cpython/Lib/idlelib/run.py

import sys
import time
import socket
import traceback
import threading
import Queue

import boolcheck

import CallTips
import RemoteDebugger
import RemoteObjectBrowser
import StackViewer
import rpc
import interrupt

import __main__

# Thread shared globals: Establish a queue between a subthread (which handles
# the socket) and the main thread (which runs user code), plus global
# completion and exit flags:

server = None                # RPCServer instance
queue = Queue.Queue(0)
execution_finished = False
exit_requested = False


def main():
    """Start the Python execution server in a subprocess

    In the Python subprocess, RPCServer is instantiated with handlerclass
    MyHandler, which inherits register/unregister methods from RPCHandler via
    the mix-in class SocketIO.

    When the RPCServer 'server' is instantiated, the TCPServer initialization
    creates an instance of run.MyHandler and calls its handle() method.
    handle() instantiates a run.Executive object, passing it a reference to the
    MyHandler object.  That reference is saved as attribute rpchandler of the
    Executive instance.  The Executive methods have access to the reference and
    can pass it on to entities that they command
    (e.g. RemoteDebugger.Debugger.start_debugger()).  The latter, in turn, can
    call MyHandler(SocketIO) register/unregister methods via the reference to
    register and unregister themselves.

    """
    global queue, execution_finished, exit_requested

    port = 8833
    if sys.argv[1:]:
        port = int(sys.argv[1])
    sys.argv[:] = [""]
    sockthread = threading.Thread(target=manage_socket,
                                  name='SockThread',
                                  args=(('localhost', port),))
    sockthread.setDaemon(True)
    sockthread.start()
    while 1:
        try:
            if exit_requested:
                sys.exit()
            # XXX KBK 22Mar03 eventually check queue here!
            pass
            time.sleep(0.05)
        except KeyboardInterrupt:
            ##execution_finished = True
            continue

def manage_socket(address):
    global server, exit_requested

    for i in range(6):
        time.sleep(i)
        try:
            server = rpc.RPCServer(address, MyHandler)
            break
        except socket.error, err:
            if i < 3:
                print>>sys.__stderr__, ".. ",
            else:
                print>>sys.__stderr__,"\nPython subprocess socket error: "\
                                              + err[1] + ", retrying...."
    else:
        print>>sys.__stderr__, "\nConnection to Idle failed, exiting."
        exit_requested = True
    server.handle_request() # A single request only


class MyHandler(rpc.RPCHandler):

    def handle(self):
        """Override base method"""
        executive = Executive(self)
        self.register("exec", executive)
        sys.stdin = self.get_remote_proxy("stdin")
        sys.stdout = self.get_remote_proxy("stdout")
        sys.stderr = self.get_remote_proxy("stderr")
        rpc.RPCHandler.getresponse(self, myseq=None, wait=0.5)


class Executive:

    def __init__(self, rpchandler):
        self.rpchandler = rpchandler
        self.locals = __main__.__dict__
        self.calltip = CallTips.CallTips()

    def runcode(self, code):
        global queue, execution_finished

        execution_finished = False
        queue.put(code)
        # dequeue and run in subthread
        self.runcode_from_queue()
        while not execution_finished:
            time.sleep(0.05)

    def runcode_from_queue(self):
        global queue, execution_finished

        # poll until queue has code object, using threads, just block?
        while True:
            try:
                code = queue.get(0)
                break
            except Queue.Empty:
                time.sleep(0.05)
        try:
            exec code in self.locals
        except:
            self.flush_stdout()
            efile = sys.stderr
            typ, val, tb = info = sys.exc_info()
            sys.last_type, sys.last_value, sys.last_traceback = info
            tbe = traceback.extract_tb(tb)
            print >>efile, 'Traceback (most recent call last):'
            exclude = ("run.py", "rpc.py", "RemoteDebugger.py", "bdb.py")
            self.cleanup_traceback(tbe, exclude)
            traceback.print_list(tbe, file=efile)
            lines = traceback.format_exception_only(typ, val)
            for line in lines:
                print>>efile, line,
            execution_finished = True
        else:
            self.flush_stdout()
            execution_finished = True

    def flush_stdout(self):
        try:
            if sys.stdout.softspace:
                sys.stdout.softspace = 0
                sys.stdout.write("\n")
        except (AttributeError, EOFError):
            pass

    def cleanup_traceback(self, tb, exclude):
        "Remove excluded traces from beginning/end of tb; get cached lines"
        orig_tb = tb[:]
        while tb:
            for rpcfile in exclude:
                if tb[0][0].count(rpcfile):
                    break    # found an exclude, break for: and delete tb[0]
            else:
                break        # no excludes, have left RPC code, break while:
            del tb[0]
        while tb:
            for rpcfile in exclude:
                if tb[-1][0].count(rpcfile):
                    break
            else:
                break
            del tb[-1]
        if len(tb) == 0:
            # exception was in IDLE internals, don't prune!
            tb[:] = orig_tb[:]
            print>>sys.stderr, "** IDLE Internal Exception: "
        for i in range(len(tb)):
            fn, ln, nm, line = tb[i]
            if nm == '?':
                nm = "-toplevel-"
            if not line and fn.startswith("<pyshell#"):
                line = self.rpchandler.remotecall('linecache', 'getline',
                                                  (fn, ln), {})
            tb[i] = fn, ln, nm, line

    def interrupt_the_server(self):
        self.rpchandler.interrupted = True
        ##print>>sys.__stderr__, "** Interrupt main!"
        interrupt.interrupt_main()

    def shutdown_the_server(self):
        global exit_requested

        exit_requested = True

    def start_the_debugger(self, gui_adap_oid):
        return RemoteDebugger.start_debugger(self.rpchandler, gui_adap_oid)

    def stop_the_debugger(self, idb_adap_oid):
        "Unregister the Idb Adapter.  Link objects and Idb then subject to GC"
        self.rpchandler.unregister(idb_adap_oid)

    def get_the_calltip(self, name):
        return self.calltip.fetch_tip(name)

    def stackviewer(self, flist_oid=None):
        if not hasattr(sys, "last_traceback"):
            return None
        flist = None
        if flist_oid is not None:
            flist = self.rpchandler.get_remote_proxy(flist_oid)
        tb = sys.last_traceback
        while tb and tb.tb_frame.f_globals["__name__"] in ["rpc", "run"]:
            tb = tb.tb_next
        item = StackViewer.StackTreeItem(flist, tb)
        return RemoteObjectBrowser.remote_object_tree_item(item)