Packet headers and alignment

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

diff --git a/ltt-events.c b/ltt-events.c
index 1d729210f83049ba3fcc7f5364988afedcfaf901..db1ac86fef6573645fc42edd0ae46f32fcfbd333 100644 (file)
--- a/ltt-events.c
+++ b/ltt-events.c
@@ -12,6 +12,7 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/jiffies.h>
+#include <linux/uuid.h>
 #include "wrapper/vmalloc.h"   /* for wrapper_vmalloc_sync_all() */
 #include "ltt-events.h"
 #include "ltt-tracer.h"
@@ -48,6 +49,7 @@ struct ltt_session *ltt_session_create(void)
                return NULL;
        INIT_LIST_HEAD(&session->chan);
        INIT_LIST_HEAD(&session->events);
+       uuid_le_gen(&session->uuid);
        list_add(&session->list, &sessions);
        mutex_unlock(&sessions_mutex);
        return session;
@@ -316,10 +318,11 @@ int lttng_metadata_printf(struct ltt_session *session,
                        ret != -ENOBUFS || !ret;
                }),
                msecs_to_jiffies(LTTNG_METADATA_TIMEOUT_MSEC));
-       if (waitret || ret) {
+       if (!waitret || waitret == -ERESTARTSYS || ret) {
                printk(KERN_WARNING "LTTng: Failure to write metadata to buffers (%s)\n",
                        waitret == -ERESTARTSYS ? "interrupted" :
                                (ret == -ENOBUFS ? "timeout" : "I/O error"));
+               printk("waitret %d retval %d\n", waitret, ret);
                if (waitret == -ERESTARTSYS)
                        ret = waitret;
                goto end;
@@ -459,7 +462,7 @@ int _ltt_event_metadata_statedump(struct ltt_session *session,
         */
        ret = lttng_metadata_printf(session,
                "       } aligned(%u);\n"
-               "};\n", ltt_get_header_alignment());
+               "};\n\n", ltt_get_header_alignment());
        if (ret)
                goto end;
 
@@ -488,7 +491,7 @@ int _ltt_channel_metadata_statedump(struct ltt_session *session,
                "stream {\n"
                "       id = %u;\n"
                "       event.header := %s;\n",
-               "};\n",
+               "};\n\n",
                chan->id,
                chan->header_type == 1 ? "struct event_header_compact" :
                        "struct event_header_large");
@@ -506,6 +509,7 @@ end:
 static
 int _ltt_session_metadata_statedump(struct ltt_session *session)
 {
+       char uuid_s[37];
        struct ltt_channel *chan;
        struct ltt_event *event;
        int ret = 0;
@@ -519,6 +523,49 @@ int _ltt_session_metadata_statedump(struct ltt_session *session)
                return -EPERM;
        }
 
+       snprintf(uuid_s, sizeof(uuid_s),
+               "%x%x%x%x-%x%x-%x%x-%x%x-%x%x%x%x%x%x",
+               uuid_s[0], uuid_s[1], uuid_s[2], uuid_s[3],
+               uuid_s[4], uuid_s[5], uuid_s[6], uuid_s[7],
+               uuid_s[8], uuid_s[9], uuid_s[10], uuid_s[11],
+               uuid_s[12], uuid_s[13], uuid_s[14], uuid_s[15]);
+
+       ret = lttng_metadata_printf(session,
+               "typealias integer {size = 8; align = %u; signed = false; } := uint8_t;\n"
+               "typealias integer {size = 32; align = %u; signed = false; } := uint32_t;\n"
+               "typealias integer {size = 64; align = %u; signed = false; } := uint64_t;\n"
+               "\n"
+               "trace {\n"
+               "       major = %u;\n"
+               "       minor = %u;\n"
+               "       uuid = %s;\n"
+               "       byte_order = %s;\n"
+               "       packet.header := struct {\n"
+               "               uint32_t magic;\n"
+               "               uint8_t  trace_uuid[16];\n"
+               "               uint32_t stream_id;\n"
+               "               uint64_t timestamp_begin;\n"
+               "               uint64_t timestamp_end;\n"
+               "               uint32_t content_size;\n"
+               "               uint32_t packet_size;\n"
+               "               uint32_t events_lost;\n"
+               "       };\n",
+               "};\n\n",
+               ltt_alignof(uint8_t) * CHAR_BIT,
+               ltt_alignof(uint32_t) * CHAR_BIT,
+               ltt_alignof(uint64_t) * CHAR_BIT,
+               CTF_VERSION_MAJOR,
+               CTF_VERSION_MINOR,
+               uuid_s,
+#ifdef __BIG_ENDIAN
+               "be"
+#else
+               "le"
+#endif
+               );
+       if (ret)
+               goto end;
+
 skip_session:
        list_for_each_entry(chan, &session->chan, list) {
                ret = _ltt_channel_metadata_statedump(session, chan);