<p>fixeria has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/c/osmocom-bb/+/19366">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">Revert "trx_toolkit/transceiver.py: implement the transmit burst queue"<br><br>This reverts commit 6e1c82d29836496b20e0d826976d9e71b32493d8.<br>Unfortunately, solving one problem it introduced even more regressions.<br><br>Change-Id: If29b4f6718cbc8af18fe18a5e3eca3912e8af01e<br>Related: OS#4658<br>---<br>M src/target/trx_toolkit/fake_trx.py<br>M src/target/trx_toolkit/transceiver.py<br>2 files changed, 4 insertions(+), 74 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/osmocom-bb refs/changes/66/19366/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/src/target/trx_toolkit/fake_trx.py b/src/target/trx_toolkit/fake_trx.py</span><br><span>index da611e8..ded8dc4 100755</span><br><span>--- a/src/target/trx_toolkit/fake_trx.py</span><br><span>+++ b/src/target/trx_toolkit/fake_trx.py</span><br><span>@@ -388,8 +388,6 @@</span><br><span> </span><br><span> # Init shared clock generator</span><br><span> self.clck_gen = CLCKGen([])</span><br><span style="color: hsl(0, 100%, 40%);">- # This method will be called on each TDMA frame</span><br><span style="color: hsl(0, 100%, 40%);">- self.clck_gen.clck_handler = self.clck_handler</span><br><span> </span><br><span> # Power measurement emulation</span><br><span> # Noise: -120 .. -105</span><br><span>@@ -458,18 +456,14 @@</span><br><span> for trx in self.trx_list.trx_list:</span><br><span> # DATA interface</span><br><span> if trx.data_if.sock in r_event:</span><br><span style="color: hsl(0, 100%, 40%);">- trx.recv_data_msg()</span><br><span style="color: hsl(120, 100%, 40%);">+ msg = trx.recv_data_msg()</span><br><span style="color: hsl(120, 100%, 40%);">+ if msg is not None:</span><br><span style="color: hsl(120, 100%, 40%);">+ self.burst_fwd.forward_msg(trx, msg)</span><br><span> </span><br><span> # CTRL interface</span><br><span> if trx.ctrl_if.sock in r_event:</span><br><span> trx.ctrl_if.handle_rx()</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- # This method will be called by the clock thread</span><br><span style="color: hsl(0, 100%, 40%);">- def clck_handler(self, fn):</span><br><span style="color: hsl(0, 100%, 40%);">- # We assume that this list is immutable at run-time</span><br><span style="color: hsl(0, 100%, 40%);">- for trx in self.trx_list.trx_list:</span><br><span style="color: hsl(0, 100%, 40%);">- trx.clck_tick(self.burst_fwd, fn)</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span> def shutdown(self):</span><br><span> log.info("Shutting down...")</span><br><span> </span><br><span>diff --git a/src/target/trx_toolkit/transceiver.py b/src/target/trx_toolkit/transceiver.py</span><br><span>index 9fc2948..19b998e 100644</span><br><span>--- a/src/target/trx_toolkit/transceiver.py</span><br><span>+++ b/src/target/trx_toolkit/transceiver.py</span><br><span>@@ -23,7 +23,6 @@</span><br><span> # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.</span><br><span> </span><br><span> import logging as log</span><br><span style="color: hsl(0, 100%, 40%);">-import threading</span><br><span> </span><br><span> from ctrl_if_trx import CTRLInterfaceTRX</span><br><span> from data_if import DATAInterface</span><br><span>@@ -123,37 +122,6 @@</span><br><span> Transceiver and all its timeslots, so using in for the BTS side</span><br><span> does not make any sense (imagine BCCH hopping together with DCCH).</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- == The transmit burst queue</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span style="color: hsl(0, 100%, 40%);">- According to 3GPP 45.002, the time difference between Uplink and</span><br><span style="color: hsl(0, 100%, 40%);">- Downlink corresponds to three TDMA timeslot periods. However,</span><br><span style="color: hsl(0, 100%, 40%);">- in general the L1 implementations (such as osmo-bts-trx and trxcon)</span><br><span style="color: hsl(0, 100%, 40%);">- never schedule to be transmitted bursts for the current TDMA frame</span><br><span style="color: hsl(0, 100%, 40%);">- immediately. Instead, they are being scheduled prematurely.</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span style="color: hsl(0, 100%, 40%);">- The rationale is that both transceiver and the L1 implementation</span><br><span style="color: hsl(0, 100%, 40%);">- are separete processes that are not perfectly synchronized in time.</span><br><span style="color: hsl(0, 100%, 40%);">- Moreover, the transceiver needs some time to prepare a burst for</span><br><span style="color: hsl(0, 100%, 40%);">- transmission. This is why the time difference between Uplink and</span><br><span style="color: hsl(0, 100%, 40%);">- Downlink is actually much higher on practice (20 TDMA frame periods</span><br><span style="color: hsl(0, 100%, 40%);">- by default, at the moment of writing this patch).</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span style="color: hsl(0, 100%, 40%);">- In order to reflect that delay in a virtual environment, this</span><br><span style="color: hsl(0, 100%, 40%);">- implementation, just like a normal transceiver (e.g. osmo-trx),</span><br><span style="color: hsl(0, 100%, 40%);">- queues all to be transmitted (L12TRX) bursts, so hey remain in</span><br><span style="color: hsl(0, 100%, 40%);">- the transmit queue until the appropriate time of transmission.</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span style="color: hsl(0, 100%, 40%);">- The API user is supposed to call recv_data_msg() in order to obtain</span><br><span style="color: hsl(0, 100%, 40%);">- a L12TRX message on the TRXD (data) inteface, so it gets queued by</span><br><span style="color: hsl(0, 100%, 40%);">- this function. Then, to ensure the timeous transmission, the user</span><br><span style="color: hsl(0, 100%, 40%);">- of this implementation needs to call clck_tick() on each TDMA</span><br><span style="color: hsl(0, 100%, 40%);">- frame. Both functions are thread-safe (queue mutex).</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span style="color: hsl(0, 100%, 40%);">- In a multi-trx configuration, the use of queue additionally ensures</span><br><span style="color: hsl(0, 100%, 40%);">- proper burst aggregation on multiple TRXD connections, so all L12TRX</span><br><span style="color: hsl(0, 100%, 40%);">- messages are guaranteed to be sent in the right order, i.e. with</span><br><span style="color: hsl(0, 100%, 40%);">- monolithically-increasing TDMA frame numbers.</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span> """</span><br><span> </span><br><span> def __init__(self, bind_addr, remote_addr, base_port, name = None,</span><br><span>@@ -209,10 +177,6 @@</span><br><span> # List of child transceivers</span><br><span> self.child_trx_list = TRXList()</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- # Tx (L12TRX) burst queue and mutex</span><br><span style="color: hsl(0, 100%, 40%);">- self._tx_queue_lock = threading.Lock()</span><br><span style="color: hsl(0, 100%, 40%);">- self._tx_queue = []</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span> def __str__(self):</span><br><span> desc = "%s:%d" % (self.remote_addr, self.base_port)</span><br><span> if self.child_idx > 0:</span><br><span>@@ -269,12 +233,10 @@</span><br><span> trx.running = True</span><br><span> elif event == "POWEROFF":</span><br><span> trx.running = False</span><br><span style="color: hsl(0, 100%, 40%);">- trx.tx_queue_clear()</span><br><span> trx.disable_fh()</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- # Reset frequency hopping parameters, clear the queue</span><br><span style="color: hsl(120, 100%, 40%);">+ # Reset frequency hopping parameters</span><br><span> if event == "POWEROFF":</span><br><span style="color: hsl(0, 100%, 40%);">- self.tx_queue_clear()</span><br><span> self.disable_fh()</span><br><span> </span><br><span> # Trigger clock generator if required</span><br><span>@@ -312,34 +274,8 @@</span><br><span> "configured => dropping..." % (self, msg.desc_hdr()))</span><br><span> return None</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- # Enque the message, it will be sent later</span><br><span style="color: hsl(0, 100%, 40%);">- self.tx_queue_append(msg)</span><br><span> return msg</span><br><span> </span><br><span> def handle_data_msg(self, msg):</span><br><span> # TODO: make legacy mode configurable (via argv?)</span><br><span> self.data_if.send_msg(msg, legacy = True)</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span style="color: hsl(0, 100%, 40%);">- def tx_queue_append(self, msg):</span><br><span style="color: hsl(0, 100%, 40%);">- with self._tx_queue_lock:</span><br><span style="color: hsl(0, 100%, 40%);">- self._tx_queue.append(msg)</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span style="color: hsl(0, 100%, 40%);">- def tx_queue_clear(self):</span><br><span style="color: hsl(0, 100%, 40%);">- with self._tx_queue_lock:</span><br><span style="color: hsl(0, 100%, 40%);">- self._tx_queue.clear()</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span style="color: hsl(0, 100%, 40%);">- def clck_tick(self, fwd, fn):</span><br><span style="color: hsl(0, 100%, 40%);">- if not self.running:</span><br><span style="color: hsl(0, 100%, 40%);">- return</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span style="color: hsl(0, 100%, 40%);">- self._tx_queue_lock.acquire()</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span style="color: hsl(0, 100%, 40%);">- for msg in self._tx_queue:</span><br><span style="color: hsl(0, 100%, 40%);">- if msg.fn == fn:</span><br><span style="color: hsl(0, 100%, 40%);">- fwd.forward_msg(self, msg)</span><br><span style="color: hsl(0, 100%, 40%);">- elif msg.fn < fn:</span><br><span style="color: hsl(0, 100%, 40%);">- log.warning("(%s) Stale TRXD message (fn=%u): %s"</span><br><span style="color: hsl(0, 100%, 40%);">- % (self, fn, msg.desc_hdr()))</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span style="color: hsl(0, 100%, 40%);">- self._tx_queue = [msg for msg in self._tx_queue if msg.fn > fn]</span><br><span style="color: hsl(0, 100%, 40%);">- self._tx_queue_lock.release()</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/osmocom-bb/+/19366">change 19366</a>. 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<div style="display:none"> Gerrit-Project: osmocom-bb </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: If29b4f6718cbc8af18fe18a5e3eca3912e8af01e </div>
<div style="display:none"> Gerrit-Change-Number: 19366 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: fixeria <vyanitskiy@sysmocom.de> </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>