uhd: added async recv message call to device api

implemented in usrp2 io impl

added async metadata type

2 files changed, 44 insertions, 11 deletions

diff --git a/host/include/uhd/device.hpp b/host/include/uhd/device.hpp
index ee297ec8a..78bb83c66 100644
--- a/host/include/uhd/device.hpp
+++ b/host/include/uhd/device.hpp
@@ -219,6 +219,17 @@ public:
      */
     virtual size_t get_max_recv_samps_per_packet(void) const = 0;
 
+    /*!
+     * Receive and asynchronous message from the device.
+     * \param async_metadata the metadata to be filled in
+     * \param timeout_ms the timeout in milliseconds to wait for a message
+     * \return true when the async_metadata is valid, false for timeout
+     */
+    virtual bool recv_async_msg(
+        async_metadata_t &async_metadata,
+        size_t timeout_ms = default_recv_timeout_ms
+    ) = 0;
+
 };
 
 } //namespace uhd
diff --git a/host/include/uhd/types/metadata.hpp b/host/include/uhd/types/metadata.hpp
index 039196250..43ddf875f 100644
--- a/host/include/uhd/types/metadata.hpp
+++ b/host/include/uhd/types/metadata.hpp
@@ -26,7 +26,7 @@ namespace uhd{
 
     /*!
      * RX metadata structure for describing sent IF data.
-     * Includes stream ID, time specification, and fragmentation flags.
+     * Includes time specification, fragmentation flags, burst flags, and error codes.
      * The receive routines will convert IF data headers into metadata.
      */
     struct UHD_API rx_metadata_t{
@@ -62,7 +62,7 @@ namespace uhd{
          * - timeout: no packet received, underlying code timed-out
          * - late command: a stream command was issued in the past
          * - broken chain: expected another stream command
-         * - overrun: an internal receive buffer has overrun
+         * - overflow: an internal receive buffer has filled
          * - bad packet: the buffer was unrecognizable as a vrt packet
          *
          * Note: When an overrun occurs in continuous streaming mode,
@@ -74,27 +74,21 @@ namespace uhd{
          * - none
          * - late command
          * - broken chain
-         * - overrun
+         * - overflow
          */
         enum error_code_t {
             ERROR_CODE_NONE         = 0x0,
             ERROR_CODE_TIMEOUT      = 0x1,
             ERROR_CODE_LATE_COMMAND = 0x2,
             ERROR_CODE_BROKEN_CHAIN = 0x4,
-            ERROR_CODE_OVERRUN      = 0x8,
+            ERROR_CODE_OVERFLOW     = 0x8,
             ERROR_CODE_BAD_PACKET   = 0xf
         } error_code;
-
-        /*!
-         * The default constructor:
-         * Sets the fields to default values (flags set to false).
-         */
-        rx_metadata_t(void);
     };
 
     /*!
      * TX metadata structure for describing received IF data.
-     * Includes stream ID, time specification, and burst flags.
+     * Includes time specification, and start and stop burst flags.
      * The send routines will convert the metadata to IF data headers.
      */
     struct UHD_API tx_metadata_t{
@@ -121,6 +115,34 @@ namespace uhd{
         tx_metadata_t(void);
     };
 
+    /*!
+     * Async metadata structure for describing transmit related events.
+     */
+    struct UHD_API async_metadata_t{
+        //! The channel number in a mimo configuration
+        size_t channel;
+
+        /*!
+         * Time specification: when the async event occurred.
+         */
+        bool has_time_spec;
+        time_spec_t time_spec;
+
+        /*!
+         * Event codes:
+         * - success: a packet was successfully transmitted
+         * - underflow: an internal send buffer has emptied
+         * - sequence error: packet loss between host and device
+         * - time error: packet had time that was late (or too early)
+         */
+        enum event_code_t {
+            EVENT_CODE_SUCCESS    = 0x1,
+            EVENT_CODE_UNDERFLOW  = 0x2,
+            EVENT_CODE_SEQ_ERROR  = 0x4,
+            EVENT_CODE_TIME_ERROR = 0x8
+        } event_code;
+    };
+
 } //namespace uhd
 
 #endif /* INCLUDED_UHD_TYPES_METADATA_HPP */