more fixes to (e)pgm transport

src/pgm_receiver.cpp

@@ -135,6 +135,11 @@ void zmq::pgm_receiver_t::in_event ()
 
     zmq_assert (pending_bytes == 0);
 
+    if (has_rx_timer) {
+        cancel_timer (rx_timer_id);
+        has_rx_timer = false;
+    }
+
     //  TODO: This loop can effectively block other engines in the same I/O
     //  thread in the case of high load.
     while (true) {
@@ -144,8 +149,15 @@ void zmq::pgm_receiver_t::in_event ()
 
         //  No data to process. This may happen if the packet received is
         //  neither ODATA nor ODATA.
-        if (received < 0)
+        if (received == 0) {
+            const int last_errno = errno;
+            if (last_errno == ENOMEM || last_errno == EBUSY) {
+                const long timeout = pgm_socket.get_rx_timeout ();
+                add_timer (timeout, rx_timer_id);
+                has_rx_timer = true;
+            }
             break;
+        }
 
         //  Find the peer based on its TSI.
         peers_t::iterator it = peers.find (*tsi);
@@ -219,5 +231,12 @@ void zmq::pgm_receiver_t::in_event ()
     inout->flush ();
 }
 
+void zmq::pgm_receiver_t::timer_event (int token)
+{
+    zmq_assert (token == rx_timer_id);
+
+    in_event ();
+}
+
 #endif
 

src/pgm_receiver.hpp

@@ -59,9 +59,16 @@ namespace zmq
 
         //  i_poll_events interface implementation.
         void in_event ();
+        void timer_event (int token);
 
     private:
 
+        //  RX timeout timer ID.
+        enum {rx_timer_id = 0xa1};
+
+        //  RX timer is running.
+        bool has_rx_timer;
+
         //  If joined is true we are already getting messages from the peer.
         //  It it's false, we are getting data but still we haven't seen
         //  beginning of a message.

src/pgm_sender.cpp

@@ -123,8 +123,19 @@ zmq::pgm_sender_t::~pgm_sender_t ()
 
 void zmq::pgm_sender_t::in_event ()
 {
+    if (has_rx_timer) {
+        cancel_timer (rx_timer_id);
+        has_rx_timer = false;
+    }
+
     //  In event on sender side means NAK or SPMR receiving from some peer.
     pgm_socket.process_upstream ();
+    const int last_errno = errno;
+    if (last_errno == ENOMEM || last_errno == EBUSY) {
+        const long timeout = pgm_socket.get_rx_timeout ();
+        add_timer (timeout, rx_timer_id);
+        has_rx_timer = true;
+    }
 }
 
 void zmq::pgm_sender_t::out_event ()
@@ -152,14 +163,36 @@ void zmq::pgm_sender_t::out_event ()
         put_uint16 (out_buffer, offset == -1 ? 0xffff : (uint16_t) offset);
     }
 
+    if (has_rx_timer) {
+        cancel_timer (rx_timer_id);
+        has_rx_timer = false;
+    }
+
     //  Send the data.
     size_t nbytes = pgm_socket.send (out_buffer, write_size);
 
     //  We can write either all data or 0 which means rate limit reached.
-    if (nbytes == write_size)
+    if (nbytes == write_size) {
         write_size = 0;
-    else
+    } else {
         zmq_assert (nbytes == 0);
+
+        if (errno == ENOMEM) {
+            const long timeout = pgm_socket.get_tx_timeout ();
+            add_timer (timeout, tx_timer_id);
+            has_tx_timer = true;
+        } else
+            zmq_assert (errno == EBUSY);
+    }
+}
+
+void zmq::pgm_sender_t::timer_event (int token)
+{
+    if (token == rx_timer_id)
+        in_event ();
+
+    zmq_assert (token == tx_timer_id);
+    out_event ();
 }
 
 #endif

src/pgm_sender.hpp

@@ -58,9 +58,16 @@ namespace zmq
         //  i_poll_events interface implementation.
         void in_event ();
         void out_event ();
+        void timer_event (int token);
 
     private:
 
+        //  TX and RX timeout timer ID's.
+        enum {tx_timer_id = 0xa0, rx_timer_id = 0xa1};
+
+        //  Timers are running.
+        bool has_tx_timer, has_rx_timer;
+
         //  Message encoder.
         encoder_t encoder;
 

src/pgm_socket.cpp

@@ -417,18 +417,55 @@ size_t zmq::pgm_socket_t::send (unsigned char *data_, size_t data_len_)
    
     const int status = pgm_send (sock, data_, data_len_, &nbytes);
 
-    if (nbytes != data_len_) {
-        zmq_assert (status == PGM_IO_STATUS_RATE_LIMITED || status == PGM_IO_STATUS_WOULD_BLOCK);
-        zmq_assert (nbytes == 0);
-    }
-    
     // We have to write all data as one packet.
-    if (nbytes > 0)
+    if (nbytes > 0) {
+        zmq_assert (status == PGM_IO_STATUS_NORMAL);
         zmq_assert ((ssize_t) nbytes == (ssize_t) data_len_);
+    } else {
+        zmq_assert (status == PGM_IO_STATUS_RATE_LIMITED || status == PGM_IO_STATUS_WOULD_BLOCK);
+
+        if (status == PGM_IO_STATUS_RATE_LIMITED)
+            errno = ENOMEM;
+        else
+            errno = EBUSY;
+    }
+
+    // Save return value.
+    last_tx_status = status;
 
     return nbytes;
 }
 
+long zmq::pgm_socket_t::get_rx_timeout ()
+{
+    if (last_rx_status != PGM_IO_STATUS_RATE_LIMITED && last_rx_status != PGM_IO_STATUS_TIMER_PENDING)
+        return -1;
+
+    struct timeval tv;
+    socklen_t optlen = sizeof (tv);
+    const bool rc = pgm_getsockopt (sock, IPPROTO_PGM, last_rx_status == PGM_IO_STATUS_RATE_LIMITED ? PGM_RATE_REMAIN : PGM_TIME_REMAIN, &tv, &optlen);
+    zmq_assert (rc);
+
+    const long timeout = (tv.tv_sec * 1000) + (tv.tv_usec / 1000);
+
+    return timeout;
+}
+
+long zmq::pgm_socket_t::get_tx_timeout ()
+{
+    if (last_tx_status != PGM_IO_STATUS_RATE_LIMITED)
+        return -1;
+
+    struct timeval tv;
+    socklen_t optlen = sizeof (tv);
+    const bool rc = pgm_getsockopt (sock, IPPROTO_PGM, PGM_RATE_REMAIN, &tv, &optlen);
+    zmq_assert (rc);
+
+    const long timeout = (tv.tv_sec * 1000) + (tv.tv_usec / 1000);
+
+    return timeout;
+}
+
 //  Return max TSDU size without fragmentation from current PGM transport.
 size_t zmq::pgm_socket_t::get_max_tsdu_size ()
 {
@@ -457,7 +494,7 @@ ssize_t zmq::pgm_socket_t::receive (void **raw_data_, const pgm_tsi_t **tsi_)
         nbytes_processed = 0;
         pgm_msgv_processed = 0;
         errno = EAGAIN;
-        return -1;
+        return 0;
     }
 
     //  If we have are going first time or if we have processed all pgm_msgv_t
@@ -479,23 +516,19 @@ ssize_t zmq::pgm_socket_t::receive (void **raw_data_, const pgm_tsi_t **tsi_)
         //  Invalid parameters
         zmq_assert (status != PGM_IO_STATUS_ERROR);
 
+        last_rx_status = status;
+
         //  In a case when no ODATA/RDATA fired POLLIN event (SPM...)
         //  pgm_recvmsg returns PGM_IO_STATUS_TIMER_PENDING.
         if (status == PGM_IO_STATUS_TIMER_PENDING) {
 
             zmq_assert (nbytes_rec == 0);
 
-            struct timeval tv;
-            socklen_t optlen = sizeof (tv);
-            const bool rc = pgm_getsockopt (sock, IPPROTO_PGM, PGM_TIME_REMAIN, &tv, &optlen);
-
-            zmq_assert (rc);
-
             //  In case if no RDATA/ODATA caused POLLIN 0 is 
             //  returned.
             nbytes_rec = 0;
             errno = EBUSY;
-            return -1;
+            return 0;
         }
 
         //  Send SPMR, NAK, ACK is rate limited.
@@ -503,15 +536,11 @@ ssize_t zmq::pgm_socket_t::receive (void **raw_data_, const pgm_tsi_t **tsi_)
 
             zmq_assert (nbytes_rec == 0);
 
-            struct timeval tv;
-            socklen_t optlen = sizeof (tv);
-            const bool rc = pgm_getsockopt (sock, IPPROTO_PGM, PGM_RATE_REMAIN, &tv, &optlen);
-
             //  In case if no RDATA/ODATA caused POLLIN 0 is 
             //  returned.
             nbytes_rec = 0;
-            errno = EBUSY;
-            return -1;
+            errno = ENOMEM;
+            return 0;
         }
 
         //  No peers and hence no incoming packets.
@@ -523,7 +552,7 @@ ssize_t zmq::pgm_socket_t::receive (void **raw_data_, const pgm_tsi_t **tsi_)
             //  returned.
             nbytes_rec = 0;
             errno = EAGAIN;
-            return -1;
+            return 0;
         }
 
         //  Data loss.
@@ -548,6 +577,7 @@ ssize_t zmq::pgm_socket_t::receive (void **raw_data_, const pgm_tsi_t **tsi_)
         zmq_assert (pgm_msgv_processed <= pgm_msgv_len);
     }
 
+    // Zero byte payloads are valid in PGM, but not 0MQ protocol.
     zmq_assert (nbytes_rec > 0);
 
     // Only one APDU per pgm_msgv_t structure is allowed.
@@ -587,6 +617,15 @@ void zmq::pgm_socket_t::process_upstream ()
     //  No data should be returned.
     zmq_assert (dummy_bytes == 0 && (status == PGM_IO_STATUS_TIMER_PENDING || 
         status == PGM_IO_STATUS_RATE_LIMITED || status == PGM_IO_STATUS_WOULD_BLOCK));
+
+    last_rx_status = status;
+
+    if (status == PGM_IO_STATUS_TIMER_PENDING)
+        errno = EBUSY;
+    else if (status == PGM_IO_STATUS_RATE_LIMITED)
+        errno = ENOMEM;
+    else
+        errno = EAGAIN;
 }
 
 #endif

src/pgm_socket.hpp

@@ -67,6 +67,9 @@ namespace zmq
         //  Receive data from pgm socket.
         ssize_t receive (void **data_, const pgm_tsi_t **tsi_);
 
+        long get_rx_timeout ();
+        long get_tx_timeout ();
+
         //  POLLIN on sender side should mean NAK or SPMR receiving. 
         //  process_upstream function is used to handle such a situation.
         void process_upstream ();
@@ -76,6 +79,8 @@ namespace zmq
         //  OpenPGM transport
         pgm_sock_t* sock;
 
+        int last_rx_status, last_tx_status;
+
         //  Associated socket options.
         options_t options;