From 4e3ec6af1f3e9089505a451702287facc2cb8f25 Mon Sep 17 00:00:00 2001
From: Andrej Babic <andrej.babic@psi.ch>
Date: Fri, 17 Apr 2020 17:58:20 +0200
Subject: [PATCH] Revert "Try to use recvmmsg"

This reverts commit 365c15a6
---
 core-buffer/src/UdpRecvModule.cpp | 104 ++++++++++++------------------
 1 file changed, 42 insertions(+), 62 deletions(-)

diff --git a/core-buffer/src/UdpRecvModule.cpp b/core-buffer/src/UdpRecvModule.cpp
index 6aaa228..49a77fc 100644
--- a/core-buffer/src/UdpRecvModule.cpp
+++ b/core-buffer/src/UdpRecvModule.cpp
@@ -2,7 +2,6 @@
 #include "jungfrau.hpp"
 #include <iostream>
 #include <UdpReceiver.hpp>
-#include <netinet/in.h>
 
 using namespace std;
 
@@ -89,84 +88,65 @@ void UdpRecvModule::receive_thread(
 
         char* frame_buffer = ring_buffer_.reserve(metadata);
 
-        auto n_msgs = JUNGFRAU_N_PACKETS_PER_FRAME;
-        jungfrau_packet recv_buffers[n_msgs];
-        iovec recv_buff_ptr[n_msgs];
-        struct mmsghdr msgs[n_msgs];
-        struct sockaddr_in sockFrom[n_msgs];
-
-        for (int i = 0; i < n_msgs; i++) {
-            recv_buff_ptr[i].iov_base = (void*) &(recv_buffers[i]);
-            recv_buff_ptr[i].iov_len = sizeof(jungfrau_packet);
-
-            msgs[i].msg_hdr.msg_iov = &recv_buff_ptr[i];
-            msgs[i].msg_hdr.msg_iovlen = 1;
-            msgs[i].msg_hdr.msg_name = &sockFrom[i];
-            msgs[i].msg_hdr.msg_namelen = sizeof(struct sockaddr_in );
-        }
+        jungfrau_packet packet_buffer;
 
         while (is_receiving_.load(memory_order_relaxed)) {
 
-            auto n_packets = udp_receiver.receive_many(msgs, n_msgs);
-
-            if (n_packets < 1) {
+            if (!udp_receiver.receive(
+                    &packet_buffer,
+                    JUNGFRAU_BYTES_PER_PACKET)) {
                 continue;
             }
 
-            for (int i_packet=0; i_packet<n_packets; i_packet++) {
+            auto* frame_metadata = metadata.get();
 
-                auto* frame_metadata = metadata.get();
-                jungfrau_packet* packet_buffer = &(recv_buffers[i_packet]);
+            // TODO: Horrible. Breake it down into methods.
 
-                // TODO: Horrible. Breake it down into methods.
+            // First packet for this frame.
+            if (frame_metadata->pulse_id == 0) {
+                frame_metadata->frame_index = packet_buffer.framenum;
+                frame_metadata->pulse_id = packet_buffer.bunchid;
+                frame_metadata->daq_rec = packet_buffer.debug;
+            // Packet from new frame, while we lost the last packet of
+            // previous frame.
+            } else if (frame_metadata->pulse_id != packet_buffer.bunchid) {
+                ring_buffer_.commit(metadata);
 
-                // First packet for this frame.
-                if (frame_metadata->pulse_id == 0) {
-                    frame_metadata->frame_index = packet_buffer->framenum;
-                    frame_metadata->pulse_id = packet_buffer->bunchid;
-                    frame_metadata->daq_rec = packet_buffer->debug;
-                    // Packet from new frame, while we lost the last packet of
-                    // previous frame.
+                metadata = make_shared<UdpFrameMetadata>();
+                metadata->frame_bytes_size = JUNGFRAU_DATA_BYTES_PER_FRAME;
+                metadata->pulse_id = 0;
+                metadata->n_recv_packets = 0;
 
-                } else if (frame_metadata->pulse_id != packet_buffer->bunchid) {
-                    ring_buffer_.commit(metadata);
+                frame_buffer = ring_buffer_.reserve(metadata);
+                memset(frame_buffer, 0, JUNGFRAU_DATA_BYTES_PER_FRAME);
 
-                    metadata = make_shared<UdpFrameMetadata>();
-                    metadata->frame_bytes_size = JUNGFRAU_DATA_BYTES_PER_FRAME;
-                    metadata->pulse_id = 0;
-                    metadata->n_recv_packets = 0;
+                frame_metadata->frame_index = packet_buffer.framenum;
+                frame_metadata->pulse_id = packet_buffer.bunchid;
+                frame_metadata->daq_rec = packet_buffer.debug;
+            }
 
-                    frame_buffer = ring_buffer_.reserve(metadata);
-                    memset(frame_buffer, 0, JUNGFRAU_DATA_BYTES_PER_FRAME);
+            size_t frame_buffer_offset =
+                    JUNGFRAU_DATA_BYTES_PER_PACKET * packet_buffer.packetnum;
 
-                    frame_metadata->frame_index = packet_buffer->framenum;
-                    frame_metadata->pulse_id = packet_buffer->bunchid;
-                    frame_metadata->daq_rec = packet_buffer->debug;
-                }
+            memcpy(
+                    (void*) (frame_buffer + frame_buffer_offset),
+                    packet_buffer.data,
+                    JUNGFRAU_DATA_BYTES_PER_PACKET);
 
-                size_t frame_buffer_offset =
-                        JUNGFRAU_DATA_BYTES_PER_PACKET * packet_buffer->packetnum;
+            frame_metadata->n_recv_packets++;
 
-                memcpy(
-                        (void*) (frame_buffer + frame_buffer_offset),
-                        packet_buffer->data,
-                        JUNGFRAU_DATA_BYTES_PER_PACKET);
+            // Frame finished with last packet.
+            if (packet_buffer.packetnum == JUNGFRAU_N_PACKETS_PER_FRAME-1)
+            {
+                ring_buffer_.commit(metadata);
 
-                frame_metadata->n_recv_packets++;
+                metadata = make_shared<UdpFrameMetadata>();
+                metadata->frame_bytes_size = JUNGFRAU_DATA_BYTES_PER_FRAME;
+                metadata->pulse_id = 0;
+                metadata->n_recv_packets = 0;
 
-                // Frame finished with last packet.
-                if (packet_buffer->packetnum == JUNGFRAU_N_PACKETS_PER_FRAME-1)
-                {
-                    ring_buffer_.commit(metadata);
-
-                    metadata = make_shared<UdpFrameMetadata>();
-                    metadata->frame_bytes_size = JUNGFRAU_DATA_BYTES_PER_FRAME;
-                    metadata->pulse_id = 0;
-                    metadata->n_recv_packets = 0;
-
-                    frame_buffer = ring_buffer_.reserve(metadata);
-                    memset(frame_buffer, 0, JUNGFRAU_DATA_BYTES_PER_FRAME);
-                }
+                frame_buffer = ring_buffer_.reserve(metadata);
+                memset(frame_buffer, 0, JUNGFRAU_DATA_BYTES_PER_FRAME);
             }
         }