Remove MSG_WAITALL on every recvmsg() socket type

[lttng-tools.git] / src / common / kernel-consumer / kernel-consumer.c

diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index 46413eda6e710d9e2f934df9e49336a5fd6fcef0..0b0592adb8a3bbe008141a4cb92196e020b752c8 100644 (file)
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -280,10 +280,21 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 
                goto end_nosignal;
        }
-       case LTTNG_CONSUMER_DATA_AVAILABLE:
+       case LTTNG_CONSUMER_DATA_PENDING:
        {
-               rcu_read_unlock();
-               return -ENOSYS;
+               int32_t ret;
+               uint64_t id = msg.u.data_pending.session_id;
+
+               DBG("Kernel consumer data pending command for id %" PRIu64, id);
+
+               ret = consumer_data_pending(id);
+
+               /* Send back returned value to session daemon */
+               ret = lttcomm_send_unix_sock(sock, &ret, sizeof(ret));
+               if (ret < 0) {
+                       PERROR("send data pending ret code");
+               }
+               break;
        }
        default:
                goto end_nosignal;
@@ -474,40 +485,30 @@ error:
 
 /*
  * Check if data is still being extracted from the buffers for a specific
- * stream. Consumer data lock MUST be acquired before calling this function.
+ * stream. Consumer data lock MUST be acquired before calling this function
+ * and the stream lock.
  *
- * Return 0 if the traced data are still getting read else 1 meaning that the
+ * Return 1 if the traced data are still getting read else 0 meaning that the
  * data is available for trace viewer reading.
  */
-int lttng_kconsumer_data_available(struct lttng_consumer_stream *stream)
+int lttng_kconsumer_data_pending(struct lttng_consumer_stream *stream)
 {
        int ret;
 
        assert(stream);
 
-       /*
-        * Try to lock the stream mutex. On failure, we know that the stream is
-        * being used else where hence there is data still being extracted.
-        */
-       ret = pthread_mutex_trylock(&stream->lock);
-       if (ret == EBUSY) {
-               goto data_not_available;
-       }
-       /* The stream is now locked so we can do our ustctl calls */
-
        ret = kernctl_get_next_subbuf(stream->wait_fd);
        if (ret == 0) {
                /* There is still data so let's put back this subbuffer. */
                ret = kernctl_put_subbuf(stream->wait_fd);
                assert(ret == 0);
-               pthread_mutex_unlock(&stream->lock);
-               goto data_not_available;
+               ret = 1;   /* Data is pending */
+               goto end;
        }
 
-       /* Data is available to be read for this stream. */
-       pthread_mutex_unlock(&stream->lock);
-       return 1;
+       /* Data is NOT pending and ready to be read. */
+       ret = 0;
 
-data_not_available:
-       return 0;
+end:
+       return ret;
 }