Update readme

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

diff --git a/ltt-events.c b/ltt-events.c
index a4bc1544189acb35fe623ccba2a59186257b0f16..e9e076d802238bc07e1aef14e0bb4f1e2914df6b 100644 (file)
--- a/ltt-events.c
+++ b/ltt-events.c
@@ -4,6 +4,8 @@
  * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
  * Holds LTTng per-session event registry.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
  */
 
 #include <linux/module.h>
@@ -12,7 +14,7 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/jiffies.h>
-#include <linux/uuid.h>
+#include "wrapper/uuid.h"
 #include "wrapper/vmalloc.h"   /* for wrapper_vmalloc_sync_all() */
 #include "ltt-events.h"
 #include "ltt-tracer.h"
@@ -32,8 +34,6 @@ int _ltt_event_metadata_statedump(struct ltt_session *session,
 static
 int _ltt_session_metadata_statedump(struct ltt_session *session);
 
-
-static
 void synchronize_trace(void)
 {
        synchronize_sched();
@@ -80,7 +80,7 @@ void ltt_session_destroy(struct ltt_session *session)
        kfree(session);
 }
 
-int ltt_session_start(struct ltt_session *session)
+int ltt_session_enable(struct ltt_session *session)
 {
        int ret = 0;
        struct ltt_channel *chan;
@@ -106,18 +106,15 @@ int ltt_session_start(struct ltt_session *session)
 
        ACCESS_ONCE(session->active) = 1;
        ACCESS_ONCE(session->been_active) = 1;
-       synchronize_trace();    /* Wait for in-flight events to complete */
        ret = _ltt_session_metadata_statedump(session);
-       if (ret) {
+       if (ret)
                ACCESS_ONCE(session->active) = 0;
-               synchronize_trace();    /* Wait for in-flight events to complete */
-       }
 end:
        mutex_unlock(&sessions_mutex);
        return ret;
 }
 
-int ltt_session_stop(struct ltt_session *session)
+int ltt_session_disable(struct ltt_session *session)
 {
        int ret = 0;
 
@@ -127,12 +124,59 @@ int ltt_session_stop(struct ltt_session *session)
                goto end;
        }
        ACCESS_ONCE(session->active) = 0;
-       synchronize_trace();    /* Wait for in-flight events to complete */
 end:
        mutex_unlock(&sessions_mutex);
        return ret;
 }
 
+int ltt_channel_enable(struct ltt_channel *channel)
+{
+       int old;
+
+       if (channel == channel->session->metadata)
+               return -EPERM;
+       old = xchg(&channel->enabled, 1);
+       if (old)
+               return -EEXIST;
+       return 0;
+}
+
+int ltt_channel_disable(struct ltt_channel *channel)
+{
+       int old;
+
+       if (channel == channel->session->metadata)
+               return -EPERM;
+       old = xchg(&channel->enabled, 0);
+       if (!old)
+               return -EEXIST;
+       return 0;
+}
+
+int ltt_event_enable(struct ltt_event *event)
+{
+       int old;
+
+       if (event->chan == event->chan->session->metadata)
+               return -EPERM;
+       old = xchg(&event->enabled, 1);
+       if (old)
+               return -EEXIST;
+       return 0;
+}
+
+int ltt_event_disable(struct ltt_event *event)
+{
+       int old;
+
+       if (event->chan == event->chan->session->metadata)
+               return -EPERM;
+       old = xchg(&event->enabled, 0);
+       if (!old)
+               return -EEXIST;
+       return 0;
+}
+
 static struct ltt_transport *ltt_transport_find(const char *name)
 {
        struct ltt_transport *transport;
@@ -167,7 +211,6 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session,
        if (!chan)
                goto nomem;
        chan->session = session;
-       init_waitqueue_head(&chan->notify_wait);
        chan->id = session->free_chan_id++;
        /*
         * Note: the channel creation op already writes into the packet
@@ -179,6 +222,7 @@ struct ltt_channel *ltt_channel_create(struct ltt_session *session,
                        read_timer_interval);
        if (!chan->chan)
                goto create_error;
+       chan->enabled = 1;
        chan->ops = &transport->ops;
        list_add(&chan->list, &session->chan);
        mutex_unlock(&sessions_mutex);
@@ -231,6 +275,7 @@ struct ltt_event *ltt_event_create(struct ltt_channel *chan,
        event->chan = chan;
        event->filter = filter;
        event->id = chan->free_event_id++;
+       event->enabled = 1;
        event->instrumentation = event_param->instrumentation;
        /* Populate ltt_event structure before tracepoint registration. */
        smp_wmb();
@@ -383,7 +428,7 @@ int lttng_metadata_printf(struct ltt_session *session,
                 * we need to bail out after timeout or being
                 * interrupted.
                 */
-               waitret = wait_event_interruptible_timeout(*chan->ops->get_reader_wait_queue(chan),
+               waitret = wait_event_interruptible_timeout(*chan->ops->get_reader_wait_queue(chan->chan),
                        ({
                                ret = chan->ops->event_reserve(&ctx, 0);
                                ret != -ENOBUFS || !ret;
@@ -397,7 +442,7 @@ int lttng_metadata_printf(struct ltt_session *session,
                                ret = waitret;
                        goto end;
                }
-               chan->ops->event_write(&ctx, &str[pos], len);
+               chan->ops->event_write(&ctx, &str[pos], reserve_len);
                chan->ops->event_commit(&ctx);
        }
 end:
@@ -470,9 +515,8 @@ int _ltt_field_statedump(struct ltt_session *session,
                length_type = &field->type.u.sequence.length_type;
                ret = lttng_metadata_printf(session,
                        "               integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
-                       "               integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[ __%s_length ];\n",
                        length_type->u.basic.integer.size,
-                       length_type->u.basic.integer.alignment,
+                       (unsigned int) length_type->u.basic.integer.alignment,
                        length_type->u.basic.integer.signedness,
                        (length_type->u.basic.integer.encoding == lttng_encode_none)
                                ? "none"
@@ -485,9 +529,14 @@ int _ltt_field_statedump(struct ltt_session *session,
 #else
                        length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
 #endif
-                       field->name,
+                       field->name);
+               if (ret)
+                       return ret;
+
+               ret = lttng_metadata_printf(session,
+                       "               integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[ __%s_length ];\n",
                        elem_type->u.basic.integer.size,
-                       elem_type->u.basic.integer.alignment,
+                       (unsigned int) elem_type->u.basic.integer.alignment,
                        elem_type->u.basic.integer.signedness,
                        (elem_type->u.basic.integer.encoding == lttng_encode_none)
                                ? "none"
@@ -501,8 +550,7 @@ int _ltt_field_statedump(struct ltt_session *session,
                        elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
 #endif
                        field->name,
-                       field->name
-                       );
+                       field->name);
                break;
        }