python/helpers/pydev/pydevd_comm.py

''' pydevd - a debugging daemon
This is the daemon you launch for python remote debugging.

Protocol:
each command has a format:
    id\tsequence-num\ttext
    id: protocol command number
    sequence-num: each request has a sequence number. Sequence numbers
    originating at the debugger are odd, sequence numbers originating
    at the daemon are even. Every response uses the same sequence number
    as the request.
    payload: it is protocol dependent. When response is a complex structure, it
    is returned as XML. Each attribute value is urlencoded, and then the whole
    payload is urlencoded again to prevent stray characters corrupting protocol/xml encodings

    Commands:

    NUMBER   NAME                     FROM*     ARGUMENTS                     RESPONSE      NOTE
100 series: program execution
    101      RUN                      JAVA      -                             -
    102      LIST_THREADS             JAVA                                    RETURN with XML listing of all threads
    103      THREAD_CREATE            PYDB      -                             XML with thread information
    104      THREAD_KILL              JAVA      id (or * to exit)             kills the thread
                                      PYDB      id                            nofies JAVA that thread was killed
    105      THREAD_SUSPEND           JAVA      XML of the stack,             suspends the thread
                                                reason for suspension
                                      PYDB      id                            notifies JAVA that thread was suspended

    106      CMD_THREAD_RUN           JAVA      id                            resume the thread
                                      PYDB      id \t reason                  notifies JAVA that thread was resumed

    107      STEP_INTO                JAVA      thread_id
    108      STEP_OVER                JAVA      thread_id
    109      STEP_RETURN              JAVA      thread_id

    110      GET_VARIABLE             JAVA      thread_id \t frame_id \t      GET_VARIABLE with XML of var content
                                                FRAME|GLOBAL \t attributes*

    111      SET_BREAK                JAVA      file/line of the breakpoint
    112      REMOVE_BREAK             JAVA      file/line of the return
    113      CMD_EVALUATE_EXPRESSION  JAVA      expression                    result of evaluating the expression
    114      CMD_GET_FRAME            JAVA                                    request for frame contents
    115      CMD_EXEC_EXPRESSION      JAVA
    116      CMD_WRITE_TO_CONSOLE     PYDB
    117      CMD_CHANGE_VARIABLE
    118      CMD_RUN_TO_LINE
    119      CMD_RELOAD_CODE
    120      CMD_GET_COMPLETIONS      JAVA

500 series diagnostics/ok
    501      VERSION                  either      Version string (1.0)        Currently just used at startup
    502      RETURN                   either      Depends on caller    -

900 series: errors
    901      ERROR                    either      -                           This is reserved for unexpected errors.

    * JAVA - remote debugger, the java end
    * PYDB - pydevd, the python end
'''
from pydevd_constants import * #@UnusedWildImport

import sys

from _pydev_imps import _pydev_time as time, _pydev_thread
from _pydev_imps import _pydev_thread as thread
import _pydev_threading as threading
from _pydev_imps._pydev_socket import socket, AF_INET, SOCK_STREAM, SHUT_RD, SHUT_WR
from pydev_imports import _queue

try:
    from urllib import quote, quote_plus, unquote, unquote_plus
except:
    from urllib.parse import quote, quote_plus, unquote, unquote_plus  #@Reimport @UnresolvedImport
import pydevconsole
import pydevd_vars
import pydevd_tracing
import pydevd_vm_type
import pydevd_file_utils
import traceback
from pydevd_utils import quote_smart as quote, compare_object_attrs, cmp_to_key, to_string
import pydev_log
import _pydev_completer

from pydevd_tracing import GetExceptionTracebackStr
import pydevd_console
from pydev_monkey import disable_trace_thread_modules, enable_trace_thread_modules



CMD_RUN = 101
CMD_LIST_THREADS = 102
CMD_THREAD_CREATE = 103
CMD_THREAD_KILL = 104
CMD_THREAD_SUSPEND = 105
CMD_THREAD_RUN = 106
CMD_STEP_INTO = 107
CMD_STEP_OVER = 108
CMD_STEP_RETURN = 109
CMD_GET_VARIABLE = 110
CMD_SET_BREAK = 111
CMD_REMOVE_BREAK = 112
CMD_EVALUATE_EXPRESSION = 113
CMD_GET_FRAME = 114
CMD_EXEC_EXPRESSION = 115
CMD_WRITE_TO_CONSOLE = 116
CMD_CHANGE_VARIABLE = 117
CMD_RUN_TO_LINE = 118
CMD_RELOAD_CODE = 119
CMD_GET_COMPLETIONS = 120

# Note: renumbered (conflicted on merge)
CMD_CONSOLE_EXEC = 121
CMD_ADD_EXCEPTION_BREAK = 122
CMD_REMOVE_EXCEPTION_BREAK = 123
CMD_LOAD_SOURCE = 124
CMD_ADD_DJANGO_EXCEPTION_BREAK = 125
CMD_REMOVE_DJANGO_EXCEPTION_BREAK = 126
CMD_SET_NEXT_STATEMENT = 127
CMD_SMART_STEP_INTO = 128
CMD_EXIT = 129
CMD_SIGNATURE_CALL_TRACE = 130



CMD_SET_PY_EXCEPTION = 131
CMD_GET_FILE_CONTENTS = 132
CMD_SET_PROPERTY_TRACE = 133
# Pydev debug console commands
CMD_EVALUATE_CONSOLE_EXPRESSION = 134
CMD_RUN_CUSTOM_OPERATION = 135
CMD_GET_BREAKPOINT_EXCEPTION = 136
CMD_STEP_CAUGHT_EXCEPTION = 137
CMD_SEND_CURR_EXCEPTION_TRACE = 138
CMD_SEND_CURR_EXCEPTION_TRACE_PROCEEDED = 139
CMD_IGNORE_THROWN_EXCEPTION_AT = 140
CMD_ENABLE_DONT_TRACE = 141
CMD_SHOW_CONSOLE = 142



CMD_VERSION = 501
CMD_RETURN = 502
CMD_ERROR = 901

ID_TO_MEANING = {
    '101':'CMD_RUN',
    '102':'CMD_LIST_THREADS',
    '103':'CMD_THREAD_CREATE',
    '104':'CMD_THREAD_KILL',
    '105':'CMD_THREAD_SUSPEND',
    '106':'CMD_THREAD_RUN',
    '107':'CMD_STEP_INTO',
    '108':'CMD_STEP_OVER',
    '109':'CMD_STEP_RETURN',
    '110':'CMD_GET_VARIABLE',
    '111':'CMD_SET_BREAK',
    '112':'CMD_REMOVE_BREAK',
    '113':'CMD_EVALUATE_EXPRESSION',
    '114':'CMD_GET_FRAME',
    '115':'CMD_EXEC_EXPRESSION',
    '116':'CMD_WRITE_TO_CONSOLE',
    '117':'CMD_CHANGE_VARIABLE',
    '118':'CMD_RUN_TO_LINE',
    '119':'CMD_RELOAD_CODE',
    '120':'CMD_GET_COMPLETIONS',
    '121':'CMD_CONSOLE_EXEC',
    '122':'CMD_ADD_EXCEPTION_BREAK',
    '123':'CMD_REMOVE_EXCEPTION_BREAK',
    '124':'CMD_LOAD_SOURCE',
    '125':'CMD_ADD_DJANGO_EXCEPTION_BREAK',
    '126':'CMD_REMOVE_DJANGO_EXCEPTION_BREAK',
    '127':'CMD_SET_NEXT_STATEMENT',
    '128':'CMD_SMART_STEP_INTO',
    '129': 'CMD_EXIT',
    '130': 'CMD_SIGNATURE_CALL_TRACE',

    '131': 'CMD_SET_PY_EXCEPTION',
    '132': 'CMD_GET_FILE_CONTENTS',
    '133': 'CMD_SET_PROPERTY_TRACE',
    '134': 'CMD_EVALUATE_CONSOLE_EXPRESSION',
    '135': 'CMD_RUN_CUSTOM_OPERATION',
    '136': 'CMD_GET_BREAKPOINT_EXCEPTION',
    '137': 'CMD_STEP_CAUGHT_EXCEPTION',
    '138': 'CMD_SEND_CURR_EXCEPTION_TRACE',
    '139': 'CMD_SEND_CURR_EXCEPTION_TRACE_PROCEEDED',
    '140': 'CMD_IGNORE_THROWN_EXCEPTION_AT',
    '141': 'CMD_ENABLE_DONT_TRACE',

    '501':'CMD_VERSION',
    '502':'CMD_RETURN',
    '901':'CMD_ERROR',
    }

MAX_IO_MSG_SIZE = 1000  #if the io is too big, we'll not send all (could make the debugger too non-responsive)
#this number can be changed if there's need to do so

VERSION_STRING = "@@BUILD_NUMBER@@"

from _pydev_filesystem_encoding import getfilesystemencoding
file_system_encoding = getfilesystemencoding()

#--------------------------------------------------------------------------------------------------- UTILITIES

#=======================================================================================================================
# PydevdLog
#=======================================================================================================================
def PydevdLog(level, *args):
    """ levels are:
        0 most serious warnings/errors
        1 warnings/significant events
        2 informational trace
    """
    if level <= DebugInfoHolder.DEBUG_TRACE_LEVEL:
        #yes, we can have errors printing if the console of the program has been finished (and we're still trying to print something)
        try:
            sys.stderr.write('%s\n' % (args,))
        except:
            pass

#=======================================================================================================================
# GlobalDebuggerHolder
#=======================================================================================================================
class GlobalDebuggerHolder:
    '''
        Holder for the global debugger.
    '''
    globalDbg = None

#=======================================================================================================================
# GetGlobalDebugger
#=======================================================================================================================
def GetGlobalDebugger():
    return GlobalDebuggerHolder.globalDbg

#=======================================================================================================================
# SetGlobalDebugger
#=======================================================================================================================
def SetGlobalDebugger(dbg):
    GlobalDebuggerHolder.globalDbg = dbg


#------------------------------------------------------------------- ACTUAL COMM

#=======================================================================================================================
# PyDBDaemonThread
#=======================================================================================================================
class PyDBDaemonThread:
    
    created_pydb_daemon_threads = {}

    def __init__(self):
        # Note: subclasses are always daemon threads.
        self.killReceived = False
        self.dontTraceMe = True

    def setName(self, name):
        self.name = name

    def start(self):
        import pydev_monkey
        start_new_thread = pydev_monkey.get_original_start_new_thread(_pydev_thread)
        start_new_thread(self.run, ())

    def run(self):
        created_pydb_daemon = self.created_pydb_daemon_threads
        created_pydb_daemon[self] = 1
        dummy_thread = threading.currentThread()
        dummy_thread.is_pydev_daemon_thread = True
        try:
            try:
                if IS_JYTHON:
                    import org.python.core as PyCore #@UnresolvedImport
                    ss = PyCore.PySystemState()
                    # Note: Py.setSystemState() affects only the current thread.
                    PyCore.Py.setSystemState(ss)
        
                self.OnRun()
            except:
                if sys is not None and traceback is not None:
                    traceback.print_exc()
        finally:
            del created_pydb_daemon[self]

    def OnRun(self):
        raise NotImplementedError('Should be reimplemented by: %s' % self.__class__)

    def doKillPydevThread(self):
        #that was not working very well because jython gave some socket errors
        self.killReceived = True

    def stopTrace(self):
        if self.dontTraceMe:
            
            disable_tracing = True
    
            if pydevd_vm_type.GetVmType() == pydevd_vm_type.PydevdVmType.JYTHON and sys.hexversion <= 0x020201f0:
                # don't run untraced threads if we're in jython 2.2.1 or lower
                # jython bug: if we start a thread and another thread changes the tracing facility
                # it affects other threads (it's not set only for the thread but globally)
                # Bug: http://sourceforge.net/tracker/index.php?func=detail&aid=1870039&group_id=12867&atid=112867
                disable_tracing = False
    
            if disable_tracing:
                pydevd_tracing.SetTrace(None)  # no debugging on this thread


#=======================================================================================================================
# ReaderThread
#=======================================================================================================================
class ReaderThread(PyDBDaemonThread):
    """ reader thread reads and dispatches commands in an infinite loop """

    def __init__(self, sock):
        PyDBDaemonThread.__init__(self)
        self.sock = sock
        self.setName("pydevd.Reader")


    def doKillPydevThread(self):
        #We must close the socket so that it doesn't stay halted there.
        self.killReceived = True
        try:
            self.sock.shutdown(SHUT_RD) #shutdown the socket for read
        except:
            #just ignore that
            pass

    def OnRun(self):
        self.stopTrace()
        buffer = ""
        try:

            while not self.killReceived:
                try:
                    r = self.sock.recv(1024)
                except:
                    if not self.killReceived:
                        self.handleExcept()
                    return #Finished communication.

                #Note: the java backend is always expected to pass utf-8 encoded strings. We now work with unicode
                #internally and thus, we may need to convert to the actual encoding where needed (i.e.: filenames
                #on python 2 may need to be converted to the filesystem encoding).
                if hasattr(r, 'decode'):
                    r = r.decode('utf-8')

                buffer += r
                if DebugInfoHolder.DEBUG_RECORD_SOCKET_READS:
                    pydev_log.debug('received >>%s<<\n' % (buffer,))

                if len(buffer) == 0:
                    self.handleExcept()
                    break
                while buffer.find('\n') != -1:
                    command, buffer = buffer.split('\n', 1)

                    args = command.split('\t', 2)
                    try:
                        cmd_id = int(args[0])
                        pydev_log.debug('Received command: %s %s\n' % (ID_TO_MEANING.get(str(cmd_id), '???'), command,))
                        self.processCommand(cmd_id, int(args[1]), args[2])
                    except:
                        traceback.print_exc()
                        sys.stderr.write("Can't process net command: %s\n" % command)
                        sys.stderr.flush()

        except:
            traceback.print_exc()
            self.handleExcept()


    def handleExcept(self):
        GlobalDebuggerHolder.globalDbg.FinishDebuggingSession()

    def processCommand(self, cmd_id, seq, text):
        GlobalDebuggerHolder.globalDbg.processNetCommand(cmd_id, seq, text)


#----------------------------------------------------------------------------------- SOCKET UTILITIES - WRITER
#=======================================================================================================================
# WriterThread
#=======================================================================================================================
class WriterThread(PyDBDaemonThread):
    """ writer thread writes out the commands in an infinite loop """
    def __init__(self, sock):
        PyDBDaemonThread.__init__(self)
        self.sock = sock
        self.setName("pydevd.Writer")
        self.cmdQueue = _queue.Queue()
        if pydevd_vm_type.GetVmType() == 'python':
            self.timeout = 0
        else:
            self.timeout = 0.1

    def addCommand(self, cmd):
        """ cmd is NetCommand """
        if not self.killReceived: #we don't take new data after everybody die
            self.cmdQueue.put(cmd)

    def OnRun(self):
        """ just loop and write responses """

        self.stopTrace()
        get_has_timeout = sys.hexversion >= 0x02030000 # 2.3 onwards have it.
        try:
            while True:
                try:
                    try:
                        if get_has_timeout:
                            cmd = self.cmdQueue.get(1, 0.1)
                        else:
                            time.sleep(.01)
                            cmd = self.cmdQueue.get(0)
                    except _queue.Empty:
                        if self.killReceived:
                            try:
                                self.sock.shutdown(SHUT_WR)
                                self.sock.close()
                            except:
                                pass

                            return #break if queue is empty and killReceived
                        else:
                            continue
                except:
                    #PydevdLog(0, 'Finishing debug communication...(1)')
                    #when liberating the thread here, we could have errors because we were shutting down
                    #but the thread was still not liberated
                    return
                out = cmd.getOutgoing()

                if DebugInfoHolder.DEBUG_TRACE_LEVEL >= 1:
                    out_message = 'sending cmd --> '
                    out_message += "%20s" % ID_TO_MEANING.get(out[:3], 'UNKNOWN')
                    out_message += ' '
                    out_message += unquote(unquote(out)).replace('\n', ' ')
                    try:
                        sys.stderr.write('%s\n' % (out_message,))
                    except:
                        pass

                if IS_PY3K:
                    out = bytearray(out, 'utf-8')
                self.sock.send(out) #TODO: this does not guarantee that all message are sent (and jython does not have a send all)
                if cmd.id == CMD_EXIT:
                    break
                if time is None:
                    break #interpreter shutdown
                time.sleep(self.timeout)
        except Exception:
            GlobalDebuggerHolder.globalDbg.FinishDebuggingSession()
            if DebugInfoHolder.DEBUG_TRACE_LEVEL >= 0:
                traceback.print_exc()




#--------------------------------------------------- CREATING THE SOCKET THREADS

#=======================================================================================================================
# StartServer
#=======================================================================================================================
def StartServer(port):
    """ binds to a port, waits for the debugger to connect """
    s = socket(AF_INET, SOCK_STREAM)
    s.bind(('', port))
    s.listen(1)
    newSock, _addr = s.accept()
    return newSock

#=======================================================================================================================
# StartClient
#=======================================================================================================================
def StartClient(host, port):
    """ connects to a host/port """
    PydevdLog(1, "Connecting to ", host, ":", str(port))

    s = socket(AF_INET, SOCK_STREAM)

    MAX_TRIES = 100
    i = 0
    while i<MAX_TRIES:
        try:
            s.connect((host, port))
        except:
            i+=1
            time.sleep(0.2)
            continue
        PydevdLog(1, "Connected.")
        return s

    sys.stderr.write("Could not connect to %s: %s\n" % (host, port))
    sys.stderr.flush()
    traceback.print_exc()
    sys.exit(1) #TODO: is it safe?



#------------------------------------------------------------------------------------ MANY COMMUNICATION STUFF

#=======================================================================================================================
# NetCommand
#=======================================================================================================================
class NetCommand:
    """ Commands received/sent over the network.

    Command can represent command received from the debugger,
    or one to be sent by daemon.
    """
    next_seq = 0 # sequence numbers

    def __init__(self, id, seq, text):
        """ smart handling of paramaters
        if sequence is 0, new sequence will be generated
        if text has carriage returns they'll be replaced"""
        self.id = id
        if (seq == 0): seq = self.getNextSeq()
        self.seq = seq
        self.text = text
        self.outgoing = self.makeMessage(id, seq, text)

    def getNextSeq(self):
        """ returns next sequence number """
        NetCommand.next_seq += 2
        return NetCommand.next_seq

    def getOutgoing(self):
        """ returns the outgoing message"""
        return self.outgoing

    def makeMessage(self, cmd, seq, payload):
        encoded = quote(to_string(payload), '/<>_=" \t')
        return str(cmd) + '\t' + str(seq) + '\t' + encoded + "\n"

#=======================================================================================================================
# NetCommandFactory
#=======================================================================================================================
class NetCommandFactory:

    def __init_(self):
        self.next_seq = 0

    def threadToXML(self, thread):
        """ thread information as XML """
        name = pydevd_vars.makeValidXmlValue(thread.getName())
        cmdText = '<thread name="%s" id="%s" />' % (quote(name), GetThreadId(thread))
        return cmdText

    def makeErrorMessage(self, seq, text):
        cmd = NetCommand(CMD_ERROR, seq, text)
        if DebugInfoHolder.DEBUG_TRACE_LEVEL > 2:
            sys.stderr.write("Error: %s" % (text,))
        return cmd

    def makeThreadCreatedMessage(self, thread):
        cmdText = "<xml>" + self.threadToXML(thread) + "</xml>"
        return NetCommand(CMD_THREAD_CREATE, 0, cmdText)


    def makeCustomFrameCreatedMessage(self, frameId, frameDescription):
        frameDescription = pydevd_vars.makeValidXmlValue(frameDescription)
        cmdText = '<xml><thread name="%s" id="%s"/></xml>' % (frameDescription, frameId)
        return NetCommand(CMD_THREAD_CREATE, 0, cmdText)


    def makeListThreadsMessage(self, seq):
        """ returns thread listing as XML """
        try:
            t = threading.enumerate()
            cmdText = "<xml>"
            for i in t:
                if t.isAlive():
                    cmdText += self.threadToXML(i)
            cmdText += "</xml>"
            return NetCommand(CMD_RETURN, seq, cmdText)
        except:
            return self.makeErrorMessage(seq, GetExceptionTracebackStr())

    def makeVariableChangedMessage(self, seq, payload):
        # notify debugger that value was changed successfully
        return NetCommand(CMD_RETURN, seq, payload)

    def makeIoMessage(self, v, ctx, dbg=None):
        '''
        @param v: the message to pass to the debug server
        @param ctx: 1 for stdio 2 for stderr
        @param dbg: If not none, add to the writer
        '''

        try:
            if len(v) > MAX_IO_MSG_SIZE:
                v = v[0:MAX_IO_MSG_SIZE]
                v += '...'

            v = pydevd_vars.makeValidXmlValue(quote(v, '/>_= \t'))
            net = NetCommand(str(CMD_WRITE_TO_CONSOLE), 0, '<xml><io s="%s" ctx="%s"/></xml>' % (v, ctx))
        except:
            net = self.makeErrorMessage(0, GetExceptionTracebackStr())

        if dbg:
            dbg.writer.addCommand(net)

        return net

    def makeVersionMessage(self, seq):
        try:
            return NetCommand(CMD_VERSION, seq, VERSION_STRING)
        except:
            return self.makeErrorMessage(seq, GetExceptionTracebackStr())

    def makeThreadKilledMessage(self, id):
        try:
            return NetCommand(CMD_THREAD_KILL, 0, str(id))
        except:
            return self.makeErrorMessage(0, GetExceptionTracebackStr())

    def makeThreadSuspendStr(self, thread_id, frame, stop_reason, message):
        """ <xml>
            <thread id="id" stop_reason="reason">
                    <frame id="id" name="functionName " file="file" line="line">
                    <var variable stuffff....
                </frame>
            </thread>
        """
        cmdTextList = ["<xml>"]

        if message:
            message = pydevd_vars.makeValidXmlValue(str(message))

        cmdTextList.append('<thread id="%s" stop_reason="%s" message="%s">' % (thread_id, stop_reason, message))

        curFrame = frame
        try:
            while curFrame:
                #print cmdText
                myId = str(id(curFrame))
                #print "id is ", myId

                if curFrame.f_code is None:
                    break #Iron Python sometimes does not have it!

                myName = curFrame.f_code.co_name #method name (if in method) or ? if global
                if myName is None:
                    break #Iron Python sometimes does not have it!

                #print "name is ", myName

                filename, base = pydevd_file_utils.GetFilenameAndBase(curFrame)

                myFile = pydevd_file_utils.NormFileToClient(filename)
                if file_system_encoding.lower() != "utf-8" and hasattr(myFile, "decode"):
                    # myFile is a byte string encoded using the file system encoding
                    # convert it to utf8
                    myFile = myFile.decode(file_system_encoding).encode("utf-8")

                #print "file is ", myFile
                #myFile = inspect.getsourcefile(curFrame) or inspect.getfile(frame)

                myLine = str(curFrame.f_lineno)
                #print "line is ", myLine

                #the variables are all gotten 'on-demand'
                #variables = pydevd_vars.frameVarsToXML(curFrame.f_locals)

                variables = ''
                cmdTextList.append('<frame id="%s" name="%s" ' % (myId , pydevd_vars.makeValidXmlValue(myName)))
                cmdTextList.append('file="%s" line="%s">"' % (quote(myFile, '/>_= \t'), myLine))
                cmdTextList.append(variables)
                cmdTextList.append("</frame>")
                curFrame = curFrame.f_back
        except :
            traceback.print_exc()

        cmdTextList.append("</thread></xml>")
        return ''.join(cmdTextList)

    def makeThreadSuspendMessage(self, thread_id, frame, stop_reason, message):
        try:
            return NetCommand(CMD_THREAD_SUSPEND, 0, self.makeThreadSuspendStr(thread_id, frame, stop_reason, message))
        except:
            return self.makeErrorMessage(0, GetExceptionTracebackStr())

    def makeThreadRunMessage(self, id, reason):
        try:
            return NetCommand(CMD_THREAD_RUN, 0, str(id) + "\t" + str(reason))
        except:
            return self.makeErrorMessage(0, GetExceptionTracebackStr())

    def makeGetVariableMessage(self, seq, payload):
        try:
            return NetCommand(CMD_GET_VARIABLE, seq, payload)
        except Exception:
            return self.makeErrorMessage(seq, GetExceptionTracebackStr())

    def makeGetFrameMessage(self, seq, payload):
        try:
            return NetCommand(CMD_GET_FRAME, seq, payload)
        except Exception:
            return self.makeErrorMessage(seq, GetExceptionTracebackStr())


    def makeEvaluateExpressionMessage(self, seq, payload):
        try:
            return NetCommand(CMD_EVALUATE_EXPRESSION, seq, payload)
        except Exception:
            return self.makeErrorMessage(seq, GetExceptionTracebackStr())

    def makeGetCompletionsMessage(self, seq, payload):
        try:
            return NetCommand(CMD_GET_COMPLETIONS, seq, payload)
        except Exception:
            return self.makeErrorMessage(seq, GetExceptionTracebackStr())

    def makeGetFileContents(self, seq, payload):
        try:
            return NetCommand(CMD_GET_FILE_CONTENTS, seq, payload)
        except Exception:
            return self.makeErrorMessage(seq, GetExceptionTracebackStr())

    def makeSendBreakpointExceptionMessage(self, seq, payload):
        try:
            return NetCommand(CMD_GET_BREAKPOINT_EXCEPTION, seq, payload)
        except Exception:
            return self.makeErrorMessage(seq, GetExceptionTracebackStr())

    def makeSendCurrExceptionTraceMessage(self, seq, thread_id, curr_frame_id, exc_type, exc_desc, trace_obj):
        try:
            while trace_obj.tb_next is not None:
                trace_obj = trace_obj.tb_next

            exc_type = pydevd_vars.makeValidXmlValue(str(exc_type)).replace('\t', '  ') or 'exception: type unknown'
            exc_desc = pydevd_vars.makeValidXmlValue(str(exc_desc)).replace('\t', '  ') or 'exception: no description'

            payload = str(curr_frame_id) + '\t' + exc_type + "\t" + exc_desc + "\t" + \
                self.makeThreadSuspendStr(thread_id, trace_obj.tb_frame, CMD_SEND_CURR_EXCEPTION_TRACE, '')

            return NetCommand(CMD_SEND_CURR_EXCEPTION_TRACE, seq, payload)
        except Exception:
            return self.makeErrorMessage(seq, GetExceptionTracebackStr())

    def makeSendCurrExceptionTraceProceededMessage(self, seq, thread_id):
        try:
            return NetCommand(CMD_SEND_CURR_EXCEPTION_TRACE_PROCEEDED, 0, str(thread_id))
        except:
            return self.makeErrorMessage(0, GetExceptionTracebackStr())

    def makeSendConsoleMessage(self, seq, payload):
        try:
            return NetCommand(CMD_EVALUATE_CONSOLE_EXPRESSION, seq, payload)
        except Exception:
            return self.makeErrorMessage(seq, GetExceptionTracebackStr())

    def makeCustomOperationMessage(self, seq, payload):
        try:
            return NetCommand(CMD_RUN_CUSTOM_OPERATION, seq, payload)
        except Exception:
            return self.makeErrorMessage(seq, GetExceptionTracebackStr())

    def makeLoadSourceMessage(self, seq, source, dbg=None):
        try:
            net = NetCommand(CMD_LOAD_SOURCE, seq, '%s' % source)

        except:
            net = self.makeErrorMessage(0, GetExceptionTracebackStr())

        if dbg:
            dbg.writer.addCommand(net)
        return net

    def makeShowConsoleMessage(self, thread_id, frame):
        try:
            return NetCommand(CMD_SHOW_CONSOLE, 0, self.makeThreadSuspendStr(thread_id, frame, CMD_SHOW_CONSOLE, ''))
        except:
            return self.makeErrorMessage(0, GetExceptionTracebackStr())

    def makeExitMessage(self):
        try:
            net = NetCommand(CMD_EXIT, 0, '')

        except:
            net = self.makeErrorMessage(0, GetExceptionTracebackStr())

        return net

INTERNAL_TERMINATE_THREAD = 1
INTERNAL_SUSPEND_THREAD = 2


#=======================================================================================================================
# InternalThreadCommand
#=======================================================================================================================
class InternalThreadCommand:
    """ internal commands are generated/executed by the debugger.

    The reason for their existence is that some commands have to be executed
    on specific threads. These are the InternalThreadCommands that get
    get posted to PyDB.cmdQueue.
    """

    def canBeExecutedBy(self, thread_id):
        '''By default, it must be in the same thread to be executed
        '''
        return self.thread_id == thread_id or self.thread_id.endswith('|' + thread_id)

    def doIt(self, dbg):
        raise NotImplementedError("you have to override doIt")


class ReloadCodeCommand(InternalThreadCommand):


    def __init__(self, module_name, thread_id):
        self.thread_id = thread_id
        self.module_name = module_name
        self.executed = False
        self.lock = _pydev_thread.allocate_lock()


    def canBeExecutedBy(self, thread_id):
        if self.thread_id == '*':
            return True  #Any thread can execute it!

        return InternalThreadCommand.canBeExecutedBy(self, thread_id)


    def doIt(self, dbg):
        self.lock.acquire()
        try:
            if self.executed:
                return
            self.executed = True
        finally:
            self.lock.release()

        module_name = self.module_name
        if not DictContains(sys.modules, module_name):
            if '.' in module_name:
                new_module_name = module_name.split('.')[-1]
                if DictContains(sys.modules, new_module_name):
                    module_name = new_module_name

        if not DictContains(sys.modules, module_name):
            sys.stderr.write('pydev debugger: Unable to find module to reload: "' + module_name + '".\n')
            # Too much info...
            # sys.stderr.write('pydev debugger: This usually means you are trying to reload the __main__ module (which cannot be reloaded).\n')

        else:
            sys.stderr.write('pydev debugger: Start reloading module: "' + module_name + '" ... \n')
            import pydevd_reload
            if pydevd_reload.xreload(sys.modules[module_name]):
                sys.stderr.write('pydev debugger: reload finished\n')
            else:
                sys.stderr.write('pydev debugger: reload finished without applying any change\n')


#=======================================================================================================================
# InternalTerminateThread
#=======================================================================================================================
class InternalTerminateThread(InternalThreadCommand):
    def __init__(self, thread_id):
        self.thread_id = thread_id

    def doIt(self, dbg):
        PydevdLog(1, "killing ", str(self.thread_id))
        cmd = dbg.cmdFactory.makeThreadKilledMessage(self.thread_id)
        dbg.writer.addCommand(cmd)


#=======================================================================================================================
# InternalRunThread
#=======================================================================================================================
class InternalRunThread(InternalThreadCommand):
    def __init__(self, thread_id):
        self.thread_id = thread_id

    def doIt(self, dbg):
        t = PydevdFindThreadById(self.thread_id)
        if t:
            t.additionalInfo.pydev_step_cmd = None
            t.additionalInfo.pydev_step_stop = None
            t.additionalInfo.pydev_state = STATE_RUN


#=======================================================================================================================
# InternalStepThread
#=======================================================================================================================
class InternalStepThread(InternalThreadCommand):
    def __init__(self, thread_id, cmd_id):
        self.thread_id = thread_id
        self.cmd_id = cmd_id

    def doIt(self, dbg):
        t = PydevdFindThreadById(self.thread_id)
        if t:
            t.additionalInfo.pydev_step_cmd = self.cmd_id
            t.additionalInfo.pydev_state = STATE_RUN

#=======================================================================================================================
# InternalSetNextStatementThread
#=======================================================================================================================
class InternalSetNextStatementThread(InternalThreadCommand):
    def __init__(self, thread_id, cmd_id, line, func_name):
        self.thread_id = thread_id
        self.cmd_id = cmd_id
        self.line = line
        self.func_name = func_name

    def doIt(self, dbg):
        t = PydevdFindThreadById(self.thread_id)
        if t:
            t.additionalInfo.pydev_step_cmd = self.cmd_id
            t.additionalInfo.pydev_next_line = int(self.line)
            t.additionalInfo.pydev_func_name = self.func_name
            t.additionalInfo.pydev_state = STATE_RUN


#=======================================================================================================================
# InternalGetVariable
#=======================================================================================================================
class InternalGetVariable(InternalThreadCommand):
    """ gets the value of a variable """
    def __init__(self, seq, thread_id, frame_id, scope, attrs):
        self.sequence = seq
        self.thread_id = thread_id
        self.frame_id = frame_id
        self.scope = scope
        self.attributes = attrs

    def doIt(self, dbg):
        """ Converts request into python variable """
        try:
            xml = "<xml>"
            valDict = pydevd_vars.resolveCompoundVariable(self.thread_id, self.frame_id, self.scope, self.attributes)
            if valDict is None:
                valDict = {}

            keys = valDict.keys()
            if hasattr(keys, 'sort'):
                keys.sort(compare_object_attrs) #Python 3.0 does not have it
            else:
                if IS_PY3K:
                    keys = sorted(keys, key=cmp_to_key(compare_object_attrs)) #Jython 2.1 does not have it (and all must be compared as strings).
                else:
                    keys = sorted(keys, cmp=compare_object_attrs) #Jython 2.1 does not have it (and all must be compared as strings).

            for k in keys:
                xml += pydevd_vars.varToXML(valDict[k], to_string(k))

            xml += "</xml>"
            cmd = dbg.cmdFactory.makeGetVariableMessage(self.sequence, xml)
            dbg.writer.addCommand(cmd)
        except Exception:
            cmd = dbg.cmdFactory.makeErrorMessage(self.sequence, "Error resolving variables " + GetExceptionTracebackStr())
            dbg.writer.addCommand(cmd)


#=======================================================================================================================
# InternalChangeVariable
#=======================================================================================================================
class InternalChangeVariable(InternalThreadCommand):
    """ changes the value of a variable """
    def __init__(self, seq, thread_id, frame_id, scope, attr, expression):
        self.sequence = seq
        self.thread_id = thread_id
        self.frame_id = frame_id
        self.scope = scope
        self.attr = attr
        self.expression = expression

    def doIt(self, dbg):
        """ Converts request into python variable """
        try:
            result = pydevd_vars.changeAttrExpression(self.thread_id, self.frame_id, self.attr, self.expression)
            xml = "<xml>"
            xml += pydevd_vars.varToXML(result, "")
            xml += "</xml>"
            cmd = dbg.cmdFactory.makeVariableChangedMessage(self.sequence, xml)
            dbg.writer.addCommand(cmd)
        except Exception:
            cmd = dbg.cmdFactory.makeErrorMessage(self.sequence, "Error changing variable attr:%s expression:%s traceback:%s" % (self.attr, self.expression, GetExceptionTracebackStr()))
            dbg.writer.addCommand(cmd)


#=======================================================================================================================
# InternalGetFrame
#=======================================================================================================================
class InternalGetFrame(InternalThreadCommand):
    """ gets the value of a variable """
    def __init__(self, seq, thread_id, frame_id):
        self.sequence = seq
        self.thread_id = thread_id
        self.frame_id = frame_id

    def doIt(self, dbg):
        """ Converts request into python variable """
        try:
            frame = pydevd_vars.findFrame(self.thread_id, self.frame_id)
            if frame is not None:
                xml = "<xml>"
                xml += pydevd_vars.frameVarsToXML(frame.f_locals)
                del frame
                xml += "</xml>"
                cmd = dbg.cmdFactory.makeGetFrameMessage(self.sequence, xml)
                dbg.writer.addCommand(cmd)
            else:
                #pydevd_vars.dumpFrames(self.thread_id)
                #don't print this error: frame not found: means that the client is not synchronized (but that's ok)
                cmd = dbg.cmdFactory.makeErrorMessage(self.sequence, "Frame not found: %s from thread: %s" % (self.frame_id, self.thread_id))
                dbg.writer.addCommand(cmd)
        except:
            cmd = dbg.cmdFactory.makeErrorMessage(self.sequence, "Error resolving frame: %s from thread: %s" % (self.frame_id, self.thread_id))
            dbg.writer.addCommand(cmd)


#=======================================================================================================================
# InternalEvaluateExpression
#=======================================================================================================================
class InternalEvaluateExpression(InternalThreadCommand):
    """ gets the value of a variable """

    def __init__(self, seq, thread_id, frame_id, expression, doExec, doTrim):
        self.sequence = seq
        self.thread_id = thread_id
        self.frame_id = frame_id
        self.expression = expression
        self.doExec = doExec
        self.doTrim = doTrim

    def doIt(self, dbg):
        """ Converts request into python variable """
        try:
            result = pydevd_vars.evaluateExpression(self.thread_id, self.frame_id, self.expression, self.doExec)
            xml = "<xml>"
            xml += pydevd_vars.varToXML(result, self.expression, self.doTrim)
            xml += "</xml>"
            cmd = dbg.cmdFactory.makeEvaluateExpressionMessage(self.sequence, xml)
            dbg.writer.addCommand(cmd)
        except:
            exc = GetExceptionTracebackStr()
            sys.stderr.write('%s\n' % (exc,))
            cmd = dbg.cmdFactory.makeErrorMessage(self.sequence, "Error evaluating expression " + exc)
            dbg.writer.addCommand(cmd)

#=======================================================================================================================
# InternalGetCompletions
#=======================================================================================================================
class InternalGetCompletions(InternalThreadCommand):
    """ Gets the completions in a given scope """

    def __init__(self, seq, thread_id, frame_id, act_tok):
        self.sequence = seq
        self.thread_id = thread_id
        self.frame_id = frame_id
        self.act_tok = act_tok


    def doIt(self, dbg):
        """ Converts request into completions """
        try:
            remove_path = None
            try:

                frame = pydevd_vars.findFrame(self.thread_id, self.frame_id)
                if frame is not None:

                    msg = _pydev_completer.GenerateCompletionsAsXML(frame, self.act_tok)

                    cmd = dbg.cmdFactory.makeGetCompletionsMessage(self.sequence, msg)
                    dbg.writer.addCommand(cmd)
                else:
                    cmd = dbg.cmdFactory.makeErrorMessage(self.sequence, "InternalGetCompletions: Frame not found: %s from thread: %s" % (self.frame_id, self.thread_id))
                    dbg.writer.addCommand(cmd)


            finally:
                if remove_path is not None:
                    sys.path.remove(remove_path)

        except:
            exc = GetExceptionTracebackStr()
            sys.stderr.write('%s\n' % (exc,))
            cmd = dbg.cmdFactory.makeErrorMessage(self.sequence, "Error evaluating expression " + exc)
            dbg.writer.addCommand(cmd)

#=======================================================================================================================
# InternalGetBreakpointException
#=======================================================================================================================
class InternalGetBreakpointException(InternalThreadCommand):
    """ Send details of exception raised while evaluating conditional breakpoint """
    def __init__(self, thread_id, exc_type, stacktrace):
        self.sequence = 0
        self.thread_id = thread_id
        self.stacktrace = stacktrace
        self.exc_type = exc_type

    def doIt(self, dbg):
        try:
            callstack = "<xml>"

            makeValid = pydevd_vars.makeValidXmlValue

            for filename, line, methodname, methodobj in self.stacktrace:
                if file_system_encoding.lower() != "utf-8" and hasattr(filename, "decode"):
                    # filename is a byte string encoded using the file system encoding
                    # convert it to utf8
                    filename = filename.decode(file_system_encoding).encode("utf-8")

                callstack += '<frame thread_id = "%s" file="%s" line="%s" name="%s" obj="%s" />' \
                                    % (self.thread_id, makeValid(filename), line, makeValid(methodname), makeValid(methodobj))
            callstack += "</xml>"

            cmd = dbg.cmdFactory.makeSendBreakpointExceptionMessage(self.sequence, self.exc_type + "\t" + callstack)
            dbg.writer.addCommand(cmd)
        except:
            exc = GetExceptionTracebackStr()
            sys.stderr.write('%s\n' % (exc,))
            cmd = dbg.cmdFactory.makeErrorMessage(self.sequence, "Error Sending Exception: " + exc)
            dbg.writer.addCommand(cmd)


#=======================================================================================================================
# InternalSendCurrExceptionTrace
#=======================================================================================================================
class InternalSendCurrExceptionTrace(InternalThreadCommand):
    """ Send details of the exception that was caught and where we've broken in.
    """
    def __init__(self, thread_id, arg, curr_frame_id):
        '''
        :param arg: exception type, description, traceback object
        '''
        self.sequence = 0
        self.thread_id = thread_id
        self.curr_frame_id = curr_frame_id
        self.arg = arg

    def doIt(self, dbg):
        try:
            cmd = dbg.cmdFactory.makeSendCurrExceptionTraceMessage(self.sequence, self.thread_id, self.curr_frame_id, *self.arg)
            del self.arg
            dbg.writer.addCommand(cmd)
        except:
            exc = GetExceptionTracebackStr()
            sys.stderr.write('%s\n' % (exc,))
            cmd = dbg.cmdFactory.makeErrorMessage(self.sequence, "Error Sending Current Exception Trace: " + exc)
            dbg.writer.addCommand(cmd)

#=======================================================================================================================
# InternalSendCurrExceptionTraceProceeded
#=======================================================================================================================
class InternalSendCurrExceptionTraceProceeded(InternalThreadCommand):
    """ Send details of the exception that was caught and where we've broken in.
    """
    def __init__(self, thread_id):
        self.sequence = 0
        self.thread_id = thread_id

    def doIt(self, dbg):
        try:
            cmd = dbg.cmdFactory.makeSendCurrExceptionTraceProceededMessage(self.sequence, self.thread_id)
            dbg.writer.addCommand(cmd)
        except:
            exc = GetExceptionTracebackStr()
            sys.stderr.write('%s\n' % (exc,))
            cmd = dbg.cmdFactory.makeErrorMessage(self.sequence, "Error Sending Current Exception Trace Proceeded: " + exc)
            dbg.writer.addCommand(cmd)


#=======================================================================================================================
# InternalEvaluateConsoleExpression
#=======================================================================================================================
class InternalEvaluateConsoleExpression(InternalThreadCommand):
    """ Execute the given command in the debug console """

    def __init__(self, seq, thread_id, frame_id, line):
        self.sequence = seq
        self.thread_id = thread_id
        self.frame_id = frame_id
        self.line = line

    def doIt(self, dbg):
        """ Create an XML for console output, error and more (true/false)
        <xml>
            <output message=output_message></output>
            <error message=error_message></error>
            <more>true/false</more>
        </xml>
        """
        try:
            frame = pydevd_vars.findFrame(self.thread_id, self.frame_id)
            if frame is not None:
                console_message = pydevd_console.execute_console_command(frame, self.thread_id, self.frame_id, self.line)
                cmd = dbg.cmdFactory.makeSendConsoleMessage(self.sequence, console_message.toXML())
            else:
                from pydevd_console import ConsoleMessage
                console_message = ConsoleMessage()
                console_message.add_console_message(
                    pydevd_console.CONSOLE_ERROR,
                    "Select the valid frame in the debug view (thread: %s, frame: %s invalid)" % (self.thread_id, self.frame_id),
                )
                cmd = dbg.cmdFactory.makeErrorMessage(self.sequence, console_message.toXML())
        except:
            exc = GetExceptionTracebackStr()
            cmd = dbg.cmdFactory.makeErrorMessage(self.sequence, "Error evaluating expression " + exc)
        dbg.writer.addCommand(cmd)


#=======================================================================================================================
# InternalRunCustomOperation
#=======================================================================================================================
class InternalRunCustomOperation(InternalThreadCommand):
    """ Run a custom command on an expression
    """
    def __init__(self, seq, thread_id, frame_id, scope, attrs, style, encoded_code_or_file, fnname):
        self.sequence = seq
        self.thread_id = thread_id
        self.frame_id = frame_id
        self.scope = scope
        self.attrs = attrs
        self.style = style
        self.code_or_file = unquote_plus(encoded_code_or_file)
        self.fnname = fnname

    def doIt(self, dbg):
        try:
            res = pydevd_vars.customOperation(self.thread_id, self.frame_id, self.scope, self.attrs,
                                              self.style, self.code_or_file, self.fnname)
            resEncoded = quote_plus(res)
            cmd = dbg.cmdFactory.makeCustomOperationMessage(self.sequence, resEncoded)
            dbg.writer.addCommand(cmd)
        except:
            exc = GetExceptionTracebackStr()
            cmd = dbg.cmdFactory.makeErrorMessage(self.sequence, "Error in running custom operation" + exc)
            dbg.writer.addCommand(cmd)


#=======================================================================================================================
# InternalConsoleGetCompletions
#=======================================================================================================================
class InternalConsoleGetCompletions(InternalThreadCommand):
    """ Fetch the completions in the debug console
    """
    def __init__(self, seq, thread_id, frame_id, act_tok):
        self.sequence = seq
        self.thread_id = thread_id
        self.frame_id = frame_id
        self.act_tok = act_tok

    def doIt(self, dbg):
        """ Get completions and write back to the client
        """
        try:
            frame = pydevd_vars.findFrame(self.thread_id, self.frame_id)
            completions_xml = pydevd_console.get_completions(frame, self.act_tok)
            cmd = dbg.cmdFactory.makeSendConsoleMessage(self.sequence, completions_xml)
            dbg.writer.addCommand(cmd)
        except:
            exc = GetExceptionTracebackStr()
            cmd = dbg.cmdFactory.makeErrorMessage(self.sequence, "Error in fetching completions" + exc)
            dbg.writer.addCommand(cmd)


#=======================================================================================================================
# InternalConsoleExec
#=======================================================================================================================
class InternalConsoleExec(InternalThreadCommand):
    """ gets the value of a variable """

    def __init__(self, seq, thread_id, frame_id, expression):
        self.sequence = seq
        self.thread_id = thread_id
        self.frame_id = frame_id
        self.expression = expression

    def doIt(self, dbg):
        """ Converts request into python variable """
        try:
            try:
                #don't trace new threads created by console command
                disable_trace_thread_modules()

                result = pydevconsole.consoleExec(self.thread_id, self.frame_id, self.expression)
                xml = "<xml>"
                xml += pydevd_vars.varToXML(result, "")
                xml += "</xml>"
                cmd = dbg.cmdFactory.makeEvaluateExpressionMessage(self.sequence, xml)
                dbg.writer.addCommand(cmd)
            except:
                exc = GetExceptionTracebackStr()
                sys.stderr.write('%s\n' % (exc,))
                cmd = dbg.cmdFactory.makeErrorMessage(self.sequence, "Error evaluating console expression " + exc)
                dbg.writer.addCommand(cmd)
        finally:
            enable_trace_thread_modules()

            sys.stderr.flush()
            sys.stdout.flush()


#=======================================================================================================================
# PydevdFindThreadById
#=======================================================================================================================
def PydevdFindThreadById(thread_id):
    try:
        # there was a deadlock here when I did not remove the tracing function when thread was dead
        threads = threading.enumerate()
        for i in threads:
            tid = GetThreadId(i)
            if thread_id == tid or thread_id.endswith('|' + tid):
                return i

        sys.stderr.write("Could not find thread %s\n" % thread_id)
        sys.stderr.write("Available: %s\n" % [GetThreadId(t) for t in threads])
        sys.stderr.flush()
    except:
        traceback.print_exc()

    return None