tools/power/mach_commands.py

   1 # This Source Code Form is subject to the terms of the Mozilla Public
   2 # License, v. 2.0. If a copy of the MPL was not distributed with this
   3 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   4
   5 from distutils.version import StrictVersion
   6
   7 from mach.decorators import Command, CommandArgument
   8
   9
  10 def is_osx_10_10_or_greater(cls):
  11     import platform
  12
  13     release = platform.mac_ver()[0]
  14     return release and StrictVersion(release) >= StrictVersion("10.10")
  15
  16
  17 # Get system power consumption and related measurements.
  18 @Command(
  19     "power",
  20     category="misc",
  21     conditions=[is_osx_10_10_or_greater],
  22     description="Get system power consumption and related measurements for "
  23     "all running browsers. Available only on Mac OS X 10.10 and above. "
  24     "Requires root access.",
  25 )
  26 @CommandArgument(
  27     "-i",
  28     "--interval",
  29     type=int,
  30     default=30000,
  31     help="The sample period, measured in milliseconds. Defaults to 30000.",
  32 )
  33 def power(command_context, interval):
  34     """
  35     Get system power consumption and related measurements.
  36     """
  37     import os
  38     import re
  39     import subprocess
  40
  41     rapl = os.path.join(command_context.topobjdir, "dist", "bin", "rapl")
  42
  43     interval = str(interval)
  44
  45     # Run a trivial command with |sudo| to gain temporary root privileges
  46     # before |rapl| and |powermetrics| are called. This ensures that |rapl|
  47     # doesn't start measuring while |powermetrics| is waiting for the root
  48     # password to be entered.
  49     try:
  50         subprocess.check_call(["sudo", "true"])
  51     except Exception:
  52         print("\nsudo failed; aborting")
  53         return 1
  54
  55     # This runs rapl in the background because nothing in this script
  56     # depends on the output. This is good because we want |rapl| and
  57     # |powermetrics| to run at the same time.
  58     subprocess.Popen([rapl, "-n", "1", "-i", interval])
  59
  60     lines = subprocess.check_output(
  61         [
  62             "sudo",
  63             "powermetrics",
  64             "--samplers",
  65             "tasks",
  66             "--show-process-coalition",
  67             "--show-process-gpu",
  68             "-n",
  69             "1",
  70             "-i",
  71             interval,
  72         ],
  73         universal_newlines=True,
  74     )
  75
  76     # When run with --show-process-coalition, |powermetrics| groups outputs
  77     # into process coalitions, each of which has a leader.
  78     #
  79     # For example, when Firefox runs from the dock, its coalition looks
  80     # like this:
  81     #
  82     #   org.mozilla.firefox
  83     #     firefox
  84     #     plugin-container
  85     #
  86     # When Safari runs from the dock:
  87     #
  88     #   com.apple.Safari
  89     #     Safari
  90     #     com.apple.WebKit.Networking
  91     #     com.apple.WebKit.WebContent
  92     #     com.apple.WebKit.WebContent
  93     #
  94     # When Chrome runs from the dock:
  95     #
  96     #   com.google.Chrome
  97     #     Google Chrome
  98     #     Google Chrome Helper
  99     #     Google Chrome Helper
 100     #
 101     # In these cases, we want to print the whole coalition.
 102     #
 103     # Also, when you run any of them from the command line, things are the
 104     # same except that the leader is com.apple.Terminal and there may be
 105     # non-browser processes in the coalition, e.g.:
 106     #
 107     #  com.apple.Terminal
 108     #    firefox
 109     #    plugin-container
 110     #    <and possibly other, non-browser processes>
 111     #
 112     # Also, the WindowServer and kernel coalitions and processes are often
 113     # relevant.
 114     #
 115     # We want to print all these but omit uninteresting coalitions. We
 116     # could do this by properly parsing powermetrics output, but it's
 117     # simpler and more robust to just grep for a handful of identifying
 118     # strings.
 119
 120     print()  # blank line between |rapl| output and |powermetrics| output
 121
 122     for line in lines.splitlines():
 123         # Search for the following things.
 124         #
 125         # - '^Name' is for the columns headings line.
 126         #
 127         # - 'firefox' and 'plugin-container' are for Firefox
 128         #
 129         # - 'Safari\b' and 'WebKit' are for Safari. The '\b' excludes
 130         #   SafariCloudHistoryPush, which is a process that always
 131         #   runs, even when Safari isn't open.
 132         #
 133         # - 'Chrome' is for Chrome.
 134         #
 135         # - 'Terminal' is for the terminal. If no browser is running from
 136         #   within the terminal, it will show up unnecessarily. This is a
 137         #   minor disadvantage of this very simple parsing strategy.
 138         #
 139         # - 'WindowServer' is for the WindowServer.
 140         #
 141         # - 'kernel' is for the kernel.
 142         #
 143         if re.search(
 144             r"(^Name|firefox|plugin-container|Safari\b|WebKit|Chrome|Terminal|WindowServer|kernel)",  # NOQA: E501
 145             line,
 146         ):
 147             print(line)
 148
 149     return 0