From d572772df3d133eb12b021174b073c8694f93036 Mon Sep 17 00:00:00 2001
From: DJ2LS <75909252+DJ2LS@users.noreply.github.com>
Date: Tue, 27 Dec 2022 17:11:46 +0100
Subject: [PATCH] use busy detection while opening a channel

---
 tnc/data_handler.py | 60 +++++++++++++++++++++++----------------------
 1 file changed, 31 insertions(+), 29 deletions(-)

diff --git a/tnc/data_handler.py b/tnc/data_handler.py
index fd66a7f0..44552860 100644
--- a/tnc/data_handler.py
+++ b/tnc/data_handler.py
@@ -1840,36 +1840,7 @@ class DATA:
         # for calculating transmission statistics
         # static.ARQ_COMPRESSION_FACTOR = len(data_out) / len(lzma.compress(data_out))
 
-        # Let's check if we have a busy channel and if we are not in a running arq session.
-        if static.CHANNEL_BUSY and not static.ARQ_SESSION:
-            self.log.warning("[TNC] Channel busy, waiting until free...")
-            self.send_data_to_socket_queue(
-                freedata="tnc-message",
-                arq="transmission",
-                status="waiting",
-                mycallsign=str(self.mycallsign, 'UTF-8'),
-                dxcallsign=str(self.dxcallsign, 'UTF-8'),
-            )
 
-            # wait while timeout not reached and our busy state is busy
-            channel_busy_timeout = time.time() + 30
-            while static.CHANNEL_BUSY and time.time() < channel_busy_timeout:
-                threading.Event().wait(0.01)
-
-            # if channel busy timeout reached, stop connecting
-            if time.time() > channel_busy_timeout:
-                self.log.warning("[TNC] Channel busy, try again later...")
-                static.ARQ_SESSION_STATE = "failed"
-                self.send_data_to_socket_queue(
-                    freedata="tnc-message",
-                    arq="transmission",
-                    status="failed",
-                    reason="busy",
-                    mycallsign=str(self.mycallsign, 'UTF-8'),
-                    dxcallsign=str(self.dxcallsign, 'UTF-8'),
-                )
-                static.ARQ_SESSION_STATE = "disconnected"
-                return False
 
         self.arq_open_data_channel(mode, n_frames_per_burst, mycallsign)
 
@@ -1945,6 +1916,37 @@ class DATA:
                     attempt=f"{str(attempt + 1)}/{str(self.data_channel_max_retries)}",
                 )
 
+                # Let's check if we have a busy channel and if we are not in a running arq session.
+                if static.CHANNEL_BUSY and not static.ARQ_STATE:
+                    self.log.warning("[TNC] Channel busy, waiting until free...")
+                    self.send_data_to_socket_queue(
+                        freedata="tnc-message",
+                        arq="transmission",
+                        status="waiting",
+                        mycallsign=str(self.mycallsign, 'UTF-8'),
+                        dxcallsign=str(self.dxcallsign, 'UTF-8'),
+                    )
+
+                    # wait while timeout not reached and our busy state is busy
+                    channel_busy_timeout = time.time() + 30
+                    while static.CHANNEL_BUSY and time.time() < channel_busy_timeout:
+                        threading.Event().wait(0.01)
+
+                    # if channel busy timeout reached, stop connecting
+                    if time.time() > channel_busy_timeout:
+                        self.log.warning("[TNC] Channel busy, try again later...")
+                        static.ARQ_SESSION_STATE = "failed"
+                        self.send_data_to_socket_queue(
+                            freedata="tnc-message",
+                            arq="transmission",
+                            status="failed",
+                            reason="busy",
+                            mycallsign=str(self.mycallsign, 'UTF-8'),
+                            dxcallsign=str(self.dxcallsign, 'UTF-8'),
+                        )
+                        static.ARQ_SESSION_STATE = "disconnected"
+                        return False
+
                 self.enqueue_frame_for_tx([connection_frame], c2_mode=FREEDV_MODE.datac0.value, copies=1, repeat_delay=0)
 
                 timeout = time.time() + 3