eric6/DebugClients/Python/MultiprocessingExtension.py

# -*- coding: utf-8 -*-

# Copyright (c) 2020 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a function to patch multiprocessing.Process to support
debugging of the process.
"""

import sys
import traceback

_debugClient = None
_originalProcess = None
_originalBootstrap = None


def patchMultiprocessing(module, debugClient):
    """
    Function to patch the multiprocessing module.
    
    @param module reference to the imported module to be patched
    @type module
    @param debugClient reference to the debug client object
    @type DebugClient
    """     # __IGNORE_WARNING_D234__
    global _debugClient, _originalProcess, _originalBootstrap
    
    _debugClient = debugClient
    
    _originalProcess = module.process.BaseProcess
    _originalBootstrap = _originalProcess._bootstrap
    
    # TODO: implement a process tracer
    # i.e. report which processes are started
    class ProcessWrapper(_originalProcess):
        """
        Wrapper class for multiprocessing.Process.
        """
        def _bootstrap(self, *args, **kwargs):
            """
            Wrapper around _bootstrap to start debugger.
            
            @param args function arguments
            @type list
            @param kwargs keyword only arguments
            @type dict
            @return exit code of the process
            @rtype int
            """
            _debugging = False
            if (
                _debugClient.debugging and
                _debugClient.multiprocessSupport
            ):
                scriptName = sys.argv[0]
                if not _debugClient.skipMultiProcessDebugging(scriptName):
                    _debugging = True
                    try:
                        (wd, host, port, exceptions, tracePython, redirect,
                         noencoding) = _debugClient.startOptions[:7]
                        _debugClient.startDebugger(
                            sys.argv[0], host=host, port=port,
                            exceptions=exceptions, tracePython=tracePython,
                            redirect=redirect, passive=False,
                            multiprocessSupport=True
                        )
                    except Exception:
                        print(
                            # __IGNORE_WARNING_M801__
                            "Exception during multiprocessing bootstrap init:"
                        )
                        traceback.print_exc(file=sys.stdout)
                        sys.stdout.flush()
                        raise
            
            exitcode = _originalBootstrap(self, *args, **kwargs)
            
            if _debugging:
                _debugClient.progTerminated(exitcode, "process finished")
            
            return exitcode
    
    _originalProcess._bootstrap = ProcessWrapper._bootstrap