Sessiond timer thread

[lttng-tools.git] / src / bin / lttng-sessiond / kernel.c

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index 2cbed381870a096350a4e8ac77ec39845850d0f1..e5f068a0cd9515408a34b4621201e8b75f714a81 100644 (file)
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -34,6 +34,12 @@
 #include "kern-modules.h"
 #include "utils.h"
 
+/*
+ * Key used to reference a channel between the sessiond and the consumer. This
+ * is only read and updated with the session_list lock held.
+ */
+static uint64_t next_kernel_channel_key;
+
 /*
  * Add context on a kernel channel.
  *
@@ -169,8 +175,10 @@ int kernel_create_channel(struct ltt_kernel_session *session,
        cds_list_add(&lkc->list, &session->channel_list.head);
        session->channel_count++;
        lkc->session = session;
+       lkc->key = ++next_kernel_channel_key;
 
-       DBG("Kernel channel %s created (fd: %d)", lkc->channel->name, lkc->fd);
+       DBG("Kernel channel %s created (fd: %d, key: %" PRIu64 ")",
+                       lkc->channel->name, lkc->fd, lkc->key);
 
        return 0;
 
@@ -291,7 +299,8 @@ int kernel_disable_channel(struct ltt_kernel_channel *chan)
        }
 
        chan->enabled = 0;
-       DBG("Kernel channel %s disabled (fd: %d)", chan->channel->name, chan->fd);
+       DBG("Kernel channel %s disabled (fd: %d, key: %" PRIu64 ")",
+                       chan->channel->name, chan->fd, chan->key);
 
        return 0;
 
@@ -315,7 +324,8 @@ int kernel_enable_channel(struct ltt_kernel_channel *chan)
        }
 
        chan->enabled = 1;
-       DBG("Kernel channel %s enabled (fd: %d)", chan->channel->name, chan->fd);
+       DBG("Kernel channel %s enabled (fd: %d, key: %" PRIu64 ")",
+                       chan->channel->name, chan->fd, chan->key);
 
        return 0;
 
@@ -525,6 +535,7 @@ int kernel_open_metadata(struct ltt_kernel_session *session)
        }
 
        lkm->fd = ret;
+       lkm->key = ++next_kernel_channel_key;
        /* Prevent fd duplication after execlp() */
        ret = fcntl(lkm->fd, F_SETFD, FD_CLOEXEC);
        if (ret < 0) {
@@ -814,38 +825,38 @@ error:
 /*
  * Get kernel version and validate it.
  */
-int kernel_validate_version(int tracer_fd)
+int kernel_validate_version(int tracer_fd,
+               struct lttng_kernel_tracer_version *version,
+               struct lttng_kernel_tracer_abi_version *abi_version)
 {
        int ret;
-       struct lttng_kernel_tracer_version version;
-       struct lttng_kernel_tracer_abi_version abi_version;
 
-       ret = kernctl_tracer_version(tracer_fd, &version);
+       ret = kernctl_tracer_version(tracer_fd, version);
        if (ret < 0) {
                ERR("Failed to retrieve the lttng-modules version");
                goto error;
        }
 
        /* Validate version */
-       if (version.major != VERSION_MAJOR) {
+       if (version->major != VERSION_MAJOR) {
                ERR("Kernel tracer major version (%d) is not compatible with lttng-tools major version (%d)",
-                       version.major, VERSION_MAJOR);
+                       version->major, VERSION_MAJOR);
                goto error_version;
        }
-       ret = kernctl_tracer_abi_version(tracer_fd, &abi_version);
+       ret = kernctl_tracer_abi_version(tracer_fd, abi_version);
        if (ret < 0) {
                ERR("Failed to retrieve lttng-modules ABI version");
                goto error;
        }
-       if (abi_version.major != LTTNG_MODULES_ABI_MAJOR_VERSION) {
+       if (abi_version->major != LTTNG_MODULES_ABI_MAJOR_VERSION) {
                ERR("Kernel tracer ABI version (%d.%d) does not match the expected ABI major version (%d.*)",
-                       abi_version.major, abi_version.minor,
+                       abi_version->major, abi_version->minor,
                        LTTNG_MODULES_ABI_MAJOR_VERSION);
                goto error;
        }
        DBG2("Kernel tracer version validated (%d.%d, ABI %d.%d)",
-                       version.major, version.minor,
-                       abi_version.major, abi_version.minor);
+                       version->major, version->minor,
+                       abi_version->major, abi_version->minor);
        return 0;
 
 error_version:
@@ -1029,12 +1040,10 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
 
                /* For each channel, ask the consumer to snapshot it. */
                cds_list_for_each_entry(chan, &ksess->channel_list.head, list) {
-                       pthread_mutex_lock(socket->lock);
-                       ret = consumer_snapshot_channel(socket, chan->fd, output, 0,
+                       ret = consumer_snapshot_channel(socket, chan->key, output, 0,
                                        ksess->uid, ksess->gid,
                                        DEFAULT_KERNEL_TRACE_DIR, wait,
                                        nb_packets_per_stream);
-                       pthread_mutex_unlock(socket->lock);
                        if (ret < 0) {
                                ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
                                (void) kernel_consumer_destroy_metadata(socket,
@@ -1044,11 +1053,9 @@ int kernel_snapshot_record(struct ltt_kernel_session *ksess,
                }
 
                /* Snapshot metadata, */
-               pthread_mutex_lock(socket->lock);
-               ret = consumer_snapshot_channel(socket, ksess->metadata->fd, output,
+               ret = consumer_snapshot_channel(socket, ksess->metadata->key, output,
                                1, ksess->uid, ksess->gid,
                                DEFAULT_KERNEL_TRACE_DIR, wait, 0);
-               pthread_mutex_unlock(socket->lock);
                if (ret < 0) {
                        ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
                        goto error_consumer;