bd3877 100644 (file)
@@ -216,6 +216,31 @@ struct loglevel_entry {
        char name[0];
 };
 
+/*
+ * Entry describing a per-session active wildcard, along with the event
+ * attribute and channel information configuring the events that need to
+ * be enabled.
+ */
+struct session_wildcard {
+       struct ltt_channel *chan;
+       struct lttng_ctx *ctx;  /* TODO */
+       struct lttng_ust_event event_param;
+       struct cds_list_head events;    /* list of events enabled */
+       struct cds_list_head list;      /* per-session list of wildcards */
+       struct cds_list_head session_list;
+       struct wildcard_entry *entry;
+       unsigned int enabled:1;
+};
+
+/*
+ * Entry describing an active wildcard (per name) for all sessions.
+ */
+struct wildcard_entry {
+       struct cds_list_head list;
+       struct cds_list_head session_list;
+       char name[0];
+};
+
 struct lttng_event_desc {
        const char *name;
        void *probe_callback;
@@ -265,6 +290,7 @@ struct ltt_event {
        } u;
        struct cds_list_head list;              /* Event list */
        struct cds_list_head loglevel_list;     /* Event list for loglevel */
+       struct cds_list_head wildcard_list;     /* Event list for wildcard */
        struct ust_pending_probe *pending_probe;
        unsigned int metadata_dumped:1;
 };
@@ -342,6 +368,7 @@ struct ltt_session {
        struct cds_list_head chan;      /* Channel list head */
        struct cds_list_head events;    /* Event list head */
        struct cds_list_head loglevels; /* Loglevel list head */
+       struct cds_list_head wildcards; /* Wildcard list head */
        struct cds_list_head list;      /* Session list */
        unsigned int free_chan_id;      /* Next chan ID to allocate */
        uuid_t uuid;                    /* Trace session unique ID */
@@ -433,4 +460,15 @@ int ltt_loglevel_create(struct ltt_channel *chan,
        struct lttng_ust_event *event_param,
        struct session_loglevel **sl);
 
+struct wildcard_entry *match_wildcard(const char *name);
+struct session_wildcard *add_wildcard(const char *name,
+       struct ltt_channel *chan,
+       struct lttng_ust_event *event_param);
+void _remove_wildcard(struct session_wildcard *wildcard);
+int ltt_wildcard_enable(struct session_wildcard *wildcard);
+int ltt_wildcard_disable(struct session_wildcard *wildcard);
+int ltt_wildcard_create(struct ltt_channel *chan,
+       struct lttng_ust_event *event_param,
+       struct session_wildcard **sl);
+
 #endif /* _LTTNG_UST_EVENTS_H */
index 7882f6d2a63b84fdc0a2659b69d3e6e6d99027c0..9650e8b0703d608492d61ac273e1ef6f1768296b 100644 (file)
@@ -75,6 +75,7 @@ struct ust_pending_probe {
 
 static void _ltt_event_destroy(struct ltt_event *event);
 static void _ltt_loglevel_destroy(struct session_loglevel *sl);
+static void _ltt_wildcard_destroy(struct session_wildcard *sw);
 static void _ltt_channel_destroy(struct ltt_channel *chan);
 static int _ltt_event_unregister(struct ltt_event *event);
 static
@@ -176,6 +177,38 @@ int pending_probe_fix_events(const struct lttng_event_desc *desc)
                }
        }
 
+       /* Wildcard */
+       {
+               struct wildcard_entry *wildcard;
+
+               wildcard = match_wildcard(desc->name);
+               if (strcmp(desc->name, "lttng_ust:metadata") && wildcard) {
+                       struct session_wildcard *sw;
+
+                       cds_list_for_each_entry(sw, &wildcard->session_list,
+                                       session_list) {
+                               struct ltt_event *ev;
+                               int ret;
+
+                               memcpy(&event_param, &sw->event_param,
+                                               sizeof(event_param));
+                               memcpy(event_param.name,
+                                       desc->name,
+                                       sizeof(event_param.name));
+                               /* create event */
+                               ret = ltt_event_create(sw->chan,
+                                       &event_param, NULL,
+                                       &ev);
+                               if (ret) {
+                                       DBG("Error creating event");
+                                       continue;
+                               }
+                               cds_list_add(&ev->wildcard_list,
+                                       &sw->events);
+                       }
+               }
+       }
+
        head = &pending_probe_table[hash & (PENDING_PROBE_HASH_SIZE - 1)];
        cds_hlist_for_each_entry_safe(e, node, p, head, node) {
                struct ltt_event *event;
@@ -216,6 +249,7 @@ struct ltt_session *ltt_session_create(void)
        CDS_INIT_LIST_HEAD(&session->chan);
        CDS_INIT_LIST_HEAD(&session->events);
        CDS_INIT_LIST_HEAD(&session->loglevels);
+       CDS_INIT_LIST_HEAD(&session->wildcards);
        uuid_generate(session->uuid);
        cds_list_add(&session->list, &sessions);
        return session;
@@ -226,6 +260,7 @@ void ltt_session_destroy(struct ltt_session *session)
        struct ltt_channel *chan, *tmpchan;
        struct ltt_event *event, *tmpevent;
        struct session_loglevel *loglevel, *tmploglevel;
+       struct session_wildcard *wildcard, *tmpwildcard;
        int ret;
 
        CMM_ACCESS_ONCE(session->active) = 0;
@@ -236,6 +271,8 @@ void ltt_session_destroy(struct ltt_session *session)
        synchronize_trace();    /* Wait for in-flight events to complete */
        cds_list_for_each_entry_safe(loglevel, tmploglevel, &session->loglevels, list)
                _ltt_loglevel_destroy(loglevel);
+       cds_list_for_each_entry_safe(wildcard, tmpwildcard, &session->wildcards, list)
+               _ltt_wildcard_destroy(wildcard);
        cds_list_for_each_entry_safe(event, tmpevent, &session->events, list)
                _ltt_event_destroy(event);
        cds_list_for_each_entry_safe(chan, tmpchan, &session->chan, list)
@@ -413,6 +450,26 @@ void _ltt_loglevel_destroy(struct session_loglevel *sl)
        _remove_loglevel(sl);
 }
 
+int ltt_wildcard_create(struct ltt_channel *chan,
+       struct lttng_ust_event *event_param,
+       struct session_wildcard **_sw)
+{
+       struct session_wildcard *sw;
+
+       sw = add_wildcard(event_param->name, chan, event_param);
+       if (!sw || IS_ERR(sw)) {
+               return PTR_ERR(sw);
+       }
+       *_sw = sw;
+       return 0;
+}
+
+static
+void _ltt_wildcard_destroy(struct session_wildcard *sw)
+{
+       _remove_wildcard(sw);
+}
+
 /*
  * Supports event creation while tracing session is active.
  */
@@ -810,6 +867,19 @@ int _ltt_event_metadata_statedump(struct ltt_session *session,
        if (ret)
                goto end;
 
+       if (event->desc->loglevel) {
+               const struct tracepoint_loglevel_entry *ll_entry;
+
+               ll_entry = *event->desc->loglevel;
+               ret = lttng_metadata_printf(session,
+                       "       loglevel.identifier = \"%s\";\n"
+                       "       loglevel.value = %lld;\n",
+                       ll_entry->identifier,
+                       (long long) ll_entry->value);
+               if (ret)
+                       goto end;
+       }
+
        if (event->ctx) {
                ret = lttng_metadata_printf(session,
                        "       context := struct {\n");
index b683b81bb24107a769cbdfe3eaeedb0be1ac85c7..9667497aac6e5f66f8309237365c6ac1851f5578 100644 (file)
@@ -34,6 +34,12 @@ static CDS_LIST_HEAD(probe_list);
 #define LOGLEVEL_TABLE_SIZE (1 << LOGLEVEL_HASH_BITS)
 static struct cds_hlist_head loglevel_table[LOGLEVEL_TABLE_SIZE];
 
+/*
+ * Wildcard list, containing the active wildcards.
+ * Protected by ust lock.
+ */
+static CDS_LIST_HEAD(wildcard_list);
+
 static
 const struct lttng_probe_desc *find_provider(const char *provider)
 {
@@ -416,3 +422,193 @@ int ltt_loglevel_disable(struct session_loglevel *loglevel)
        loglevel->enabled = 0;
        return 0;
 }
+
+/* WILDCARDS */
+
+/*
+ * Return wildcard for a given event name if the event name match the
+ * one of the wildcards.
+ * Must be called with ust lock held.
+ * Returns NULL if not present.
+ */
+struct wildcard_entry *match_wildcard(const char *name)
+{
+       struct wildcard_entry *e;
+
+       cds_list_for_each_entry(e, &wildcard_list, list) {
+               /* If only contain '*' */
+               if (strlen(e->name) == 1)
+                       return e;
+               /* Compare excluding final '*' */
+               if (!strncmp(name, e->name, strlen(e->name) - 1))
+                       return e;
+       }
+       return NULL;
+}
+
+/*
+ * marshall all probes/all events and create those that fit the
+ * wildcard. Add them to the events list as created.
+ */
+static
+void _probes_create_wildcard_events(struct wildcard_entry *entry,
+                               struct session_wildcard *wildcard)
+{
+       struct lttng_probe_desc *probe_desc;
+       struct lttng_ust_event event_param;
+       int i;
+
+       cds_list_for_each_entry(probe_desc, &probe_list, head) {
+               for (i = 0; i < probe_desc->nr_events; i++) {
+                       const struct lttng_event_desc *event_desc;
+                       int match = 0;
+
+                       event_desc = probe_desc->event_desc[i];
+                       /* compare excluding final '*' */
+                       assert(strlen(entry->name) > 0);
+                       if (strcmp(event_desc->name, "lttng_ust:metadata")
+                                       && (strlen(entry->name) == 1
+                                               || !strncmp(event_desc->name, entry->name,
+                                                       strlen(entry->name) - 1))) {
+                               match = 1;
+                       }
+                       if (match) {
+                               struct ltt_event *ev;
+                               int ret;
+
+                               memcpy(&event_param, &wildcard->event_param,
+                                               sizeof(event_param));
+                               memcpy(event_param.name,
+                                       event_desc->name,
+                                       sizeof(event_param.name));
+                               /* create event */
+                               ret = ltt_event_create(wildcard->chan,
+                                       &event_param, NULL,
+                                       &ev);
+                               if (ret) {
+                                       DBG("Error creating event");
+                                       continue;
+                               }
+                               cds_list_add(&ev->wildcard_list,
+                                       &wildcard->events);
+                       }
+               }
+       }
+}
+
+/*
+ * Add the wildcard to the wildcard hash table. Must be called with
+ * ust lock held.
+ */
+struct session_wildcard *add_wildcard(const char *name,
+       struct ltt_channel *chan,
+       struct lttng_ust_event *event_param)
+{
+       struct wildcard_entry *e;
+       struct session_wildcard *sw;
+       size_t name_len = strlen(name) + 1;
+       int found = 0;
+
+       /* wildcard entry */
+       cds_list_for_each_entry(e, &wildcard_list, list) {
+               if (!strcmp(name, e->name)) {
+                       found = 1;
+                       break;
+               }
+       }
+
+       if (!found) {
+               /*
+                * Using zmalloc here to allocate a variable length element. Could
+                * cause some memory fragmentation if overused.
+                */
+               e = zmalloc(sizeof(struct wildcard_entry) + name_len);
+               if (!e)
+                       return ERR_PTR(-ENOMEM);
+               memcpy(&e->name[0], name, name_len);
+               cds_list_add(&e->list, &wildcard_list);
+               CDS_INIT_LIST_HEAD(&e->session_list);
+       }
+
+       /* session wildcard */
+       cds_list_for_each_entry(sw, &e->session_list, session_list) {
+               if (chan == sw->chan) {
+                       DBG("wildcard %s busy for this channel", name);
+                       return ERR_PTR(-EEXIST);        /* Already there */
+               }
+       }
+       sw = zmalloc(sizeof(struct session_wildcard));
+       if (!sw)
+               return ERR_PTR(-ENOMEM);
+       sw->chan = chan;
+       sw->enabled = 1;
+       memcpy(&sw->event_param, event_param, sizeof(sw->event_param));
+       sw->event_param.instrumentation = LTTNG_UST_TRACEPOINT;
+       CDS_INIT_LIST_HEAD(&sw->events);
+       cds_list_add(&sw->list, &chan->session->wildcards);
+       cds_list_add(&sw->session_list, &e->session_list);
+       sw->entry = e;
+       _probes_create_wildcard_events(e, sw);
+       return sw;
+}
+
+/*
+ * Remove the wildcard from the wildcard hash table. Must be called with
+ * ust_lock held. Only called at session teardown.
+ */
+void _remove_wildcard(struct session_wildcard *wildcard)
+{
+       struct ltt_event *ev, *tmp;
+
+       /*
+        * Just remove the events owned (for enable/disable) by this
+        * wildcard from the list. The session teardown will take care
+        * of freeing the event memory.
+        */
+       cds_list_for_each_entry_safe(ev, tmp, &wildcard->events, list) {
+               cds_list_del(&ev->list);
+       }
+       cds_list_del(&wildcard->session_list);
+       cds_list_del(&wildcard->list);
+       if (cds_list_empty(&wildcard->entry->session_list)) {
+               cds_list_del(&wildcard->entry->list);
+               free(wildcard->entry);
+       }
+       free(wildcard);
+}
+
+int ltt_wildcard_enable(struct session_wildcard *wildcard)
+{
+       struct ltt_event *ev;
+       int ret;
+
+       if (wildcard->enabled)
+               return -EEXIST;
+       cds_list_for_each_entry(ev, &wildcard->events, list) {
+               ret = ltt_event_enable(ev);
+               if (ret) {
+                       DBG("Error: enable error.\n");
+                       return ret;
+               }
+       }
+       wildcard->enabled = 1;
+       return 0;
+}
+
+int ltt_wildcard_disable(struct session_wildcard *wildcard)
+{
+       struct ltt_event *ev;
+       int ret;
+
+       if (!wildcard->enabled)
+               return -EEXIST;
+       cds_list_for_each_entry(ev, &wildcard->events, list) {
+               ret = ltt_event_disable(ev);
+               if (ret) {
+                       DBG("Error: disable error.\n");
+                       return ret;
+               }
+       }
+       wildcard->enabled = 0;
+       return 0;
+}
index 25f213bbc1ce1bf72fd09194459177f9bfce5064..716a2cc9d1a13efe8d8e943a6c41ad6c98395413 100644 (file)
@@ -204,6 +204,7 @@ static const struct lttng_ust_objd_ops lttng_channel_ops;
 static const struct lttng_ust_objd_ops lttng_metadata_ops;
 static const struct lttng_ust_objd_ops lttng_event_ops;
 static const struct lttng_ust_objd_ops lttng_loglevel_ops;
+static const struct lttng_ust_objd_ops lttng_wildcard_ops;
 static const struct lttng_ust_objd_ops lib_ring_buffer_objd_ops;
 static const struct lttng_ust_objd_ops lttng_tracepoint_list_ops;
 
@@ -697,6 +698,44 @@ objd_error:
        return ret;
 }
 
+static
+int lttng_abi_create_wildcard(int channel_objd,
+                             struct lttng_ust_event *event_param)
+{
+       struct ltt_channel *channel = objd_private(channel_objd);
+       struct session_wildcard *wildcard;
+       int wildcard_objd, ret;
+
+       event_param->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
+       wildcard_objd = objd_alloc(NULL, &lttng_wildcard_ops);
+       if (wildcard_objd < 0) {
+               ret = wildcard_objd;
+               goto objd_error;
+       }
+       /*
+        * We tolerate no failure path after wildcard creation. It will
+        * stay invariant for the rest of the session.
+        */
+       ret = ltt_wildcard_create(channel, event_param, &wildcard);
+       if (ret < 0) {
+               goto wildcard_error;
+       }
+       objd_set_private(wildcard_objd, wildcard);
+       /* The wildcard holds a reference on the channel */
+       objd_ref(channel_objd);
+       return wildcard_objd;
+
+wildcard_error:
+       {
+               int err;
+
+               err = lttng_ust_objd_unref(wildcard_objd);
+               assert(!err);
+       }
+objd_error:
+       return ret;
+}
+
 /**
  *     lttng_channel_cmd - lttng control through object descriptors
  *
@@ -740,7 +779,12 @@ long lttng_channel_cmd(int objd, unsigned int cmd, unsigned long arg)
                if (event_param->instrumentation == LTTNG_UST_TRACEPOINT_LOGLEVEL) {
                        return lttng_abi_create_loglevel(objd, event_param);
                } else {
-                       return lttng_abi_create_event(objd, event_param);
+                       if (event_param->name[strlen(event_param->name) - 1] == '*') {
+                               /* If ends with wildcard, create wildcard. */
+                               return lttng_abi_create_wildcard(objd, event_param);
+                       } else {
+                               return lttng_abi_create_event(objd, event_param);
+                       }
                }
        }
        case LTTNG_UST_CONTEXT:
@@ -1003,6 +1047,60 @@ static const struct lttng_ust_objd_ops lttng_loglevel_ops = {
        .cmd = lttng_loglevel_cmd,
 };
 
+/**
+ *     lttng_wildcard_cmd - lttng control through object descriptors
+ *
+ *     @objd: the object descriptor
+ *     @cmd: the command
+ *     @arg: command arg
+ *
+ *     This object descriptor implements lttng commands:
+ *     LTTNG_UST_CONTEXT
+ *             Prepend a context field to each record of events of this
+ *             wildcard.
+ *     LTTNG_UST_ENABLE
+ *             Enable recording for these wildcard events (weak enable)
+ *     LTTNG_UST_DISABLE
+ *             Disable recording for these wildcard events (strong disable)
+ */
+static
+long lttng_wildcard_cmd(int objd, unsigned int cmd, unsigned long arg)
+{
+       struct session_wildcard *wildcard = objd_private(objd);
+
+       switch (cmd) {
+       case LTTNG_UST_CONTEXT:
+               return -ENOSYS; /* not implemented yet */
+#if 0
+               return lttng_abi_add_context(objd,
+                               (struct lttng_ust_context *) arg,
+                               &wildcard->ctx, wildcard->chan->session);
+#endif
+       case LTTNG_UST_ENABLE:
+               return ltt_wildcard_enable(wildcard);
+       case LTTNG_UST_DISABLE:
+               return ltt_wildcard_disable(wildcard);
+       default:
+               return -EINVAL;
+       }
+}
+
+static
+int lttng_wildcard_release(int objd)
+{
+       struct session_wildcard *wildcard = objd_private(objd);
+
+       if (wildcard)
+               return lttng_ust_objd_unref(wildcard->chan->objd);
+       return 0;
+}
+
+/* TODO: filter control ioctl */
+static const struct lttng_ust_objd_ops lttng_wildcard_ops = {
+       .release = lttng_wildcard_release,
+       .cmd = lttng_wildcard_cmd,
+};
+
 void lttng_ust_abi_exit(void)
 {
        lttng_ust_abi_close_in_progress = 1;
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