Introduce ustctl_write_one_packet_to_channel

[lttng-ust.git] / liblttng-ust-ctl / ustctl.c

diff --git a/liblttng-ust-ctl/ustctl.c b/liblttng-ust-ctl/ustctl.c
index 67aae68294fdfcf64782fe291568e14f5b3d3544..28dee5e9cdf80118113f53522dc296460f66b1af 100644 (file)
--- a/liblttng-ust-ctl/ustctl.c
+++ b/liblttng-ust-ctl/ustctl.c
@@ -63,10 +63,14 @@ struct ustctl_consumer_stream {
 };
 
 extern void lttng_ring_buffer_client_overwrite_init(void);
+extern void lttng_ring_buffer_client_overwrite_rt_init(void);
 extern void lttng_ring_buffer_client_discard_init(void);
+extern void lttng_ring_buffer_client_discard_rt_init(void);
 extern void lttng_ring_buffer_metadata_client_init(void);
 extern void lttng_ring_buffer_client_overwrite_exit(void);
+extern void lttng_ring_buffer_client_overwrite_rt_exit(void);
 extern void lttng_ring_buffer_client_discard_exit(void);
+extern void lttng_ring_buffer_client_discard_rt_exit(void);
 extern void lttng_ring_buffer_metadata_client_exit(void);
 
 volatile enum ust_loglevel ust_loglevel;
@@ -752,9 +756,7 @@ int ustctl_send_channel_to_ust(int sock, int session_handle,
                return ret;
        ret = ustcomm_recv_app_reply(sock, &lur, lum.handle, lum.cmd);
        if (!ret) {
-               if (lur.ret_val >= 0) {
-                       channel_data->handle = lur.ret_val;
-               }
+               channel_data->handle = lur.ret_val;
        }
        return ret;
 }
@@ -958,7 +960,7 @@ struct ustctl_consumer_channel *
                        attr->subbuf_size, attr->num_subbuf,
                        attr->switch_timer_interval,
                        attr->read_timer_interval,
-                       attr->uuid);
+                       attr->uuid, attr->chan_id);
        if (!chan->chan) {
                goto chan_error;
        }
@@ -1052,6 +1054,40 @@ end:
        return ret;
 }
 
+/*
+ * Write at most one packet in the channel.
+ * Returns the number of bytes written on success, < 0 on error.
+ */
+ssize_t ustctl_write_one_packet_to_channel(
+               struct ustctl_consumer_channel *channel,
+               const char *metadata_str,       /* NOT null-terminated */
+               size_t len)                     /* metadata length */
+{
+       struct lttng_ust_lib_ring_buffer_ctx ctx;
+       struct lttng_channel *chan = channel->chan;
+       const char *str = metadata_str;
+       ssize_t reserve_len;
+       int ret;
+
+       reserve_len = min_t(ssize_t,
+                       chan->ops->packet_avail_size(chan->chan, chan->handle),
+                       len);
+       lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len,
+                       sizeof(char), -1, chan->handle);
+       ret = chan->ops->event_reserve(&ctx, 0);
+       if (ret != 0) {
+               DBG("LTTng: event reservation failed");
+               assert(ret < 0);
+               reserve_len = ret;
+               goto end;
+       }
+       chan->ops->event_write(&ctx, str, reserve_len);
+       chan->ops->event_commit(&ctx);
+
+end:
+       return reserve_len;
+}
+
 int ustctl_channel_close_wait_fd(struct ustctl_consumer_channel *consumer_chan)
 {
        struct channel *chan;
@@ -1576,7 +1612,7 @@ int ustctl_recv_register_event(int sock,
                goto signature_error;
        }
        /* Enforce end of string */
-       signature[signature_len - 1] = '\0';
+       a_sign[signature_len - 1] = '\0';
 
        /* recv fields */
        if (fields_len) {