[python-win32] Ref-count bug in win32file.GetQueuedCompletionStatus

[Fred Gansevles]

Hi,
    I think I've found a ref-count bug in win32file.GetQueuedCompletionStatus

    running "svcbug.py s" starts a correct server and "svcbug.py s b"
    starts a buggy server.
    running "svcbug.py c" starts a client

____________________________________________________________________________
# svcbug.py
import win32file, win32pipe, pywintypes

PIPE = r"\\.\pipe\Bug.Svc"
BUFSIZE = 512

class Iocp:
    def __init__(self, object):
        self.port = win32file.CreateIoCompletionPort(-1, 0, 0, 0)
        win32file.CreateIoCompletionPort(object.handle, self.port, 1, 0)

    def wait_buggy(self):
        win32file.GetQueuedCompletionStatus(self.port, -1)

    def wait_good(self):
        # keep a reference to the overlapped object
        self.result = win32file.GetQueuedCompletionStatus(self.port, -1)[3]

class PipeService:
    def __init__(self):
        self.handle = win32pipe.CreateNamedPipe(PIPE,
                          win32pipe.PIPE_ACCESS_DUPLEX|
                          win32file.FILE_FLAG_OVERLAPPED,
                          win32pipe.PIPE_TYPE_MESSAGE|
                          win32pipe.PIPE_READMODE_MESSAGE|
                          win32pipe.PIPE_WAIT,
                          1, BUFSIZE, BUFSIZE,
                          win32pipe.NMPWAIT_WAIT_FOREVER,
                          None)
        self.overlapped = pywintypes.OVERLAPPED()
        win32pipe.ConnectNamedPipe(self.handle, self.overlapped)

    def serve(self):
        data = win32file.ReadFile(self.handle, BUFSIZE)[1]
        win32file.WriteFile(self.handle, data)

    def __del__(self):
        win32pipe.DisconnectNamedPipe(self.handle)

if __name__ == '__main__':
    import sys
    if 's' in sys.argv:
        svc = PipeService()
        iocp = Iocp(svc)
        if 'bug' in sys.argv:
            iocp.wait_buggy()
        else:
            iocp.wait_good()
        print sys.getrefcount(svc.overlapped)
        svc.serve()
    elif 'c' in sys.argv:
        print win32pipe.CallNamedPipe(PIPE, "Hello there", BUFSIZE, 0)

____________________________________________________________________________
 Fred Gansevles <mailto:Fred.Gansevles at ewi.utwente.nl> Phone: +31 53 489 4613
 Org.: Twente University, Fac. of EWI, Box 217, 7500 AE Enschede, Netherlands
    "Linux is like a wigwam, No windows, no gates and an apache inside"