author Chris H-C <>
Mon, 04 Jul 2016 11:16:05 -0400
changeset 312997 df28918fe2361f0b54ca9ce4773a29c4c0675d06
parent 303772 80eb5947da076120f095ac7dd6a32670032e0134
permissions -rwxr-xr-x
bug 1218576 - Support remote accumulation via JS histograms. r=gfritzsche The JS histograms, too, need to dispatch their accumulations from child to parent. JSHistograms_Add now only supports histograms that are in gHistogramsMap or that were created in the parent process. After bug 1288745, maybe we'll be able to change this to be less convoluted. MozReview-Commit-ID: 3qTH89YKbGP

# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at

# The beginning of this script is both valid shell and valid python,
# such that the script starts with the shell and is reexecuted with
# the right python.
'''which' python2.7 > /dev/null && exec python2.7 "$0" "$@" || exec python "$0" "$@"

from __future__ import print_function, unicode_literals

import os
import sys

def ancestors(path):
    while path:
        yield path
        (path, child) = os.path.split(path)
        if child == "":

def load_mach(dir_path, mach_path):
    import imp
    with open(mach_path, 'r') as fh:
        imp.load_module('mach_bootstrap', fh, mach_path,
                        ('.py', 'r', imp.PY_SOURCE))
    import mach_bootstrap
    return mach_bootstrap.bootstrap(dir_path)

def check_and_get_mach(dir_path):
    bootstrap_paths = (
        # test package bootstrap
    for bootstrap_path in bootstrap_paths:
        mach_path = os.path.join(dir_path, bootstrap_path)
        if os.path.isfile(mach_path):
            return load_mach(dir_path, mach_path)
    return None

def get_mach():
    # Check whether the current directory is within a mach src or obj dir.
    for dir_path in ancestors(os.getcwd()):
        # If we find a "config.status" and "mozinfo.json" file, we are in the objdir.
        config_status_path = os.path.join(dir_path, 'config.status')
        mozinfo_path = os.path.join(dir_path, 'mozinfo.json')
        if os.path.isfile(config_status_path) and os.path.isfile(mozinfo_path):
            import json
            info = json.load(open(mozinfo_path))
            if 'mozconfig' in info and 'MOZCONFIG' not in os.environ:
                # If the MOZCONFIG environment variable is not already set, set it
                # to the value from mozinfo.json.  This will tell the build system
                # to look for a config file at the path in $MOZCONFIG rather than
                # its default locations.
                # Note: subprocess requires native strings in os.environ on Windows
                os.environ[b'MOZCONFIG'] = str(info['mozconfig'])

            if 'topsrcdir' in info:
                # Continue searching for mach_bootstrap in the source directory.
                dir_path = info['topsrcdir']

        mach = check_and_get_mach(dir_path)
        if mach:
            return mach

    # If we didn't find a source path by scanning for a mozinfo.json, check
    # whether the directory containing this script is a source directory. We
    # follow symlinks so mach can be run even if cwd is outside the srcdir.
    return check_and_get_mach(os.path.dirname(os.path.realpath(__file__)))

def main(args):
    mach = get_mach()
    if not mach:
        print('Could not run mach: No mach source directory found.')

if __name__ == '__main__':
    if sys.platform == 'win32':
        # This is a complete hack to work around the fact that Windows
        # multiprocessing needs to import the original module (ie: this
        # file), but only works if it has a .py extension.
        # We do this by a sort of two-level function interposing. The first
        # level interposes forking.get_command_line() with our version defined
        # in my_get_command_line(). Our version of get_command_line will
        # replace the command string with the contents of the fork_interpose()
        # function to be used in the subprocess.
        # The subprocess then gets an interposed imp.find_module(), which we
        # hack up to find 'mach' without the .py extension, since we already
        # know where it is (it's us!). If we're not looking for 'mach', then
        # the original find_module will suffice.
        # See also:
        # And:
        import inspect
        from multiprocessing import forking
        global orig_command_line

        def fork_interpose():
            import imp
            import os
            import sys
            orig_find_module = imp.find_module
            def my_find_module(name, dirs):
                if name == 'mach':
                    path = os.path.join(dirs[0], 'mach')
                    f = open(path)
                    return (f, path, ('', 'r', imp.PY_SOURCE))
                return orig_find_module(name, dirs)

            # Don't allow writing bytecode file for mach module.
            orig_load_module = imp.load_module
            def my_load_module(name, file, path, description):
                # multiprocess.forking invokes imp.load_module manually and
                # hard-codes the name __parents_main__ as the module name.
                if name == '__parents_main__':
                    old_bytecode = sys.dont_write_bytecode
                    sys.dont_write_bytecode = True
                        return orig_load_module(name, file, path, description)
                        sys.dont_write_bytecode = old_bytecode

                return orig_load_module(name, file, path, description)

            imp.find_module = my_find_module
            imp.load_module = my_load_module
            from multiprocessing.forking import main; main()

        def my_get_command_line():
            fork_code, lineno = inspect.getsourcelines(fork_interpose)
            # Remove the first line (for 'def fork_interpose():') and the three
            # levels of indentation (12 spaces).
            fork_string = ''.join(x[12:] for x in fork_code[1:])
            cmdline = orig_command_line()
            cmdline[2] = fork_string
            return cmdline
        orig_command_line = forking.get_command_line
        forking.get_command_line = my_get_command_line