trace: add audio tracing and plotting script

Change-Id: Ie5c8fe1d9cc4e5a38a623a1cd4755c00ad4f4904

tools/trace/audio/.gitignore

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+out.png

tools/trace/audio/audio.py

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+#!/usr/bin/env python3
+"""
+Quick-and-dirty script to plot lttng trace data of the jami audio system
+
+Depends on `python3-bt2` package:
+https://babeltrace.org/docs/v2.0/python/bt2/
+
+If using a virtual environment, you need to link the system babeltrace2 python3
+  package to your virtual environment, something like:
+`ln -s /usr/lib/python3/dist-packages/bt2 "$VIRTUAL_ENV"/lib/python3*/site-packages/`
+
+"""
+
+import re
+import dataclasses
+from typing import Dict, List
+import sys
+
+import bt2
+import matplotlib.pyplot as plt
+
+
+@dataclasses.dataclass
+class Intervals:
+    """Keep track of timestamps and the interval intervals between them"""
+
+    intervals: List[int] = dataclasses.field(default_factory=list)
+    times: List[int] = dataclasses.field(default_factory=list)
+    last_timestamp: int = 0
+
+    def add_event(self, timestamp: int):
+        """Add a new timestamp and calculate the interval"""
+        if self.last_timestamp == 0:
+            self.intervals.append(0)
+        else:
+            self.intervals.append(timestamp - self.last_timestamp)
+
+        self.times.append(timestamp)
+
+        self.last_timestamp = timestamp
+
+    def filter(self, earliest: int, latest: int):
+        """Filter out entries that are not in between `earliest` and `latest` timestamps"""
+        new_intervals = []
+        new_times = []
+        for i, val in enumerate(self.times):
+            if val > earliest and val < latest:
+                new_times.append(val)
+                new_intervals.append(self.intervals[i])
+
+        self.times = new_times
+        self.intervals = new_intervals
+
+
+def analyze(filename: str):
+    """Process trace file"""
+    # running_averages: Dict[str, RunningAverage] = {}
+    intervals: Dict[str, Intervals] = {}
+    desired_event_regex = re.compile("jami:(call|audio|conference)")
+
+    for message in bt2.TraceCollectionMessageIterator(filename):
+        # pylint: disable=protected-access
+        if not isinstance(message, bt2._EventMessageConst):
+            continue
+        ns_from_origin = message.default_clock_snapshot.ns_from_origin
+        name = message.event.name
+
+        if not desired_event_regex.match(name):
+            continue
+
+        if "id" in message.event.payload_field and name != "jami:conference_add_participant":
+            name = f"{name}({str(message.event.payload_field['id'])})"
+
+        if not name in intervals:
+            # running_averages[name] = RunningAverage()
+            intervals[name] = Intervals()
+
+        # running_averages[name].add_val(ns_from_origin)
+        intervals[name].add_event(ns_from_origin)
+
+        # print(f"{ns_from_origin / 10e9:.9f}: {name}")
+
+    for key, val in intervals.items():
+        print(
+            f"event: {key}, average: {(sum(val.intervals) / len(val.intervals)) / 1e9:.9f}"
+        )
+
+    earliest_recorded = intervals["jami:audio_layer_put_recorded_end"].times[0]
+    latest_recorded = intervals["jami:audio_layer_put_recorded_end"].times[-1]
+
+    earliest_recorded += int(1e9)  # start graph 1 second later
+
+    print(
+        f"earliest: {earliest_recorded / 1e9 :.9f}, latest: {latest_recorded / 1e9:.9f}"
+    )
+
+    for _, interval_val in intervals.items():
+        interval_val.filter(earliest_recorded, latest_recorded)
+
+    # convert from unix timestamp to seconds since start
+    for _, interval_val in intervals.items():
+        for i, _ in enumerate(interval_val.times):
+            interval_val.times[i] -= earliest_recorded
+
+    plot(intervals, filename)
+
+
+def plot(intervals: Dict[str, Intervals], filename: str):
+    """Plot audio event data"""
+    add_part = intervals["jami:conference_add_participant"]
+
+    fig, axis = plt.subplots(figsize=(20, 9))
+
+    axis.set_xlabel("seconds since start")
+    axis.set_ylabel("interval between events (seconds)")
+    axis.set_title("jami:audio*")
+
+    # only plot audio events
+    events_to_plot_regex = re.compile("jami:audio")
+
+    # plot each desired interval
+    for interval_key, interval_val in intervals.items():
+        if not events_to_plot_regex.match(interval_key):
+            continue
+
+        axis.plot(
+            [i / 1e9 for i in interval_val.times],
+            [i / 1e9 for i in interval_val.intervals],
+            label=interval_key,
+        )
+
+    # generate vertical line for each time a new participant is added to conference
+    for time in add_part.times:
+        axis.axvline(
+            time / 1e9,
+            color="black",
+            ls="--",
+        )
+
+    axis.legend()
+
+    # save it as out.png
+    filename = "out.png"
+    fig.savefig(filename, dpi=100)
+    print(f"png saved as {filename}")
+
+
+if __name__ == "__main__":
+    if len(sys.argv) < 2:
+        print("usage: python3 audio.py <lttng trace directory>", file=sys.stderr)
+        sys.exit(-1)
+    analyze(sys.argv[1])

tools/trace/audio/lttng-setup.sh

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+#!/bin/sh
+
+# this script sets up an lttng session and enables triggers for call start and conference end
+# ideally, this script would be more configurable, right now it's hardcoded and hacky
+
+if lttng status | grep -q "Recording session"; then
+    echo "lttng session already active, exiting"
+    exit 1
+fi
+
+SESSION="jami"
+
+# Prepare a capture session
+
+lttng create "$SESSION"
+
+# Enable kernel and user channels
+
+# lttng enable-channel -k --subbuf-size 4096K kernel
+lttng enable-channel -u --subbuf-size 1024K user
+
+# Enable all kernel syscalls tracing
+# lttng enable-event --kernel --syscall --all --channel=kernel
+
+# Enable sched_* (scheduler) functions tracing
+# lttng enable-event --kernel --channel=kernel "$(lttng list --kernel  | grep sched_ | awk '{ print $1 }' | xargs  | sed -e 's/ /,/g')"
+
+# Enable net_* functions tracing
+# lttng enable-event --kernel --channel=kernel "$(lttng list --kernel  | grep net_ | awk '{ print $1 }' | xargs  | sed -e 's/ /,/g')"
+
+# Userspace tracing
+# Add support for tracef() traces
+# You need to link application with @-llttng-ust@
+# lttng enable-event --userspace 'lttng_ust_tracef:*' --channel=user
+
+# Add context for libc (including malloc, etc)
+export LD_PRELOAD="$LD_PRELOAD":liblttng-ust-libc-wrapper.so
+lttng enable-event --userspace  'lttng_ust_libc:*' --channel=user
+lttng add-context --userspace -t vtid -t procname
+
+# Add context for pthread (including mutexes)
+export LD_PRELOAD="$LD_PRELOAD":liblttng-ust-pthread-wrapper.so
+lttng enable-event --userspace 'lttng_ust_pthread:*' --channel=user
+
+# Add context for function profiling
+export LD_PRELOAD="$LD_PRELOAD":liblttng-ust-cyg-profile.so
+lttng enable-event --userspace --all --channel=user
+lttng add-context --userspace -t vpid -t vtid -t procname
+
+# loop over lines in our for-loop, since triggers might have spaces in their names
+OLDIFS="$IFS"
+IFS='
+'
+
+# remove all triggers
+for trigger in $(lttng list-triggers | sed -nr 's/- name: (.*)$/\1/p'); do
+    echo "removing trigger: $trigger"
+    lttng remove-trigger "$trigger"
+done
+
+IFS=$OLDIFS
+
+# add start and end trigger
+lttng add-trigger --name "jami call start" --condition=event-rule-matches --type=user --name='jami:call_start' --action=start-session $SESSION
+lttng add-trigger --name "jami conference end" --condition=event-rule-matches --type=user --name="jami:conference_end" --action=stop-session $SESSION