[Interpreter] Enable tracing of bytecode handler dispatches.

tools/ignition_plot_handler_counters.py

Index: tools/ignition_plot_handler_counters.py
diff --git a/tools/ignition_plot_handler_counters.py b/tools/ignition_plot_handler_counters.py
new file mode 100755
index 0000000000000000000000000000000000000000..4b2eb0458162556b5f73928a244fe94255880d56
--- /dev/null
+++ b/tools/ignition_plot_handler_counters.py
@@ -0,0 +1,131 @@
+#! /usr/bin/python
+#
+# Copyright 2016 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+#
+

[rmcilroy, 2016/04/08 11:24:44]

Name should be something like plot_ignition_bytecode_dispatches.py. Also, should
this be in a directory of ignition specific tracing tools (along with your other
tool when you land it)?

[Stefano Sanfilippo, 2016/04/08 14:42:44]

Done.

+import argparse
+import json
+import matplotlib as mpl
+#mpl.use('Agg')  ## Uncomment this line if running headless

[rmcilroy, 2016/04/08 11:24:44]

Remove?

[Stefano Sanfilippo, 2016/04/08 14:42:44]

It might be of some use if this script is run on a server or as part of some
automated process. Whether we keep it or not, it's the same for me, though.

About the weird positioning, this is because it must come before the other
matplotlib imports.

+import matplotlib.colors as colors
+import matplotlib.pyplot as plt
+import numpy as np
+import struct
+
+
+__COUNTER_BITS = struct.calcsize("P") * 8  # Size in bits of a pointer
+__COUNTER_MAX = 2**__COUNTER_BITS - 1
+
+
+def load_counters_data(stream):
+  counters_matrix = json.load(stream)
+  raw_labels = [x[0] for x in counters_matrix]
+  raw_values = np.array([x[1] for x in counters_matrix])
+  return raw_labels, raw_values
+
+
+def check_saturated_counters(raw_labels, raw_values):
+  # np.where() returns two arrays of x and y coordinates,
+  # zip them together to get (x,y) tuples.
+  saturated_cells = zip(*np.where(raw_values == __COUNTER_MAX))
+  for coords in saturated_cells:
+    labels_chain = " -> ".join(raw_labels[coord] for coord in coords)
+    print "WARNING: counter may have saturated: {}".format(labels_chain)
+
+
+def prepare_data_for_plot(raw_labels, raw_values):
+  xlabels = raw_labels
+  ylabels = list(reversed(xlabels))
+  values = np.flipud(raw_values)
+  return xlabels, ylabels, values
+
+
+def plot_handler_to_handler_counters(values, xlabels, ylabels, figure, axis):
+  image = axis.pcolor(
+    values,
+    cmap='jet',
+    norm=colors.LogNorm(),
+    edgecolor='grey',
+    linestyle='dotted',
+    linewidth=0.5
+  )
+
+  axis.xaxis.set(
+    ticks=np.arange(0.5, len(xlabels)),
+    label="From bytecode handler"
+  )
+  axis.xaxis.tick_top()
+  axis.set_xlim(0, len(xlabels))
+  axis.set_xticklabels(xlabels, rotation='vertical')
+
+  axis.yaxis.set(
+    ticks=np.arange(0.5, len(ylabels)),
+    label="To bytecode handler",
+    ticklabels=ylabels
+  )
+  axis.set_ylim(0, len(ylabels))
+
+  figure.colorbar(
+    image,
+    ax=axis,
+    fraction=0.01,
+    pad=0.01
+  )
+
+
+def parse_command_line():
+  command_line_parser = argparse.ArgumentParser(
+    description="Plot Ignition counters file.",
+  )
+  command_line_parser.add_argument(
+    "--plot_size", "-s",
+    metavar="N",
+    default=30,
+    help="shorter side, in inches, of the output plot",
+  )
+  command_line_parser.add_argument(
+    "--interactive", "-i",
+    action="store_true",
+    help="open an interactive viewer, rather than writing to file.",
+  )
+  command_line_parser.add_argument(
+    "--output_filename", "-o",
+    metavar="<output filename>",
+    default="v8.ignition_dispatches_table.svg",
+    help=("file to save the plot file to. File type is deduced from the "
+          "extension. PDF, SVG, PNG supported")
+  )
+  command_line_parser.add_argument(
+    "input_filename",
+    metavar="<input filename>",
+    default="v8.ignition_dispatches_table.json",
+    nargs='?',
+    help="Ignition counters JSON file.",
+  )
+
+  return command_line_parser.parse_args()
+
+
+def main():
+  program_options = parse_command_line()
+
+  with open(program_options.input_filename) as stream:
+    raw_labels, raw_values = load_counters_data(stream)
+
+  check_saturated_counters(raw_labels, raw_values)
+  xlabels, ylabels, values = prepare_data_for_plot(raw_labels, raw_values)
+
+  figure, axis = plt.subplots()
+  plot_handler_to_handler_counters(values, xlabels, ylabels, figure, axis)
+
+  if program_options.interactive:
+    plt.show()
+  else:
+    figure.set_size_inches(program_options.plot_size, program_options.plot_size)
+    plt.savefig(program_options.output_filename)
+
+
+if __name__ == "__main__":
+  main()