Re: [PATCH v3 3/6] scripts: python: thread sample processing to create thread with schemas

[Ian Rogers]

On Mon, Jul 10, 2023 at 4:13 PM Anup Sharma <anupnewsmail@xxxxxxxxx> wrote:
>
> The _addThreadSample function is responsible for adding a sample
> to a specific thread. It first checks if the thread exists in
> the thread_map dictionary.
>
> The markers structure defines the schema and data for
> thread markers, including fields such as 'name',
> 'startTime', 'endTime', 'phase', 'category', and 'data'.
>
> The samples structure defines the schema and data for thread
> samples, including fields such as 'stack', 'time', and
> 'responsiveness'.
>
> The frameTable structure defines the schema and data for frame
> information, including fields such as 'location', 'relevantForJS',
> 'innerWindowID', 'implementation', 'optimizations', 'line',
> 'column', 'category', and 'subcategory'.
>
> The purpose of this function is to create a new thread structure
> These structures provide a framework for storing and organizing
> information related to thread markers, samples, frame details,
> and stack information.
>
> The call stack is parsed to include function names and the associated
> DSO, which are requires for creating json schema. Also few libaries
> has been included which will be used in later commit.

nit: s/requires/required.
nit: I think the "Also few..." statement is out-of-date.

> Signed-off-by: Anup Sharma <anupnewsmail@xxxxxxxxx>
> ---
>  .../scripts/python/firefox-gecko-converter.py | 70 +++++++++++++++++++
>  1 file changed, 70 insertions(+)
>
> diff --git a/tools/perf/scripts/python/firefox-gecko-converter.py b/tools/perf/scripts/python/firefox-gecko-converter.py
> index 765f1775cee5..0b8a86bdcab1 100644
> --- a/tools/perf/scripts/python/firefox-gecko-converter.py
> +++ b/tools/perf/scripts/python/firefox-gecko-converter.py
> @@ -21,6 +21,7 @@ sys.path.append(os.environ['PERF_EXEC_PATH'] + \
>  from perf_trace_context import *
>  from Core import *
>

A comment and type information would be useful here. map is another
word for a dictionary, which is somewhat implied. So the information
here is that this data structure will hold something to do with
threads.  Perhaps say, "a map from TID to a Thread." A better variable
name may then be tid_to_thread_map, but as map is implied you could
do: tid_to_thread: Dict[int, Thread].

> +thread_map = {}
>  start_time = None
>
>  def trace_end():
> @@ -28,6 +29,57 @@ def trace_end():
>
>  def process_event(param_dict):
>         global start_time
> +       global thread_map
> +
> +       def _createThread(name, pid, tid):
> +               markers = {
> +                       'schema': {
> +                               'name': 0,
> +                               'startTime': 1,
> +                               'endTime': 2,
> +                               'phase': 3,
> +                               'category': 4,
> +                               'data': 5,
> +                       },
> +                       'data': [],
> +               }
> +               samples = {
> +                       'schema': {
> +                               'stack': 0,
> +                               'time': 1,
> +                               'responsiveness': 2,
> +                               },
> +                       'data': [],
> +               }
> +               frameTable = {
> +                       'schema': {
> +                               'location': 0,
> +                               'relevantForJS': 1,
> +                               'innerWindowID': 2,
> +                               'implementation': 3,
> +                               'optimizations': 4,
> +                               'line': 5,
> +                               'column': 6,
> +                               'category': 7,
> +                               'subcategory': 8,
> +                       },
> +                       'data': [],
> +               }
> +               stackTable = {
> +                       'schema': {
> +                               'prefix': 0,
> +                               'frame': 1,
> +                       },
> +                       'data': [],
> +               }
> +               stringTable = []

Is there a missing return here?

> +
> +       def _addThreadSample(pid, tid, threadName, time_stamp, stack):
> +               thread = thread_map.get(tid)
> +               if not thread:
> +                       thread = _createThread(threadName, pid, tid)
> +                       thread_map[tid] = thread
> +
>         # Extract relevant information from the event parameters. The event parameters
>         # are in a dictionary:
>         time_stamp = (param_dict['sample']['time'] // 1000) / 1000
> @@ -37,3 +89,21 @@ def process_event(param_dict):
>
>         # Assume that start time is the time of the first event.
>         start_time = time_stamp if not start_time else start_time
> +
> +       # Parse the callchain of the current sample into a stack array.
> +       if param_dict['callchain']:
> +               stack = []
> +               for call in param_dict['callchain']:
> +                       if 'sym' not in call:
> +                               continue
> +                       stack.append(call['sym']['name'] + f' (in {call["dso"]})')

Rather than mix an append and an f-string, just have the f-string ie:
stack.append(f'{call["sym"]["name"]} (in {"call["dso"]})')

> +               if len(stack) != 0:
> +                       stack = stack[::-1]
> +                       _addThreadSample(pid, tid, thread_name, time_stamp, stack)
> +
> +       # During perf record if -g is not used, the callchain is not available.
> +       # In that case, the symbol and dso are available in the event parameters.
> +       else:
> +               func = param_dict['symbol'] if 'symbol' in param_dict else '[unknown]'
> +               dso = param_dict['dso'] if 'dso' in param_dict else '[unknown]'
> +               _addThreadSample(pid, tid, thread_name, time_stamp, [func + f' (in {dso})'])

Similarly:
f'{func} (in {dso})'

Thanks,
Ian

> --
> 2.34.1
>