Microsoft KB Archive/889087

= FIX: The select function and the write function do not handle the non-blocking serial I/O correctly =

Article ID: 889087

Article Last Modified on 11/15/2007

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APPLIES TO


 * Microsoft Windows Services for UNIX 3.5

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SYMPTOMS
The migration of the Portable Operating System Interface for UNIX (POSIX) subsystems from SCO to Interix is held up because of one of the following conditions:
 * The select function incorrectly indicates that the serial port is ready for the write operation even though it is not yet ready. The select function also does not work when you set the action parameter of the tcflow function to TCOOFF or TCOON.

Note The TCOOFF action parameter value is for suspending output. The TCOON action parameter value is for restarting suspended output.
 * The write function blocks when the serial device is not ready. This behavior occurs even if the O_NONBLOCK flag is set. This problem can occur at the start of the write operation or if the device is disconnected during the write operation.



Hotfix information
A supported hotfix is now available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next service pack that contains this hotfix.

To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to obtain the hotfix, visit the following Microsoft Web site:

http://go.microsoft.com/?linkid=6294451

Note If additional issues occur or any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. To create a separate service request, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Restart requirement
You must restart your computer because the POSIX subsystem is replaced when you apply this hotfix.

Hotfix replacement information
This hotfix does not replace any other hotfixes.

File information
The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.   Date         Time   Version      Size     File name 09-Nov-2004 04:51  8.0.1969.20  130,048  Posix.exe 09-Nov-2004 04:51  8.0.1969.20  104,448  Psxrun.exe 09-Nov-2004 04:51  8.0.1969.20  763,904  Psxss.exe



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.



MORE INFORMATION
For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

